Current Issue : April - June Volume : 2012 Issue Number : 2 Articles : 8 Articles
Levafix yellow CA (LY) is a reactive azo dye widely used in textile industries and its removal from wastewater is difficult due to complex structural properties. This paper deals with a hybrid electrochemical degradation-chemical adsorption approach for the removal of LY from aqueous solution. The dye solution containing sodium chloride (NaCl) electrolyte was first electrolyzed using graphite electrodes, followed by adsorption onto magnesium oxide (MgO) or zinc oxide (ZnO) nanoparticles. MgO was found to be a better adsorbent than ZnO. The progress of dye removal was monitored by CV, UV-VIS spectrophotometry, total organic carbon (TOC) measurements and also by Mass spectral analysis. Almost 100% decolourization was achieved by electrolysis while about 90.3 % TOC removal was achieved through adsorption with MgO nanoparticles....
Some types of land development can be associated with increased impervious area that causes increase\nin surface runoff and decrease in ground water recharge. Both of these processes can have large-scale\nramifications through time. Increased runoff results in higher flows during rainfall events. On the other\nhand, groundwater recharge decreases due to increase impervious surfaces and decrease rate. Hence,\nthere is a need to quantify the impacts of landuse changes from the point of minimizing potential\nenvironmental degradation. The objective of this study is to develop a model for assessing the impacts\non the watershed runoff due to changes in landscape patterns. While conceptual or physical based\nmodels are of importance in the understanding of hydrologic processes, there are many practical\nsituations where the main concern is with making accurate predictions at specific locations. For this\npurpose, artificial neural network (ANN) model was developed. Landsat data was used in this study in\nview of its ability to provide useful information on landuse dynamics. The model�s performance in both\ntraining and testing phases were evaluated using mean absolute error (MAE), mean square error (MSE),\nU Theil�s coefficient and regression analysis. The correlation coefficients between simulated and real\ndata were found to be 0.94 and 0.89 for the training and testing phases respectively. Most of the data\npoints were within the confidence level of 95%. The model can be used as a decision making tool when\nformulating landuse policies. It can be a practical tool for hydrologists, engineers, and town and country\nplanners....
Constructed wetlands have emerged as a feasible alternative for treatment of domestic wastewater in areas with landscape precincts, poor soil conditions, and high water tables, which limit installation of full-scale adsorption fields. Good removal efficiencies, relatively low costs, water and nutrient reuse opportunities and other ancillary benefits ensured that constructed treatment wetlands (CWs) have become an accepted option for the treatment of domestic wastewater. This research consider the use of constructed wetland ecosystem in waste water treatment on small scale and how it may be exploited for the treatment of waste water from the local community. A vertical subsurface constructed wetland was prepared using ceramic pipe of 10 cm diameters and 28cm length filled with locally available soil-sand mixture (40:60). Five local plants Typha latifolia, Phragmites karka, Canna indica, Syngonium podophyllum and Panicum mutica were used in different constructed wetlands. The efficiency of these plants was compared with a system containing soil and sand alone. Each system was fed intermittently with same volume (0.5305m3) and flow rate (0.425 lit/day) of sewage having a hydraulic loading rate of 0.801m3 /per day for 5 days of hydraulic retention time. Treatment efficiency was evaluated for parameters such as BOD5 ,COD, DO, pH Typha latifolia, Phragmites karka, Canna indica, Syngonium podophyllum, Panicum mutica and unplanted wetland cells were found to have BOD5 (44.80%, 56.84%, 31.85%, 36.04%, 40.20.00%, 7.54%), COD (35.26%, 43.71%,27.21%, 22.91%, 30.12%, 5.59%) removal respectively. Wetland planted with Phragmites karka was found to have high removal efficiency than wetland planted with other plant. In all the six wetland sets DO was found to be increased significantly....
The modelling of water treatment processes is challenging because of its complexity, nonlinearity, and numerous contributory\r\nvariables, but it is of particular importance since water of low quality causes health-related and economic problems which have a\r\nconsiderable impact on peopleââ?¬â?¢s daily lives. Linear and nonlinear modelling methods are used here to model residual aluminium\r\nand turbidity in treated water, using both laboratory and process data as input variables. The approach includes variable selection\r\nto find the most important factors affecting the quality parameters. Correlations of ~0.7ââ?¬â??0.9 between the modelled and real values\r\nfor the target parameters were ultimately achieved. This data analysis procedure seems to provide an efficient means of modelling\r\nthe water treatment process and defining its most essential variables....
El Dakhla depression occupies a structurally localized depression at 100 to140 m (amsl), below a 400 m\nescarpment bordering the Libyan Plateau, Western Desert of Egypt. In this area, groundwater of the\nNubian Sandstone aquifer is the unique source of fresh water. The increasing demand of groundwater\nin El Dakhla depression has resulted in an indiscriminate exploitation of this source causing\nenvironmental hazards such as decline of groundwater levels. In this paper, the study of this problem is\nconducted. The methodology introduced in this paper includes application of mathematical and genetic\nalgorithm (GA) techniques. The proposed model of optimization is based on the combination of the\nMODFLOW simulation with GA. The performance of the proposed model is tested on groundwater\nmanagement problem (maximization of total pumping rate from Nubian aquifer at steady-state). The\nresults of the simulation show that the present groundwater extractions (511783 m3/day) will affect the\ngroundwater flow patterns in the northeastern areas of El Dakhla depression causing a significant head\ndecline of about 26 m in some wells at the year 2050. The increase of the groundwater extractions from\nthe concerned aquifer by 25% (126355 m3/day) will cause a great head decline of about 60 m in some\nwells and accordingly a cone of depression around the wells in the year 2050. In addition, the GA\nsolutions solve these management problems in the groundwater of Nubian aquifer. The results show\nthat under the increasing of pumping rate by 25% (which equalizes an increase in the cultivated area by\n6000 ha), the optimal pumping rate and drawdown range from 638137.9 to 595977.9 m3/day and from\n4.292 to 10.36 m respectively. This result seems to be the best for optimal management of groundwater....
Correlation between the diversity and primary production index of phytoplanktons of Manakudy estuary in Kanyakumari District, Tamil Nadu, India was assessed from January to December 2009. Average phytoplankton primary production varied significantly during the period of study. Maximum diversity and primary productivity were record in the months of February to April. The inflow of water during the monsoon into the reservoir was the prime factor that influenced input of the nutrients and appeared to enhance the primary production during this period. Shennon ââ?¬â?? Weiner diversity index varied between 1.232 and 1.667 during the period of study. Likewise, Sympson index varied from 0.812 to 0.868 and evenness from 212 to 546. The value of annual average of phytoplankton biomass was 186 Nos-1. The value of annual average of gross primary production and net primary production were 2318 mg C/m3/d and 1530 mg C/m3/d respectively....
This study determined and characterized the quality of water from Lake view drive and jawahar baal Udhyaan Lake of Bhopal. The research involved the levels of physico-chemical properties of Lake Water samples. About 40% of the pH values were below the WHO recommended minimum allowable value of 6.5 whiles most of the physical parameters fell within the recommended values of WHO. In general, the water quality of the studied lakes can be said to be fairly good with respect to the monitored elements and Thus on the basis of the physico-chemical studies, it can be said that the comparative study of Lake view drive and Jawahar Baal Udhyaan Lake in Bhopal district is nutrient rich and suitable for aquatic organisms. Slight alkaline medium and high amount of nutrients provide favorable conditions for aqua culture....
Geophysical mapping involving VLF Electromagnetic profiling along seven profiles, ten Offset Wenner\nand two azimuthal soundings were employed in the study of perennial spring sites at Iloyin community\nin Akure metropolis, southwest Nigeria. Geophysical methods are useful in mapping areas of natural\nwater resource for groundwater abstraction or construction of containment such as dam or fishpond.\nLinear inversion of the Electromagnetic measurements involved application of the Fraser and Karous-\nHjelt filter on the measured real components of the field data and generation of pseudo sections. The\nazimuthal sounding data were presented as azimuthal graphs in both Cartesian and Polar coordinates\nin conjunction with the polar plots of the Offset Wenner resistances (RD1 and RD2). The topsoil is\ngenerally thin with resistivity values ranging between 65 to 612 Ohm-m and thickness from 0.5 to 2.9 m.\nThe underlying layer with resistivity value ranging from 25 to 468 ohm-m is the main aquifer recognized\nas quartzite bed and quartzite impregnated clayey aquifer. The Aquifer layer thickness varies between\n0.9 to 32.6 m. The basement rocks, which graduate from highly weathered/fractured to fresh bedrocks,\nare characterized by resistivity values ranging from 827 to 11064 Ohm-m. Aquifer units in the area\ncomprise brecciated quartzite, clayey sand and fractured bedrock. The topsoil is highly loose and\nunprotected which makes the aquifer in the study area susceptible to infiltration and groundwater being\nprone to pollution....
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