American Journal of Water Resources

This study aimed at exploring whether product quality, membrane fouling and salt reverse flow would be challenges in forward osmosis (FO) of seawater using NH₄₃as an osmotic agent. Experiments were conducted with a lab scale FO system containing effective membrane area of 95 cm². Synthetic seawater (SSW) with 3.5-7.0 mg/L boron and a real seawater (RSW) were used as feeds and 1.5-2.5 M NH₄₃ as draw solutions. The experimental operation could be stablized within 0.5 h. For the SSW, boron rejection ranged of 47-85% and increased with increasing water flux while boron in the permeate was greater than 0.8mg/L. Water flux with RSW was 3 times lower than that with SSW, indicating that there might be serious membrane fouling with RSW. It was surprisingly observed that non volatile organic in the FO permeate was 8-10 mg/L, which was from the draw solution although NH₄₃used was analytical grade. Additional water cost would be $0.4/m³because of NH₄₃loss. It was concluded that product quality in terms of high TOC contaminant in NH₄₃and low boron removal, serious fouling with RSW and salt reverse flow could be challenges for the FO process using NH₄₃as osmotic agent for seawater desalination.

American Journal of Water Resources. 2013, 1(3), 51-55. DOI: 10.12691/ajwr-1-3-6
Pub. Date: November 20, 2013

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Remote Sensing Based Unravelling of Landcover and Groundwater Scenarios Relationships for the Middle Save Sub Catchment of South Eastern Zimbabwe

by David Chikodzi

Original Research

The impact of landcover/landuse type on the groundwater scenarios has not been investigated extensively in Zimbabwe due to lack of groundwater observation data. The research was aimed at using remote sensing to unravel the groundwater scenarios under different landcover/landuse types in the middle Save catchment of Zimbabwe. The research used the gravity recovery and climate experiment (GRACE) satellite to measure regional groundwater fluctuations from 2004-2010. Landsat satellite images were also used to classify the study area into three landcover/landuse types: grasslands, forests and shrublands. The results showed that grasslands occupy 59% of the land area, forests occupy 22% of the place and shrublands cover19% of the study area. On seasonal groundwater scenarios, areas under forests had the highest magnitude of groundwater recharge (up to 20cm) and also the highest levels of groundwater lose (up to -20cm). Shrublands had recharge levels of up 13cm and loses of about -14cm. Grasslands had the least recharge of about 6cm at peak and the lowest magnitude of groundwater loses of about -7cm. The research also showed that from 2004- 2010 groundwater levels have been in a state of decline in the study area. The research concluded that landcover/landuse affects only seasonal not year on groundwater fluctuations. Geographical information systems and remote sensing were shown to be capable of producing groundwater scenarios of the study area in the absence of systematic ground based groundwater observations.

American Journal of Water Resources. 2013, 1(3), 45-50. DOI: 10.12691/ajwr-1-3-5
Pub. Date: November 13, 2013

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Designated Protected Marsh within Mesopotamia: Water Quality

by Ali Abdul Zahra Douabul, Hamid Talib Al-SAAD, Dawood Salman Abdullah and Nadir Abid Salman

Original Research

This survey was carried out during wet and dry seasons in three stations represent the upper, middle and lower reaches of Huweza Marsh, Southern Iraq. Physical and chemical parameters including the natural water quality parameters such as temperature, pH, salinity, turbidity, electrical conductivity, dissolved oxygen, bicarbonates and total hardness along with nutrients levels were monitored for the period from July 2007 to April 2008. Results showed that water quality parameters of Huweza marsh are all within the standard criteria for freshwater habitats with pronounced seasonal variation between dry and wet seasons. Significant differences were also recorded between upper and lower stations in the marsh which can be attributed to local conditions. In general all parameters are within the tolerance limits of fresh water plants and animals except water salinity which needs to be monitored seasonally and spatially, as variations are noticed between various parts of the marsh and at different seasons. Some recorded levels exceed the normal favorable levels for freshwater fauna and flora. The marsh water is rich in nutrient especially nitrate and phosphate, reflecting high productivity in similar manner to other Iraqi marshes. Results were compared with other studies in the area. The present survey can act as a basis for future monitoring and recovery of the marshland ecosystem.

American Journal of Water Resources. 2013, 1(3), 39-44. DOI: 10.12691/ajwr-1-3-4
Pub. Date: November 13, 2013

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Water Quality Assessment in Terms of Water Quality Index

by Shweta Tyagi, Bhavtosh Sharma, Prashant Singh and Rajendra Dobhal

Review Article

Water quality index (WQI) is valuable and unique rating to depict the overall water quality status in a single term that is helpful for the selection of appropriate treatment technique to meet the concerned issues. However, WQI depicts the composite influence of different water quality parameters and communicates water quality information to the public and legislative decision makers. In spite of absence of a globally accepted composite index of water quality, some countries have used and are using aggregated water quality data in the development of water quality indices. Attempts have been made to review the WQI criteria for the appropriateness of drinking water sources. Besides, the present article also highlights and draws attention towards the development of a new and globally accepted “Water Quality Index” in a simplified format, which may be used at large and could represent the reliable picture of water quality.

American Journal of Water Resources. 2013, 1(3), 34-38. DOI: 10.12691/ajwr-1-3-3
Pub. Date: August 14, 2013

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Hydrogeochemistry and Stable Isotopes (δ¹⁸O and δ²H) Assessment of Ikogosi Spring Waters

by Abel O. Talabi

Original Research

Ikogosi warm spring is a unique tourist centre where warm and cold spring waters flow together. Consequently, understanding the hydrochemical processes and recharge source are critical to the sustainability and management of the warm spring. Hence, stable isotopes (δ¹⁸O and δ²H) and hydrochemical study of Ikogosi spring waters was carried out to conceptualize the recharge source and the extent of water-rock interaction on the hydrochemical evolution of the waters. The study approach involved field sampling and in-situ measurements of physico-chemical parameters followed by laboratory hydrochemical and stable isotope analyses of the spring water samples. The hydrochemical analysis revealed that Ikogosi spring water is alkaline in nature with values ranging between 7.4 and 9.0. The TDS ranges from 14.3 to 66.8 mg/L with mean value of 49.2mg/L while the TH is from 6.3 to 39.0mg/L with mean value of 27.61mg/L. All EC values for the sampled spring waters were below 1000µS/cm indicating fresh water. Ca²⁺ was the dominant cation with value ranging from 2.2-9.6mg/L while Cl- was the dominant anion with value ranging from 88.6-144.0mg/L. The spring water is low mineralized and hydrochemically potable. Rock-water interactions were the dominant processes controlling the major ion composition of the spring while the dominant water was Ca (Mg)-Cl type. Stable isotopes analysis revealed recharge from recent precipitation. Conclusively, Ikogosi spring waters have low EC and TDS along with low total hardness (TH) values suggesting a low mineralized soft fresh water system recharged from recent precipitation with limited residence time.

American Journal of Water Resources. 2013, 1(3), 25-33. DOI: 10.12691/ajwr-1-3-2
Pub. Date: August 09, 2013

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Removal of Turbidity, Suspended Solids and Ions of Fe from Aqueous Solution using Okra Powder by Coagulation-Flocculation Process

by Edilson de Jesus, Paulo Victor Cruz, José Adair Pacífico and Antônio Santos Silva

Original Research

This work evaluates the efficiency of okra powder in removing turbidity, suspended solids and ions of Fe from synthetic raw water through coagulation-flocculation process. The raw water samples with initial turbidity of 100 NTU were prepared using natural red clay (-32+100 mesh particle size). The jar tests were carried out by varying the pH and the dose of okra powder. The initial pH 8.0 of synthetic raw water and 30 mgL^-1 okra powder caused 80.92% reduction of Fe ions and 99% turbidity removal after 10 minutes of sedimentation. The efficiency of Fe the removal was evaluated by characterization EDX sludge formed after sedimentation with and without okra powder and the jar tests were carried out using a solution of ferric sulfate as the coagulating agent.

American Journal of Water Resources. 2013, 1(3), 20-24. DOI: 10.12691/ajwr-1-3-1
Pub. Date: July 04, 2013

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25459 Views9003 Downloads34 Likes11 Citations