Pollution

The water budget, constituent budget and flushing model of Oguta Lake were determined using Atomic Absorption Spectrophotometer (AAS), digital meters and standard equations. Results revealed that the total annual water inflow into the lake is about 29,461,800m3 while the total annual outflow is about 13,476,300m3 which implies a water storage of 16,185,500m3/year. The investigation further revealed that about 87.6% of the total water inflow into the lake comes from channel flow from Rivers Njaba, Utu and Awbana while about 70.2% of the water outflow is from channel outflow. Similarly, there seems to be continuous loading of constituents into the lake but at a very low rate; the low loading rate is actually attributed to the moderately high flushing rate of constituents in the lake. Total alkalinity has the highest loading rate (0.40 mgl-1/year) while phosphate has the lowest (0.003 mgl-1/year). The results also showed that the highest annual maximally flushed constituent in the lake is bicarbonate while the lowest is magnesium. The lake witnessed low influx of nutrients (phosphate, nitrate and dissolved silica) during the study period thus indicating low level of eutrophication. Excessive flushing rate can cause nutrient imbalance and this can alter the resource status and usefulness of the lake. In conclusion, the constituent budget and flushing model of the Oguta lake are therefore favorable for water supply , irrigation activities and fisheries development.

The use of fibrous material is effective in increasing the surface area of the support media in fixed film reactors. Several fibrous biomass support mediums are available for use in attached growth system .one of these support materials are areca fibers. In this study the experiment was conducted for a batch mode of operation. The bio-reactors were continuously aerated and fed with residential wastewater having an initial average COD of 860 mg/L, BOD of 450 mg/L and NH3-N of 70 mg/L. This present study reveals the study of COD, BOD and NH3-N removal in two reactors, one filled with gravel bed and other areca fibers. Two sets of experiments were conducted to study the effects of detention time, elevated NH3-N concentration. The reactors with gravel bed and areca fibers showed reasonable amount of COD removal (72-74%), BOD removal (92%-94%) and NH3-N removal (58%-60%) within 4-16 hrs of detention period. In both the reactors denitrification was almost absent. Here comparative study of both reactors has been done and it is hypothecated that at fixed MLSS concentration of 2210 mg/L, efficiency of areca fibers bio-reactor seems to be satisfactory and effective for batch mode of operation.

As mercury (Hg) amalgamation is an inexpensive, quick and simple way to extract gold, it is currently the method most commonly used in Artisanal gold mining in Ghana and most developing countries. However, the activities of these Artisanal miners result in the release of Hg into the environment by amalgamation tailings and amalgam burning. These amalgamation tailings often left behind forms Hg “hotspots” in both terrestrial and aquatic ecosystem, forming the main source of Hg dispersion. An investigation was conducted in the Asutifi district, hosts for several artisanal gold mining centres to ascertain the levels and the degree of mercury contamination in amalgamation tailings. The degree of contamination were assessed using mathematical model index approach, geoaccumulation index (Igeo) and enrichment factors (EF). The average Igeo for Hg in tailings (0.5) denoted uncontaminated to moderately contaminated, whilst the EF indicated very high to extremely high enrichment.

Analytical solutions are obtained for advection-dispersion equation in one-dimension longitudinal finite domain. The solute dispersion parameter is assumed temporally dependent along uniform flow. The retardation coefficient and first order decay term which inversely proportional to the dispersion coefficient is also considered. Initially the space domain is solute free. Solution are obtained for two cases, first one for uniform input and second one for increasing input condition.

The concentration and spatial distribution of trace metals Cr, Cd, Pb, Zn, Cu and Hg were measured in surface water and sediment of East Usambara Mountains (EUMs) River in Tanzania. Concentrations ranged from below detection limit (bdl) to 4.86 mg/l and bdl to 157.98 mg/kg dw in surface water and sediments, respectively. The levels of the metals in water were within the Tanzanian drinking water limit standards, but exceeded the World Health Organisation (WHO) drinking water limit guidelines. Concentrations of the metals in sediments in most of the locations were observed to be higher than the average concentration in the upper Earth’s crust. Wastes from artisanal gold mining and agricultural runoff were considered to be the major sources of the elevated metal concentrations in water and sediments of the study area. The extent of the trace metals pollution in surface water and sediments of EUMs rivers catchment implies that acute health consequences could be insignificant, but chronic adverse health effects due to prolonged pollution and long term exposure through food contamination, washings, animal keeping and fishing could be certain.

Car washing is among businesses that erupted recently in urban Tanzania. The business in many areas has been done informally and hence not fully regulated polluting receiving environments. Results show solid waste and wastewater in the selected carwashes were predominant waste (25,732.5 kg/yr and 9,415,540 l/yr, respectively). Management of solid wastes were through collection, storage and transfer by trucks to municipal disposal sites. While wastewater discharge in municipal sewerage systems, onsite collection tanks, on soil and/or into water bodies. Wastewater management mechanisms were environmentally unfriendly. Henceforth, the study recommended upgrading hybrid carwash facility by introducing hydroponic vertiver grass cultivation.

The present investigation was carried to monitor simultaneously the physico-chemical characteristics of water and sediments of Dal Lake over a period of one year from March 2014-Feb.2015. In all 17 parameters from surface water and 13 parameters from sediments were analysed. The parameters analysed during the study were pH, conductivity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), dissolved oxygen (DO), ammonical nitrogen, phosphate, sulphate, total hardness (TH), chloride (Cl-), and metals (Na, K, Fe, Ca, Mg). The results of both water and sediment samples revealed an overall increase in the concentration of the parameters than the permissible limits due to pollution.

The research aimed to evaluate the current water quality status of Lake Hawassa in order to identify potential pollution sources, and put in place monitoring programs. Eleven potential sampling sites were included in the study. Selected water quality parameters were considered and the results were compared with WHO and FAO standards. And the values of TDS (381.7 to 1286.0 mg/L), SC (733.7 to 2151.3 µS/cm), turbidity (8.20 to 87.3 NTUs), BOD5 (4.02 to 76.2 mg/L) , phosphate (0.348 to 1.90 mg/L), fluoride (11.6 to 17.5 mg/L), chromium(0.173 to 0.665 mg /L), manganese(0.133 to 1.83 mg/L), and copper (1.40 L to 18.2 mg/L) were found above the prescribed limit of WHO guidelines for drinking purposes, while all the analyzed water quality parameters fall within the FAO standard limit for irrigation purposes. These suggested that both point and non-point pollution sources such as human sewage, industrial waste from ceramics, dyes, plastics and food processing industries, urban stormwater, agricultural runoff and land development were impacting the lake. Thus, mitigation measures should be put in place to prevent the Lake from further deterioration

Present paper ardently deals with the groundwater vulnerability assessment of Bagh River Watershed (WGW-1/B-designated by central ground water board) of Gondia District of Maharashtra State, India. The groundwater vulnerability assessment of the watershed is analyzed according to the guidelines provided by the APHE, ICMR, WHO and BIS10500. The parameters such as pH, EC, TDS, as well as Chloride, Nitrates, and Fluoride pre and post monsoon have been analyzed. Majority of the samples do not comply with EPA, ICMR, BIS and WHO norms for most of the water quality parameters measured. In order to protect groundwater Vulnerability of Bagh River Watershed of Gondia district, various parameters such as the industrial activities in the area, land cover/use data, hydro geological characteristics of upper aquifers, the lithology and nature of the soil zone for the area, and various predominant contaminating sources have been considered.

The aim of this study was to assess the biochemical and structural changes associated with exposure to gasoline vapour in rat. Twenty-four female rats were divided into test and control groups. After the exposure period, all animals were sacrificed, blood was obtained for biochemical analysis, and the liver was removed, and processed for histopathological examination. Abnormal liver architecture, liver enzymes, bilirubin, and malondialdehyde were significantly higher while serum protein were significantly lower in the exposed group than in the unexposed group (p < 0.05). Exposure to GV may represent a significant risk factor for a wide spectrum of liver disorders