Current Issue : April - June Volume : 2017 Issue Number : 2 Articles : 5 Articles
Treatment wetlands are increasingly needed to remove nitrate from agricultural drainage\nwater to protect downstream waters, such as the Gulf of Mexico. This project sought to develop a\nnew edge-of-field treatment wetland, designed to remove nitrate-nitrogen and enhance phosphorus\nremoval by plant harvest and to monitor its effectiveness. A 0.10 ha wetland was designed and\ninstalled to treat subsurface drainage flow from farmland in southwestern Minnesota, USA, in 2013,\nand monitored for three years by recording flow, nitrate-nitrogen, total phosphorus (TP) and soluble\northophosphorus (OP) input to and output from the wetland. Prior to construction, a level-pool\nrouting, mass balance approach with DRAINMOD flow inputs was used to predict nitrate removal\nefficiency. Nitrate load removal averaged 68% over three years, nearly matching model predictions.\nHowever, most denitrification occurred in the sub-soil of the wetland rather than in surface flow as\npredicted. Phosphorus removal was approximately 76% over three years, and phosphorus removed\nby plant uptake exceeded inflow mass in the third year. The edge-of-field design has potential as a\ncost-effective method to treat field outflows because agricultural landowners can adopt this treatment\nsystem with minimal loss of productive farmland. The wet-prairie vegetation and shallow depth also\nprovide the opportunity to remove additional phosphorus via vegetative harvest....
Coagulation-Flocculation plays a significant role in drinking water treatment. Laboratory\nexperiments were carried out in order to assess the effectiveness of using Conocarpus\nLeaves Solution (CLS) as a natural coagulant in conjunction with the synthetic\nchemical represented by Alum in the water purification. Biological test was\ncarried out to confirm that these leaves are not toxic, followed by optimizing the dosage\nof alum and then Alum and CLS were applied to the turbid water whose turbidity\nlevel has two ranges, (20 - 35) NTU and (90 - 120) NTU, using the JAR Test. The\nparameters determined before and after coagulation were turbidity, pH and temperature.\nThe experiments showed that the optimum dose of alum coagulant (individually)\nfor high turbid water is about 18 mg/l with PH = 7 and 24 mg/l f with PH = 5\nand 9. In addition, for the low turbidity water, the optimum dose of alum was lower\nthan in the high turbid water. In terms of using Alum in conjunction with CLS, at\nhigh range of turbidity, the results show that at 33% ratio of leaves solution to alum\ncoagulant, there are 50% and 75% turbidity reduction performed for the PH equal to\n5 and 9 respectively. Although about 62% and 65% turbidity reduction were achieved\nat PH = 7 and PH = 9 in the low range level. However, low reduction in turbidity has\noccurred when the water PH = 5. The amount of leaves solution added to the water\nin the water treatment plant is highly important, hence it decreases the amount of\nusing the synthetic chemicals by about 33% of the quantity that required for water\ntreatment and that will help both, the water industry and the human health. More\nstudies need to be achieved in particular different concentration of the Conocarpus\nleaves solution in order to improve the percentage of using the natural material as a\ncoagulant....
Groundwater movement beneath watershed divide is one component of the hydrological\ncycle that is typically ignored due to difficulty in analysis. Numerical groundwater\nmodels, like TAGSAC, have been used extensively for predicting aquifer responses\nto external stresses. In this paper TAGSAC code was developed to identify the\ninter-basin groundwater transfer (IBGWT) between upper Awash River basin (UARB)\nand upper rift valley lakes basin (URVLB) of Ethiopia. For the identification three\nsteady state groundwater models (for UARB, URVLB and for the two combined basins)\nwere first created and calibrated for the 926 inventoried wells. The first two\nmodels are conceptualized by considering the watershed divide between the two basins\nas no-flow. The third model avoids the surface water divide which justifies\nIBGWT. The calibration of these three models was made by changing the recharge\nand hydrogeologic parameters of the basins. The goodness of fit indicators (GoFIs)\nobtained was better for the combined model than the model that describes the\nURVLB. Furthermore, the hydraulic head distribution obtained from the combined\nmodel clearly indicates that there is a groundwater flow that doesn�t respect the surface\nwater divide. The most obvious effect of IBGWT observed in these two basins is\nthat it diminishes surface water discharge from URVLB, and enhances discharge in\nthe UARB. Moreover, the result of this study indicates potential for internal and\ncross contamination of the two adjacent groundwater....
In this paper, Fenton process was determined to be an effective technique to treat the\nrefractory nonylphenol ethoxylates (NPEOs) wastewater. The chemical oxygen demand\n(COD) removal efficiencies above 89% were obtained when the initial COD\nconcentration was 12,000 mg/L. However, a large amount of ferric sludge (SS = 8.724\ng/L) would be produced after the Fenton oxidation of the wastewater and must be\ndisposed appropriately. A novel process for Fenton sludge reused by low-cost ferrous\nsulfide (FeS) was also investigated. Experimental results show that the Fenton sludge\ncould be reduced to produce a certain amount of Fe2+ in the acidic mixed liquor by\nFeS. This mixed liquor from Fenton sludge could be used as the new catalyst in the\nFenton process and was also highly effective for the NPEOs wastewater treatment.\nThe residual FeS from the mixed liquor could be used for the next batch of the reaction....
In the present study the physical and nuIn the present study the physical and nutrients characteristics of Vellar estuary were studied during May 2014 to\nApril 2015. Four stations were selected based on salinity gradient and the environmental parameters such as temperature, dissolved oxygen, salinity, pH, TSS, turbidity and nutrients (nitrite, nitrate, inorganic phosphors, total nitrogen and reactive silicate) were recorded seasonally in the Vellar estuary. The correlation of all the parameters was done to know the interrelationship of the physico-chemical parameters. The maximum, minimum, mean and standard deviation values of water temperature was from 27.3 to 35.1, 30.4�±1.79�°C, pH 7.3 to 8.2, 7.7�±0.100, salinity 20.2 to 34, 29.5�±2.5 psu, dissolved oxygen\n5.56 to 8.71, 5.8�±0.35 �¼mg/l, biological oxygen demand 0.8 to 2.8, 1.7�±0.1 ml/l, total suspended solid 60.00 to 176.00, 129.13�±34.35 ppm and turbidity 4.51 to 8.31, 6.6�±0.8 NTU. The higher and lower values of nutrients parameters such as ammonia 0.47 to 1.14, 0.73�±0.095 �¼mo/l, nitrite 0.5 to 1.8, 0.9�±0.13 �¼mol/l, nitrate 3.33 to 5.62, 4.36�±0.20 �¼mol/l, total nitrogen 21.5 to 29.2, 25.1�±0.70 �¼mol/l, inorganic phosphorus 0.0134 to 1.135, 1.27�±0.28 �¼mol/l, total phosphorus 1.0 to 2.1, 1.6�±0.09 �¼mol/l and silicate 17.1 to 72.9, 42.9�±5.81 �¼mol/l fluctuated significantly. The water quality determines the diversity of flora and fauna of an area and therefore regular monitoring of physico-chemical parameters is essential to know the health of an aquatic ecosystem.trients characteristics of Vellar estuary were studied during May 2014 to April 2015. Four stations were selected based on salinity gradient and the environmental parameters such as Temperature, Dissolved Oxygen, Salinity, pH, TSS, Turbidity and nutrients (Nitrite, Nitrate, Inorganic Phosphors, Total Nitrogen and Reactive Silicate) were recorded seasonally in the Vellar estuary. The correlation of all the parameters was done to know the inter-relationship of the physico-chemical parameters. The maximum, minimum, mean and standard deviation values of water temperature was from 27.3 to 35.1, 30.4�±1.79�°C, pH 7.3 to 8.2, 7.7�±0.100, Salinity 20.2 to 34, 29.5�±2.5 psu, Dissolved Oxygen 5.56 to 8.71, 5.8�±0.35 �µmg/l, Biological Oxygen Demand 0.8 to 2.8, 1.7�±0.1 ml/l, Total Suspended Solid 60.00 to 176.00, 129.13�±34.35 ppm and Turbidity 4.51 to 8.31, 6.6�±0.8 NTU. The higher and lower values of nutrients parameters such as Ammonia 0.47 to 1.14, 0.73�±0.095 �µmo/l, Nitrite 0.5 to 1.8, 0.9�±0.13 �µmol/l, Nitrate 3.33 to 5.62, 4.36�±0.20 �µmol/l, Total Nitrogen 21.5 to 29.2, 25.1�±0.70 �µmol/l, Inorganic Phosphorus 0.0134 to 1.135, 1.27�±0.28 �µmol/l, Total Phosphorus 1.0 to 2.1, 1.6�±0.09 �µmol/l and Silicate 17.1 to 72.9, 42.9�±5.81 �µmol/l fluctuated significantly. The water quality determines the diversity of flora and fauna of an area and therefore regular monitoring of physico-chemical parameters is essential to know the health of an aquatic ecosystem....
Loading....