American Journal of Environmental Sciences

Published by Science Publications
Online ISSN: 1553-345X
Publications
Article
The adsorption of Rhodamin B on Iraqi bentonite at the concentration range from 50 to 250 µg mL −1 was studied, Nano compounds; ZnO, TiO 2 , Al 2 O 3 m and SDS in different amounts 0.01-0.1 g 10 −1 g of Bentonite were used to modified the adsorption capacity of bentonite to remove the Rhodamin B from aqueous solutions. The study indicated that using 0.05 g and 0.1 of Sodium Dodecyl Sulfate (SDS) lead to increase the percentage removal (%R) from 79.3% for pure bentonite to 99.3%. While using 0.05 g TiO 2 lead to increase the %R to 98.9%, 0.05 of ZnO to 98.6%. The other amount additives and Al 2 O 3 using was not success to increase the %R for the Rhodamin B on bentonite surface. SEM measurement was achieved to discover the Nanoparticl exists in the bentonite surfaces.
 
Article
Radon and its descendants are the main causes of lung cancer in non-smokers. Therefore, the study of the behavior of radon and its descendants in indoor air is of the highest importance, in ordre to limit the risk of radiation dose due to inhalation of indoor air by members of the public. This article focuses to study the effect of meteorological parameters on the concentration and distribution of radon and its descendants inside a traditional Hammam by using CFD simulation. The results of modeling are qualitative and show that the concentration and distribution of radon and its descendants decrease when the ventilation rate increases, as well as, as the temperature increases; however, it increases with the increase relative humidity. Moreover, the committed equivalent doses due to 218 Po and 214 Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of air inside the traditional Hammam. The influence of the activity of 218 Po and 214 Po and mass of the tissue on the committed equivalent doses per hour of exposure was investigated. The annual effective dose due to radon short-lived progeny from the inhalation of air inside the traditional Hammam by the members of the public was investigated.
 
The locations of the studied serpentine massifs in Peninsular Malaysia 
Article
The unpleasant effect of serpentine soil on plant life has been a topic of many studies for several decades. Infertility and flora selectivity nature of serpentine soils are the features, which made them of interest throughout the world. This research includes a geochemical study on two Malaysian serpentine massifs to introduce their harmful factors concerning vegetation. X-ray fluorescence results on 11 soil samples showed that serpentine soils comprise large values of iron and magnesium (up to 55 wt and 65 wt% respectively) and high amounts of some heavy metals like chromium (1248-18990 µg g −1), nickel (189-1692 µg g −1) and cobalt (95-478 µg g −1). However, soil extraction by ammonium acetate solution revealed that only magnesium is plant available. Besides, serpentine soils are poor in some major plant nutrients such as nitrogen, potassium and phosphorus. This substantial paucity is the main cause of bareness in these lands. Soils in the studied areas are moderately acidic and have the adequate cation holding capacity. Their Ca/Mg quotient is very low (less than 1). The latter with the low availability of the calcium (0.34 m-equiv 100 g −1 in average) is another challenging parameter in serpentine soils, which exerts negative influence on plant growing.
 
Article
Problem statement: The absolute necessity of compulsory fuel utilities, no matter small or big has resulted into substantial high hazards pollutants. Petroleum refineries are major industrial installations that are necessary for providing the best suited fuel for various necessary utilities, but are responsible of the emission of several hazardous pollutants into the atmosphere. Hydrocarbons are among the most perilous air pollutants that are emitted from almost all refining processes in petroleum refineries. Approach: Every day leaks and gaseous discharge from relief valves and liquid discharge, which are often directed to knock-out drums, are flared to minimize the impact of hydrocarbons emissions. But these flares are not that efficient and result into partial discharge of pollutants that have severe impact on the industrial area and urban localities in the vicinity of industrial refining complex. Results: In the present study, a thorough investigation has been completed to estimate the total emissions of sulfur dioxide SO 2 and non methane hydrocarbons NMHC (VOCs) and to assess their impact on the air quality in industrial and suburban areas. The latest version AMS/EPA Regulatory Model (AERMOD) specially designed to support the US Environmental Protection Agency (EPA)'s was used to predict the ground level concentrations of SO 2, VOCs from AL-Ahmadi and Al-Shuiba Refineries of total refining capacity of 646 thousand barrels/day. Conclusion/Recommendations: These concentrations are compared with EPA standards to indicate the ambient air quality. The dispersion model was corroborated with extensive one year hourly record of the surface and upper air meteorological data for year 2006 and emission rates of the specified pollutants, with detailed refinery stacks parameters, such as stack height, diameter, exit flue gas velocity and temperature to determine the fraction of total study area in the vicinity of refineries that had substantially high concentration of these pollutants. It's found that 10 % of selected area under study has exceedance for SO 2, 13 % exceedance for non-methane hydrocarbons NMHC, and there is no exceedance for NO 2 which is considered about 50 % of total NOx emissions.
 
Schematic of the experimental facility. S1, S2, 
Evolution of filter bed performance in terms 
Abundance 
Article
The current work study the efficiency of biological wastewater treatment by an aerobic reactor which could be used in small agglomerations. RBC reduced physicochemical and microbiological load of wastewater but values remain above Tunisian standard. Approach: Experiments were conducted on a sand filled PVC column fed with wastewater treated by Rotating Biological Contactor (RBC) at a pulsed rhythm of 8 sequences per day. For performances study process, physicochemical and bacterial analyses effluent at inlet and outlet of column were realized. Results: The results showed that through filter mass (D10 = 0.55 mm, D60 = 1.3 mm and coefficient uniformity = 2.36) 96% of suspended solids, 99% of NH 4 + -N (during first phase), 92% of COD, 91% of BOD 5 and 46% of phosphorus are retained by surface filtration. The microbial abatement results is <1.6 Log units of indicators fecal contamination (fecal coliforms, fecal streptococci and E. coli). The microbial water quality is slightly higher than Tunisian standards. The removal of microbial indicators in the considered reactor depends on the depth of the filter and negatively correlated with NO 3 --N (r = -0.99, with E. coli at 3rd OPD). Conclusion/Recommendation: Results confirmed that the reactor tested is performed as an advanced treatment system for DBO, COD, SS, NH 4 + -N and NO 3 --N. Despite that 96% of SS efficiency reduction, clogging is not achieved quickly that due to biofilm detachment phenomena. The removal of microbial indicators in the considered reactor depends on the depth of the filter and negatively correlated with NO 3 --N. Disinfection performances for the considered reactor reduce microbial load, however chlore, ozone or UV disinfection should be considered.
 
Schematic representation of the experimental nitrification/denitrification reactors. (*, Biofilm sampling point).
Partial sequence analysis of (amoA gene) major bands recovered from different DGGE profiles
Article
Problem statement: The current work study the efficiency of biological wastewater treatment by an aerobic reactor which could be used in small agglomerations. RBC reduced physicochemical and microbiological load of wastewater but values remain above Tunisian standard. Approach: Experiments were conducted on a sand filled PVC column fed with wastewater treated by Rotating Biological Contactor (RBC) at a pulsed rhythm of 8 sequences per day. For performances study process, physicochemical and bacterial analyses effluent at inlet and outlet of column were realized. Results: The results showed that through filter mass (D10 = 0.55 mm, D60 = 1.3 mm and coefficient uniformity = 2.36) 96% of suspended solids, 99% of NH4 +-N (during first phase), 92% of COD, 91% of BOD5 and 46% of phosphorus are retained by surface filtration. The microbial abatement results is
 
Variations of daily AOD and rain rate of monsoon seasons during 2008, 2009 and 2010 over Rajshahi 
Variations of daily AOD and rain rate of monsoon seasons during 2008, 2009 and 2010 over Sylhet AOD for Sylhet ranged from 0.61 to 0.12 and the rain rate was 0.325 mm/h during 2008; in 2009, the AOD varied from 0.66 to 0.10 and the rain rate was 0.287 mm/h; in 2010, AOD ranged between 0.64 and 0.14 and rain rate was 0.439 mm/h. Figure 2 illustrates the variations of AOD and rain rate during monsoon period over Sylhet. Maximum AOD was noticed in June 2010; in the monsoon season, the city received its highest rain rate in 2010 and lowest rain rate in 2009 and the highest AOD was found in June while the lowest AOD was obtained in July. It was concluded that the AOD, rainfall and cloud interactions are still very complicated phenomena and 
Variations of cloud parameters, AOD and rainfall over Rajshahi. (a) COD, CER and AOD variations; (b) COD, CER and RR variations 
Monthly mean of ground station and TRMM satellite rain rate (RR) in Rajshahi division of Bangladesh during 2001-2010 
Article
Aerosol-cloud interactions influence the global precipitation patterns that influence significantly the Earth's climate system. Anthropogenic aerosols alter the clouds and their optical properties. The present study has investigated the Aerosol Optical Depth (AOD), cloud parameters and rainfall interactions for three different monsoon periods (2008-2010) and also compared the satellite rainfall with ground based observations, by using MODIS and TRMM datasets. The highest average of AOD was in the month of June and lowest was in July for both Rajshahi and Sylhet divisions. Comparing between Rajshahi and Sylhet, Rajshahi was in the peak of aerosol contamination than Sylhet. The cloud parameters, such as COD and CER, were positively correlated with rainfall except CER in Rajshahi during the 2010 monsoon season and in Sylhet during the 2008 monsoon season. The investigation has showed complex interaction among AOD, cloud parameters and rainfall in both regions during the study period. In addition TRMM satellite-derived rainfall has compared with ground-measured values. The result indicated that TRMM rainfall data were in good agreement with ground measurements with correlation coefficient of above 0.90 in Rajshahi.
 
Article
The cement industry is the major source of cement dust which contains heavy metals like nickel, cobalt, lead, chromium, arsenic and hazardous substances like dioxins and furans. Exposure to these substances can cause health problems to human, animals and vegetation. A continuous pilot scale quartz sand filter was constructed and uses to study the effect of important design parameters (temperature, pre-loaded dust on the collector, diameter of the filter, bed depth, collector size and superficial velocity) on its performance for cleaning of cement dust from air. Initial penetration and initial pressure drop (after 180s) were measured and compared for different variables used in this study. The dirty bed was cleaned by means of reverse air flow when the pressure drop across the filter rises to 20 cmH2O. A macroscopic model describes the filter clogging was used to predict the effluent histories based on initial collection efficiency (?0)exp which was determined from experimental data. A removal efficiency of more than 99% was obtained. The results show that 0.4% of cement dust still adheres on the quartz sand bed after 5 min of cleaning cycle. The presence of 0.4% of pre-load dust on the quartz sand filter enhanced the efficiency and low initial penetration, moderate initial pressure drop was obtained. At given Empty Bed Contact Time (EBCT), with different filter diameters 30 and 15 cm, a sharp decrease in initial penetration from 0.41-0.03 was obtained respectively. A nonlinear relationship between penetration and temperature was found. The initial penetration can be reduced by using smaller filter diameter, small collector size and collector with pre-load dust with 0.4%. The experiment that operates at a filter diameter of 15 cm and temperature of 25°C represent the minimum penetration among all the experiments.
 
Article
Geothermal springs are natural geological phenomena that occur throughout the world, and South Africa (SA) is endowed with several springs of this nature. Most of the geothermal springs in SA (31%) are found in Limpopo Province. Assessment of geochemistry of Siloam and Tshipise geothermal springs were undertaken during 2014 winter (May – July) and summer (October – December) seasons. Water samples were collected from the springs and stored at low temperatures (+/- 4°C) for analysis of hydrochemical parameters and acidification was carried out before trace metals analyses. The results show that Siloam and Tshipise geothermal springs water are not suitable for drinking due to high pH, high fluoride concentrations and some metals such as Hg, Ni and Pb. Various index methods such as Sodium Percentage (SP), Sodium Absorption Ration (SAR), Residual Sodium Carbonate (RSC), Permeability Index (PI), Kelly’s index (KR) and Electrical Conductivity (EC) were used to evaluate groundwater quality for irrigation and most of the index has a similar result. Hence, the spring water is suitable for irrigation purposes. The water type is Na-Cl in both seasons for both site except for Siloam in winter having NaHCO3. There were slight variations in the hydrochemical compositions of geothermal spring water, although they were not significant (p>0.05). However, there were significant differences in mean trace elements concentrations in geothermal spring water in summer compared to winter season (p<0.1) for both Siloam and Tshipise springs. This can be attributed to the rainfall in summer which aids in more dissociation of rock particles and the release of more trace elements. Variations in mean trace elements concentrations could also be linked to the differences in fundamental changes in water chemistry from deep sources of the geothermal springs. It has thus been established and/or inferred that the dominant processes controlling the geothermal water are geothermal gradient, silicate weathering, mineral dissolution, cation exchange and inverse cation exchange.
 
The chemical compositions of tested Pigeon pea varieties on-station of Jinka Agricultural Research Center under rain fed condition in 2017 and 2017 cropping years
Article
The pigeon pea species could play an important role in providing a significant amount of high quality dry matter yield and digestible crude protein to the livestock. Therefore, this study was initiated to evaluate the dry matter yield and chemical composition of five pigeon pea varieties under rain fed condition in 2017 and 2018 main cropping years at on-station of Jinka Agricultural Research Center. The five pigeon pea varieties were evaluated in randomized complete block design with three replications per variety. The data on dry matter yield, plant height, branches per plant, leaf to stem ratio and chemical compositions were analyzed using the General Linear Model procedures of SAS and Least Significance Difference was used for mean comparisons. The significantly higher (P<0.05) dry matter yield (21.84 t/ha) and crude protein (274.6 g/Kg, DM) were obtained for 16555 pigeon pea variety and whereas, the lowest dry matter yield (13.92 t/ha) and crude protein (179.90 g/Kg, DM) were observed for local pigeon pea variety. Based results from this study it was concluded that the farmers who living in mid land areas of South Omo Zone and other areas having comparable agro-ecology could plant pigeon pea 16555 variety as superior candidate for higher dry matter yield and crude protein. Moreover, we suggested that future research will be considered the effect of planting space on dry matter yield and supplementation effect of superior candidate pigeon pea 16555 on the sustainable livestock production performances (meat, milk and growth).
 
Residues evolution of glyphosate and AMPA in the extractable residues in silt clay loam soil during incubation at 20°C  
Evolution of different portions of 14 C-glyphosate residues (extractable, mineralization as 14 CO 2 and Non extractable) in silt clay loam soil during incubation at 20°C  
Radioactivity leached from lysimeters of the investigated soils treated with 14 C-glyphosate under outdoor conditions  
Article
Glyphosate [N-phosphonomethyl]glycine is a systematic, non-selective, organophosphorus herbicide used worldwide in agriculture and industrial zones. Following its application, residues of glyphosate can threaten soil or aquatic organisms in adjacent water. In this study, we followed the degradation, stabilization, remobilization and leaching of 14C-glyphosate in three agricultural soils in laboratory incubations and in lysimeters under field conditions. Glyphosate degradation was relatively rapid with a half-life of 14.5 days in the silt clay loam soil incubated at 20°C. Glyphosate’s degradation product, Aminomethylphosphonic Acid (AMPA), represented more than 85% of residues after 80 days of laboratory incubation. Leaching of glyphosate in lysimeters of three different investigated soils under outdoor conditions was very slow, less than 1% of the initial applied amount has been detected in the leachates after 100 days of experimentation. Glyphosate rapidly formed non-extractable residues after treatment. In summary, glyphosate was removed from soil very rapidly and its leaching seems to be very slow regardless the type of treated soil. On the other hand, the contamination risk of groundwater with its metabolite AMPA at long term is probably due to the release of the non-extractable residues.
 
Article
Soil drought, that can be enhanced by global warming increases ammonia (NH 3) volatilization. This laboratory study was conducted with two soils: Krome Gravelly Loam (KGL) from Florida and Warden Silt Loam (WSL) from Washington State and two fertilizers: Ammonium sulfate [(NH 4) 2 SO 4 ] or ammonium nitrate (NH 4 NO 3). Two water regimes including 20 and 80% Field Capacity (FC) were used at 20°C which is the average temperature in the potato growing season in Washington State. The data demonstrated that variation in NH 3 volatilization subject to different soil water regimes can be explained by changes in Gibbs free energy of Nitrogen (N) fertilization in soils with varying water contents. The absolute values of Gibbs free energy of (NH 4) 2 SO 4 or NH 4 NO 3 applied to soil at 20% FC soil water regime were 5-fold greater than at 80% FC. Accordingly, the equilibrium constant (K) of deprotonation of ammonium ions in soil solutions at 20% FC was 3,000-or 50-fold greater than that at 80% FC for (NH 4) 2 SO 4 or NH 4 NO 3 , respectively. Nitrogen loss via NH 3 volatilization was 4-to 7-fold greater at 20% FC than that at 80% FC. This study suggests potential acceleration of NH 3 volatilization from soils under drought. Therefore, optimal water management is critical to mitigate NH 3 volatilization from agricultural soils.
 
Geographical location of Yunnan Province. The inset map indicated the location of Xishuangbanna Dai This Map was produced on 18th December 2019 by Misiani Zachary.
Upland Rice Varieties Comparison in 2005, 2007 and 2009 (statistics from 2009, 2010 investigation data).
Continued.
Comparison between Shifting agriculture and Rubber Plantation.
Article
Land-use and land-cover changes directly impact biological diversity, and may cause land degradation by altering ecosystem services and livelihood support systems, thereby disrupting the socio-cultural practices and institutions associated with managing those biophysical systems. The most important is the gradual disappearance of human's traditional ecological knowledge and cultural diversity. Xishuangbanna is one of regions that have the richest biodiversity and cultural diversity in the world. In recent years, academic scholars, government departments at different levels and media have increasingly paid close attention on the relationship between rubber cultivation and biodiversity in Xishuangbanna. However, such attention on the relationship between rubber plantation and cultural diversity is few. Conclusively, social and cultural practice on natural resource management carried out by local people and relevant institutions are greatly changing in the context of implementing rubber plantation. During this process, traditional ecological knowledge is also experiencing changes. The paper will elaborate impacts from the rubber plantation on Bulang society in Xishuangbanna, explore changes on local subsistence, social and cultural practice and relevant institutions, and further analyze relationships between the rubber plantation, cultural diversity and traditional ecological knowledge, and threats and challenges faced by Bulang people. Through the case study of Bulang people, we see that the traditional ecological knowledge not only includes natural resource management and genetic resource protection, but also recognition of ethnical identities and heritage of biological and cultural diversity.
 
Effect of the size of the dose of alum on the 
Effect of the size of the dose of turmeric extract on the effectiveness of removing boron
Structure 
Article
Problem statement: Boron exists in an environment naturally either through weathering of rocks or volcanic activity but due to anthropogenic activity, boron had been distributed widely into our surroundings. Boron was a problematic pollutant due to the difficulty to remove it from the water. Turmeric which had been widely used as a spice and traditional medicine, were investigated to determine its capabilities to aid in coagulation-flocculation process to remove boron. Optimizing coagulation-flocculation process might be effective to remove boron to a lower concentration. Approach: In this study, the optimum parameter for pH, dose of aluminium sulfate (alum) and a dose of turmeric extract were determined by conducting a set of jar test experiment. The coagulation flocculation process was performed to study the effectiveness of the turmeric extract as a coagulant aid in boron removal. Results: The result demonstrated that coagulation-flocculation process with the aid of turmeric extract can remove boron effectively at optimum conditions rather than coagulation flocculation process without the aid of turmeric extract. The optimum conditions for boron removal were achieved at pH 7, an alum dosage of 18, 367 mg L -1 and turmeric extract dosage of 82 mg L -1. Conclusion/Recommendations: Result showed that removal of boron depends on pH, alum dosage and turmeric extract dosage. The boron removal percentage of the aqueous solution using the coagulation-flocculation process aided by the addition of turmeric extract and without the addition of turmeric extract were 95 and 62%, respectively. In addition, there was a significance difference between both processes. Turmeric extract as a coagulant aid demonstrated promising performance in boron removal and can be used as an alternative treatment to treat boron-containing wastewater.
 
Article
The study investigates the urban heat island effect in Malaysian historic town Malacca through seven mobile traverses, as carried out on 10 December 2011. It aims to identify the intra-urban air temperature differences between heritage core zone, new development area and outskirts of the city. Air temperature variations were also analyzed across three different zones; namely the outskirts, the heritage site and the city center district. Heat index values were then calculated based on air temperature and relative humidity to gauge the level of outdoor thermal comfort within the study area. Based on the indications, one may conclude that the heritage place’s core zone is currently threatened by escalating temperatures and that its current temperature range falls within the “caution” and “extreme caution” categories. Furthermore, no significant difference was observed between the peak temperatures of the old city quarters and newer areas; despite the disparities in their urban forms. Therefore, it is hoped that the study, with its implications, will be able to influence future environmental consideration in heritage city of Malacca.
 
Article
An investigation was conducted to assess the air quality impact and possible health risk of solid waste disposal on surrounding environment of Matuail landfill site in Dhaka city. Three different locations were selected for soil and plant samples. Leachate samples were collected from active dumping area and fish samples from treated leachate pond. Seven different locations were selected for air quality and health risk assessments. It is found that Cu, Zn and Pb concentrations were high in the soil of dumping and abandoned areas that exceeded the permissible limits. The heavy metal concentrations in plant samples did not show any significant contamination except Cu, Zn and Pb that also exceeded the permissible limits. The concentrations of DO, BOD, COD and TDS of the untreated leachate were found 1.34 mg L 1 , 96 mg L 1 , 1343 mg L 1 and 7120 mg L 1 , respectively that exceeded inland surface water standard but after treatment its concentrations were found within the permissible limits. The presence of heavy metals in leachate sample was not contaminated as it was below the toxic limits. The bioaccumulation of fish sample from treated pond is extremely high of Fe, Mn, Pb and Ni that exceeded the WHO's permissible limits. The air quality results showed that the Matuail landfill surrounding sites did not have an adverse effect. The air pollutants such as NOx, SO2, SPM, PM10, PM2.5 and CO contents are within national standard limits. Overall, the risk assessments demonstrated that potential air emissions from the Matuail Landfill site do not pose public health risks. It is clear that if the dumping landfill site is properly managed by segregating the waste according to their source, then this waste could be used as compost or organic manures. However, by maintaining disposal sites with controlled placement and proper treatment of the waste may reduce the possible adverse impact on air, human health and agri-environmental ecosystems. Further investigation on the impacts related to the final disposal of solid waste and the future landfill requirement at different composting and a comparative study is suggested.
 
Article
This study assessed the ambient air quality status after the period of biomass burning through shifting cultivation (i.e. summer) and in other seasons when there was no shifting cultivation. The present study performed the assessment of air quality with respect to suspended particulate matter (SPM), respirable suspended particulate matter (RSPM), nitrogen dioxide (NO 2) and sulphur dioxide (SO 2) at two sites namely Ramrikawn (peri-urban area) and Tanhril (rural area) of an Indo-Burma hotspot region. The average concentration of SPM and RSPM were found to be higher in the peri-urban area than rural area. Apart from this NO 2 and SO 2 levels at both sites remain under prescribed limits of Central Pollution Control Board (CPCB) of India. It has been observed that the concentrations of the particulate pollutants are high in summer in comparison to the winter and rainy seasons. The average air quality index (AQI) value of peri-urban area was recorded higher than rural area. The deviations in seasonal air quality particularly in context of SPM and RSPM may be attributed to the impact of biomass burning through shifting cultivation.
 
Scheme of the sampling campaign for the joint monitoring of the two compartments; a. NO 2 indoor air levels were not continuously monitored, grab samples were analyzed occasionally  
Time series plots of different parameters continuously monitored  
Correlation matrix of the anion extracted from the activated carbon  
Article
Can passive technology effectively enhance the indoor air quality? To improve classroom indoor air quality, an increase in ventilation and/or air purifiers are often suggested. In this study, a short-term intervention was implemented and investigated to evaluate the effects of a passive adsorbent surface on the pollutant deposition velocity and to improve the overall classroom air quality. We found that furnishing the classroom wall with adsorbent cloth surfaces results in decreased levels of indoor-generated pollutants. The main indoor parameters monitored (CO2, relative humidity, particulate matter) in the presence of a passive sorbent material are lowered: the indoor relative humidity lower than a 7% and carbon dioxide of about 5%. The NO2 deposition velocity has been estimated to 5.1*10-2 (1.8- 6.0)*10-2 cm/s while for SO2 equals to 0.24 (0.02-1.25)*10-2 cm/s. These results suggest that in low-polluted areas, activated carbon cloth may well be used to improve classroom indoor air quality.
 
Map of locations of cities used in study
Annual mean variation of (a) NOx (ppb) emissions (b) NO (µg/m 3 ) emissions (c) NO 2 (µg/m 3 ) emissions and (d) PM 2.5 (µg/m 3 ) emissions with meteorological parameters from 2008-2010. Primary y-axis all metrological parameters (minimum temperature (°C), maximum temperature (°C) and rainfall (mm) were presented, on secondary y-axis all the emission concentrations are presented
Annual mean concentration and relative percentage of each of pollutant type in the atmosphere of Islamabad, Lahore and Karachi, Pakistan Emissions Yearly mean count %age contribution to total atmosphere
Article
Environmental pollution being fatal for all living organisms is growing adversely due to excessive industrialization and urbanization. Vehicular emissions have aggravated the situation and pose detrimental effects on human health. In this study, the trend of ambient air quality was analyzed in the three metropolitan cities of Pakistan, including Karachi, Lahore and Islamabad for a period of three years (2008-2010). Air pollutants, such as NO, NOx, NO2 and PM2.5 were recorded usingmobile air quality monitoring stations in the target areas. Results from statistical analysis revealed PM2.5 with highest levels in all the cities, albeit exceeded the World Health Organization (WHO) guideline limits. Spearman correlation revealed that the levels of air pollutants were negatively correlated with the temperature and rainfall, whereas positively correlated with the wind speed. Annual and seasonal variations in the concentrations of the air pollutants was also observed and the highest concentration was recorded in Karachi during the winter season that could be attributed to inversion phenomenon. In addition, the elevated vehicular emissions were observed in Lahore, implied comparatively high air pollution loads, comparison to those of Karachi and Islamabad. The widespread use of low-quality fuel, coupled with a dramatic expansion in the number of vehicles has led to significant air pollution problems, especially in Lahore and Karachi. Therefore, the efficient mass transit system and urban forests should be introduced to abate the ever-increasing levels of organic pollutants and improve the state of ambient air quality in the major cities of Pakistan
 
Article
The water-energy nexus reveals that large amounts of energy is stored in used water, and can be used as an energy source. Anaerobic fermentation is an excellent ecological waste treatment and a way of producing low cost electrical and thermal energy. By using digestate resulting from biogas production instead of synthetic fertilizers derived from natural gas, we can save energy, cut consumption of fossil fuels and reduce our carbon footprint. The aim of this study then is to determine the effect of digestate on the yield and quality of crop production as well as its effect on the immediate environment. A ratio of raw materials in biogas, pig manure and vegetable wastes of 70:30 was used on lettuce as an indicator culture. The studies were carried out on two different soil types. Digestate was applied at various percentages, tested with untreated soil as control. The results are encouraging indicating that digestate as a biomass is rich in macro and micronutrients and can be used in agriculture for the improvement of soil fertility. Keywords: digestate, biogas, anaerobic fermentation, sustainable energy.
 
Article
The present study was conducted to investigate the biochemical attributes of Nymphaea alba (also known as the European White Water lily or Nenuphar), an annual or perennial aquatic flowering plant at three study sites viz., site I (Nagoo Mohalla, near residential area); site II (Ashaibagh-adjacent to floating gardens) and site III (Marzibagh-Nigeen boat club) in Nigeen Basin of Dal Lake, Kashmir. The sampling was done on monthly basis and the entire study period was divided into two phases i.e., the active growth phase (summer-June, July and August) and the senescence phase (early winter-September, October and November). Comparative biochemical assessment of three sites revealed chlorophyll ‘a’ ranging from 2.371µg/ml (site-III) to 3.266µg/ml (site-I); chlorophyll ‘b’- 0.382µg/ml (site-III) to 0.588µg/ml (site-I); total chlorophyll, 3.184µg/ml (site-III) to 4.262µg/ml (site-I), while as carotenoids varied between 0.438µg/ml (site-III) to 1.083 µg/ml (site-I). Proteins and amino acids elevated from a range of 0.328 mg/ml (site-III) to 0.578 mg/ml (site-I) and 2.884 mg/ml (site-III) to 3.823 mg/ml (site-I) respectively. The starch and carbohydrate content obtained a concentration range of 8.486 mg/ml (site-III) to 10.302mg/ml (site-I) and 10.009 mg/ml (site III) to 12.769 mg/ml (site-I) respectively. The results revealed that the biosynthesis of various biomolecules accelerated during the active growth phase at Site-I (June) due to optimum physico-chemical parameters of water such as temperature (270C); pH (8.9); free carbon dioxide (20.0mg/l); and high concentrations of nitrate-nitrogen (427.3µg/l) and total phosphorous (226.8µg/l) while as, low range of biomolecules was observed at site-III in the senescence phase (November) due to decrease in various physico-chemical parameters of water (temperature,5.00C; pH,7.2; free carbon dioxide,16.4mg/l; nitrate-nitrogen,201.7µg/l; and total phosphorous, 203.5µg/l) from summer to early winter season. The study concludes that high nutrient load owing to various anthropogenic activities during active growth phase enhanced the growth of Nymphaea alba at site I as it increased biosynthesis of its various biomolecules in comparison to site III (control site) which is attributed to various clean-up activities taken up around this site. The study, thus recommends urgent scientific measures including proper management, conservation and restoration of lake. Furthermore, human habitation around the lake catchment demands sustainable protection measures to limit further degradation of the lake.
 
Article
A qualitative and quantitative study on the epiphytic microalgae and epiphytic zooplankton were conducted in order to follow up their community structures on seaweeds in relation to some physicochemical variables in the coastal waters of the Eastern Harbor of Alexandria. Water and macroalgal samples were collected seasonally during two years successively: Winter, summer, autumn (2012) and spring (2013). The collected seaweeds were Ulva fasciata (green alga), Corallina mediterranea, Corallina officinalis, Gelidium sp., Pterocladiella capillacea, Hypnea musciformis and Grateloupia doryphora (red algae). The studied water quality parameters were pH, salinity, dissolved oxygen, oxidizable organic matter and nutrient salts. The abundance of epiphytes were significantly different between morphotypes (two-way ANOVA), p≤0.05; ranking the branched thalli as the first preference for microalgal epihytes, sheet-like thalli with a smooth surface as the second one, while the lowest rank was for the mucilaginous species. The same result was found for epiphytic zooplankton. The results of the statistics revealed insignificant seasonal variations in the epiphytic microalgae and very weak correlations between the abundance of microalgae and the physico-chemical parameters. In contrast, there were significant differences for epiphytic zooplanktonic seasonal variations. Whereas, the zooplankton count was correlated preferably with environmental water salinity, followed by nutrients.
 
Article
A qualitative and quantitative study on the epiphytic microalgae and epiphytic zooplankton were conducted in order to follow up on their community structures on seaweeds in relation to some physico-chemical variables in the coastal waters of the Eastern Harbor of Alexandria. Water and macroalgal samples were collected seasonally during two years successively: Winter, summer, autumn (2012) and spring (2013). The collected seaweeds were Ulva fasciata (green alga), Corallina mediterranea, Corallina officinalis, Gelidium sp., Pterocladia capillacea, Hypnea musciformis and Grateloupia doryphora (red algae). The rhodophyte Ceramium diaphanum was the only recorded macroalgal epiphytic species on the collected seaweeds during this study. The studied water quality parameters were pH, salinity, dissolved oxygen, oxidizable organic matter and nutrient salts. The abundance of epiphytes were significantly different between morphotypes (two-way ANOVA), p≤0.05; ranking the branched thalli as the first preference for microalgal epihytes, sheet-like thalli with a smooth surface as the second one, while the lowest rank was for the mucilaginous species. The same result was found for epiphytic zooplankton. The results of the statistics revealed insignificant seasonal variations in the epiphytic microalgae and very weak correlations between the abundance of microalgae and the physicochemical parameters. In contrast, there were significant differences for epiphytic zooplanktonic seasonal variations. Whereas, the zooplankton count was correlated preferably with environmental water salinity, followed by nutrients.
 
Article
In the present study the acute toxicity of Chromium in fingerlings of Catla catla an Indian major carp was evaluated with renewal bioassay method. In vivo studies were designed to assess the extent of Micronucleus Assay, Comet Assay under the exposure of common heavy-metal compounds, viz. Chromium Nitrate, using Catla catla (2n = 20), as a test model. The laboratory acclimatized fishes were divided into four groups. Group I served as positive control, and the other three as exposed groups for three different time durations of 7, 14 and 21 days and were subjected to uninterrupted sub lethal concentrations (50% of 96 h LC50); the experiments were planned in such a way that fish from all the groups were sacrificed on the same day. The frequencies of micronuclei and bi nuclei were evaluated comparatively in peripheral erythrocytes. As a result, it was observed that, the fishes and different tissues showed differential sensitivity to the heavy-metal treatment. A significant increase in the frequencies of micronucleated and binucleated cells and percentage increase in DNA tail (p<0.001) through Alkaline Comet Assay were observed after 21 days of exposure to chromium. Our results also showed decrease in enzyme superoxide dismutase (SOD) activity and increase in catalase enzyme due to increasing chromium concentration. The bio-concentration factor profiles of Chromium in Catla catla during sub lethal toxicity study was also calculated.
 
Study area showing sampling sites  
Means + SD of total Hg (µg.g −1 ) in fish from the main rivers (A) and sample sites (B). Vertical bars denote confidence interval of 0.95. Same letters denote no statistically significant differences among main rivers and among sample sites (ANOVA)  
Mercury (Hg) concentration found for each fish species
Article
Mercury contamination is a long-standing environmental and social problem, notably in the Amazon. The widespread use of mercury in artisanal and small-scale gold mining has driven contamination of the environment and the people, threatening biodiversity, human health and livelihoods of traditional populations. Along the border area between Brazil and French Guiana, illegal gold mining is considered a critical threat to biodiversity, a social and economic problem and a political and diplomatic issue. On the Brazilian side in Amapá state, stands the world´s largest tropical forest National Park-Tumucumaque National Park (TNP). Despite its critical importance for the maintenance of ecosystem services, little is known about anthropic impacts in the area, including mercury contamination. The present study aims to assess the current levels of mercury contamination of carnivorous fish species in the TNP region as the starting point for the assessment of its impact over the integrity of protected areas and local communities. Fish samples were collected at 33 sampling sites within TNP and its surroundings. Samples of 187 most consumed local fish belonging to eight carnivore species were analyzed. Mercury was detected in 81% of the collected fish, the majority of them with individual levels above the WHO health safety limit (0.5 µg.g −1). Furthermore, samples from all rivers assessed presented some level of contamination. The contamination of important locally consumed fish is widespread in the study area. Important river basins in the Northern Amazon area are affected and even protected areas might be impacted by mercury. Our results suggest mercury as a significant threat to biodiversity and human health in the region. Additional studies should be conducted towards identifying the extent of the problem in the region and mitigation strategies addressing the effects of contamination must be incorporated in decision makers' priority agenda.
 
Coordinates of sampling positions
Linear Regression between the results of Pb obtained via quartz tube flame AAS and furnace AAS technique for soil samples
Lead level in the soil samples determined by furnace and quartz tube technique
Lead level in mosses samples determined by furnace and quartz tube technique
Article
The aim of this study was to compare the results of the lead levels obtained by two different techniques in the soil and mosses samples taken from the entire territory of the Republic of Kosovo. The atmospheric deposition of lead through the biomonitoring technique was done for the first time in Kosovo by using quartz tube flame Atomic Absorption Spectroscopy (AAS) and furnace AAS. The analytical results obtained by both techniques were very close to each other for the concentration of lead up to 0.15 mg kg-1. Mosses were used as bioindicators due to the purpose that they take the food from the rainfall and atmospheric dust. Two types of terrestrial mosses (Pseudosclerpodium purum and Hypnum cupressiforme) and the soil, collected in June-July 2011 at 25 sites evenly distributed over the whole region of Kosovo, were used in this study. The lead concentration varies from ~ 11-416 mg kg-1 in the soil and from ~ 3-50 mg kg-1, DW in mosses, depending on the pollution zone. From the obtained results, we conclude that the lead levels are higher at the sampling positions near the polluted area of industry and heavy traffic.
 
Coordinates of sampling positions
Linear Regression between the results of Pb obtained via quartz tube flame AAS and furnace AAS technique for soil samples
Lead level in the soil samples determined by furnace and quartz tube technique
Lead level in mosses samples determined by furnace and quartz tube technique
Article
The aim of this study was to compare the results of the lead levels obtained by two different techniques in the soil and mosses samples taken from the entire territory of the Republic of Kosovo. The atmospheric deposition of lead through the biomonitoring technique was done for the first time in Kosovo by using quartz tube flame Atomic Absorption Spectroscopy (AAS) and furnace AAS. The analytical results obtained by both techniques were very close to each other for the concentration of lead up to 0.15 mg kg-1. Mosses were used as bioindicators due to the purpose that they take the food from the rainfall and atmospheric dust. Two types of terrestrial mosses (Pseudosclerpodium purum and Hypnum cupressiforme) and the soil, collected in June-July 2011 at 25 sites evenly distributed over the whole region of Kosovo, were used in this study. The lead concentration varies from ~ 11-416 mg kg-1 in the soil and from ~ 3-50 mg kg-1, DW in mosses, depending on the pollution zone. From the obtained results, we conclude that the lead levels are higher at the sampling positions near the polluted area of industry and heavy traffic."
 
Article
The study investigated the effects of temperature on strength of concrete produced in Anambra State, Nigeria. The study is an experimental research. Concrete were produced at different temperature within the study area. Cement, aggregates (fine and coarse) and water were used in mixing concrete. Dangote Cement was used for all the concrete produced. The fine aggregates used was obtained from River Sand (Onitsha), coarse aggregate is crushed stones from Nkwelle Ezunaka and water used for the concrete mixing is fit for drinking. These concrete produced were tested in the laboratory (Anambra State Material Testing Laboratory) for workability and compressive strength and the result obtained were presented in simple tables and graphs. The study found out that there is great variation in strength of concrete produced at different temperatures. The average compressive strength at 27.6 0 C is 14.83N/mm 2. At temperatures above 30 0 C, the strength of concrete tends to diminish/reduce. Compressive strength of concrete at 33.85 0 C and 35.1 0 C was 11.6N/mm 2 and 11.1N/mm 2 respectively. Also, the result of the slump value ranges from 48.4mm-103.5mm (indicating that all the concrete mix is workable). The graph in Figure 3 indicates that concrete produced in early hours of the day yielded the highest compressive strength (28 th day) while as temperature increases, the compressive strength of concrete diminishes. The study was concluded by recommending that the best time for concrete production is in the morning when atmospheric temperature is still below 30 0 C within the study area. From the results of the study, it can be clearly noticed that with increase in temperature, there is there is significant increase slump of concrete mix as well as decrease in crushing load and compressive strength of concrete.
 
Article
The presence and accumulation of antibiotics in the water environment has become emerging contaminants of concern causing disruption of ecosystems worldwide. We describehere the seasonal variation and the occurrence of antibiotic residues in Fez city surface water (Morocco). During one year between February 2014 and January 2015, 8 surface water samples were collected monthly. Quantification of the 7 antibiotics was performed byon-line Solid Phase Extraction (SPE) liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 96 surface water samples were investigated and the results revealed that 100% of the sites were contaminated by at least one antibiotic. Amoxicillin had the highest concentration with maximum concentration (4107 ng L −1), followed by ciprofloxacin (1058 ng L −1) and sulfamethoxazole was the most widely detected (93%). Seasonal variation showed that the concentrationof antibiotics was higher in winter for trimethoprim (96 ng L −1), ciprofloxacin (438 ng L −1) and in summer for amoxicillin (1113 ng L −1), sulfamethoxazole (162 ng L −1) and erythromycin (47 ng L −1). The results from this research show that antibiotics are frequent contaminants in Fez city surface water. This is the first attempt to assess the occurrence of these 7 pharmaceutical residues in water samples in Fez Morocco.
 
Article
Banana production is seriously threatened by Fusarium wilt, also known as Panama disease worldwide. Regulatory control and the use of biological control agent, Trichoderma harzianum showed to be effective in minimizing the development and spread of the disease in the area. Some studies also showed the potential of some commercially-available fungicides in managing the disease. In this study, different commercial products applied singly and in combinations were evaluated against FocTR4 causing Fusarium wilt of banana and the most effective treatment combinations for the management of FocTR4 was determined under in vitro test condition. Treatments used in the experiment were as follows: T1-Control; T2-B. subtilis alone; T3-Fosetyl-Aluminum alone; T4-Fluopyram alone; T5-B. subtilis + Fosetyl-Aluminum; T6-B. subtilis + Fluopyram; T7-Fosetyl-Aluminum + Fluopyram and T8-B. subtilis + Fosetyl-Aluminum + Fluopyram. The experiment was laid out in Completely Randomized Design (CRD) with three replications. Data were statistically analyzed using the Analysis of Variance (ANOVA) and the treatment means were compared using Tukey's Honest Significant Difference (HSD). Results of the study showed that treatments of B. subtilis in combinations with Fosetyl-Al or Fluopyram and the combinations of these three products had totally inhibited and killed FocTR4. Single treatment of Fosetyl-Al and the combinations of the products had totally inhibited the growth and spore production of FocTR4 however, validation test revealed that Fosetyl-Al alone and its combination to Fluopyram induces chlamydospore production instead of killing the pathogen.
 
Nigeria with the Study area outlined for context (Gayawan et al. 2014)
Example of (a) Landsat 2009 Cluster unsupervised classification of the study area (the different colours represent various Identified spectral values of the pixels) and (b) Example of the result of Reclassified images of Landsat 2009 images of the study area. (Vegetation class is dominant, but when expanded on a GIS software the hidden classes can be clearly observed)
(a) Year 2009 OBIA Image Segmentation of Landsat (b) shows result of object-oriented classification of Landsat of year 2009 image of the study area
Article
In this work a study of gully erosion in southeast Nigeria is presented. The study of gully development on a regional scale is currently undermined by the inherent costs associated with consistent field monitoring and the lack of historic measurements to perform time series analysis. As a result, there are very few studies which implement long term analyses of gullies in the region as a collective. Consequently, the building of knowledge of the role of environmental changes on the development of gullies is inhibited. Remote sensing methodologies, via the Landsat archive, are used as low economic data source that assisted in the analyses of gullies over the time period 1986 to 2015. The Landsat data is used to establish land cover changes over the time period, via pixel and object-based classification, to identify its role in gully development. The use of classification for this purpose identifies this study as a first of its kind in Nigeria. Aiming to link environmental characteristics and land cover changes with gully development and erosion rates at multiple current locations. In terms of the correlation between vegetation area and gully/openland development, Pixel based classification produced a correlation of r =-0.9 (p<0.05). A similar strength of correlation was exhibited for OBIA with r =-0.9 (p<0.05) with both results indicating a very strong and significant negative correlation between the amount of vegetated area and Gully/open-land development over the study period 1986-2015.
 
Article
The aim of this study was to assess the levels of various trace metals present in water and sediment of Fresh water Aquatic Ecosystem during the post monsoon season. The study was extended to identify the trace metal contamination in the water and sediment samples collected along the shores of Lambapur and Peddagattu the tribal villages in India using an Inductively Coupled Plasma Optical Emission Spectrometer (ICPMS). The trace metal contents in water samples were copper- 24.2 to 47.5, chromium - 4.4 to 8.2, cadmium- 0.1 to 0.3, lead- 2.1 to 3.8, Nickel-5.9 to 9.7, Zinc-4.6 to 9.7, Manganese - 10.8 to 13.2, Iron- 52.9 to 157.2 (µg L-1) cobalt and arsenic were in BDL, and the values were within the limits of Indian drinking water standards (BIS 10500:1991). The trace metals concentration in the sediment samples ranged from (mg kg-1): copper- 61.5 to113.7, chromium- 138.4 to 177.5, cobalt- 33.2 to 42.7, cadmium 1.0 to 2.1, lead 57.9 to 103.4, Nickel 36.1 to 56.6, Zinc- 51.2 to 102.1, Manganese 610.8 to 1301.7, and Iron 2.5- 2.9%. The multivariate statistical analysis were done for the interrelationships among elements and the Enrichment Factor (EF) was calculated to differentiate the origin of metals between anthropogenic and natural sources. The data generated were used to determine the quality of the sediments based on the Enrichment Factor, Contamination Factor & Degree of Contamination, Geochemical Index, and Pollution Load Index (PLI).
 
Article
Many industrial and chemical dyes are used in many industrial processes, a variety of different uses. Among the most important of these industries, fabric dyeing, many textiles, papermaking, printing and leather processing, and most food products, and other industries, use industrial dyes, and the waste emitted from these dyes in most industries in which most of the polluted waste resulting from these remnants is produced factories. Therefore, the best methods were adopted to treat and dispose of these dyes in order to preserve the aquatic environment .In the current study, the adsorption characteristics of two dyes, Maxillon blue (GRL) and Direct yellow (DY12), from an aqueous solution were evaluated. The effect of several factors, for example, initial concentration, pH solution, temperature, adsorbent mass, and equilibrium time, have been study. The adsorption capacity and percentage of color removed upraised by elevating contact time and surface area, also elevated by the upraised temperature solution for GRL and DY12, and also the adsorption efficiency decreased by the raised adsorbent dosage. The optimum equilibrium for contact time to be completed is found to be (60 min) 1 hour. It is essentially due to the saturation of the active site that does not let further adsorption to take place. The adsorption was proved through utilizing (FT-IR) and (F.E-SEM) analysis. In addition, TGA appears that the NTADCIP/P (AA-co-AM) composite is stable in high temperatures. GRL adsorbent surfaces best adsorption found to be at pH = 10. In fact, adsorption was found to increase through the rise in solution pH. However DY12 maximum dye adsorption was found to be at pH = 3. The applicability of isotherms adsorption to study the adsorption behavior has to been analyzed via isotherm models Freundlech and Langmuir were utilized to illustrate the experimental model and isotherm's constants. It was found the Freundlech model gives the best fits when compare with Langmuer isotherm for two dyes.
 
Pb(II) removal efficiency in batch equilibrium 
Pb(II) recovery efficiency in column filtration experiments with 0.010 and 0.100 mol dm -3 EDTA pH=8.0. Pb(II)= 3.30 × 10 − 3 kg, yellow sand: 0.0385 kg. Flow rate 0.30 dm 3 h − 1 , T= 
Article
Problem statement: To remove Pb(II) from wastewater using local UAE sand and then to recover the removed Pb(II). Approach: Removal efficiency of Pb(II) from wastewater was investigated using white, yellow and red United Arab Emirates sand with pore sizes < 300 μm. Two methods were employed: batch equilibrium and column filtration. In the batch equilibrium study, the effect of sand type and dosage on Pb(II) removal efficiency was investigated. In the column filtration study, removal efficiencies were measured using yellow sand at 0.100 dm 3 intervals while continuously injecting 300 ppm Pb(II) solution into the column. Pb(II) concentrations were determined using inductively coupled plasma- atomic emission spectrometer (ICP-AES). Measurements were carried out until saturation of the column by Pb(II) was attained. Recovery efficiency of Pb(II) was initially investigated using distilled water, 0.100 mol dm -3 HNO 3 and pH 8.0 aqueous solutions. Recovery via chelation with Ethylenediaminetetraacetic Acid (EDTA) was then attempted. Results: Batch experiments showed that yellow sand was more efficient than either white or red sand in removing Pb(II), with a maximum removal capacity of 0.030 kg Pb(II) per kg yellow sand. Accordingly, yellow sand was selected for column filtration experiments. In column filtration, the removal capacity rose to a maximum of 0.086 kg Pb(II) per kg sand. When sand containing removed Pb(II) in batch experiments was equilibrated overnight with EDTA solutions in stoichiometric excess, 86.6% recovery was observed. By comparison, recovery using EDTA in column filtration was 94.7%. Recovery by injection of either water or 0.100 mol dm -3 HNO 3 solution was either negligible or much lower than that obtained with EDTA. Conclusion: Column filtration using UAE yellow sand is an efficient and inexpensive method to remove Pb(II) from wastewaters. Pb(II) can be efficiently recovered from yellow sand columns by chelation with EDTA.
 
Article
This study investigated how to utilize multiple frequency components of pressure data from periodic pulse tests to estimate the intra-well permeability and compressibility distribution and also the presence of heterogeneities in a real field case. Periodic well testing is a technique in which injection or production pulses of a fluid are applied to a well in a periodic fashion. One of its main advantages is that ongoing operations do not have to be interrupted during the test as the superposed harmonic components can be identified using Fourier analysis. Further, modeling calculations are much faster than calculations in the time domain as no time-stepping is required and only the frequencies observed in the test need to be evaluated. We applied an earlier developed numerical code in the frequency domain to evaluate periodic-test results in a shallow aquifer and obtained a good match between data and calculations. The interpreted formation heterogeneity is in line with the local geology. Joints of various orientations constitute the main hydraulic conduits of the tested subsurface but they do not directly connect the wells. Thus communication between the wells has to be established through low-permeability features. The interwell periodic testing has corroborated the geological understanding of the aquifer and helped understanding the fluid flow pattern.
 
Article
Knowledge of Land Use and Land Cover (LULC) changes is important for many planning and management activities. It is thought to be an essential element for modeling and understanding the major land forms, especially in arid regions like Saudi Arabia. This study investigates the LULC changes in Dirab region of Saudi Arabia between 1980 and 2010, using Landsat TM/ETM+images. After the geometric correction and radiometric normalization, multi-temporal image data sets were spectrally enhanced separately using Principal Component Analysis (PCA) and Tasseled Cap Transformation (TCT). Each image was then separately subjected to supervised classification and processed to identify and quantify LULC changes (vegetation, barren land and built-up area). Post Classification Comparison (PCC) method was adopted for LULC change detection. Change trajectories (“from-to” classes) and accuracy assessments were made by comparing the detected land use change layers with medium/high resolution images of Google Earth data base. The TCT enhanced procedure gave better identification of the changed areas than PCA based method. The overall accuracy of PCA based change detection was 64.58, 62.68 and 62.12% for 1980- 1990, 1990-2000 and 2000-2010 images, respectively. However, the TCT based change detection resulted in higher accuracy of 77.78, 75.62 and 77.92% for 1980-1990, 1990-2000 and 2009-2010, respectively. The results suggested that significant land use changes occurred in Dirab area from 1980 to 2010, which may be related to rapid development of agriculture between 1980 and 2000 and economic development and urban expansion between 2000 and 2010. It was further noted that most changes occurred in cropland areas due to urban encroachment.
 
Map of the study area location, Jazan, Saudi Arabia 
Concentrations of selected insecticides in groundwater samples (μg L − 1 ) 
Frequency of selected compounds detection in groundwater samples 
Concentrations of selected insecticides in dams water samples (μg L − 1 ) 
Frequency of investigated compounds detection in dams water samples 
Article
The application of pesticides indoors and on agricultural lands increased dramatically in recent years in the Jazan area (Saudi Arabia) to control termites and the vectors of diseases, such as Rift Valley Fever (RVF) and malaria. This practice increased the potential risk of pesticide contamination of surface water and groundwater. In this study, samples of 44 wells and 3 dams were collected; the samples were analysed for the presence of 15 pesticides used in the Jazan area. The results showed that the most detected compounds in the surface water samples were diazinon, Dichlorodiphenyltrichloroethane (DDT), fenitrothion and cyfluthrin, with average concentrations of 0.098, 0.104, 0.321 and 0.394 μg L−1, respectively. In the groundwater samples, the most detected insecticides were diazinon, dieldrin and fenthion, with average concentrations of 0.117, 0.005 and 0.472 μg L−1, respectively. In general, detected concentrations of organophosphorus insecticides slightly exceeded the allowed Maximum Residue Limit (MRL) of the European Union, which is 0.1 μg L−1, in some samples. However, the findings of this study about the safety of water resources in the Jazan area were not alarming because the detected concentrations were below the MRL and lower than the limit of the sum of all individual compounds detected in the same sample. More extended investigations are highly recommended.
 
Article
Saudi Arabia has limited renewable water resources and the groundwater is the main source of water in Saudi Arabia which. With an arid climate, it receives about 50-100 mm/year of rainfall in Central, Eastern and Northern regions. There are few studies investigating the future regional climate change and some has predicted a decrease in precipitation but with extreme climate events such as flood and stormy rainfall events. Authors have evaluated the thirty-one years record of the rainfall in different parts of the Kingdom and found an increasing trend in annual maximum daily rainfalls at investigated locations signifying the more extreme rainfall evens and resulting floods of short-durations. A brief review of the Rainwater Harvesting and Management (RWHM) practices in the Arab region and the current use of rainwater in Saudi Arabia is presented and keeping in mind the climate impacts on the water resources, authors have suggested rooftop RWHM as a soft-path water management strategy to avoid short-term flooding problems in urban areas. Cooperation between government and non-government sectors is also recommended for successful implementations of small-scale, decentralized and cost-effective practice of RWHM at individual/community levels.
 
The monthly average ET o variations during the year in KSA  
Relationship between the average annual ET o (mm day −1 ) as related to station latitudes. Notice that no trend found to show  
Relationship between the average annual ET o (mm day −1 ) as related to station longitudes.  
Time variation of the average, maximum and minimum ET o for the study period
Contour plots of Kendall Z statistic for the average monthly ET o trend in various months during the past 29 years  
Article
Problem statement: Climate variability is receiving much attention recently because it has significant effects on water resources and therefore on the livelihood of society especially in water scarce countries such the Kingdom of Saudi Arabia (KSA). Approach: The aim of this study was to explore changes in the reference evapotranspiration (ET o) using data from 27 weather stations through years 1980-2008 and to identify trend directions in the ET o as an indicator to climate variability in the region. ET o was calculated using FAO-56 Penman Monteith method and trends analyses were performed with non-parametric statistics proposed by Mann-Kendall and Sen slope estimator. Results: Results indicated that the average ET o varied from 5 mm day -1 in January to more than 15 mm day -1 in July with extreme average values ranged from 4 mm day -1 in January to 18 mm day -1 in July. The trend analyses indicated that the average annual maximum and minimum daily ET o steadily increased over the study period. The ET o annual daily average had increased from about 9.6 mm day -1 in 1980 to 10.5 mm day -1 in 2008. Trend analysis with Mann-Kendall and Sen Slope gave consistent results and were able to detect trend direction and its significant level for each month and for each station. In general, most of stations showed an increasing trend especially in the Northern parts of KSA and along the longitudinal line of 45°. 'Yenbo' station showed a significant increasing trend in ET o for the entire year. The increasing trends prevailed during most of the year except in the winter months from October to January. Even during these winter months, significant decreasing trends were observed for only four stations. Conclusion: It is recommended to perform similar studies on other parts of the Arabian Peninsula using wider databases, and to consider the increasing trend of ET o in the planning for agricultural and water resources projects.
 
Article
Problem statement: This research assesses the direct effects of urban expansion on land cover/use, river flow, water quality and the indirect effects of these variables in the rate of gastrointestinal disease in people in Arequipa, Peru through the combined use of satellite remote sensing and geographic information systems. Approach: It also uses information about demographic changes, hydrologic data and land cover change in the Arequipa region for the last 17 years. The goal is to understand the relationship between urbanization, water quality in the Chili River and incidence of gastrointestinal diseases. Results: Landsat imagery was used to determine this relationship and to extrapolate business as usual trends into the future ten years from now. Results indicate that there has been notable urban growth and a loss in volcanic material land and cropland between 1990 and 2007, as new urban developments have appeared in these areas. The population expansion over volcanically active area is particularly troubling since it poses a potential human health risk. We also model a business as usual scenario out to the year 2020, which shows continued loss of these land use types and serves as a warning for land managers to consider alternate policies. Conclusion/Recommendations: The analysis also shows a direct correlation between urbanization with the decrease of water quality and the increase in the incidence of gastrointestinal diseases.
 
Article
Problem statement: This research assesses the direct effects of urban expansion on land cover/use, river flow, water quality and the indirect effects of these variables in the rate of gastrointestinal disease in people in Arequipa, Peru through the combined use of satellite remote sensing and geographic information systems. Approach: It also uses information about demographic changes, hydrologic data and land cover change in the Arequipa region for the last 17 years. The goal is to understand the relationship between urbanization, water quality in the Chili River and incidence of gastrointestinal diseases. Results: Landsat imagery was used to determine this relationship and to extrapolate business as usual trends into the future ten years from now. Results indicate that there has been notable urban growth and a loss in volcanic material land and cropland between 1990 and 2007, as new urban developments have appeared in these areas. The population expansion over volcanically active area is particularly troubling since it poses a potential human health risk. We also model a business as usual scenario out to the year 2020, which shows continued loss of these land use types and serves as a warning for land managers to consider alternate policies. Conclusion/Recommendations: The analysis also shows a direct correlation between urbanization with the decrease of water quality and the increase in the incidence of gastrointestinal diseases.
 
Article
The actual quantity of Soil Organic Carbon (SOC) stored in wetlands can only be estimated within a broad range of uncertainty. An accurate assessment of the size and distribution of the SOC storages in wetland resources is very difficult to obtain, therefore, the proposed research objective is to measure SOC storage and its pool on wetland soils of Arial beel in Bangladesh. Initial results of Arial beel soil profiles indicates SOC concentrations are high in surface soils ranges from 1.67 to 1.95% but its concentrations are decreasing with depth whereas SOC stock in kg C m 2 is increased with depth due to increse soil bulk density with depth. However, carbon in deeper layers may be more stable than that in surface soils due to difference in source, composition and environmental conditions. Soil organic C stored in the three different locations of wetlands soils to 1 m depth such as 16.47, 18.27 and 17.22 kg C m 2 , respectively with an average of 17.32 kg C m 2. On the other hand, SOC stored in upland soils to 1m depth such as 11.24 kg C m 2 , significantly less than the wetland soils, which indicates that wetland soils serve as a major source of SOC. However, this SOC act as a conditioner to enhance fertility status while combating with climatic extremes, not only that it is a vital component of soil with important effects on the functioning of terrestial ecosystems. For SOC pool, different extraction methods are used such as, highly labile fraction of SOC extracted with hot water (about 3-8% of toal SOC), water soluble fraction of SOC extracted with water (about 1% of total SOC), labile fraction is extracted using CaCl2 (about 1% of total SOC), moderately labile fraction extracted by pyrophosphate (about 4-10% of total SOC), polyaromatic SOC is extracted using toluene + methanol (trace amount of total SOC), microbial biomass C extracted by K2SO4 (about 2-5%) and the resistant fraction remaining after extraction. However, the SOC concentration is high in surface layer but with depth concentration decreases. In addition, soil bulk density and thickness values increase with depth, as a result deeper layers stored more carbon than surface layer in Arial beel soils. There is increasing evidence from the results that wetlands have an important and underestimated role in carbon storage and its pool the regualation of greenhouse gas emission. Some types of wetlands play a particularly key role as C stores, these include forested wetlands and vegetated inter-tidal wetlands and hence, Sundarban mangrove forest and Tengarchar SOC stocks and pools measurement are an urgent issue for the Climate Change researchers and policy makers.
 
Article
A study was conducted to determine the organic carbon fractions in the vertical sections of a benchmark wetland soil of Bangladesh (Arial Beel) and their dynamics that directly affect the biogeochemistry of soil, water and plant biomass ecosystem. Two distinctive soil series viz. Sara and Arial are characterized such as pH, moisture content, textural class, CEC, organic carbon (SOC), bulk density and total organic matter etc. Different extraction methods were used for the fractionation of dissolved organic carbon such as water-soluble Fraction (WSC), hot water extractable fraction (HWC; 80°C), labile fraction (CaCl 2-extractable; LF), moderately labile fraction (Pyrophosphate-extractable; MLF), polyaromatic fraction (toluene + methanol extractable), Microbial Biomass C Fraction (MBF) and the remaining Resistant Fraction (RF). The total organic carbon content ranges from 0.72 to 1.95%; surface horizons had higher C than underneath horizons and prolonged inundation increased the C content mostly. Higher CEC of the soils had a positive correlation to HWC, MBC and RF. The DOC content particularly MLF was found higher in surface and substratum than subsurface horizons in most of the soils. The HWC and ML fraction had highly significant (p<0.01) effect to increase the MBC. Resistant Fraction (RF) was the most prominent SOC fraction of the soils. The substratum of all the Arial soils had a significant amount of organic C storage (>1%) which is relatively resistant to further degradation and might be considered as sequestered C. Short inundated period and scope of winter Robi crops might have caused Sara soil to have relatively lower organic C and RF than Arial. Moreover, the amount of DOC fractions in Sara series was lower and that decreased with depth but in Arial series, fractions varied within the profile.
 
Article
Time series analysis and forecasting has become a major tool in many applications in air pollution and environmental management fields. Among the most effective approaches for analyzing time series data is the model introduced by Box and Jenkins. In this study, we used Box-Jenkins methodology to build Autoregressive Integrated Moving Average (ARIMA) model on the average of monthly ozone data taken from three monitoring stations in Klang Valley for the period of 2000 to 2010 with a total of 132 readings. Result shows that ARIMA (1,0,0)(0,1,1)12 model was successfully applied to predict the long terms trend of ozone concentrations in Klang Valley. The model performance has been evaluated on the basis of certain commonly used statistical measures. The overall model performance is found to be quite satisfactory as indicated by the values of Root Mean Squared Error, Mean Absolute Percentage Error and Normalized Bayesian Information Criteria. The finding of a statistically significant upward trend of future ozone concentrations is a concern for human health in Klang Valley since over the last decade, ozone appears a one of the main pollutant of concern in Malaysia.
 
The study area around ATPP as identified by GPM model and the locations of each sampling point (The dimensions of the two parts are not the same)  
Activity concentrations (Bq Kg −1 ) of 226 Ra, 232 Th and 40 K of surface soil samples around from ATPP 
The percentage of 226 Ra, 232 Th and 40 K of the total gamma activity of the soil samples  
The location of the pond in the north of ATPP and the location of soil samples around the pond  
The effective doses for infants, children and adults in mSv yr −1 due to the total ingestions of water samples which were collected from wells quite close to ATPP  
Data
The natural radioactivity level of heavy oil, ash and soil samples around Assiut Thermal Power Plant (ATPP) in Egypt was determined using gamma ray spectrometry. The average concentrations of 226 Ra, 232 Th and 40 K in fly ash were found to be 2307±143, 1281±80 and 1218±129 Bq kg −1 , respectively, while the corresponding values in soil samples were 2670±107, 1401±78 and 1495±100 Bq kg −1 , respectively. These are extremely high and higher by several orders of magnitude than the worldwide population-weighted average values in soil. The radium equivalent activity, the air absorbed dose rate, external hazard index and the annual effective dose rate were calculated and compared with the international recommended values. All averages of these parameters are much higher by several orders of magnitude than the international recommended values, indicating significant radiological health hazards around ATPP due to the radionuclides in the soil. Moreover, the water samples investigated have high activity concentrations indicating that the water is highly contaminated with radioactive materials. The results of the current study highlight the severity of this radioactive pollution on the population in the vicinity of ATPP.
 
Map of sampling sites in Zanzibar Urban-West Region  
Comparison of As and Be values to maximum allowed limits (USA EPA, 2009) and (WHO, 2008)  
Proportions (percentage occurrences) of the measured water samples' parameters
Article
The occurrence of carcinogenic and heavy metals in groundwater sources in Urban-west region of Zanzibar Island is an issue that is not very well known. This could be also coupled with the absence of drinking water treatment plants. This study for the first time reports on the occurrence and the levels of three carcinogenic metals-Arsenic (As), Beryllium (Be) and lead (Pb) in thirty groundwater samples collected from Zanzibar's Urban/West region. The levels of alkalinity, Magnesium (Mg) and Thallium (Tl) were also determined. The concentrations of As, Be, TI and Pb in the water samples were determined by the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Palintest photometry procedures were used to determine the levels of total alkalinity and magnesium. Be, As, Tl and Pb were not detected (nd) in some water samples. The ranges of concentrations of Be, As, TI and Pb in the samples were; nd to 6100 ng L-1, nd to 6600 ng L-1, nd to 11600 ng L-1 and nd to 31400 ng L-1 respectively. The levels of total alkalinity varied from 38 to 380 (mg L-1 as CaCO3). The proportions of water samples contaminated with Be, Tl, As and Pb were 43.3, 66.7, 70 and 96.7% respectively. About 23% of the water samples had Pb concentrations beyond WHO limits for safe drinking water, while 30 and 56.67% of the samples had Be and Tl concentrations beyond the US EPA's maximum limits. The concentration of arsenic in each water sample was within WHO limits. The occurrence and the levels of carcinogenic metals in water sources could be a potential cause of cancer cases in Zanzibar. Therefore, prompt action is required to control the levels of these hazardous metals, and other possible contaminants in Zanzibar's domestic water systems.
 
Article
Problem statement: The South and South East Asian countries are characterized by their rich biodiversity as well as cultural diversity. Agricultural expansion for livelihood security is leading to an increase in pesticide application in this region. It has been observed that because of the hot and humid conditions prevalent in this region, most farmers and pesticide applicators do not use proper protective gear, thereby exposing themselves to the hazards of pesticide poisoning. Another important issue is the exposure of infants and children to toxic pesticides, especially in congested urban slums and tenements. Approach: The biodiversity contained in the six biodiversity hotspots located in this region was also at considerable risk from the toxic effects of pesticides from agricultural fields as well as plantations of tea, coffee, rubber, oil palm, which were often present in close proximity of protected areas. Though a large number of countries in this region had ratified and/or signed important international conventions on pesticide manufacture, export-import and trans boundary movements such as the Stockholm, the Rotterdam and the Basel conventions. Results: A large number of hazardous pesticides was still in use in this region and require to be phased out. Information was lacking on the use status of several pesticides in smaller countries, thereby retaining a certain amount of ambiguity. Conclusion: Despite the grave nature of the pesticide use regulation issue in the Asia-Pacific, clear and uniform policy response is lacking in most countries of this region. These issues need to be addressed through dialogues and mutual cooperation both at national as well as international levels.
 
Top-cited authors
Lawrence Duffy
  • University of Alaska Fairbanks
Mahmoud M. Smadi
  • Jordan University of Science and Technology
Mohd. Ikhwan Toriman
  • Universiti Sultan Zainal Abidin | UniSZA
Awonusi Julius Awomeso
  • University of Agriculture, Abeokuta
Adewale Matthew Taiwo
  • University of Birmingham