Journal of Water Resource and Protection

In order to study the effect of saw powder on reducing leachate production, accelerating degradation of rubbish, COD and NH₃-N concentration of leachate, three cylinder reactors for anaerobic landfill disposal were built to simulate the operation of landfill. In the experiment, leachate quantity, settling height of rubbish layer, COD and NH₃-N concentration were monitored. The results come from experiment data indicate that saw powder has strong effect on reducing leachate quantity and accelerating degradation of rubbish. In 60 days, saw powder mixed in rubbish layer can reduce 1200-1300 mL leachate every liter rubbish, moreover, rubbish layer saw powder mixed in settled more 5 cm than rubbish layer no saw powder mixed in. The experimental results indicate that saw powder can reduce COD concentration of leachate and adsorp NH₃-N too.

In this paper, a novel method is developed to predict the effect of estrogen on human living cells. This method is based on dynamic measurements coupled with a Michaelis-Menten type of mathematical modeling and parameter estimation procedure. The novelty of this method is the use of dynamic measurements generated by a real-time cell electronic sensor (RT-CES) system and the development of a mathematical model to predict the cell proliferation caused by estrogen stimulation.

Bangladesh has made impressive progress in agriculture sector in the last three decades and has almost be-come self-sufficient in food grain production. This is a tremendous achievement owing to its small territory and huge population and this was achieved through agricultural mechanization and modernization. Irrigation is one of the leading inputs has direct influence to increase yield, food grains production and plays vital role for ensuring food security in Bangladesh. The present study examined the growth of irrigated area and its impact on food grain production during last three decades. Time series data were used for the study. Different statistical methods such as mean, percentage, linear and exponential growth model were applied for get-ting meaningful findings. Various technologies have been used for irrigating crops which have contributed to rapid expansion of irrigated area. The conventional irrigation methods (Low Lift Pump, Dhone, Swing Basket, Treadle Pump etc.) were replaced by modern methods (i.e Deep Tube Well and Shallow Tube Well). In addition, surface water irrigation also sharply declined, losing its importance due to lack of new surface irrigation project and the ineffectiveness of earlier project. Groundwater covered 77 percent of total irrigated area and major (62%) extractions occurred through Shallow Tube Wells (STWs). The rapid expansion of ground water irrigation in respect to STWs irrigation was due to government’s withdrawal on restrictions on tube well setting rule, encouraging private sector and the cost effectiveness of Chinese engine which have been affordable to the small and medium farmers. Irrigated area thus, increased by about three times and cropping intensity also increased from 154 to 176 percent. Boro rice, an irrigated crop, consumed 73 percent of the total crop irrigation and contributed to a greater extent in total rice production in Bangladesh. Boro rice alone contributed to 55 percent of total food grain and was also highest (3.44 MT per hectare) compared to aus rice (1.66 MT per hectare) and aman rice (1.99 MT per hectare) per unit production. Consequently, the cultivated area of boro rice increased by 1168 to 4068 thousand hectares. The higher productivity of boro rice has almost helped the nation to meet her food requirements (about 24 Million MT). Boro rice production was highly correlated (r = .978) with irrigated area. Expansion of one hectare of irrigated area added 3.22 MT of boro rice in Bangladesh. Finally, the study suggested for expansion of irrigated areas (ground water and surface water), adoption of modern technologies and formulation of farmers’ friendly policy.

At Kuwana illegal dumping site in Japan, where hazardous waste was illegally dumped, groundwater was severely contaminated by Volatile Organic Compounds (VOCs). Groundwater was already remedied by conducting Pump-and-Treat (P&T) after containment of all the waste by vertical slurry walls from 2002 to 2007. However, 1,4-dioxane was detected in both waste and groundwater outside of slurry walls after it was newly added into Japan environmental standards in late 2009, which suggested that the walls did not contain 1,4-dioxane completely. Our previous study developed a model to predict the 1,4-dioxane distribution in groundwater after the previous remediation at the site. In this study, numerical simulation was applied for remediation planning at the site based on the concept of Verified Follow Up (VF-UP) that had been proposed as a new approach to complete remediation effectively with consideration of future risks. The amount of waste to be removed and pumping plans were discussed by numerical simulation to achieve the remedial objective in which 1,4-dioxane in groundwater outside of walls is remedied within 10 years and 1,4-dioxane spreading throughout the walls is prevented in the case where a portion of waste is remained. Firstly, the amount of waste to be removed considering pumping plans for P&T was determined by scenario analysis. As a result, at least two-third of waste should be removed by combining with P&T. However, if the waste is remained, future risks of 1,4-dioxane spreading through the slurry walls may occur. Our simulation suggested that groundwater within the remaining waste must be pumped up at least 20 m3/d for containment of 1,4-dioxane within the remaining waste. In conclusion, our numerical simulation determined the amount of waste to be removed and the pumping plans for P&T to achieve the remedial objective effectively considering future risks based on the concept of VF-UP.

The aim of this work was to evaluate the sunflower stalk (SS) as an adsorbent in the removal of red acid 114 (AR 114) and basic blue 3 (BB 3) in aqueous solutions, without any physicochemical treatment, where temperature and concentration were the studied variables. The research was developed by using the batch processing mode; the contact time was one hour, with constant agitation of 200 rpm and pH of 7000 ± 0.050, using a central composite design. The adsorbent was characterized through BET, SEM, acid sites and basic sites, charging point, and infrared. The results indicated that the sunflower stalk was a viable and economical alternative for the removal of water that had been contaminated by dyes, showing a better performance for the AR 114 dye, reaching a 71.96% of removal with respect to the initial load. In addition, the EPI Web software was used to model the environmental performance of colorants.

Salmonella is one of the major pathogenic bacteria present in contaminated water. 16-23S rRNA spacer region has been reported to be polymorphic at serovar level in Salmonella. Salmonella isolates obtained from Ganges river water were studied for 16-23S rRNA spacer region polymorphism. Thirty three isolates belonging to eight serovars (S. Typhimurium, S. Abuja, S. Pantypridd, S. Lagos, S. Chinkual, S. Zwickau, S. Goldenberg and S. Oritamerin) were studied for the polymorphism. Out of 33 isolates, 15 different profiles were observed no serovar specific profile. Our findings indicate that 16-23S rRNA spacer region is not specific at serovar level, but can be used for differentiation of different Salmonella isolates.

Wetland ecosystems are one of the most vulnerable worldwide and they require careful management strategies for future conservation. Studies on the size and changes in species composition for wetlands in South Africa over time are very limited. This study was undertaken to provide quantitative data using a range of techniques. Remote sensing has become popular in assisting the development of these management plans due to its spatiotemporal advantages and easily reproducible vegetation and land cover maps. The Wakkerstroom wetland was examined using aerial photography to examine possible changes in extent and Landsat imaging was used to map its vegetation communities. In order to assess the distribution of vegetation types on Wakkerstroom wetland in situ recording of vegetation types and their GPS coordinates was conducted and a Random Forest model was used to extract spectra from Landsat images for each vegetation type at the in situ co-ordinates. In situ sampling occurred once in the dry season and four remote sensing images were acquired – two each from Landsat 5 Thematic Mapper (TM) and Landsat 8 Operation Land Manager (OLI). The Wakkerstroom wetland has increased in extent by 0.483km2 from 1938 to 2009 (3.769 km2 - 4.252 km2). The P. australis population density increased significantly over time (r = 0.89), whereas the T. capensis population density had a strong negative correlation over time (r = -0.70). A strong negative relationship between P. australis and T. capensis existed (r= -0.88). The plant community classifications were interpreted with limited accuracy due to reflectance overlap and not attempting the model with other sensors of varying spatial and spectral resolutions. A need exists to introduce a management tool that will create a greater mosaic of vegetation communities thus ensuring a greater bird, reptile and amphibian diversity. The Wakkerstroom wetland plays a valuable role in providing ecosystem services to the community. Although it has increased in size it may now be at threat due to a proposed construction of a water pipeline which will destroy the integrity of the wetland and the water supply into the wetland.

Sediment yield dynamics on the Edwards Plateau region of Texas were dramatically influenced by a multi-year drought that occurred there during the 1950s. To assess the effect of this drought on sediment yield, we used the Soil and Water Assessment Tool (SWAT) to identify the factors that contributed erosion and to propose potential mitigation measures in case of future drought recurrence. The basins of interest to this study were Brady Creek one (BC 1) and Deep Creek three (DC 3), located in McCulloch County, Texas. Although the streams in these basins are not gauged, the land cover and reservoir sediment budgets have been assessed in a past study. Calibration of SWAT flow simulation was accomplished using parameter transfer from a gauging station located in San Saba River. The results showed that sediment yield from storms above 60 mm were five times more during and immediately after drought period than during continuous wet seasons. Approximately half of the total drought period sediment yield was from five major rainstorms. The multi-year drought coupled with historical high grazing intensity resulted in significant loss of plant cover, which is considered critical in determining erosion and sedimentation rates. To test this hypothesis, the model was run for the periods of high land cover (1990s) using the1950s multi-year drought data that showed sediment yield was 24% of that simulated for 1950s land cover. It was concluded that maintenance of surface cover could play a critical role associated with multi-year drought extreme events.

The CIEH piezometer, located in the center of Ouagadougou city presents a water level record spanning the West African Drought which peaked during the 80s and 90s. Its water level is investigated as a potential proxy for groundwater water re-sources in West African basement rock aquifers submitted to climate changes. 23 boreholes and wells in various land uses and within a 2 km radius around the CIEH piezometer were monitored during the 2013-2014 hydrologic year. The minimum water level occurred in May, at the end of the dry season, while the maximum took place in October, one month after the end of the rainy season. The mean water level amplitude is 3 m, the minimum amplitude being reached at the CIEH piezometer (0.76 m). Moreover, the CIEH piezometer is located in a 2 m am-plitude water table depression either in May and in October. Simplified 2d model-ing using a general basement aquifer structure shows that (i) the water level in the piezometer is under ongoing influence of the spillway raise of the nearby dam#3 lake in 2002, (ii) the whole 1978-2004 period cannot be modelled with constant parameters. A 3% decrease of water uptake is adopted after 1985, presumably re-sulting from land use changes in the Ouagadougou city. The water table at the CIEH piezometer is presently at its 1978 level, which can considered as a pre-drought value. However this includes a 1.5 m contribution of the two above-mentioned anthropic effects Further quantitative interpretations of the CIEH pie-zometer record will require additional geophysical and hydrological investiga-tions.

On the Cavally River, located on the border between Côte d’Ivoire and Liberia,several hydraulic structures such as bridges and diversion channels are planned to be made in recent years in the operating perimeter of the Ity mining company. A 1D-2D hydraulic model was developed to design a diversion channel to cut a meander of the Cavally River in order to ensure hydraulic operation similar to the initial conditions of the river (water levels, flow and velocities). This model was designed with a flow rate of 240 m3/s and a Manning coefficient of 0.052 m1/3.S−1 for the minor bed and 0.06 m1/3.S-1 for the major bed. The results from the hydraulic model show that the hydraulic conditions (water levels, velocities) in the channel before and after the diversion remain almost like those of the Cavally River.

Drought has been analyzed by various indices based on rainfall, temperature, evapotranspiration or soil moisture data. Remoste-sensing based data has spatial continuity with certain resolution and is useful for drought monitor. The purpose of this study was to investigate quality used of grid relative soil moisture, the spatial and temporal variation of soi moisture, and soil moisture drought based on relative soil moisture over China during 2008-2016. The results show that the relative soil moisture data set can reflect the spatial characteristics of the development of drought in China during 2008-2016. From the spatial distribution analysis, the northwest to northeast, south part of China, and other major arid areas, the performance is particularly evident. The results show that the use of CLDAS V1.0 real-time products, access to time and space continuous soil relative humidity products, can achieve the drought in China real-time monitoring

Due climatic variability and anthropogenic changes, floods have been raised lately in several regions world-wide. The resulting impact from floods is often harmful. This can be applied to Saudi Arabia, the country which is known by dry climatic conditions, and it became lately a typical region for such natural hazard. Hence, floods are observed as a yearly disaster with high magnitude of influence. Jeddah, a coastal Saudi city on the Red Sea to the west, has witnessed severe event in November 2009, when flooded water and sediments (torrents) invaded the urban areas and resulted decease of many people and destroyed the infra-structure and civilized zones. The lack of mitigation implements exacerbated the problem. This study implies an assessment of flood hazard risk in Jeddah region. It aims to identify the zones subjected to flood and then inducing the influencing factors at different levels of effect. For this purpose space techniques were utilized, with a focus on IKONOS satellite images, which are characterized by high resolution in identifying terrain features. In addition Geographic Information System (GIS) was also used to support space techniques. Thus, damaged areas and the mechanism of flooding process were recognized. This helps avoiding further urban expansion in areas under flood risk and will aid decision maker to put new strategies for hazard management.

Radium isotopes can be analyzed by different analytical methods based on gamma spectrometric measurements or alpha spectrometry. An improved method was developed to determine radium isotopes from water using gamma spectrometry after radiochemical separation. The Radium was selectively extracted from acidified samples using co-precipitation procedure with iron hydroxide and followed by precipitation of radium as radium sulphate Ba(Ra)SO4. The precipitate Ba(Ra)SO4 was filtered through the Millipore filter paper, dried and weighed to calculate chemical yield. 226Ra and 228Ra activities were measured using low-background gamma spectrometry in water samples. Radium was pre-concentrated from environmental samples by co-precipitation with BaSO4. The amounts of 226Ra and 228Ra on the sample were obtained by gamma-ray spectrometry for the 351 keVγ-ray from 214Pb and for the 911 keV γ-ray from 228Ac, both in radioactive equilibrium with precursors, respectively. The accuracy, selectivity, traceability, applicability and Minimum Detectable Activity (MDA) of the technique were discussed. Also, the effect of physical and chemical characteristics of the water samples such as TDS, pH, soluble species, sulphate and bicarbonate that effect on the radium determination were taking into consideration. The method has been validated with a certified reference material supplied by the International Atomic Energy Agency and reliable results were obtained. The radiochemical yields for radium were 70% - 90% and recovery was 97% and 80% for 226Ra and 228Ra, respectively.

Groundwater is vital to the sustenance and well-being of man-kind, although it is constantly under immense pressure. For this reason, there is need to develop an effective, reliable, scientific and sustainable means of delineating zones of groundwater occurrence and distribution with high precision in other to effectively explore for this resource. In this study, remote sensing (RS) and geographical information system (GIS) have been combined to de- velop thematic maps of the zones of groundwater occurrence and distribution based on variable factors such as; elevation, drainage, lineament, slope, lithology and soil. The analytical hierarchy procedure (AHP) was employed to classify and subsequently assign weight to each variable factor through weighted overlay analysis. Integration of these factors with their relative classes defined was used to produce a 2D-model for predicting surface aquifers mapped within Obubra. The study delineated three (3) surface aquifer zones representing groundwater potential zones. Zones representing high groundwater potential cover an area of approximately 331.94 Km2, accounting for 29.58% of the study area. The region that represents moderate to good groundwater occurrence and distribution covers an estimated area of approximately 648.42 Km2,occupying 57.78% of the study area. Zones with groundwater of low potential account for a total surface area of approximately 141.81 Km2 which is about 12.64% of the entire study area. Regions that show good to moderate and high groundwater potentials, have a wider distribution all across the study area except at the southernmost part. The study therefore shows that it is effective in delineating surface potential zones and hitherto a 2D surface aquifer model for groundwater exploration campaigns within Obubra and its environs.

The proper characterization of coastal aquifers requires modeling variable density flow effects. However, most models estimate processes as saline intrusion based on 2D models with constant density and are rarely calibrated to honor salinity measurements. These facts limit the model predictions reliability, affecting the estimated hydrodynamic parameters, external stresses, and other model outputs that can be critical for planning or management decisions. This paper describes the re-assessment of a coastal aquifer model (Oropesa-Torreblanca, eastern Spain) subjected to moderate-to-high saline intrusion with a transient 3D variable density flow model. Previous models were based on 2D low-resolution grids without variable density effects. The new model honors the observed trends of both piezometric and salinity data. Results show the importance of the variable density effects having on critical outputs as sea intrusion and the discharges to a local wetland of high environmental value. The widespread intrusion process and its current stabilization are confirmed but, compared to previous models, the annual average intrusion is 156% higher, discharge to the wetland increases 30%, and the inflows from neighboring formations increase 22%. The more accurate aquifer models, as well as the new discharges and intrusion estimations, are important contributions for future water and environmental planning decisions in the area.

The objective of this study was to evaluate the performance of anaerobic digestion (AD) within the intermediate zone, specifically at 45oC. Single-stage batch anaerobic digestion system was developed in the lab and performance was monitored for more than 2 years. The AD system was able to achieve high biogas production with about 62 - 67% methane content. The digester exhibited high acetate accumulation, but sufficient buffering capacity was observed as the pH, alkalinity and volatile fatty acids-to-alkalinity ratio were within recommended values. The system achieved 36.5% reduction of total solids (TS) and 47.8% reduction of volatile solids (VS), which exceed the required VS destruction efficiency for Class A biosolids. The pathogen counts were less than 1,000 MPN/g total solids in the effluent, which also satisfied Class A biosolids requirements. The accumulation of acetate was presumably due to the high temperature which contributed to high hydrolysis rate. Consequently, it produced large amount of toxic salts that combined with the acetate, making them not readily available to be consumed by methanogens. The slower degradation of acetate was observed by the kinetic parameters. Accumulation of acetate contributed to 52 to 71% reduction in acetate degradation process, but was not completely inhibitory. The methanogens existing in the system were mostly thermo-tolerant acetate-utilizing methanogens, and specifically from Methanosarcinaceae species.

Based on agricultural nitrogen (N) balance model and field experiments, the impacts of farming system changes of Taihu Region of China on surface water environment were studied. During past 60 years, farming systems changed greatly in Taihu Region. The traditional method of manure collection and application was replaced by chemical fertilizer utilization gradually. Chemical N fertilization intensity decreased greatly due to the abolition of “3 crops per year” and reduction of cropland area in 1990-2010. Crops depleting soil fertility increased, while those improving soil fertility decreased, leading to an excessive dependence on chemical fertilizer application, which increased the risks of soil N loss to surface water environment in Taihu region. However, field experiments showed that the agricultural N loss with runoff only accounted for 2% of fertilizer N application rate. The majority of N was exported by crop harvesting. Our findings showed that the agricultural N loss might not be the main source of N pollution in Lake Tai after 2000. To control N pollution of Lake Tai, more attention should be paid to industrial and domestic wastewater from urban and rural areas, wastes from livestock and poultry breeding, bait input for aquaculture, etc in the Taihu Region, China.

The Aydar Arnasay Lakes System (AALS) is an artificial lake system which was created in 1969 by diverting flood water from Chardarya reservoir. It has developed into a wetland of 4000 km 2 area recognized by the Ramsar Convention as of global importance. It is not only a refuge for birds and wildlife but also has seen the emergence of fishery and tourism since. Understanding of its behavior with respect to the quantitative and qualitative aspects of water resources is important for future use and management, especially for further development of fishery and ecotourism. The factors influencing changes in quantity and quality of ААLS water were studied between 1993 and 2011. Starting from 1993 the water level and water volume of the lake progressively increased. The spatio-temporal distributions of pH, dissolved oxygen, ammonium, nitrite, nitrate, phosphate, chloride, and biochemical oxygen demand (BOD5) during 2003-2005 and 2009-2011 were determined. On the basis of the conducted hydrological and hydro-chemical research fishery development in ААLS is recommended. The question is posed what requirements have to be in met in the future in order to guarantee the prolonged existence of the lake at a suitable water quality.

ABSTRACT Determination of the infiltration rate in a watershed is not easy and in empirical and theoretical point of view, it is important to access average value of infiltration. Infiltration models has main role in managing water sources. Therefore different types of models with various degrees of complexity were developed to reach this aim. Most of the estimating methods of soil infiltration are expensive and time consuming and these methods estimate infiltration with hypothesis of zero slope. One of the conceptual and physical models for estimating soil infiltration is Green-Ampt model which is similar to Richard model. This model uses slope factor in estimating infiltration and this is the power point of Green-Ampt model. In this research the empirical model of Green-Ampt was optimized with integrating artificial neural network model (ANN) and a model of geographical information system WMS to estimate the infiltration in Kakasharaf watershed. Results of the comparison between the output of this method and real value of infiltration in region (through multiple cylinders) showed that this method can estimate the infiltration rate of Kakasharaf watershed with low error and acceptable accuracy (Nash-Sutcliff performance coefficient 0.821, square error 0.216, correlation coefficient 0.905 and model error 0.024).

In abandoned mine sites, i.e., mine sites where mining operations have ended, wide spread contaminations are often evident, but the potential sources and pathways of contamination especially through the subsurface, are difficult to identify due to inadequate and sparse geochemical measurements available. Therefore, it is essential to design and implement a planned monitoring net-work to obtain essential information required for establishing the potential contamination source locations, i.e., waste dumps, tailing dams, pits and possible pathways through the subsurface, and to design a remediation strategy for rehabilitation. This study presents an illustrative application of modeling the flow and transport processes and monitoring network design in a study area hydrogeologically resembling an abandoned mine site in Queensland, Australia. In this preliminary study, the contaminant transport process modeled does not incorporate the reactive geochemistry of the contaminants. The transport process is modeled considering a generic conservative contaminant for the illustrative purpose of showing the potential application of an optimal monitoring design methodology. This study aims to design optimal monitoring network to: 1) minimize the contaminant solute mass estimation error; 2) locate the plume boundary; 3) select the monitoring locations with (potentially) high concentrations. A linked simulation optimization based methodology is utilized for optimal monitoring network design. The methodology is applied utilizing a recently developed software package CARE-GWMND, developed at James Cook University for optimal monitoring network design. Given the complexity of the groundwater systems and the sparsity of pollutant concentration observation data from the field, this software is capable of simulating the groundwater flow and solute transport with spatial interpolation of data from a sparse set of available data, and it utilizes the optimization algorithm to determine optimum locations for implementing monitoring wells.

The reduction of helminth eggs, fecal coliforms and somatic coliphages present in sewage sludge after treatments and abatement by application to soil was determined. Traditional stabilization processes produced small changes in the concentrations of the parameters studied. In contrast, thermal treatments and liming produced dramatic reductions. Fecal coliforms were the most affected by both types of treatments; somatic coliphages showed some persistence after 30 minutes at 60°C; and both somatic coliphages and helminth eggs showed some persistence to storage in quick lime. However, both treatments supplied biosolid suitable for unrestricted application in agriculture. Abatement in soils in the climatic conditions tested (mild to cold temperatures and high relative humidity) was slow and took several months to reach the background levels. These results suggest that environmental conditions (temperature and humidity) play the main role in inactivating the microorganisms, since abatement was similar in different soil types. The extended permanence of pathogens and microbial indicators in soil after the application of treated sludges indicates that, in the normal weather conditions of the areas where the study was performed and the amounts of sludges applied, contaminant microbes are not easily mobilized from the complex matrixes that constitute the treated sludges and that consequently in normal conditions their release as diffuse pollution is of lesser importance.

In this article the potential stoarativity of groundwater in the alluvial deposits along the King Abdullah Canal (KAC) in Deir Alla-Sulikhat area is studied. In this study geological, geo-electrical and Hydro-geochemical methods were used with the aim of storing some water of the Canal during water excess times in the underground to be extracted for use as drinking source for human during shortages in the Canal water and in emergency causes of Canal water pollution. The results show the existence of appropriate underground space in the alluvial deposits for water storage and that the water/ water and water/rock interactions are also be minimal and will not present and detriment to the different groundwater bodies. Implementing groundwater artificial recharge in the Jordan Valley area to create storage for King Abdullah Ca-nal (KAC) water will enhance the drinking water supply during the dry season and it will also serve as a reserve for emergency causes, especially pollution accidents in King Abdullah Canal (KAC), such as those taking place almost every year.

Water samples from streams, hand-dug wells and boreholes in high background radiation areas in Abeokuta, Nigeria have been collected in order to determine the activity concentrations of 40K, 226Ra and 232Th in the samples as well as their physicochemical characteristics. These parameters were evaluated in order to deter-mine the quality of these water sources to the local population, who use these water resources for drinking and domestic activities. Measurements of radioactivity in the water samples were carried out using γ-ray spectroscopy, while standard chemistry methods were used for the physicochemical determinations of these quality parameters. A total of fourteen representative water samples from streams (7), boreholes (4), and hand dug wells (3) were collected for study. The determined activity concentrations of the radionuclides in these samples were used to calculate the effective dose to the population from due to ingestion of and drink-ing the locally available water. The total annual ingestion effective doses were found to vary between 115.00 ± 1.15μSv and 1362.30 ± 438.02 μSv. The physicochemical parameters where found to be lower than the prescribed standard safe limits in the water sources except for the nitrate and phosphate levels which were particularly high in the water samples from boreholes and hand-dug wells. The radiation effective ingestion dose due to ingestion of water from dug wells and streams was found to be higher than the dose due to inges-tion of water from borehole sources in the studied areas. The results obtained in this study, have been taken as a baselines for physicochemical parameters and activity concentrations of natural radionuclides in water samples within Odeda and Obafemi-owode parts of Abeokuta, Nigeria.

The impact of anthropogenic disturbances on water quality parameters, diversity of macrophytes and benthic macro fauna of Abesan River, Lagos, Nigeria is reported. Some physico-chemical and biological assessment were carried out at three sampling stations located at downstream (AR-1), midstream (AR-2) and upstream (AR-3) with different levels of disturbance. Results of measured physico-chemical parameters showed that there was no significant difference (P > 0.05) in temperature, total acidity and chloride values between the sampling stations. Although, Total solids, conductivity, DO, Sulphate, BOD and COD were significantly higher (P < 0.05) at Stn.AR-1 than at Stns. AR-2 and AR-3, all physico-chemical parameters measured were within the limits of the Lagos State Environmental Protection Agency (LASEPA) and the World Health Or-ganization (WHO) regulatory standards except for high COD concentration in downstream station. Aquatic vegetation (macrophyte) diversity was relatively abundant at upstream and downstream stations, suggesting possible impact of human activities on macrophyte diversity at midstream station where highest level of dis-turbance occurred. Chironomid larvae were the most abundant invertebrate fauna found in all three sampling stations but more abundant at sampling station AR-2 which corresponds to point of effluent entry to river where human activities is most intense. There is evidence that anthropogenic activities impact on the water quality of Abesan River. Biotic indices such as Sorensenen's Index of Similarity and Margalef Index show that Abesan River is lightly polluted. The implications of these results and the need to monitor the water quality of Abesan River are highlighted.

This study aims to examine the quality and quantity of the groundwater resources from hand-dug wells, within two of these slums—Anoumabo (Marcory) and Adjouffou (Port-Bouet), both located in the southern part of the city. Twenty-eight representative groundwater samples were collected from different domestic wells within the study area. In addition, water samples were collected from the adjoining surface water bodies—the ebrie lagoon and the Atlantic Ocean. The water samples were also tested for microbial indicators of fecal contamination using the conventional membrane filtration method. The groundwater samples are alkaline to acidic with pH ranging between 4.4 and 8.1. They are slightly mineralized with electrical conductivity, EC values ranging between 388 μS/cm and 1494 μS/cm. The dominant hydrochemical facies are Na-Cl, Na-SO4, Ca-Cl and Ca-SO4. Although, majority of the water samples have anions and cations concentrations conforming to the World Health Organization, alerting levels of nitrate contamination was recorded in the area. About 67 percent of the tested samples have nitrate values greater than the recommended WHO limit for drinking water (NO3 > 50 mg/ι). Exceeding high nitrate concentrations in drinking water have been medically proven to be detrimental to infant health. Microbial analyses reveal bacterial contamination at varying degrees in all of the water wells. The presence of these microbial organisms in the samples is also indicative of the presence of some other disease causing pathogens, responsible for sicknesses like cholera, diarrhea, typhoid, etc. The water wells located within Anoumabo have relatively higher levels of groundwater contaminants in comparison to those located within Adjouffou. This is obviously due to the poor well designs and prevalent unhygienic and poor sanitary habits of its inhabitants. These waters though completely unsuitable for drinking and domestic purposes, can be used for irrigation purposes with very little or no sodium problems.

This research involved attempting to improve water quality at the Abu-Rawash WWTP by using aluminum chloride (AlCl3) as a coagulant combined with injection of carbon dioxide (CO2). The Abu-Rawash WWTP is the main source of water quality degradation at the Rosetta branch, Egypt. Sewage samples were collected from the effluent of the grit removal chamber. Jar tests were performed to estimate the optimum pH value and the coagulant dosage required to obtain acceptable treatment. Eleven samples were prepared with equal dosages of aluminum chloride (10.0 mg/L) and different pH values. The optimal pH values for the elimination of the biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and turbidity ranged from 6.10 to 6.20 for the aluminum chloride. Results indicated that the appropriate AlCl3 dosage was 2.0 mg/L, especially at pH between 6.1 and 6.2. The results also showed that the AlCl3 was cost effective, especially after reducing pH value. It is also more cost effective than the other proposed solutions such as changing the effluent path of the Abu-Rawash WWTP to the desert.

Pueblo Viejo Lagoon is an estuary with restricted communication with the sea, so the freshwater influence tends to be more important. Therefore, the study focused on testing the hypothesis that the seasonal changes in species abundance would be mainly related to the local rainfall pattern. Monthly samplings were carried out over a one-year, using a seine net. A total of 9108 individuals were caught, corresponding to 66 species of fish, most of them with marine origin. Canonical correspondence analysis revealed that the rainfall-salinity gradient was revealed to be the most important driving force in the seasonal variation of fish composition. In this way, it was observed that seasonal fluctuations in total fish number were linked to preceding fluctuations (one month) in local rainfall. Similar pattern was exhibited by the abundance of Anchoa mitchilli (the most abundant species), Oreochromis mossambicus and Ariopsis felis, and this delayed effect was significant (cross-correlation analyses). In addition, the rainfall showed a direct influence (significant positive correlations) on abundance of D. auratus and M. martinica. The association between fish number and the rainfall regime seems to be related to lagoon productivity and the trophic responses of these species. By contrast, Brevoortia gunteri and Menidia beryllina showed an inverse correlation with rainfall. Other environmental variables (also influenced by rainfall regime) showed a significant relationship with A. hepsetus (salinity), B. chrysoura (depth) and M. curema (turbidity). Thus, at least 12 species showed some relationship with local rainfall, which accounted for 81.27% of the total number of fish collected. Although it is difficult to separate the relative importance of physiological tolerances and biological functions such as trophic responses, the results suggest that rainfall is a primary factor governing seasonal variation in fish species abundance of Pueblo Viejo lagoon.

Acacia bark efficiency for disinfecting polluted water for the purpose of using it for drinking purposes was tested. Five polluted water samples were collected from different locations in Jordan, namely, King Abdullah Canal, an Agricultural pond in the Jordan Valley, Yajouz wells, Hazeir spring, and Wadi-Seer spring. Different volumes of the water samples were treated with 10 g of the shredded acacia bark (obtained from Somalia) for different retention times. The volumes used were 1 L, 2.5 L, and 5 L and the detention times were 2, 4, and 24 hours. The samples were tested for total coliform, E. coli, electrical conductivity, pH, total dissolved solids, turbidity and color before and after treatment with the acacia bark. Results revealed that the optimum conditions for disinfec-tion were: 1 L polluted water treated with 10 g acacia bark for 24 hours. Log removals of about 2.5 for E. coli were obtained under these conditions. Higher removals could be achieved by using larger amounts of the acacia bark, but the chemical water quality regarding turbidity and color will not be suitable for drinking purposes and levels of tannic acids present in the acacia bark might reach toxic levels. Toxic levels will not be reached if 1 glass of water/kg body weight every 4-5 hours daily is consumed.

At the present day the United Arab Emirates (UAE) is on the flank of the Arabian plate, but some way away from the major modern earthquake epicentres. It normally experiences only minor earthquakes whose epicentres lie along the suture between the Arabian and Asiatic plates in Iran, the Arabian Gulf and the Gulf of Oman. In March 2002 a series of earthquakes occurred in several areas in the northern UAE, with foci along fault lines within the UAE. What made these earthquakes different from earlier earthquakes was their strength and frequency. For the first time in the area, earthquakes of a magnitude 5.5 (on the Richter scale) occurred, and continued over a period of three days. The causes appear to involve more than fault zone and plate tectonics, and may be related to human activity. Tracing the earth-quakes during the past three decades indicates that the earthquakes followed major groundwater over-pumping, itself a result of population growth, growth in the number of farms and number of bottled water factories.

Water resource access in the Nouhao sub-basin, assessed based on the availa�bility of drinking water mobilization facilities, the availability of water for uses and the quality of drinking water, revealed that in 2017 the basin was covered by 1249 modern water point, main drinking water sources. On aver�age, the sub-basin shows a ratio of 271 users per drinking water point. Com�munal level shows some disparity with Bittou recording the highest number of people per drinking water point, i.e., around 537. Water that can be cap�tured in the entire sub-basin meets only 42% of the total water needs from the three mains uses: irrigation, domestic consumption and livestock. The highest demander among these uses is Irrigation with 75% of the need, i.e., approximately 12,859,995 m3. Water in 33% drinking sources of this sub basin is of poor quality. Arsenic, one of the quality parameters studied, is found in some communes of the sub-basin. 11% of the water points in Bissiga are arsenic polluted making this commune the most arsenic contaminated location. The vulnerability maps deducted from lack of water for uses; lack of drinking water works and poor water quality shows so, the exposure level of the sub-basin’ communes to some potential risks related to low water resources access.

This paper is premised on the hypothesis that the amount of rainfall in Nigeria decreases with increasing distance from the coastal areas to the north semi arid lands. This belief widely held in some circles does not really follow this pattern due to other climatic factors. This paper examined rainfall pattern and its variability in northeastern Nigeria and its impacts on access to water supply. Data on the mean monthly rainfall over a period of 33 years (1970-2002) were collected from the Nigeria Meteorological Agency (NIMET) in Abuja, Nigeria. The result of the analysis indicates that the mean annual rainfall in the study area is not dependent on distance but some other climatic factors such as relief, solar radiation, temperature, winds, and nature of soil among others. Thus, the amount of rainfall received in Taraba and Borno states which are located in the southern most and extreme end of the study area respectively were higher than that of Gombe state which lies in between them.