Description: Publication date: Available online 11 November 2014 Source: Water Science Author(s): Zeinab El-Fakharany , Akram Fekry Nile valley quaternary aquifer is in direct hydraulic interaction with Nile River, canals and drains. Therefore, implementation of new Esna barrage leads to enhancement of seepage flow from Nile River toward adjacent agricultural lands, impedance of drainage conditions and increase in the shallow groundwater levels beneath buildings in urban areas. Therefore, Esna city was selected as the study area to assess the impact of the barrage effect on groundwater aquifer and to propose mitigation measures. The most powerful method for studying the problem is developing a groundwater model based on monitored groundwater levels and simulating the effect of the proposed measures. Results indicated that Nile River in reaches upstream the barrage feeds the aquifer. Then, a model is used to test the effect of the mitigation measures on the surrounding settlements. Results also indicated that using cut off drains with depth of 2.5 m is the most effective and safe solution, in terms of direct impact on the buildings without need for operation cost – only maintenance cost will be needed. Also, implementing a sewage network in the city as a long-term solution is recommended.

Description: Publication date: Available online 1 April 2015 Source: Water Science Author(s): Abdel Razik A. Zidan , Mahmoud M. El-Gamal , Ahmed Ali Rashed , Mohamed Ahmed Abd El-Hady Eid Wastewater treatment through horizontal subsurface flow (HSSF) constructed wetlands (CWs) using three different treatment media (gravel, pieces of plastic pipes, and shredded tire rubber chips) were investigated in Samaha village, Dakahliya, Egypt. The study focused on the wetland setup stage during the first months of its operation (setup stage). In this stage media porosity, bacterial biofilm, and plant roots growth were in progress and it was prior to the operational steady state stage. Objectives of this paper are to study the change in media porosity of HSSF wetland cells in order to estimate duration of wetland setup stage, and to evaluate the use of different bed media on biological oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS) treatment. The results showed that after 180 days of operation, the wetland cells had reached steady porosity and had started stable treatment. Also performance of plastic media bed in pollutants reduction was better than gravel and rubber beds and gravel media was in advanced than rubber media.

Description: Publication date: Available online 13 August 2015 Source: Water Science Author(s): C.M. Pilgrim, E.A. Mikhailova, C.J. Post, J.J. Hains, S.K. Cox Spatial and temporal land cover changes can reduce or accelerate lake sedimentation. This study was conducted to examine morphometry and bathymetry, and the long-term changes (over 75 years) in sedimentation in the Lake Issaqueena reservoir, South Carolina. The watershed and catchment areas were delineated using Light Detection and Ranging (LiDAR) based data. Trends in lake surface area and riparian buffer condition (vegetated or unvegetated) were determined from historical aerial photography. From 1938 to 2009, the lake experienced a decrease in surface area of approximately 11.33 ha while catchment area increased by 6.99 ha, and lake volume decreased by 320,800.00 m 3 . Lake surface area decreased in years corresponding to equal coverage or largely unvegetated riparian buffers. Surface area and average annual precipitation were not correlated; therefore other factors such as soil type, riparian buffer condition and changes in land use likely contributed to sedimentation. Shift from agricultural land to forestland in this watershed resulted in a decrease in sedimentation rates by 88.28%.

Description: Publication date: Available online 16 October 2014 Source: Water Science Author(s): Hanan S. Abd El-Gawad In this study, the detergent's concentrations in aquatic environment principally drinking and surface water along River Nile and near rural village were determined to report the influence of different physicochemical characteristics on the distribution of linear alkylbenzene sulfonate (LAS) that lead to toxicity in human beings. The removal efficiency of LAS using zeolite and granular activated carbon technique was assessed. The results showed wide variations observed between surface (0.07–0.38 mg LAS/l) and bottom water (0.05–0.17 mg LAS/l) due to increase in population density and human activities that recorded highest concentration along rural area (surface: 1.24–2.45 and bottom: 0.93–1.083 mg LAS/l). Low concentration of surfactants was found in drinking water (0.005–0.007 mg LAS/l) compared to the concentration of the corresponding water samples along the River Nile. In conclusion, the study indicated that the treatment processes for drinking water production were insufficient for the complete removal of surfactants and adsorption process by using zeolite as low cost, most beneficial, economically feasible method as well as easy to operate for producing high quality of water.

Description: Publication date: Available online 1 October 2014 Source: Water Science Author(s): Ibrahim H. Elsokkary , Alaa F. Abukila The objectives of this study were to explore the effect of irrigation by treated wastewater (TWW) on some chemical characteristics of cultivated lacustrine and calcareous soils, the growth and macronutrients contents of soybean, corn, faba bean and wheat; and the chemical composition and quality of drainage waters from these soils. For this, greenhouse experiments, using PVC tank of 50 kg soil capacity were carried out. The soils were irrigated by FW, TWW or 1:1 FW/TWW. The results suggest that tested plants can be irrigated with reused water since visual damage is minimal, which seems to be related to the plant's low accumulation of saline ions. The dilution of TWW with FW reduced the negative effects observed. The results have also shown a significant increase in the concentration of EC and in the counts of TC and FC in soils of the upper layer (0–20 cm) than in those of the lower layer (20–40 cm).

Description: Publication date: Available online 16 July 2016 Source: Water Science Author(s): Sahar Salim Kamrakji, Abdel-Wahab Mohamed Amer, Sherif M.A. El-Didy, Ahmed Mohamed Tawfik In arid and semi-arid regions, soil salinity is a common problem threatening fertility of irrigated lands. The Lower Euphrates valley in Syria suffers from salt accumulation in soil because of the inappropriate climatic conditions, using the traditional methods in irrigation; flood irrigation. HYDRUS 1-D model was used to simulate water flow, salt transport and root water uptake processes in this area. Data from seventy soil profiles were acquired from the pedological reports obtained from the Ministry of Irrigation in Syria. Representative monthly evapotranspiration (ET 0 ) values in Deir Ez-Zor were taken from the FAO CLIMWAT database. The seventy soil profiles were grouped in fourteen zones distributed over the study area. For each zone, the monthly recharge and its salt concentration was estimated. The model was run for 24-month duration. The results showed increasing in soil salinity and, consequently, increasing in salts load transmitted into groundwater. Accordingly, mitigation measures have been suggested.

Description: Publication date: Available online 16 July 2016 Source: Water Science Author(s): Sumita Rani, Meenal Aggarwal, Mukesh Kumar, Sumit Sharma, Dinesh Kumar Methylene blue (MB) and rhodamine B dyes (RB) were degraded from water using zirconium oxide (ZrO 2 ) and zirconium oxide/graphene composites (ZrO 2 /GR) as photocatalyst. The photocatalytic efficiency was calculated from absorption spectra obtained using UV–visible spectroscopy. It has been observed that photodegradation time as well as photocatalytic efficiency increase with the concentration of catalyst up to a certain limit after which effect was reversed. The degradation was studied as a function of pH also. It was found that photocatalytic efficiency was more in alkaline medium than acidic medium. Degradation of RB takes place at higher value of pH as compared to MB. The degradation time for MB was 1 h using ZrO 2 which get reduced to 32 min using ZrO 2 /GR composite and for RB it reduced to 40 min (using ZrO 2 /GR) from 80 min (ZrO 2 ).

Description: Publication date: Available online 16 July 2016 Source: Water Science Author(s): Md. Bodrud-Doza, A.R.M. Towfiqul Islam, Fahad Ahmed, Samiran Das, Narottam Saha, M. Safiur Rahman This study investigates the groundwater quality in the Faridpur district of central Bangladesh based on preselected 60 sample points. Water evaluation indices and a number of statistical approaches such as multivariate statistics and geostatistics are applied to characterize water quality, which is a major factor for controlling the groundwater quality in term of drinking purposes. The study reveal that EC, TDS, Ca 2+ , total As and Fe values of groundwater samples exceeded Bangladesh and international standards. Ground water quality index (GWQI) exhibited that about 47% of the samples were belonging to good quality water for drinking purposes. The heavy metal pollution index (HPI), degree of contamination ( C d ), heavy metal evaluation index (HEI) reveal that most of the samples belong to low level of pollution. However, C d provide better alternative than other indices. Principle component analysis (PCA) suggests that groundwater quality is mainly related to geogenic (rock–water interaction) and anthropogenic source (agrogenic and domestic sewage) in the study area. Subsequently, the findings of cluster analysis (CA) and correlation matrix (CM) are also consistent with the PCA results. The spatial distributions of groundwater quality parameters are determined by geostatistical modeling. The exponential semivariagram model is validated as the best fitted models for most of the indices values. It is expected that outcomes of the study will provide insights for decision makers taking proper measures for groundwater quality management in central Bangladesh.

Description: Publication date: April 2016 Source: Water Science, Volume 30, Issue 1

Description: Publication date: Available online 17 August 2016 Source: Water Science Author(s): Indu S. Nair, K. Brindha, L. Elango This study aims to use fluoride as an additional indicator for seawater intrusion apart from the known effective geochemical indicators such as EC, TDS, sodium, chloride and bromide. Groundwater in a coastal part of Arani-Koratalaiyar river basin located north of Chennai, Tamil Nadu, India was assessed to determine its suitability for domestic purpose and to delineate the region affected by seawater intrusion. Fluoride concentration in groundwater samples from forty nine locations varied from 0.02 mg/l to 2.9 mg/l with an average of 0.5 mg/l. As per the Bureau of Indian Standards, the permissible range of fluoride in drinking water is 0.6–1.5 mg/l. Fluoride concentration in groundwater of this area exceeds 1.5 mg/l in 6% of the groundwater samples and is below 0.6 mg/l in 74% of the groundwater samples. There is no known geological source for fluoride in this area. Spatial variation in fluoride concentration in groundwater indicates that the coastal areas have comparatively high fluoride due to seawater intrusion which was similar in comparison with EC and bromide concentration measured in groundwater. This study indicates that fluoride can be used as an indicator of seawater intrusion in coastal areas.