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Determination of total petroleum hydrocarbons and heavy metals in soils within the vicinity of facilities handling refined petroleum products in Lagos metropolis
Abstract
This article discusses the determination of total petroleum hydrocarbons (TPH) and heavy-metal contamination in soils within areas of refined petroleum products handling in Lagos metropolis. Soil samples were collected randomly from two petrol stations, two auto-mechanic workshops, and a National Electric Power Authority (NEPA) station. Control samples were taken from two low-density residential areas. TPH were estimated gravimetrically following standard methods of TPH analysis, while the heavy metals were determined by atomic absorption spectrophotometry. Sites studied had higher levels of TPH and heavy metals compared to the control samples. For TPH, the petrol stations have mean values of 399.83+/-106.19 and 450.83 +/- 90.58 microg/g, respectively; mechanic workshops, 362.60 +/- 185.84 and 428.55 +/- 119.00 microg/g, respectively; while the NEPA station has 356.20 +/- 210.30 microg/g compared to the control mean of 26.63 +/- 4.58. It revealed that the improper handling of refined petroleum products are potential sources of soil contamination in the sampled sites. This is indicated by the statistically significant levels of TPH and heavy metals observed between the control samples and those collected from the petroleum products handling sites. Bioremediation using microorganisms and plants is recommended.
... Some studies suggest that sustainability practices positively affect the performance of oil and gas businesses (Abu-Mahfouz et al., 2023;Hasan et al., 2024;Longoni and Cagliano, 2018;Goodland, 2019;Nangpiire et al., 2024). However, other scholars argue that sustainability practices have no impact on industry performance (Sarkis, 2017;Pagell and Wu, 2017;Alfreados, 2018). This discrepancy highlights the need for further research to clarify these findings. ...
... However, the study also revealed that the pursuit of sustainability has a positive impact on the environment and society. It has also been reported in another study that the drive for sustainability in the industry is declining, mainly due to recent research indicating that while sustainability does impact business performance, the effect is considered insignificant (Alfreados, 2018). The study further noted that most of the driving forces for sustainability in the industry are external, such as legal requirements and other external mandates necessary for exploration and production processes to begin (Alfreados, 2018). ...
... It has also been reported in another study that the drive for sustainability in the industry is declining, mainly due to recent research indicating that while sustainability does impact business performance, the effect is considered insignificant (Alfreados, 2018). The study further noted that most of the driving forces for sustainability in the industry are external, such as legal requirements and other external mandates necessary for exploration and production processes to begin (Alfreados, 2018). ...
Sustainability has long been a focal point in the oil and gas industry, with significant discussions addressing its importance in mitigating the environmental impacts of these sectors. This study investigates the relationship between sustainability practices and operational performance within the oil and gas industry of Ghana. Using a cross-sectional design and a simple random sampling technique, the study targeted a population of 569 participants, of which 168 usable questionnaires were returned. The study findings reveal that sustainable management practices significantly and positively predicted operational performance of firms in the oil and gas industry. It was further revealed that economic and environmental sustainability were highly embraced while social sustainability was poorly practiced. The study recommends future studies should focus on finding more efficient and sustainable management approaches to improve social sustainability practices, thereby enhancing operational performance in the oil and gas sector.
... Only Hg, Be, Sr, V, Tl, and Sb have concentrations higher than the acceptable limits. There are significant differences in the concentration of heavy metals in the groundwater of the contaminated wells within the study area and the control sample, this report is similar to the output of the research carried out by [18][19]. The results show that there is an indication of heavy metal concentration in groundwater polluted with petroleum hydrocarbon. ...
... The results show that there is an indication of heavy metal concentration in groundwater polluted with petroleum hydrocarbon. [18]; [20]; [19]. The values of concentration of heavy metals in the groundwater are high causing public concerns about the health implications [21]. ...
This research investigated the extent of heavy metals present in the groundwater due to its contamination by petroleum hydrocarbon. Ten hand-dug wells were sampled within the test area and tested for 23 selected heavy metals. A carefully selected well at the upstream with no history of contamination was selected for the control samples. Concentrations of heavy metals were found to be lower in the Control Well compared to the petroleum hydrocarbon-contaminated wells. The Contaminated wells are dominated by B, Zn, Fe, Mn, and Ni in order of B>Zn>Fe>Mn>Ni respectively. Other metals were found in very low concentrations and largely below maximum acceptable concentrations by World Health Organization and United States Environmental Protection Agency. A comparison between the low concentration of heavy metals observed in the Control Well and the relatively high concentrations in contaminated wells showed strong indications of petroleum-hydrocarbon pollution.
... • Identification, testing, and determination of the optimal recipes for stabilizing the acid tar in the lagoon. The characterization of untreated and treated acid tars in each site is conventionally accomplished through expensive sampling and testing of numerous borehole samples using highly sensitive and specific analytical procedures involving extraction and subsequent gravimetric or chromatographic techniques [4,13,28]. These procedures are laborious, expensive, time-consuming, and inadequate when high spatial and temporal resolutions of petroleum hydrocarbon content are required [15]. ...
... During the investigation, monitoring, and remediation of a site polluted with acid tars, the concentration of pollutants is an important factor in identifying the pollution level and spatial distribution [28]. ...
Featured Application
Python application that uses data science and machine learning to estimate the main properties of acid tars. Its main advantage is that determinations for acid tar properties are no longer necessary, thus saving time and money. However, good machine learning estimations are highly dependent on the number and quality of the training data, meaning that the larger and more consistent the training database, the better the estimations.
Abstract
Hazardous petroleum wastes are an inevitable source of environmental pollution. Leachates from these wastes could contaminate soil and potable water sources and affect human health. The management of acid tars, as a byproduct of refining and petrochemical processes, represented one of the major hazardous waste problems in Romania. Acid tars are hazardous and toxic waste and have the potential to cause pollution and environmental damage. The need for the identification, study, characterization, and subsequently either the treatment, valorization, or elimination of acid tars is determined by the fact that they also have high concentrations of hydrocarbons and heavy metals, toxic for the storage site and its neighboring residential area. When soil contamination with acid tars occurs, sustainable remediation techniques are needed to restore soil quality to a healthy production state. Therefore, it is necessary to ensure a rapid but robust characterization of the degree of contamination with hydrocarbons and heavy metals in acid tars so that appropriate techniques can then be used for treatment/remediation. The first stage in treating these acid tars is to determine its properties. This article presents a software program that uses machine learning to estimate selected properties of acid tars (pH, Total Petroleum Hydrocarbons—TPH, and heavy metals). The program uses the Automatic Machine Learning technique to determine the Machine Learning algorithm that has the lowest estimation error for the given dataset, with respect to the Mean Average Error and Root Mean Squared Error. The chosen algorithm is used further for properties estimation, using the R² correlation coefficient as a performance criterion. The dataset used for training has 82 experimental points with continuous, unique values containing the coordinates and depth of acid tar samples and their properties. Based on an exhaustive search performed by the authors, a similar study that considers machine learning applications was not found in the literature. Further research is required because the method presented therein can be improved because it is dataset dependent, as is the case with every ML problem.
... Only Hg, Be, Sr, V, Tl, and Sb have concentrations higher than the acceptable limits. There are significant differences in the concentration of heavy metals in the groundwater of the contaminated wells within the study area and the control sample, this report is similar to the output of the research carried out by [18][19]. The results show that there is an indication of heavy metal concentration in groundwater polluted with petroleum hydrocarbon. ...
... The results show that there is an indication of heavy metal concentration in groundwater polluted with petroleum hydrocarbon. [18]; [20]; [19]. The values of concentration of heavy metals in the groundwater are high causing public concerns about the health implications [21]. ...
This research investigated the extent of heavy metals present in the groundwater due to its contamination by petroleum hydrocarbon. Ten hand-dug wells were sampled within the test area and tested for 23 selected heavy metals. A carefully selected well at the upstream with no history of contamination was selected for the control samples. Concentrations of heavy metals were found to be lower in the Control Well compared to the petroleum hydrocarbon-contaminated wells. The Contaminated wells are dominated by B, Zn, Fe, Mn, and Ni in order of B>Zn>Fe>Mn>Ni respectively. Other metals were found in very low concentrations and largely below maximum acceptable concentrations by World Health Organization and United States Environmental Protection Agency. A comparison between the low concentration of heavy metals observed in the Control Well and the relatively high concentrations in contaminated wells showed strong indications of petroleum-hydrocarbon pollution.
... Only Hg, Be, Sr, V, Tl, and Sb have concentrations higher than the acceptable limits. There are significant differences in the concentration of heavy metals in the groundwater of the contaminated wells within the study area and the control sample, this report is similar to the output of the research carried out by [18][19]. The results show that there is an indication of heavy metal concentration in groundwater polluted with petroleum hydrocarbon. ...
... The results show that there is an indication of heavy metal concentration in groundwater polluted with petroleum hydrocarbon. [18]; [20]; [19]. The values of concentration of heavy metals in the groundwater are high causing public concerns about the health implications [21]. ...
... environment [2]. They cannot be degraded or destroyed Though, the heavy metal tolerance ability of many because they are stable and so persistent environmental soil bacteria have been established [9][10][11][12][13] but that of contaminants are inevitable [3]. The environmental stress cellulolytic soil bacteria [14] have been relegated to the caused by heavy metals, generally decreases the diversity background. ...
... J. Microbiol. Res.,9 (1):[7][8][9][10][11][12][13][14][15] 2018 ...
The tolerance ability of cellulolytic soil bacteria to Lead (Pb), Copper (Cu), Mercury (Hg) and Zinc (Zn) was evaluated in-vitro. The emphasis was placed on two different dumpsites (Soulos dumpsite and Olusosun landfills) naturally polluted with heavy metals in the city of Lagos, Nigeria. Soil samples were randomly collected from these dumpsites and evaluated for bacteria contents. Out of all the bacteria isolated and identified, Pseudomonas spp. and Bacillus spp. predominated in comparison to others such as Klebsiella spp., Micrococcus spp., Escherichia spp., Serratia spp. and Enterobacter spp. Based on evaluation, heavy metal tolerance bacteria with potentials to utilize cellulose were selected. Unfortunately, none of the isolates grow in the presence of Hg even at the lowest concentration level. Despite the challenges of soil physicochemical characteristics, level of metal concentrations and tolerance peculiarities, Micrococcus roseus and Pseudomonas cepacia were outstanding in their tolerance ability. Specifically, Cu and Zn were the best tolerated metals for Micrococcus roseus while Pseudomonas cepacia exhibited multi-tolerance ability to Pb, Cu and Zn. Thus, the biodegradation of heavy metal polluted soil could be achieved using indigenous cellulose utilizers.
... Many of the chemicals present in these solvents pose significant risks to human health and the environment (Imevbore and Adeyemi, 1981). Improper handling of these chemicals can lead to their contamination of the soil, surface water, groundwater, and even the atmosphere (Adeniyi and Afolabi, 2002). Numerous parts cleaners and solvents pose health hazards, and used oil may contain toxic components such as lead, cadmium, barium, and other potentially harmful metals (Edebiri and Nwanokwale, 1981;USEPA, 2001). ...
The pH values of soil samples collected from the topsoil to a depth of 50cm range from 5.78 to 6.64, with an average of 6.284, indicating slightly acidic soil. Water samples near auto-mechanic workshops fall below NSDWQ and WHO standards. Soil heavy metal levels mostly meet ACV and Dutch guidelines, except for Iron (Fe), Copper (Cu), Zinc (Zn), Cadmium (Cd), and Chromium (Cr). Soil contamination analysis shows a high to extreme degree of contamination, likely from the auto-mechanic workshop. Positive correlations between metal pairs suggest a common source and transport to the soil. Principal Component Analysis (PCA) of soil samples reveals Cu, Zn, Fe, Ni, and Pb as dominant metals, while Ni-Cr shows negative correlations with others. In water samples, Cu, Cd, and Co dominate, indicating a different contamination source. Soil and water samples generally meet NSDWQ and WHO standards, but Total Dissolved Solids (TDS), Electrical Conductivity (EC), and Salinity exceed these standards. Understanding these findings is crucial for managing and mitigating contamination risks near auto-mechanic workshops.
... The BOD value is frequently used as a substitute for the amount of organic water contamination [9]. The average BOD level in the current study was 83 mg/L (Fig. 4). ...
... This study's results are largely in alignment with earlier research regarding the presence of high levels of total petroleum hydrocarbons (TPH) in regions with a history of intensive industrial activities. The TPH levels observed in Suraxanı and Baku correspond closely to the ranges documented in studies such as those by Adeniyi and Afolabi (2002), Li et al. (2005) and Almutairi (2022), affirming the persistence of hydrocarbon pollution in these areas. Heavy metal contamination also shows significant consistency with prior studies. ...
This study aims to assess the extent of hydrocarbon and heavy metal contamination in soils from specific areas on Azerbaijan's Absheron Peninsula, including Absheron, Suraxanı, and Baku, and to evaluate the impact of this contamination on soil properties. Soil samples were analyzed for Total Petroleum Hydrocarbons (TPH) and heavy metals, including aluminum, arsenic, cadmium, lead, and iron, alongside assessments of soil physical, chemical and biological properties. The results revealed significant contamination across all studied areas, particularly in Suraxanı, where TPH levels reached 190 ± 20 mg/kg, exceeding the environmental standard of 100 mg/kg. Similarly, Suraxanı soils exhibited alarmingly high concentrations of heavy metals, with aluminum at 30,128 ± 1,500 mg/kg, arsenic at 50.94 ± 2.5 mg/kg, and cadmium at 0.153 ± 0.01 mg/kg, all surpassing acceptable limits. These contaminants severely degraded soil health, evidenced by increased bulk density (1.7 g/cm³ in Suraxanı) and reduced soil porosity. Microbial activity, a key indicator of soil fertility, was also markedly lower in contaminated regions, with the total bacterial count in Suraxanı being less than half that of the uncontaminated area. The findings underscore the urgent need for comprehensive soil management practices and stricter environmental regulations to mitigate contamination's adverse effects and protect both ecosystems and public health in Azerbaijan’s petroleum contaminated areas.
... Though petroleum has played an important role in the economy of the country, over the past three decades, Niger delta ecosystem has been subjected to destruction by petroleum product spillage and other effluents resulting from operational activities, Adeniyi and Afolabi [6] with increase in processed petroleum products (effluents) that are discharged with little regard to aquatic environment. The contents of the effluents have serious toxicological effects on aquatic environment and humans. ...
Effluents from Nigerian National Petroleum Corporation (NNPC) depot in Calabar, Cross River State, Nigeria were evaluated for some physicochemical parameters and hydrocarbon content. The physicochemical parameters of effluents were all below Federal Ministry of Environment (FMEnv) permissible limits except for temperature which was +0.2°C above the standard for temperature of 30.0°C, THC value for the effluent was 0.8mg/l. It was observed that the physicochemical parameters of the depot’s effluent were below FMEnv’s standards which make it safe for discharge. Environmental Regulatory Agencies should therefore ensure compliance from firms, industries, plants and oil depots (oil terminals) which generate effluents by frequent monitoring of their activities.
... Additionally, emissions from the exhausts of the cars being repaired at these workshops can be washed down through rain to the soil around the workshop. Attention has been drawn to the health risks associated with human contact with soil contaminated with PAHs (Wcisło, 1998;Adeniyi and Afolabi, 2002;Dong and Lee, 2009;Kwon and Choi, 2014). PAHs are found to have a negative effect on human health as they can lead to cancer, as well as having a mutagenic and teratogenic effect (Boström et al., 2002). ...
Background
This study determined the levels of polycyclic aromatic hydrocarbons (PAHs) in the soil around typical automobile repair workshops in Nigeria. Risk assessment associated with human contact with the soil was carried out using hazard quotient (HQ) and incremental life cancer risk (ILCR) from human unconscious ingestion and dermal contact with the soil.
Methods
Soil samples were obtained at different automobile workshops in Ado-Ekiti, Western Nigeria. The PAHS in the samples were extracted using dichloromethane and extracts were cleaned up using silica-alumina gel open column chromatography. Analysis of PAHs in the soil was done using a gas chromatograph coupled to a mass selective detector operated on electron ionization mode.
Results
The results showed the mean PAHs concentration at the sampling locations ranged from 5.58 – 6.4 μg/g and the mean ∑ carcinogenic PAHs was 58.4 μg/g, equivalent to 59.39 % of total PAHs observed. The mean Toxicity equivalence (TEQs) ranged from 0.02 - 6.680 μg/g. Benzo (a) pyrene and dibenzo(a,h)anthracene have the highest toxicity equivalent. The total ILCRs from accidental ingestion and dermal contact in adults were 1 ×10^(-3) and 9.8 ×10^(-5), for adults and children respectively; both are higher than the permissible limit stipulated by the World Health Organization.The HQs obtained are several folds higher than 1. This implies high carcinogenic and non-carcinogenic risks for children and adults.
Conclusions
The study revealed the levels of PAHs and also revealed the risks associated with human contact with the soil around automobile repair workshops.
... Additionally, emissions from the exhausts of the cars being repaired at these workshops can be washed down through rain to the soil around the workshop. Attention has been drawn to the health risks associated with human contact with soil contaminated with PAHs (Wcisło, 1998;Adeniyi and Afolabi, 2002;Dong and Lee, 2009;Kwon and Choi, 2014). PAHs are found to have a negative effect on human health as they can lead to cancer, as well as having a mutagenic and teratogenic effect (Boström et al., 2002). ...
Background : This study determined the levels of polycyclic aromatic hydrocarbons (PAHs) in the soil around typical automobile repair workshops in Nigeria. Risk assessment associated with human contact with the soil was carried out using hazard quotient (HQ) and incremental life cancer risk (ILCR) from human unconscious ingestion and dermal contact with the soil. Methods : Soil samples were obtained at different automobile workshops in Ado-Ekiti, Western Nigeria. The PAHS in the samples were extracted using dichloromethane and extracts were cleaned up using silica-alumina gel open column chromatography. Analysis of PAHs in the soil was done using a gas chromatograph coupled to a mass selective detector operated on electron ionization mode. Results : The results showed the mean PAHs concentration at the sampling locations ranged from 5.58 – 6.4 μg/g and the mean ∑ carcinogenic PAHs was 58.4 μg/g , equivalent to 59.39 % of total PAHs observed. The mean Toxicity equivalence (TEQs) ranged from 0.02 - 6.680 μg/g. Benzo (a) pyrene and dibenzo(a,h)anthracene have the highest toxicity equivalent. The total ILCRs from accidental ingestion and dermal contact in adults were 1 ×10^(-3) and 9.8 ×10^(-5) , for adults and children respectively; both are higher than the permissible limit stipulated by the World Health Organization.The HQs obtained are several folds higher than 1. This implies high carcinogenic and non-carcinogenic risks for children and adults. Conclusions : The study revealed the levels of PAHs and also revealed the risks associated with human contact with the soil around automobile repair workshops.
... It has been determined that petrochemical industries are significant organic pollution emission sources (Nadal et al., 2007). A considerable quantity of organic contaminants, TPH, and HMs have been recorded in the vicinity of oil refineries (Adeniyi & Afolabi, 2002;Cetin et al., 2003;Iturbe et al., 2004;Mohebian et al., 2021;Tiwari et al., 2011). The term "heavy metals" often refers to metals that are harmful to both living things and the environment and have a specific density greater than 5 g/cm 3 (Järup, 2003). ...
Several refinery complexes exist in the Kurdistan Region of Iraq that produce various kinds of petroleum products. During the refining process, different types of gases, metals, hydrocarbons, and liquids are discharged into the environment. This study aimed to determine the concentration of eight heavy metals in soil and plant leaves collected around the refineries along Erbil-Gwer Road on two occasions throughout the study period. Additionally, we aimed to evaluate the levels of Total Petroleum Hydrocarbons (TPH) in the soil samples from the area. The results of the analysis revealed significant differences (P<0.05) in the concentrations of Pb, Ni, Cd, Cr, As, and Mn between the dry and wet seasons in the soil samples. However, no significant differences were observed for Cu and Zn between the two seasons. The levels of metals for both periods were as follows: Mn> Cr> Zn> Ni> Cu> Pb> As> Cd in successive forms. Regarding the plant leaves, significant differences (P<0.05) were found between the study periods for Pb, Cu, Zn, and Cd, whereas no significant differences were observed for the other metals. Furthermore, the concentration of TPH in the soil samples located alongside the refinery effluent stream was higher compared to the other areas.
... Additionally, emissions from the exhausts of the cars being repaired at these workshops can be washed down through rain to the soil around the workshop. Attention has been drawn to the health risks associated with human contact with soil contaminated with PAHs (Wcisło, 1998;Adeniyi and Afolabi, 2002;Dong and Lee, 2009;Kwon and Choi, 2014). PAHs are found to have a negative effect on human health as they can lead to cancer, as well as having a mutagenic and teratogenic effect (Boström et al., 2002). ...
Background : This study determined the levels of polycyclic aromatic hydrocarbons (PAHs) in the soil around typical automobile repair workshops in Nigeria. Risk assessment associated with human contact with the soil was carried out using hazard quotient (HQ) and incremental life cancer risk (ILCR) from human unconscious ingestion and dermal contact with the soil.
Methods : Soil samples were obtained at different automobile workshops in Ado-Ekiti, Western Nigeria. The PAHS in the samples were extracted using dichloromethane and extracts were cleaned up silica gel open column chromatography. Analysis of PAHs in the soil was done using a gas chromatograph coupled to a mass selective detector operated on electron ionization mode.
Results : The results showed the mean PAHs concentration at the sampling locations ranged from 5.58 – 6.4 μg/g and the mean ∑ carcinogenic PAHs was 58.4 μg/g , equivalent to 59.39 % of total PAHs observed. The mean Toxicity equivalence (TEQs) ranged from 0.02 - 6.680 μg/g . Benzo (a) pyrene and dibenzo(a,h)anthracene have the highest toxicity equivalent. The total ILCRs from accidental ingestion and dermal contact in adults were 1 ×10^(-3) and 9.8 ×10^(-5) , for adults and children respectively; both are higher than the permissible limit stipulated by the World Health Organization. The HQs obtained are several folds higher than 1. This implies high carcinogenic and non-carcinogenic risks for children and adults.
Conclusions : The study revealed the levels of PAHs and risks associated with human contact with the soil around automobile repair workshop.
... The mean TPH values at the two MVs are lower than the earlier mean TPHs (> 1000 mg/kg) reported by Ogeleka et al. (2018), Ibeto et al. (2019) and Jolaoso et al. (2019) in other MVs within Southern Nigeria. However, the range of TPH values in spent oil-contaminated soils within Sagamu MV obtained in this study fall within the reported range of TPH content (100-500 mg/ kg) in hydrocarbon-contaminated soil by Adeniyi and Afolabi (2002) and Martins and Peixoto (2012). Our range of TPH content in the top 30 cm of soils in Sagamu MV also agrees with the TPH range of 34-1247 mg/kg reported by Akomah and Osayande (2018) in contaminated soils of automobile mechanic workshops in southern part of Nigeria. ...
This report presents the findings of the concentrations, distributions and health risks assessment of heavy metals (HMs) and volatile organic compounds (VOCs) in topsoils of two typical automobile mechanic villages (MVs) situated within Ogun State, Nigeria. One of the MVs is located in basement complex terrain (Abeokuta), while the second is in the sedimentary formation (Sagamu). Ten composite samples were collected at depth of 0–30 cm with the aid of soil auger from spent oil-contaminated spots within the two MVs. The chemical parameters of interest were Pb, Cd, benzene, ethylbenzene, toluene, total petroleum hydrocarbon (TPH) as well as oil and grease (O&G). In addition, soil pH, cation exchange capacity (CEC), electrical conductivity (EC) and particle size distribution were also evaluated in order to find out their impacts on assessed soil pollutants. Results revealed that the soils in both MVs are of sandy loam texture, slight acidic to neutral pH, mean CEC < 15 cmol/kg and mean EC > 100 μS/cm. The mean concentration of each of analyzed HMs and VOCs in soils from the two MVs was < 5 mg/kg, while the mean values of TPH and O&G content were > 50 mg/kg. The mean Cd values in soils of both MVs were higher than the national soil screening level of 0.8 mg/kg, but lower than the Canadian and Italian guidelines. There is no significant correlation between each of HMs/VOCs and any of assessed soil physicochemical variables. The non-cancer risk expressed in terms of hazard index (HI) was > 1 via oral ingestion route for adults and children at the two MVs, indicating adverse non-carcinogenic health risk. The HI > 1 value was obtained for adults only through the dermal absorption pathway in Abeokuta MV. However, HI values for the two age groups at the two MVs via inhalation route were < 1, indicating no likelihood of any non-carcinogenic effects via the breathing exposure. The potential of non-cancer risk via oral ingestion route in both MVs was derived from the contributive ratios of HMs and VOCs in the order: Cd > benzene > Pb > toluene. The carcinogenic risk (CR) values due to ingested Cd, benzene and Pb for both age groups at the two MVs exceed the safe limit range of 10–6 to 10–4. Cadmium, benzene and lead made considerable contributions to the estimation of CR through dermal exposure for adults only in Abeokuta MV. The CR values via inhalation pathway for adults and children in both MVs were within the threshold range. Artisans and children should circumvent accidental ingestion of contaminated soils in addition to wearing of protective clothes during routine vehicle maintenance activities.
... For instance, TPH has been detected in the vicinity of facilities handling refined petroleum oil in Lagos, Nigeria. TPH was calculated in three nearby locations (a mechanic workshop, a Nigerian Electricity Power Authority (NEPA) station, and a Petrol station, respectively [5]. The effects of these three stations were compared and contrasted. ...
After oil-contaminated soil samples were collected from the affected area of an extensive oil spillage near the Tobruk refinery (El Hariga Terminal), a DOP-UNI biological product was used in this bioremediation field trail. DOP-UNI has the largest concentration of microorganisms, leading to the fastest rate of degradation in soils and water Gas. Chromatography with a flame ionization detector was used to test the collected samples. The overall petroleum hydrocarbon (TPH) concentrations in untreated soil samples ranged from 2700± 28 to 2800± 26 µg g-1, while the treated samples had concentrations ranging from 3.5± 0.1 to 210.2 ±54 µg g-1. This represents a 97 percent removal of total hydrocarbons from the polluted soil samples. Findings show that bioremediation is stronger and quicker in samples exposed to direct sunlight.
... People set up their workshops indiscriminately and disposal of hazardous wastes such as brake fluid, greases, spent oil, radiator coolant, soot, fuel, metal scraps, chemicals and other volatile compounds into the soil and water drains. These waste, persist in the soil because they are not degradable and from auto mechanic workshops, they find their way into the air, water, soil, lakes and streams (Adeniyi and Afolabi, 2002;Adesuyi et al., 2015). Trace of these pollutants within and around automobile mechanic workshops implies that according to Nwachukwu et al. (2010) water bodies (surface and groundwater) within and away from their vicinity may equally be polluted with trace metals due to continuous interactions between soil and water and high dispersion rate in the tropical rain forest belt). ...
This study was undertaken to investigate the mycofiltration of soil leachate from automobile repairs and servicing workshop Ikoku, Port Harcourt using Lentinus squarrosulus. To ascertain the contamination levels of the soil, sterilized sawdust was bagged, inoculated with mushroom spawn and allowed for 2 weeks to colonize the substrate. Then water extracted from the soil leachate was dispensed into the hole borne in the middle of the substrate then allowed to filter through into a sterile container which was subjected for physicochemical and microbiological analysis within 24 hours. Statistical analysis of data obtained after a 24-48 hours mycofiltration treatment, revealed a significant (P<0.05) reduction in the concentration of pH, Colour, Turbidity, Electrical conductivity, Total Dissolved Solid, Total Suspended Solid, Nitrite, Nitrate, Phosphate and Chemical Oxygen Demand. Electrical conductivity (µs cm-1) was reduced from 751 to 297, total dissolved solid (mg L-1) from 3.40 to 1.42, total suspended solid (mg L-1) from 2.81 to 1.07, nitrate (mg L-1) from 0.187 to 0.127, phosphate (mg L-1) from 1.04 to 0.72, turbidity level from 1028 to 401, biological oxygen demand (mg L-1) from 4.16 to 0, dissolved oxygen (mg L-1) from 401 to 0 and chemical oxygen demand (mg L-1) from 16.25 to 13.87. L. squarrosulus also exhibited a remarkable reduction in total heterotrophic count and total coliform count, which made it a potential purifying agent. The findings from this study showed that mycofiltration technique is a useful, efficient and affordable technology for removing pollutants from the soil in the automobile repairs and servicing workshop.
... Prior research on the disposal or reclamation of these contaminated soils has ignored the interference of heavy metals. However, many oilpolluted sites are co-contaminated with heavy metals [3]. In earlier studies, petroleum hydrocarbons and heavy metals were detected in contaminated soils near gas stations, automobile repair workshops, and power stations. ...
The contamination of soils with petroleum and its derivatives is a longstanding, widespread, and worsening environmental issue. However, efforts to remediate petroleum hydrocarbon-polluted soils often neglect or overlook the interference of heavy metals that often co-contaminate these soils and occur in petroleum itself. Here, we identified Acinetobacter baumannii strain JYZ-03 according to its Gram staining, oxidase reaction, biochemical tests, and FAME and 16S rDNA gene sequence analyses and determined that it has the ability to degrade petroleum hydrocarbons. It was isolated from soil contaminated by both heavy metals and petroleum hydrocarbons. Strain JYZ-03 utilized diesel oil, long-chain n-alkanes, branched alkanes, and polycyclic aromatic hydrocarbons (PAHs) as its sole carbon sources. It degraded 93.29% of the diesel oil burden in 7 days. It also had a high tolerance to heavy metal stress caused by arsenic (As). Its petroleum hydrocarbon degradation efficiency remained constant over the 0–300 mg/L As(V) range. Its optimal growth conditions were pH 7.0 and 25–30 °C, respectively, and its growth was not inhibited even by 3.0% (w/v) NaCl. Strain JYZ-03 effectively bioremediates petroleum hydrocarbon-contaminated soil in the presence of As stress. Therefore, strain JYZ-03 may be of high value in petroleum- and heavy-metal-contaminated site bioremediation.
... This may explain the almost 2-fold increased cadmium and lead contents in the soil noted in this experiment. The concentrating effect of petroleum-derivative contamination on the lead, cadmium, and nickel contents in the soil was also reported by Onyeike et al. [58], Adeniyi and Afolabi [59], and Adesina and Adelasoye [60]. An increase in the mobility coefficients for trace elements (Cd, Cu, Pb, Ni, Cr, Zn, and Mn) and in their content in soils contaminated with crude oil compared to the control (non-contaminated) object was demonstrated by Iwegbue [61]. ...
The global use of petroleum hydrocarbons as raw materials and an energy source in industry results in serious environmental, health, and ecological problems. Consequently, there is growing interest in the development of technologies for the rehabilitation of contaminated areas. This study was undertaken in order to determine the effect of different phytostabilising materials (compost, bentonite, and CaO) on the trace element content in soil contaminated with unleaded petroleum 95 (0, 2.5, 5, and 10 cm³ kg⁻¹ of soil). The doses of petroleum applied to the soil were based on the previously conducted preliminary experiment. The highest petroleum dose (10 cm³ kg⁻¹ of soil) significantly reduced the chromium, zinc, and cobalt contents in the soil. Petroleum increased the cadmium, lead, nickel, and copper contents in the soil. The materials used for phytostabilisation (compost, bentonite, calcium oxide) had a significant effect on the trace element content in the soil. The application of mineral materials (bentonite and calcium oxide) was more effective than the application of compost, compared to the control series (without soil amendments) as they reduced the contents of cadmium, chromium, nickel, and cobalt in the soil to the greatest extent. The reduction effect of bentonite and calcium oxide on the content of these trace elements in the soil was stronger than compost.
... Since most of the HMs are non-biodegradable and have a long residence time in the food chain and marine biota, they constitute a risk to the environmental matrices and human health (Ametepey et al. 2018;Islam et al. 2020). Some soluble forms of HMs are particularly toxic, and their accumulation in natural systems is extremely hazardous, even at low concentrations (Adeniyi and Afolabi, 2002). The coastal zone covers 47,201 km 2 , 32% of the total land mass of Bangladesh, where 37 to 38 million people live ( Fig. 1) (Islam 2004;Sarwar 2005). ...
The coastal zone of Bangladesh, with a population density of 1278 people per square kilometer, is under serious threat due to heavy metal pollution. To date, many studies have been conducted on the heavy metal contamination in soils, water, aquatic animals, and plants in the coastal zone of Bangladesh; however, the available information is dispersed. In this study, previous findings on the contamination levels, distributions, risks, and sources of heavy metals in sediments and organisms were summarized for the first time to present the overall status of heavy metal pollution along coastal regions. Earlier research found that the concentrations of various heavy metals (HMs), particularly Co, Cd, Pb, Cu, Cr, Mn, Fe, and Ni in water, sediment, and fish in most coastal locations, were above their permissible limits. High concentrations of HMs were observed in sediments and water, like Cr of 55 mg/kg and 86.93 mg/l in the ship-breaking areas and Karnaphuli River, respectively, in coastal regions of Bangladesh. Heavy metals severely contaminated the Karnaphuli River estuary and ship-breaking area on the Sitakundu coast, where sediments were the ultimate sink of high concentrations of metals. Sedentary or bottom-dwelling organisms like gastropods and shrimp had higher levels of heavy metals than other organisms. As a result, the modified PRISMA review method was used to look at the critical research gap about heavy metal pollution in Bangladesh’s coastal areas by analyzing the current research trends and bottlenecks.
Graphical abstract
... Human health and ecosystems can be in risk due to released hydrocarbons (Teng et al., 2013) and produced wastes by the oil industry (Vidaković, Papeš, & Tomić, 1993). Petroleum hydrocarbons and heavy metals can impact in ecosystems reducing the quality of resources and affecting them due to their toxicological and health implications into the food chain (Adeniyi & Afolabi, 2002). Depending on local conditions, contaminants can migrate and contaminate groundwater, which could be a source of drinking water (Teng et al., 2013). ...
Contamination from oil exploration and production activities was investigated in the site Aguarico 06, a well site in the northern Ecuadorian Amazon. An environmental site assessment was performed to assess the pollution and to propose a remediation technology. Soil and water samples were taken and included in the general assessment. Concentrations above the permissible levels of petroleum hydrocarbons in soil, sediments and groundwater are the main concern. Four reserve pits are considered as the main source of contamination because the content of the pits have seeped underneath the pit limits, reaching lower soil layers and the groundwater table. Additionally, LNALP spreads vertically as result of fluctuation on the water table during rain periods. 53 in situ and ex situ technologies were evaluated to remediate both soil (28 technologies) and groundwater (25 technologies). Biopiles are recommended to treat soil. To remediate groundwater, it is recommended air sparging. The performance of most of the technologies evaluated in this study is reduced due to geological and hydrogeological condition of the study area.
... The impact of industrial effluents on aquatic and terrestrial ecosystems has drawn a lot of attention worldwide because of its overwhelming environmental significance (Achudume, 2009). Adeniyi and Afolabi (2002) documented that industrial effluents are not only concentrated but also plentiful, so the pollution potential of industrial effluents is by far greater than that of domestic effluents. Most industrial effluents are usually extremely complex mixtures containing inorganic as well as organic compounds (Edema et al., 2008). ...
The operations of Kaduna Refinery and Petrochemical Company (KRPC)
lead to the generation of effluents. Plants growing in the drain are in
constant exposure to these effluents. Mariscus longibrateatus, which is the
most abundant plant species growing in the drain, was studied to determine
the effects of the effluents on the plant. Plant samples and soil on which the
plant grows, were analyzed for heavy metals. Manganese (1.30mg/g) and
copper (1.30mg/g) had the highest concentration of heavy metals in the
roots. The plant samples had thinner leaves than the control plant, which
may be attributed to dehydration and some hidden injuries. The leaf whole
vascular bundle of the studied plants ranged from 19085–20790µm2
whereas phloem and xylem area ranged from 3995 – 4290µm2 and 6584-
7004µm2 respectively. Transfer and bioaccumulation factors revealed that
heavy metals were not effectively transferred from the root to the stem, but
the plant was able to survive in the drain containing KRPC effluents. It is
concluded that the effluents caused some changes in the plant. It can be
inferred that Mariscus longibrateatus are tolerant to the toxicants in the
effluents, and therefore, this plant species is recommended for
bioremediation study because of its tolerant ability to heavy metals.
... The major sources of the direct pollution of the soil and surface of the soil can be as a result of the leakage from surface and the underground tanks, separators, wastewater treatment plants slurries and waste pits of tar, underground pipelines. Solid residues stored, which can pollute the soil come from solid impurities involved in crude oil, sewage sludge from waste water treatment plants and raw water treatment, solid waste from the maintenance and clearing of incinerator ash sludge, powder catalyst [3][4] There were different concentration of hydrocarbons and physiochemical parameters within the impacted and control stations at different depths [5][6][7]. The existing data on Niger Delta Environmental Investigation conducted on crude oil degradation momentum shows that higher concentration of hydrocarbons indicates serious hydrocarbon contamination. ...
Investigation was carried out to examine the effect of crude oil contamination of Aluu soil and some of the physiochemical parameters. The physiochemical parameters studied were temperature, pH value, electrical conductivity and available phosphorus. The result obtained revealed the significant effect of the crude oil contamination on the physicochemical parameter investigated. The statistical analyses used were analysis of variance (ANOVA) and regression analysis. The time has effect on temperature and pH. P<0.05 significant but has no effect on available phosphorus and electrical conductivity P<0.05 not significant. There were high positive correlations between physiochemical parameters and time.
... When it comes to handling their wastewater effluents, the chemical industry faces several regulatory hurdles (Adeniyi and Afolabi, 2002). Solid waste and sludge from refineries and petrochemical industries contain organic and inorganic substances, as well as heavy metals. ...
Due to high concentrations of numerous harmful and hazardous pollutants, particularly heavy metals, industrial wastewater has become a major problem. Heavy metal pollution and its implications for human health and the environment have increased research in developing low cost and sustainable remediation technology. Diverse conventional physicochemical and green biological methods are applied to remove heavy metals (HMs). This review article covers both the conventional and biotechnological approaches used for removal of HMs from wastewater and evaluate them based on their efficiency. Adsorption, coagulation, flocculation, chemical precipitation, membrane separation, ion exchange, flotation, and electrochemical technologies are examples of conventional methods. In some circumstances, these procedures produce quick results, although they are less efficient and cost more than biotechnological heavy metals removal (HMR). The current state and prospects of biosorption and bioaccumulation for environmental bioremediation are reviewed. Environmental considerations are evaluated, with a focus on the removal efficiency of biosorption and bioaccumulation. HMR efficiency and cost effectiveness of a range of biosorbents for the removal of pollutants are described. Furthermore, the equilibrium, kinetic, and thermodynamic behavior of the heavy metal biosorption process, based on kinetic and isotherm models, are presented. Overall, this study provides clear information of biological processes, which will help surmount technological limitations of bioseparation process application.
... Heavy metals constitute an ill-defined group of inorganic chemical hazards, and those most commonly found at contaminated sites are lead (Pb), chromium (Cr), arsenic (As), zinc (Zn), cadmium (Cd), copper (Cu), mercury (Hg), and nickel (Ni) (Wuana et al., 2011). Pollutants specific, to a former ramp and depot for loading and unloading petroleum products in a Romanian refinery, are total petroleum hydrocarbon (TPH) benzene and mono and dialkylated benzene compounds: toluene, ethylbenzenes and (ortho, para and meta) xylenes, lead compounds (Adeniyi et al., 2002). In this context, the paper presents the assessment of soils exposed to oil products expressed by total petroleum hydrocarbons (TPH) measure. ...
... Environmental reports have shown that high level of organic (including petroleum hydrocarbons) and inorganic chemicals have impacted on the environment, due to the activities of these industries. Their effects have been adverse and have exceeded both international and national acceptable limits in different environments [29][30][31][32]. The activities of petroleum industries have severe environmental impacts and consequences on the inhabitants or the particular environment where the activity took place. ...
The level of contamination of Orashi River by total petroleum hydrocarbons were investigated through the collection of surface water samples and sediment samples from four locations along the river. Determination of the level of contamination was done with the use of gas chromatography-flame ionization detector after following laid down clean-up procedures. The results obtained showed that total petroleum hydrocarbons in the surface water were 10.913±2.2022mg/L, 7.645±2.683mg/L, 9.074±2.1654mg/L and 12.212±3.3034mg/L for stations 1, 2, 3 and 4 respectively with a mean value of 9.961±2.5885mg/L, while in the sediment samples concentration values recorded were 22.3925±5.2104mg/Kg, 35.1071±9.9652mg/Kg, 50.4431±15.9916mg/Kg and 29.3869±8.0410mg/Kg for stations 1, 2 3 and 4 respectively with a mean value of 34.3324±9.8021mg/Kg. The partition coefficient calculations revealed that the sediment phase is more stable for total petroleum hydrocarbons as compared to the water phase. The analysis of the randomly collected samples revealed that total petroleum hydrocarbons have contaminated the river and therefore adequate steps should be taken to remedy the present condition of the Orashi River in order to mitigate any probable rise in the quantity of total petroleum hydrocarbons in the river above allowable limit.
... These in turn contributes to elevated levels of heavy metals in plants grown in and around it (Ukpebor and Unuigbe, 2003;Chien, 2004;Hargreaves et al., 2008;Hogarh et al., 2008). Heavy metal contamination within waste dump sites and agricultural soils has been extensively studied (Ukpebor and Unuigbe, 2003;Feng et al., 2007;Adeniyi et al., 2008;Hargreaves et al., 2008;Hogarh et al., 2008;Agyarko et al., 2010;Dasaram et al., 2011 andAkintola, 2014).A geochemical implication of heavy metal contamination on soils and sediment has also been evaluated by various researchers using various geochemical indices (Loring and Rantala, 1992;Zwolsman et al, 1993;Adeniyi and Afolabi, 2002;Sharma and Reddy, 2004;Lim et al, 2008and Agyarko et al., 2010. Heavy metals distribution in plant body depends upon their concentration in soil and water as well as plant species and its population (Seilsepour and Bigdeli, 2008).Heavy metals accumulation in agricultural soils may result in increased metal uptake by plants which in turn may affect food quality and safety (Lazat, 2000 andZheng et al, 2007). ...
Heavy metal contamination has become a critical environmental concern and poses a serious threat to the environment leading to hazardous health effect as they enter food chain. One of the main processes of human exposure to heavy metal through the food chain is transfer of nutrients from the soil to the plants. This study assessed heavy metal concentrations in Chromolaena odorata and the soils around Lapite dumpsite in Ibadan. Five C. Odorata samples (root, stem, leaf) each were taken from control, contaminated and waste dump sites considered in this study. Composite soil samples were collected from the topsoil (0-20m) around each of the site. Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) instrumentation technique was used to determine the heavy metals (iron (Fe), zinc (Zn), lead (Pb), copper (Cu), nickel (Ni), cadmium (Cd), chromium (Cr), cobalt (Co) and Arsenic (AS) in soil samples and C. odorata tissues. These results showed that C. odorata and soil samples had significantly high levels of heavy metals in waste dump and contaminated sites than control site. Heavy metal concentrations in C. odorata and soil samples showed decreasing order of Fe> Zn> Cu> Pb> Ni> Co> Cr>Cd>As. The ability of C. Odorata to accumulate the metals was consistent with the high translocation ratio values of more than 1 and the low transfer factor values of less than 1.Heavy metals in soils showed positive correlation coefficient of 0.46-0.99 with the levels in C. Odorata plants. This study has shown the ability of C. Odorata plant to bio-accumulate translocate heavy metals.
... Factorial design (FD) is normally used in screening variables (both dependent and independent) and also in optimizing response surfaces. The latter is frequently used for experimental designs involving experimental procedures [31]. FD has been employed in some oil biodegradation studies of constituent's optimization that may induce the microbial debasement phenomenon hereby contributing to the progress of oil spill bioremediation process. ...
Land farming technique was used to treat hydrocarbon contaminated soil collected from a crude oil spill sites in Edo State, Nigeria. Calibrated standard auger was used to collect soil samples from the site at depth below 30 cm. The samples were characterized and classified. Cow dung and NPK fertilizer were added as additives to complement the nutriments of the soil samples before total petroleum hydrocarbon (TPH) quantification and remediation procedures. Factorial design was applied to vary the input parameters such as pH, mass of substrate, moisture content and turning times of land farming so to ascertain the optimal conditions for the procedure. The result revealed that the in-situ TPH value was 5000 mg kg − 1 on the average and after 90 d of treatment, TPH reduced to 646 mg kg − 1. The turning rate, pH, moisture content and mass of substrate hade 83, 4.36, 0.48 and 0.046% contribution, respectively, for the degradation process using land farming treatment. Numerical optimization techniques applied in the optimum point for land farming input parameters to achieve predicted maximum removal of 99% were evaluated as pH, mass of substrate, moisture content and turning rate to be 6.01, 1 kg, 10% and 5 times in a week, respectively. TPH removed at this optimum point was 98% reducing from 5000 to 636 mg kg − 1. The high coefficient of determination (r 2 = 0.9865) as observed in the closeness of predicted and experimental values reflects the reliability of the model and hence, land farming practice with close attention on turning rate as revealed by this study, is recommended for TPH contaminated soil remediation.
... Their effect is more evident from the abnormal values of a set of physical and chemical parameters. The significance of trace elements in marine sediment is increasingly becoming an issue of global concern and needs proper assessment [15,16]. Thereby, assessment of heavy metals pollution at the Bengal marine coastal area is of considerable interest of both scientific and 2 Journal of Toxicology regulatory communities. ...
elements in the surficial sediments were studied in an attempt to establish their concentration in the Bengal coast. It was revealed that the majority of the trace elements have been introduced into the Bengal marine from the riverine inflows that are also affected by the impact of industrial, ship breaking yard, gas production plant, and urban wastes. The concentration of heavy metals was measured using Atomic Absorption Spectroscopy and Energy Dispersive X-ray fluorescence instruments. The highest concentrations for several trace elements were thus recorded which generally decrease with distance from the coast. It was observed that the heavy metal concentrations in the sediments generally met the criteria of international marine sediment quality. However, both the contamination factor and pollution load index values suggested the elevation of some metals' concentrations in the region. Constant monitoring of the Bengal coast water quality needs to be recorded with a view to minimizing the risk of health of the population and the detrimental impacts on the aquatic ecosystem.
... This is due to the release of different greenhouse gases into the atmosphere resulting to substantial air pollution (Carla, 2002). Aside air pollution impacts; there are also waste water concern, risk of industrial accidents such as fire and explosion (Adeniyi and Afolabi, 2002).A non-conventional refining plant is not concerned with the chemical changes in crude oil rather it involves the physical changes found in simple distillation. It has been reported that petroleum refining contributes to solid, liquid and gaseous wastes in the environment (Nwankwo and Irrechukwu, 1998). ...
The physico-chemical analysis of the impacted soil in Bodo community was carried out due to severe degradation of the environment and the aesthetic destruction of the terrestrial environment, the need to access the effect of non-conventional refining plants on the physico-chemical parameters of the soil. The pH, conductivity, total nitrogen, phosphate, cation exchange capacity and so on were analyzed using the standard method. From the result, it was observed that the impacted soil recorded mean and standard error as 54.1258 and 24.162 respectively while the non-impacted soil recorded 18.4176 and 6.323 respectively. Amongst the physical parameters, soil textural analysis revealed that the soil is mainly sandy loamy and small percentage of clay loamy. This therefore requires appropriate remediation measures to avoid infiltration into the groundwater.
... Factorial design (FD) is normally used in screening variables (both dependent and independent) and also in optimizing response surfaces. The latter is frequently used for experimental designs involving experimental procedures [31]. FD has been employed in some oil biodegradation studies of constituent's optimization that may induce the microbial debasement phenomenon hereby contributing to the progress of oil spill bioremediation process. ...
Land farming technique was used to treat hydrocarbon contaminated soil collected from a crude oil spill sites in Edo State, Nigeria. Calibrated standard auger was used to collect soil samples from the site at depth below 30 cm. The samples were characterized and classified. Cow dung and NPK fertilizer were added as additives to complement the nutriments of the soil samples before total petroleum hydrocarbon quantification and remediation procedures. Factorial design was applied to vary the input parameters such as pH, mass of substrate, moisture content and turning times of land farming so to ascertain the optimal conditions for the procedure. The result revealed that the in-situ total petroleum hydrocarbon (TPH) value was 5,000 mg kg -1 on the average and after 90 days of treatment, TPH reduced to 645.907 mg kg -1 . The turning rate, pH, moisture content and mass of substrate had 82.79%, 4.36%, 0.48% and 0.046% contributions respectively to the degradation process using land farming treatment. Numerical optimization techniques applied in the optimum point for land farming input parameters to achieve predicted maximum removal of 98.60% were evaluated as pH, mass of substrate, moisture content and turning rate to be 6.01, 1 kg, 10% and 5 times in a week respectively. TPH removed at this optimum point was 97.83% reducing from 5,000 to 635.907 mg kg -1 . The high coefficient of determination (r 2 = 0.9865) as observed in the closeness of predicted and experimental values reflects the reliability of the model and hence, land farming practice with close attention on turning rate as revealed by this study, is recommended for TPH contaminated soil remediation.
The increasing need to solve the problem of environmental pollution by oil spills in the Niger Delta Areas resulted in the quest to isolate and identify bacteria species with highest degradability of hydrocarbon. Samples were collected from polluted Okulu River in Eleme Local government Area of Rivers State, Nigeria. Physicochemical analysis was done on the samples following the methods described by American Public Health Association. Cultural and molecular methods were used to isolate and characterize bacteria species in the water samples. The physicochemical parameters measured showed increased concentration of heavy metals, biological oxygen demand, total organic carbon, nitrate, phosphate, suspended and dissolved solids, elevated pH and temperature and elevated hydrocarbon concentration. A total of twelve (12) bacterial genera were isolated and characterized. Percentage occurrence of the isolates were Pseudomonas aeruginosa (19.2%), Enterobacter asburiae (14.1%), Micrococcus luteus (10.6%), Escherichia coli (9.6%), Staphylococcus massilliensis (8.6%), Serratia marcescens (8.1%), Bacillus cereus (7.1%), Bacillus subtilis (6.1%), Klebsiella pneumoniae (4.5%), Providencia alcalifaciens (4%), Pectobacterium atrosepticum (2%), Brevibacillus laterosporus (2%). Of these, only five were further characterized using 16S rRNA sequencing. These five bacteria species isolated were identified as Lysinibacillus fusiformis, Alcaligenes faecalis, Enterobacter cloacae, Lysinibacillus sphaericus and Lysinibacillus macroides. They were 99%, 98%, 83%, 96% and 99%, respectively related to their relatives in the gene bank. The increase in temperature, biological oxygen demand, nutrient, salinity and pH favoured the growth of the isolates.
Heavy metal pollution is a silent killer and has become a pervasive issue in various regions worldwide, particularly within developing nations such as Nigeria. This study undertook a thorough examination of 120 scholarly articles published from 2000 to 2019, aimed at evaluating the prevalence of heavy metal pollution in soils, aquatic environments, and food sources including crops, meat, and dairy products. Methodologies employed for sample collection and metal quantification were critically assessed, alongside an extensive discussion on the concentrations, sources, and levels of contamination observed. The investigation revealed elevated concentrations of cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn), cobalt (Co), chromium (Cr), iron (Fe), and arsenic (As) across all examined locales, with average metal concentrations surpassing World Health Organization/Food and Agriculture Organization (WHO/FAO) guidelines for soil. Furthermore, higher metal concentrations were detected in surface and well waters, whereas borehole groundwaters were relatively pollution-free. Analysis of food crops, meat, and milk demonstrated metal concentrations exceeding WHO/FAO standards across all urban areas studied. Contrary to expectations of lithogenic toxicity, the primary sources of contamination were identified as anthropogenic, stemming from dumpsites, landfill sites, mining operations, runoff and seepage from automotive repair workshops, petroleum hydrocarbon spills, and effluents from industrial plants. The geo-accumulation index (Igeo) analysis revealed significant soil contamination with Fe and Cd, classified under extremely serious and moderate contamination levels, respectively. This comprehensive review highlights the necessity for viable and clear policy interventions to mitigate heavy metal pollution and advocates for the rigorous monitoring and control of industrial activities.
Hydrocarbon pollution from the petroleum industry is one of the world's most critical environmental problems. Polluting the environment by inadvertent release of petroleum products is a serious concern. Hydrocarbon components have long been recognized as organic pollutants with well-documented carcinogenic and neurological effects. There are three major categories of hydrocarbons in petroleum: pyrogenic, petrogenic, and biological. Numerous petroleum waste and organic contaminants are consistently produced throughout oil exploration and processing. Leaks of petroleum oil, sewage sludge, and tarry or creosote waste are additional environmentally hazardous sources of petroleum hydrocarbons. The most harmful hydrocarbons evaporate quickly following oil spills, causing damage to the ecology in this way. Aromatic compounds, nitrogen, aliphatic, amines, and oxides are all part of the petroleum wastes. However, the composition may change from place to place due to differences in the local biological and geologic factors. As the demand for petroleum products increase, this ultimately increases environmental concern for its dumping. As there is no suitable dumping method, this causes various impacts on the ecosystem, affecting humans, soil, aquatic life, plants, etc. In plants, it leads to inhibition in seed germination enzymatic dysfunction and affects the process of photosynthesis by causing changes in chlorophyll concentration. In humans, it affects the respiratory system, such as lung (pneumonia) or lung damage, skin and eye irritation, dizziness, headache, etc. Similarly, it affects aquatic life by affecting reproductive process, lowering the production of eggs, and decreasing oxygen content, which affects flora, fauna, and aquatic animals. Several physicochemical and biological methods are used for the remediation of petroleum hydrocarbon wastes. Physiochemical methods are generally not environment-friendly and cost-effective; hence, we go for various biological methods such as phytoremediation, bioaugmentation, and biostimulation.
Determination of petroleum hydrocarbons in soil has long been an area of active
investigation and still attracting interest as there are important and complex
environmental contaminants. Several standardised lab-based analytical techniques
providing both accuracy and analytical precision are being used for their
determination and quantification in soil. However, the procedures involved can be
time-consuming and expensive, and therefore not always providing cost effective
approaches to the assessment of sites contaminated with petroleum hydrocarbons.
Over the past decade, the emergence of various field analytical techniques has
enabled real-time petroleum hydrocarbons detection and on-site measurement,
which has the potential to drastically reduce cost and time of analysis, sampling
design and site assessment compared with traditional technologies. In this review,
we have designed and developed a practical guide on the use of field analytical
technologies to rapidly assess petroleum hydrocarbons in soil. The basic principle
along the advantages and limitations of each field analytical technique, and the
recent developments over the past years, are highlighted.
The synthesis of information outlined in this review provides a firm foundation for
an informed decision process in the selection of field analytical technologies for the
detection and characterisation of petroleum hydrocarbons in soil.
In the present study, the concentrations of six petroleum hydrocarbons, including n-alkane hydrocarbons (total petroleum hydrocarbons [TPH] (C6–C9) and (C10–C40)), BTEX(benzene, toluene, ethylbenzene, and m- and p-xylene), in 261 soil (0–14 cm), 31 groundwater, and 4 soil gas samples were measured to determine their spatial distribution and human health risks. The study integrated the model by Johnson and Ettinger and the HJ 25.3–2019 technical standards for risk assessment of soil contamination with localized parameters using Chinese demographic characteristics and site features to determine Health risk assessments. The results revealed that TPH (C6–C9) was the main contaminant in oil refineries, and the m- and p-xylene concentrations exceeded the screening values in groundwater and soil gas but not in soil. According to the spatial distribution characteristics, the contaminants were mainly concentrated in the refining workshop and around the storage tank, and the migration ability of linear-chain petroleum hydrocarbons in the soil was stronger than that of BTEX. TPH (C6–C9), TPH (C10–C40), and benzene in soil and groundwater pose a threat to human health. The pathway of steam invasion in soil gas and the carcinogenic risk and hazard quotient assessment of benzene in soil gas were 0–4 and 1–3 orders of magnitude higher than those in soil. Aliphatic hydrocarbons [AHCs] (C10–C12) had the highest non-carcinogenic risk among all TPH (C10–C40) parts. The present study provides a reference to accurately determine the toxicological parameters of TPH (C6–C9) and TPH (C10–C40) and to improve the BTEX risk assessment methods.
The global use of petroleum hydrocarbons for the production of various type of energy has been increased, with an extensive release of contaminants into the environment, affecting the soil, groundwater and vegetation. The dispersal of vanadium (V) was evaluated in the soil, vegetables, fruits and animal feeds samples cultivated in agriculture field dressing with waste soil/mud produced during drilling of oil well, termed as test samples. Similar environmental, vegetables and animal feed samples cultivated in agricultural land devoid of any mining and industrial activities were chosen as the controls. The total and bioavailable forms of V were determined in both test and control soils samples. The V in soil, vegetable, grass and fruit was determined by inductive couple plasma omission spectrometry, after acid digestion. The resulted data indicated that the test soil samples have two to three fold higher V than control samples. The results indicated that the concentration of V in test crops was > 2.0 µg/g (optimal recommended limit). The animal feed grown on exposed soil contained V about three folds higher than control samples. The risk was assessed by estimation of daily intake of V via consuming ground water, vegetable and fruit obtained from exposed agricultural land.
Streams are often recipients of pollution from agricultural, domestic and industrial sources though they are important sources of water supply and habitats of several aquatic species. Regular monitoring is required to protect this fragile but important ecosystem. Therefore, some physico-chemical parameters and macroinvertebrate assemblages of Temidire Stream, a perennial stream that flows through the Nigeria National Petroleum Corporation (NNPC) depot and Temidire community in Apata, Ibadan metropolis were investigated in order to determine the pollution status of the water and sediment and its impact on the biological community. Water and sediment samples were collected from five stations in the stream and from an adjacent stream monthly between August, 2019 and January, 2020 for physico-chemical parameter and benthic macroinvertebrate analyses. Dissolved oxygen, conductivity and total dissolved solids (TDS), and pH were determined in situ using EXTECH EC400 and C933 pH meters, respectively. Heavy metals were determined by atomic absorption spectrophotometry. Benthic macroinvertebrates were collected by kick sampling method. The results showed that TDS and conductivity of station 1 differed significantly from the other stations (p< 0.05). The concentrations of Pb, Ni and Cd exceeded the recommended levels for surface water and Pb and Cd in water and sediment correlated mostly with PC 1. The average Igeo class for the heavy metals in all the stations was >2 indicating uncontaminated to moderately/heavily contaminated sediment. Ninety-six (96) individuals of macroinvertebrates from seven families and six orders were encountered and aquatic insects were dominant (75%). Taxa richness (0-0.82) and diversity (0-0.59) were lower in all the stations compared to the control site. Exceedance of WHO limits by some heavy metals and paucity of macroinvertebrates, especially pollution-sensitive species in the stream suggests that it is polluted. Regular monitoring of the stream is advocated to minimize pollution.
Auto-mechanic workshops in developing countries such as Nigeria are a major source of potentially toxic substances which can leach into the water table and contaminate groundwater. Several physical and chemical methods have been employed to remediate pollutants in oil-contaminated soils, some of these methods are simply a transfer of contaminants from one place to another, which may also require additional treatments. A combination of treatments consisting of the application of NPK (nitrogen, phosphorous, and potassium) fertilizer, sawdust, horse manure and exposure to oxygen was evaluated in situ during 70 days for the remediation of cadmium, chromium, lead and total petroleum hydrocarbon in used engine oil-contaminated soils. The soils received 447.6 kg of horse manure, 48 kg of sawdust and 4.2 kg of NPK fertilizer per 2 m2 of surface area. The total heterotrophic bacteria count at the start-up of the experiment was 0.018 × 106 CFU/g in the contaminated soil and thus increased to 80.5 × 106 CFU/g during the 70 days treatment. In addition, the combined treatment showed 87% total petroleum hydrocarbon degradation, 71% Cd and 62% Pb reduction. Hence, the results of this study showed that nutrient enhanced bioremediation can achieve the degradation of petroleum hydrocarbon and heavy metals in oil-contaminated soils under the prevailing tropical conditions of Nigeria.
Sanayinin gelişmesi, nüfusun artması, şehirleşme gereksinimi sonucunda daha çok enerjinin ve kimyasal maddenin tüketim ve kullanımının bir sonucu olarak akaryakıt istasyonlarının sayısı 1990’lı yıllara göre artan bir ivme göstermiştir. Enerji Piyasası Denetleme Kurulu (EPDK) 2022 verilerine göre Türkiye genelinde yaklaşık on üç bin lisanslı aktif akaryakıt istasyonu olduğu ve bu istasyonların faaliyetleri gereği yeraltı akaryakıt tanklarında sürekli olarak binlerce litre akaryakıt ürünleri barındırdıkları bilinmektedir. Akaryakıt istasyonlarının birçoğunun mücavir alan sınırları içerisinde olması, mevcut yeraltı akaryakıt tanklarının yaşlarının 10, hatta 20 yıl üzerinde olması, yeraltı ve yerüstü kaynaklarına yakın mesafede kurulmuş olmaları, gaz detektörü olmayan bodrum katlarının olması, yakıt istasyonlarında olası parlama, patlama, sızıntı gibi nedenlerle toprak ve yeraltı suyu kirliliği başta olmak üzere, çevre ve halk sağlığı açısından birçok potansiyel riski de beraberinde oluşturmaktadır. Bu çalışmanın amacı, 8.6.2010’de yayımlana ve 237 adet sektörü ve binlerce tesisi kapsayan Toprak Kirliliğinin Kontrolü ve Noktasal Kaynaklı Kirlenmiş Sahalara Dair Yönetmelik (TKKNKKSDY)’in, faaliyetleri sebebiyle binlerce litre petrol ve türevi kimyasal barındıran akaryakıt istasyonlarının özelinde incelenmesi ve buralarda olası toprak ve yeraltı suyu kirliliğinde çevre ve halk sağlığı açısından TKKNKKSDY aşamalarının ortaya konmasıdır. Bu şekilde yaşanan zorlukları azalacağına ve olası kafa karışıklıklarını giderileceğine inanılmaktadır.
Landfill liners blended with industrial by-product seems to outperform the conventional liners. This paper presents the influence of sawdust (SD) admixed with bentonite and locally available lateritic soil on consistency limits, free swell index (FSI), compaction characteristics, unconfined compressive strength (UCS), hydraulic conductivity and leachate characteristics. SD content was varied as 10%, 15% and 20%. Diesel oil contaminants (DOC) and deionised water (DIW) were used as the test fluids. From the test results, consistency limits, FSI, maximum dry density, leachate concentration of heavy metals and UCS decreased, whereas optimum moisture content and hydraulic conductivity increased with increasing sawdust content. Furthermore, the energy-dispersive X-ray spectrometer revealed the absence of calcium in the blends which have resulted in poor cementation and decreased the UCS. X-ray diffraction showed that the presence of cellulose in sawdust and montmorillonite in bentonite adsorb the heavy metals in DOC. Based on the test results, 15% Saw dust content in the blends proves to be the optimum in retaining the heavy metal concentrations, improving the geotechnical properties and qualifying as a landfill liner material.
Contamination of soil with crude oil is a serious ecological problem with potential adverse public health effects. This study assessed the germ cell toxicity of simulated leachates from crude oil-contaminated soil before and after bioremediation using the murine sperm abnormality assay, sperm count, and testes histopathology. The levels of Total Testosterone (TT), Follicle Stimulating Hormone (FSH), and Luteinizing Hormone (LH); and activities of catalase (CAT), alkaline phosphatase (ALP), superoxide dismutase (SOD), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were determined. The physicochemical, Total Petroleum Hydrocarbon (TPH), and heavy metal analyses of the leachates were also carried out. Male mice were exposed to 50, 25, 10, 5, and 1% (v/v; leachate:distilled water) of the leachate samples for five consecutive days, and were sacrificed after 35 days. The result showed a statistically significant (p < 0.05), concentration-dependent increase in abnormal sperm cells in exposed mice, with aberrations such as folded sperm, amorphous head, wrong tail attachment, distal droplet, no hook, and looped tail. Data further showed a concentration-dependent significant reduction in mean sperm count in the exposed mice. Alterations of seminiferous tubules with different lesions and activities of ALT, AST, ALP, FSH, LH, and TT were also recorded. The high level of selected heavy metals (As, Cr, Cd, Cu, and Pb) and TPH was believed to contribute to the observed reproductive toxicity and modulated enzyme activities in the treated mice. It is therefore concluded that the microbial remediation of the crude oil contaminated soil produced a reduction in the levels of heavy metals and TPH in the soil, reduced reproductive toxicity, and modulation of enzyme activities. However, the induced reproductive toxicity by the bioremediated soil is still significant, hence, further work could be done to employ a consortium of bacteria and extend the period of the bioremediation process to ensure complete removal of the contaminants.
Total petroleum hydrocarbon (TPH) pollution in oilfield soils is a worldwide environmental problem. In this study, we analysed the spatial variation of residual TPH components and the ecological risk they pose. The soils of five selected oilfields in China, across 11 degrees of latitude and 17 degrees of longitude were selected for the investigation. The results showed that the non-zonal composition of the residual TPHs in the soil was similar to the that of the crude oil input. Principal component analysis (PCA) suggested that the effect of zonal environmental factors explained 81.5% of the variability in the residual indexes of saturated and aromatic hydrocarbons. The first principal component, the soil clay and organic matter, correlated positively with the residual TPH index. The second principal component, the accumulated temperature, however, correlated negatively with the residual TPH index in the soil. Moreover, the application of the soil quality index (SoQI) and a Monte Carlo simulation for estimating the residual TPH content suggested that the ecological risk caused by residual TPHs in the soil decreased when the oilfield latitude and clay and organic matter content in the oilfield soil were lower. This study provides a basis for the assessment and monitoring of ecological risk in oilfield soils worldwide.
Background
Ecological risk assessment of the levels of polycyclic aromatic hydrocarbons in soils of the abandoned sections of Orji Mechanic Village, Owerri, Imo State, Nigeria. The main objective of the study was to determine the levels of soil contamination from polycyclic aromatic compounds (PAHs) due to anthropogenic events in the mechanic village before reclamation.
Results
Analysis of soil samples revealed mean PAH levels ranging from 1.22E−02 ± 0.00 to 5.60E−02 ± 0.01 mg/kg, with higher PAH concentrations observed at 0–10 cm compared to other depths. The sum of PAHs (∑PAHs) ranged from 1.58E−01 to 6.71E−01 mg/kg, as the sum of low molecular weight PAHs (∑LPAHs) varied from 7.16E−03 to 1–1.60E−01 mg/kg, while the sum of high molecular weight PAHs (∑HPAHs) ranged from 1.81E−02 to 5.42E−01 mg/kg. The sum of carcinogenic PAHs (∑Carcino-PAHs) varied from 5.39E−01 to 9.74E−02 mg/kg, indicating elevated levels of carcinogens in the sampled soils. Diagnostic ratio, principal component, and correlation analysis of the results revealed that pyrogenic sources were primarily responsible for the observed PAHs owing to the activities of automobile mechanics in the Orji Mechanic Village. Benzo(a)pyrene equivalent (BePeq) of the PAHs indicated high carcinogenic potency for sample A. The total cancer risk was above 1 × 10 –6 , indicating a greater risk of cancer due to contact with the contaminated soil samples; hence, the result of this study is a serious ecological concern.
Conclusion
There may be accumulation of these contaminants in the investigated area, which will eventually contaminate the groundwater as well as surface water resources. Remedial measures to prevent possible health problems due to the PAHs which results from the activities of automobile mechanics are therefore recommended.
Cadmium in ~10% of root and leafy vegetables sold through the Sydney Market exceeds the maximum permitted concentration (MPC) set by the Australia New Zealand (ANZ) Food Authority (0.05 mg kg-1 fresh weight). The leafy vegetables are mostly produced in the Greater Sydney Region; therefore, we investigated Cd contamination in the soils and vegetables of the Region. The crops and topsoils (0-15 cm) from 29 farms and uncropped (background) top soils were sampled and analyzed. Fruit generally had the lowest Cd levels and leafy vegetables the highest, with 0 and 27% exceeding the MPC. Cadmium in cropped soils was 0.11 to 6.37 mg kg-1 (mean 1.33 mg kg-1) and in background soils averaged 0.36 mg kg-1. Soils derived from shale had the highest background Cd levels. Additions of P, Zn, and Cd in fertilizer and poultry manure explained significant proportions of the increases in soil concentrations of P (r2 = 0.62, P < 0.001) and Zn (r2 = 0.29, P < 0.05), but not of Cd. Cadmium increases were more closely related to increases in Zn (r2 = 0.26) and exchangeable cations (r2 = 0.34), which result from a history of heavy, annual applications of poultry manure. Typical rates of Cd addition were about 10 times the sustainable rate. Finally, the ANZ environmental investigation guideline for soil Cd (3 mg kg-1), was a poor indicator of crop contamination, because ~0.3 mg Cd kg-1 soil resulted in lettuce (Lactuca sativa L.) and broccoli (Brassica oleracea) exceeding the MPC.
Etude preliminaire des arriere-effets des metaux lourds dans un sol traite par des boues residuaires avant 1961 sur les mycorhizes aborigenes et sur une mycorhize introduite (Glomus mosseae) en essais en pots
The abundance and production of pelagic bacteria, phytoplankton primary production and chlorophyll content were studied in coastal waters receiving the effluent from an oil refinery in the Arabian Gulf. The area also receives unknown amounts of other effluents rich in organic matter and nutrients. The abundance of bacteria was measured by epifluorescent direct counts, and productivity was estimated by 3H-thymidine uptake measurements. The results showed a clear stimulation of the primary productivity as well as elevated amounts of chlorophyll a in the area receiving the effluent. Both bacterial abundances and production were an order of magnitude higher in a small area close to the refinery outlet, but dropped rapidly and reached background values outside an impacted area of c 10 km2. The increased bacterial production in this area corresponded to a substrate demand of 4 to 11 tonnes of carbon per day, 4 to 12 times the daily discharge of some 0·9 tonnes of carbon in the form of petroleum hydrocarbons from the oil refinery. These data, plus the low petroleum hydrocarbon concentrations found in the sediments and in bivalves outside the impacted area, suggest that bacterial degradation of the petroleum hydrocarbons from the refinery could be a major process restricting the area impacted by oil pollution.
km from 32 tilled/cultivated plots of yam, rice, and cassava in urban, rural, and the derelict Enyibga lead-zinc mine (EM) in the Abakaliki area, Nigeria during the rainy season in September, 1992. In the derelict mine, mean elemental contents increased in the order Cd < ni="">< cu="">< mn="">< pb="">< zn;="" while="" in="" the="" urban,="" rural,="" and="" all="" soils="" combined,="" the="" order="" increased="" as="" follows:="" cd="">< cu="">< ni="">< pb="">< zn="">< mn.="" the="" overall="" mean="" distribution="" of="" all="" soils="" shows="" mn="" and="" zn="" to="" approach="" and="" exceed="" toxic="" levels,="" respectively.="" in="" all="" soils,="" the="" total="" mean="" concentrations="" of="" cu="" and="" ni="" are="" well="" below="" toxic="" levels.="" the="" abakaliki="" area="" is="" less="" likely="" to="" be="" subjected="" to="" cd-contaminated="" soils.="" pb="" was="" excessively="" high="" at="" em="" and,="" moderately="" high="" at="" mgbowo="" street="" in="" the="" urban="" area,="" but="" very="" less="" so="" in="" the="" rural="" areas.="" the="" rural="" agricultural="" areas="" of="" agbaja,="" nkwaegu,="" and="" amaegu,="" including="" the="" isolated="" ezza="" road="" as="" well="" as="" the="" peripheral="" expressway="" had="" relatively="" lower="" levels="" of="" heavy="" metals,="" ph="" and="" organic="" matter="" content="" than="" the="" urban="" conglomeration="" of="" mile="" 50,="" mgbowo="" street,="" and="" azuiyiokwu="" including="" the="" derelict="" mining="" village="" of="" enyigba="" and="" em;="" except="" that="" ezza="" road="" had="" ph="
In an interlaboratory study to determine the concentration of petroleum hydrocarbons (PHCs) in an above ground bioreactor at a refinery site in Montreal we found that the EPA Method # 418.1 for the analysis of semivolatile hydrocarbons gave concentrations up two fold higher than expected. The silica mixing step used to clean-up the crude Soxhlet extract and the inclusion of chlorobenzene or benzene in the composition of the IR quantitative standard were later implicated as major sources of bias in the Method. In another comparative study we have determined water effect on the recovery of PHCs from wood preserving soil using the Soxhlet EPA Method # 3450 (with Freon-113) and the SFE Method # 3560 (with CO2). In the Soxhlet method water did not seem to affect the recovery of PHCs since variations in PHC concentrations did not exceed RSD values, i. e., +/- 2% to +/- 8%. While in SFE, an optimal extraction efficiency occurred when the water content in the soil was around the 20% limit, similar to what has been described in the EPA Method # 3560. In the case of a bioslurry both SFE and Soxhlet showed that water removal enhanced the recovery of PHCs, i. e., a reduction in the water content by a factor of two resulted in an increase in the recovery of PHCs by roughly a factor of two.
A significant proportion of the naturally occurring hydrocarbon-degrading populations within Alaskan sediments affected by the Exxon Valdez oil spill had both the xylE and alkB genes and could convert hexadecane and naphthalene to carbon dioxide; a greater proportion of the population had xylE than had alkB, reflecting the composition of the residual oil at the time of sampling; nearly equal populations with xylE alone, alkB alone, and xylE + alkB genes together were found after exposure to fresh crude oil; populations with xylE lacking alkB increased after enrichment on naphthalene. Thus, the genotypes of hydrocarbon-degrading populations reflected the composition of the hydrocarbons to which they were exposed.
Closed-vessel microwave solvent extraction of organic compounds may serve a promising tool for the quick low-cost method of determining the total petroleum hydrocarbons contaminating the soil. Using alternative solvent systems, the method yields results comparable to current standard methods. Investigations showed that solvent temperatures above their normal boiling point are obtainable. Because of these higher temperatures, extraction times are significantly reduced compared to standard Soxhlet extraction methods. Solvent volumes are also reduced by as much as a factor of 10. Temperature capabilities of the system provided precise and reproducible extraction conditions.
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Heavy metal contamination can impact soil ecosystems sufficiently to result in significant losses in soil quality. The negative impact of heavy metals results from their toxicity to biological processes, including processes catalyzed by soil microorganisms. Therefore, it is postulated that the soil microbial community could serve as an indicator of losses in soil quality due to heavy metal contamination and of changes in soil quality resulting from reclamation. In this study, the size, activity, and structure of microbial communities from remediated and unremediated soils in the vicinity of a Zn smelter were evaluated. Both total and soluble metal loadings in these soils increased with proximity to the smelter. Indicators of microbial activity (dehydrogenase activity) and viable population size (plate counts) were negatively affected by the elevated metal levels. Microbial community structure also varied with increasing contamination, as indicated by cluster analysis and principal component analysis of BIOLOG community metabolic profiles. Remediated soils at this site were treated by surface application of a mixture of sewage sludge and fly ash. Remediation resulted in a decrease in soluble metals and an increase in indicators of biological activity and viable population size. Remediated soils also showed metabolic profiles that were more similar to the least contaminated site, suggesting recovery of the microbial populations. These data suggest that the microbial community may be a useful indicator of changes in soil quality with management of these highly contaminated soils.
The effects of sublethal concentrations of phenol and cadmium on the phototactic responses of the stage II nauplii of the barnacle Balanus amphitrite were investigated. Increased toxicant concentrations caused a reduction in phototactic responses. Balanus amphitrite nauplii exposed to nominal phenol concentrations of 100 ppm and higher for 1–12 h failed to exhibit phototactic responses, while longer exposure times of 24 and 48 h reduced the lowest observable effect concentration (LOECs) to 80 and 60 ppm, respectively. For cadmium, the LOECs, based on nominal concentrations, for B. amphitrite following 1, 6, 12, 24, and 48 h exposures were 20, 4.5, 4.0, 1, and 0.75 ppm, respectively. The LOECs can be significantly reduced by increasing the duration of exposure to the toxicants. A good relationship exists between the phototactic response and toxicant concentration as well as exposure time. Results of this study indicate that the toxicant-induced reduction in phototactic responses of barnacle larvae can be used in a sensitive, rapid screening test for ecotoxicological assessments. ©1997 by John Wiley & Sons, Inc. Environ Toxicol Water Qual 12: 231–236, 1997
Seasonal variations of the potential of Gulf coast marshes to degrade crude oil naturally or under nutrient-enhanced conditions is essentially unknown. Seasonal variations in crude oil mineralization were determined under ambient and enhanced nutrient conditions for both a fresh- and a salt- water marsh in Louisiana's Barataria basin over a 1-yr period. Mineralization of (14C) phenanthrene and hexadecane was measured by radiorespirometry in marsh soil slurries dosed with crude oil under ambient and enhanced nutrient conditions. Background nutrient conditions in these marsh systems, as well as numbers of hydrocarbon-utilizing microorganisms, were also monitored. Seasonal variations were found in both marsh systems, although they were greater in the salt marsh. Seasonal trends in mineralization rates were different for phenanthrene and hexadecane as well as for each marsh. Hexadecane mineralization rates ranged from 0.2 to 2.4%/d (ambient nutrient conditions) and 3.1 to 10.4%/d (enhanced nutrient conditions) for the salt marsh and 0.81 to 3.1%/d (ambient nutrient conditions) and 2.1 to 7.3%/d (enhanced nutrient conditions) for the fresh marsh. Phenanthrene mineralization rates ranged from 0.5 to 4.5%/d (ambient nutrient conditions) and 1.9 to 12.1%/d (enhanced nutrient conditions) for the salt marsh and 2.8 to 5.5%/d (ambient nutrient conditions) and 2.4 to 5.6%/d (enhanced nutrient conditions) for the fresh marsh. Nutrient enhancement reduced the lag time of hexadecane mineralization in both salt and fresh marsh soils but had little effect on phenanthrene mineralization lag time. The population of hydrocarbon utilizers was correlated to phenanthrene mineralization rates under ambient and enhanced nutrient conditions in the fresh marsh, and to hexadecane mineralization rates under ambient and enhanced nutrient conditions for the salt marsh. Mineralization rates of phenanthrene and hexadecane appear to be uncorrelated for both marshes. Both the fresh marsh and salt marsh soils examined had a substantial capacity to degrade representative crude oil components under ambient conditions. Nutrient enhancement had the greatest benefit in the salt marsh studies, and seasonal differences in the rates of hexadecane and phenanthrene mineralization under both ambient and enhanced nutrient conditions were significant.
This study investigated the occurrence of Pb, Zn, Cu, and Cd in the topsoil of an inner-city suburb of Sydney, Australia. The total heavy metal concentrations in the topsoil of Glebe were determined along with their spatial distribution. These concentrations were compared with environmental investigation limits. Stratified random sampling was conducted within 1-ha square areas taking a samples at 1 m separation from each stratum as a means to investigating spatial variation. Total metal concentrations were determined on an aqua regia extract analysed using atomic absorption spectroscopy. Fifty percent of total Pb, Zn, and Cu concentrations and 2.5% of Cd concentrations were above the ANZECC and NH&MRC (Australia & New Zealand Environment Conservation Council and National Health & Medical Research Council) guidelines of 300, 200, 60, and 3 mg/kg, respectively. Some spatial clustering was evident and a geostatistical analysis showed some large high-risk areas. Fuzzy clustering showed 5 groups of increasing contamination. Soil disturbance and distance from road explained 24% of the variation in total Pb concentration, 15% in total Zn and Cu concentrations, and 13% in total Cd concentration.
The distribution of total petroleum hydrocarbon in topsoils from various parts of Ibadan city, Nigeria, was studied. Samples were selected from around the following zones: a) railway tracks, b) petrol stations, c) refuse dumps, d) residential areas, e) high traffic density areas, f) mechanical workshops, and g) control zones. Contamination of the topsoil with hydrocarbons was significant only around petrol stations and mechanical workshops where the factors of accumulation were 10.1 and 4.72, respectively. The general trend in hydrocarbon levels was petrol station > mechanical workshop > refuse dumps > high traffic areas > rail tracks > control zones residential areas. The results highlight the need to monitor urban environments that are remote from petroleum exploration activities for petroleum hydrocarbon contamination.
Rufus Chaney has his eye on plants with a lusty appetite for toxic heavy materials. Chaney foresees a day when these remarkable plants will be used to clean contaminated soils at smelter and mining sites, landfills, nuclear waste dumps, farmland, or at any urban or rural site contaminated with lead, cadmium, zinc, nickel, or radioactive isotopes such as uranium or cobalt. The plants would take up the toxic metals or isotopes through their roots and transport them to stems or leaves where they could be easily removed by harvesting. A U.S. Department of AGriculture agronomist, Chaney says the cost of using plants to clean polluted soil {open_quotes}could be less than one-tenth the price tag for either digging up and trucking the soil to a hazardous waste landfill or making it into concrete.{close_quotes} Chaney, a heavy-metals expert at USDA`s Agricultural Research Service Environmental Chemistry Laboratory in Beltsville, Maryland, says the cost could be further offset by recovering heavy metals from the plants and selling them. The metal-scavenging plants, called hyperaccumultors, would be grown and harvested like hay, Chaney says. {open_quotes}Burning the hay allows recovery and recycling of the metals. The ash is similar to commercial ore and could be sold as {open_quote}Bio-Ore{close_quote}.{close_quotes} Chaney calls the process {open_quotes}green remediation.{close_quotes} He says that without intervention, heavy metals stay in soil for centuries.
Biodegradation of petroleum contaminants is an effective and generally inexpensive approach for reducing their concentrations in soils. However, little information is available on the toxicological status of contaminated soils and the fate of target hydrocarbons following bioremediation. Four texturally distinct soils were contaminated with diesel fuel and bioremediated in microcosms at 22°C, with moisture contents of 85% of soil water holding capacity, and nitrogen (N) and/or phosphorus (P) nutrient amendments. The progress of bioremediation was monitored using chemical and toxicological analyses. Soil toxicity was measured using five short-term bioassays: seed germination, red blood cell hemolysis, solid-phase Microtox, SOS-chromotest, and Toxi-chromotest. Reductions in target compound concentration were not always predictive of reductions in soil toxicity. Conflicting trends were indicated by the toxicity test results. For example, total petroleum hydrocarbon analysis revealed decreased hydrocarbon concentrations in all four soils following bioremediation but seed germination and seedling emergence data indicated increased soil toxicity. In contrast, the Microtox test data indicated decreased toxicity in two of the four soils. These results suggest that measurements of target contaminant concentrations should be complemented with several different soil toxicity bioassays, particularly when evaluating the ability of bioremediation to reduce the adverse effects of contaminants in soil. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 117–126, 1998
Lead is a widely spread environmental pollutant known to affect both male and female reproductive systems in humans and experimental animals. The present study investigated the effect of an acute exposure to lead (75 μg lead per gram of body weight) 1 or 24 h before hormone treatment on different parameters of estrogen stimulation in the rat uterus. Lead pretreatment enhanced some parameters of estrogen stimulation and inhibited other estrogenic responses, and the remaining parameters were unaltered. The interaction with responses to estrogen was different depending on whether lead pretreatment was 1 or 24 h before hormone stimulation. The estrogenic responses mostly affected were uterine eosinophilia, endometrial edema, uterine luminal epithelial hypertrophy, and mitosis in various—but not all—uterine cell types. In some cell types, estrogen-induced mitotic response developed earlier under the effect of lead exposure. Results revealed an interaction with the different mechanisms of estrogen action in the uterus at various levels, that some cell types are more sensitive to lead than others, and that the effect of exposure changed with time after lead pretreatment. The relevance of the results are discussed in relation to lead-induced infertility, mutagenicity, and carcinogenicity; possible mechanisms of action are proposed. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 43–53, 1998
The inhibition of acetylcholinesterase activity (AChE) in Moina macrocopa homogenized with sodium dodecylbenzenesulfonate (DBSS), lead (Pb), crude oil (PO), and their mixtures was investigated. When the homogenized cladoceran were exposed to these compounds in vitro, AChE activity revealed that PO was the most potent anticholinesterase agent, followed by Mixture IV (DBSS-PO), Mixture I (DBSS), Mixture III (PO-DBSS), Pb, DBSS, and Mixture II (Pb-DBSS). All compounds and their mixtures caused inhibition of M. macrocopa homogenized cholinesterase. This bioassay technique seems to have considerable potential as a rapid, sensitive, and inexpensive procedure for hazard assessment and environmental evaluation. ©1997 by John Wiley & Sons, Inc. Environ Toxicol Water Qual 12: 211–215, 1997
Soil and microbiological properties of a tropical rain forest soil were evaluated 17 years after oil spillage to access the chronic effects of, and interrelationship between population of petroleum hydrocarbon utilizing and nitrifying microorganisms. The spatial distribution of petroleum hydrocarbons (oil), the nutrient status and the abundance of heterotrophic microbes along soil transect lines in the contaminated zones served as the index for corroborating the results. The pH status of soil in the contaminated (Heavy impact — HI, and moderate inpact — MI) zones varied from acidic, that is 4.0 to near neutral PH, that is 6.0. The C content of soils decreased from 3.6% at the HI zones to 2.84% at the MI zones. Total N in the HI and MI zones differed by a factor of 0.10%. Available P was higher at the MI than HI zone, while CEC decreased from a combined mean of 6.48 at the HI zones to 4.46 at the MI zones. Although residual oil content was higher in the HI zones than MI zone, the soil nutrient status within these two zones did not vary significantly (P=0.05). However, soil microbes responded differently. For instance, petroleum hydrocarbon utilizers correlated positively with the distribution of oil in the environment. But, not the nitrifying microorganisms. Aerobic nitrifiers were abundant at the HI than MI zones, while anaerobic nitrifiers were higher at the MI than HI zones. With the presence of petroleum hydrocarbon utilizers anf nitrifying microbes. It is possible to enhance the degradation of oil in the 17 yr old spillage by adopting bioremediation.
A combined statistical and computergraphic approach is proposed for apportionment and attribution of soil contaminants in
complex areas. The field test site lies north of Swansea, south Wales and contains two major pollutant sources, an active
nickel refiner and (4 km away) the site of major base metal smelting in the nineteenth century (the Lower Swansea Valley reclamation
study area). Soil samples (70 samples, 0–15 cm) were collected on a regular grid of 1000 m interval. They were extracted using
0.05 M diammonium EDTA and the extracts analysed for Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn. Soil pH and %organic content were
also determined. Factor analysis yielded three groups which explained 73.8% of the data variance (1: Cd, Cu, %OM, Pb, Zn,
Ni; 2: Cd, Zn, Mn, pH; 3: Cu, Mn, Co, Ni, Fe). Isoline plots were classifiable into the same three groups. It was concluded
that factor 3 contained those elements associated with smelter emissions, factor 1 with contamination from the Lower Swansea
Valley and in factor 2 pedogenetic processes control the occurrence of the elements.
The Cd, Cu, Fe, Pb, Mn, and Zn concentrations in soil and water leaf (Talinum triangulare) collected from dump sites and control sites were determined by atomic absorption spectrophotometry to evaluate the effect of waste disposal on the levels of these metals in the vegetable. A statistically significant difference was found between the concentration of analysed elements in soils and vegetables collected from dump sites and control sites.
Amounts of microbial biomass were measured in soils from two different U.K. field experiments, one on a sandy loam (15% clay) at Luddington (Wick series) and the other on a silty loam soil (21% clay) at Lee Valley (Hamble series), where sewage sludges, mainly enriched with single metals, were applied 22 yr ago. No single metal (Zn, Cu, Ni and Cd) at or below current EC permitted total soil metal concentrations, or limits, decreased the amounts of soil microbial biomass. However, Cu at about two and a half times permitted metal limits decreased the amounts of biomass by about 40% at both sites and caused an increased accumulation of organic C and total N of about 30% in the sandy loam and about 13% in the silty loam soil. Zinc, at about the same concentration, decreased the biomass by about 40% in the sundy loam and 30% in the silty loam soil while soil organic matter accumulation increased by only 9–14%. Cadmium, at about twice current EC limits did not affect the amount of biomass or soil organic matter in the silty loam soil. Similarly, neither were affected by Ni at 2–3 times current metal limits. The amount of microbial biomass C as a percentage of total soil organic C was much lower (< 1.0%) in soils contaminated with Zn and Cu at about two-and-a-half times current permitted limits than in soils containing less metal. This also suggested that the metals were causing decreased microbial biomass at these metal concentrations.
We present an experimental approach for investigating the potential for bioremediation of volatile organic compounds (VOCs) in fractured rock vadose zones. The experimental work was performed with rock samples and indigenous microorganisms from the site of the United States Department of Energy's Idaho National Engineering and Environmental Laboratory (INEEL), located in a basalt flow basin where VOC contamination threatens the Snake River Aquifer. Our approach has four components: (1) establishing a conceptual model for fluid and contaminant distribution in the geologic matrix of interest; (2) identification of important features of liquid distribution by means of seepage experiments in the fracture plane; (3) identification of the presence and activity of microorganisms by non-destructive monitoring of biotransformations on rock surfaces at the micron-scale; and (4) integration of flow and biological activity in natural rock “geocosms”. Geocosms are core-scale flow cells that incorporate some aspects of natural conditions, such as liquid seepage in the fracture plane and moisture content. Fluid flow and distribution within fracture networks may be a significant factor in the ability of microorganisms to degrade VOCs, as they affect the availability of substrate, moisture and nutrients. Flow visualization and tracer breakthrough curves in transparent fracture replicas for unsaturated inlet conditions exhibited the channelized and intermittent nature of liquid seepage. The seepage of water and non-aqueous phase liquids (NAPLs) of varying physical and chemical properties into an initially dry replica showed only subtle differences in liquid distribution. In contrast, the seepage of a NAPL into the fracture replica containing residual water resulted in complex trapping of NAPL along the solid/water/air contact lines and diversion of NAPL to previously dry parts of the fracture. We found that a mixed culture of viable bacteria exists on the natural rock surfaces. Microbial activity measurably changed in response to changing relative humidity (RH). Biological activity in the geocosm produced changes in liquid surface tension and seepage patterns over time.
Incluye bibliografía e índice
Preface 1. Introduction 2. The sources of seasonality 3. Seasonality and the disadvantaged 4. Seasonality and the environment 5. Coping with seasonality 6. Seasonal labour migration 7. Special problems of developing countries I. Market failure and market distortions 8. Special problems of developing countries: II. Technological change in a changing environment 9. Implications for policy and planning Appendix: Seasonal labour migration at the national level: an approach to rapid appraisal References and sources List of tables.
Heavy metal pollution is a principle source of environmental contamination. We analyzed heavy metal impacted soil microbial communities and found that, in general, although lead adversely affected biomass, metabolic activity, and diversity, autochthonous lead- and cadmium-resistant isolates were found. In several metal-stressed soils, the microbial community consisted of two populations, either resistant or sensitive to lead. Additionally, a lead-resistant isolate was isolated from a control soil with no known previous exposure to lead, suggesting widespread lead resistance. Lead-resistant genera isolated included Pseudomonas, Bacillus, Corynebacterium, and Enterobacter species. Plasmids, ranging from 5 to 260 kb, were not detected through standard purifications from lead-resistant isolates. Positive correlations existed between antibiotic resistance and isolation habitat for lead-resistant strains, microbial metabolic activity and soil type, soluble lead concentration and microbial diversity, and arsenic concentration and total or viable cell concentrations.
Measurements of total petroleum hydrocarbon (TPH) concentrations in 77 core samples collected in 1992 from the bottom sediments of the Arabian Gulf were used to delineate oil pollution levels and their distribution in the region. Seven chronic moderately (TPH 50-89 microg g(-1)) and heavily (TPH 266-1448 microg g(-1)) polluted areas were identified; three in the northern part of the region and four in the southern part. Oil pollution in these areas was attributed to natural oil seepage, accidental damage to pipelines, accidental spillage from tankers, the Nowruz oil slick, and tanker deballasting. Present-day intermediate (TPH 50-114 microg g(-1)) and high (TPH 200-1122 microg g(-1)) pollution levels were identified in 10 areas. Of these, three polluted areas in the northeastern corner, offshore Saudi Arabia and offshore Bahrain, Qatar and United Arab Emirates are probably directly affected by the Kuwait oil slick. A new scenario is suggested for the movement and fate of the oil slick, in which additional large oil discharges from northern sources, as well as substantial quantities of eroded oiled sediments and oil floating from heavily impacted tidal flats along the Saudi Arabian coastline, serve as sources of oil pollution. A definite relationship exists between the grain-size distribution and the TPH content of bottom sediments, with the highest TPH concentrations in the muddy sediments, suggesting that adsorption onto muds is the primary mechanism of oil pollutant accumulation in the Arabian Gulf. Total organic carbon measurements do not correlate positively with the grain-size distribution and TPH contents of the sediments, and hence cannot be used as indicators for petroleum hydrocarbon pollution in the Arabian Gulf.
The documeneed adverse health effects of soil Cd and Pb have led to public concern over soil contamination with metals. A 4-year field experiment was conducted to study the transfer of Cd, Pb, and Zn from soil contaminated by smelter flue-dust to crop plants grown in a rotation. The soil was amended with Pb?Zn smelter flue-dust (2-66.8 kg per 10 m(2) plot) to simulate the long-term effect that the smelting of non-ferrous metal ore has on arable soils. The treated soil became strongly contaminated with metals (Cd 3.2-106 mg/kg, Pb 146-3452 mg/kg, Zn 465-11 375 mg/kg). Concentrations of Cd, Pb, and Zn in barley grain, barley straw meadow bluegrass, red clover, and potatoes were generally low. The highest metal concentrations were found in potato tubers (intact), meadow bluegrass, and barley straw. The observed reduction in crop yield was probably the result of possible nutrient imbalances rather than of metal (Zn, Cu) phytotoxicities. Zn and Cd uptake by the plants can be described by the saturation (plateau) model (y = ax(b), b < 1). The relationship between Pb in the soil and plants was linear with an extremely low slope (0.0001-0.0003). No excessive dietary intake of Cd is expected when Cd concentrations in barley grain and potato tubers grown on the contaminated soil are not higher than 0.6 and 1.0 mg/kg, respectively. Based on the risk analysis and taking into account the saturation model of the soil-plant metal relationship, it was concluded that, under the conditions of this experiment (neutral soil pH), soil with Cd concentrations of up to 30 mg/kg is still safe for production of these crop plants.
A comparative evaluation of heavy metals in Lagos dumpsites
- Adeniyi Aa
- J Fashola
- Ekanem
Adeniyi AA, Fashola J, Ekanem O. A comparative evaluation of heavy metals in Lagos dumpsites. Niger J Rev Sci 1993;1:65 – 9.
Petroleum hydrocarbon pollution in Nigerian waters and sediments around Lagos and Niger Delta areas of Nigeria Adeniyi AA. Determination of cadmium, copper, iron, lead, manganese and zinc in water leaf (Talinum triangulare) in dumpsites
- Adekambi
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Adekambi EO. Petroleum hydrocarbon pollution in Nigerian waters and sediments around Lagos and Niger Delta areas of Nigeria. PhD thesis, University of Ibadan, Ibadan, Nigeria, 1989. Adeniyi AA. Determination of cadmium, copper, iron, lead, manganese and zinc in water leaf (Talinum triangulare) in dumpsites. Environ Int 1996;22:259 – 62.
Ecology and management of terrestrial oil pollution in Nigeria
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Kinako PDS, Zuofa K. Ecology and management of terrestrial oil pollution in Nigeria. Bureaucrat 1991;17:65 – 71.
Rehabilitating crude oil polluted land
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Ogoke NJ. Rehabilitating crude oil polluted land. In: Aina EOA, Adedipe NO, editors. The petroleum industry and the environmental impact in Nigeria. FEPA Monograph, vol.
Soil microbiology — exploratory approach. London: Delman, 1999. Davies BE. Heavy metal contaminated soils in an old industrial area of Wales, Great Britain: source identification through statistical data inter-pretation
- Ms Coyne
Coyne MS. Soil microbiology — exploratory approach. London: Delman, 1999. Davies BE. Heavy metal contaminated soils in an old industrial area of Wales, Great Britain: source identification through statistical data inter-pretation. Water, Air Soil Pollut 1997;94:85 – 98.
Total petroleum hydrocarbon determination by micro-wave solvent extraction. Paper presented at the 1994 Pittsburg Confer-ence and Exhibition Final report on environmental baseline studies for the establishment of control criteria and standards against petroleum related pollution in Nigeria
- Hasty E Revesz R Hayes
- Michael J Mo
- Murdy
Hasty E, Revesz R. Total petroleum hydrocarbon determination by micro-wave solvent extraction. Paper presented at the 1994 Pittsburg Confer-ence and Exhibition, Chicago, 1994. Hayes MO, Michael J, Murdy M. Final report on environmental baseline studies for the establishment of control criteria and standards against petroleum related pollution in Nigeria. Lagos: Petroleum Inspectorate, Nigeria National Petroleum Corporation (NNPC), 1985. pp. 100 – 2.
Mycorrhizal infection of white clover is delayed in soils contaminated with heavy metals from past sewage sludge applications
- I Koomen
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- Giller
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Koomen I, McGrath SP, Giller KE. Mycorrhizal infection of white clover is delayed in soils contaminated with heavy metals from past sewage sludge applications. Soil Biol Biochem 1990;22:871 – 3.
Chemical principles of environmental pollution New York: Blackie, 1994. p. 202. Amadi A, Abbey SD, Nma A. Chronic effects of oil spill on soil properties and micro flora of a rainforest ecosystem in Nigeria
- Bj Alloway
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Alloway BJ, Ayres DC. Chemical principles of environmental pollution. New York: Blackie, 1994. p. 202. Amadi A, Abbey SD, Nma A. Chronic effects of oil spill on soil properties and micro flora of a rainforest ecosystem in Nigeria. Water, Air Soil Pollut 1996;86:1 – 11.
Ecology principles and applications. Cambridge: Cambridge Univ. Press
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Chapman JL, Reiss MJ. Ecology principles and applications. Cambridge: Cambridge Univ. Press, 1995. pp. 95 – 108.
Levels of cadmium and some other metals in insects
- Nourteva
Nourteva P, Elberg K. Levels of cadmium and some other metals in insects. Proc XXIV Nord Congr Entomol, Tartu, Estonia 1999;125 – 37.
Disposal of used oil from motor garages and petroleum stations in some Nigeria coastal towns. Field survey study on environmental sector plan for Nigeria
- O Osibanjo
- S Abumere
- Akintola
Osibanjo O, Abumere S, Akintola F. Disposal of used oil from motor garages and petroleum stations in some Nigeria coastal towns. Field survey study on environmental sector plan for Nigeria (1983 – 2000).
Genetically-engineered microorganisms in the oil industry
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Olukoya DK. Genetically-engineered microorganisms in the oil industry.
Human impact on the biosphere. Biology — the unity and diversity of life
- C Starr
- Taggart
Starr C, Taggart R. Human impact on the biosphere. Biology — the unity and diversity of life. London: Wadsworth, 1998. pp. 882 – 9.
A comparative evaluation of heavy metals in Lagos dumpsites
- Adeniyi
Human impact on the biosphere
- Starr
Petroleum hydrocarbon pollution in Nigerian waters and sediments around Lagos and Niger Delta areas of Nigeria
- E O Adekambi