Organic Pesticides In Clean Water

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Various activities such as farming, fishing, forestry, construction, mining, urban development and land pollution occurring in or near the watershed of a reservoir could bring about water quality problems and disruption in fish [1]. Chlorinated organic pesticides are very stable in both fresh and salt water and are resistant to photo degradation [2]. They will disappear from the water with secondary mechanisms such as, absorption on sediment, biological breakdown by microflora and fauna, and absorption by fish through gills, skin and feeding. They are poorly hydrolyzed and slowly biodegrades in environment. Therefore, these compounds are persistent in food chains and are readily accumulated in animal tissues. Fish absorb these compounds directly…show more content…
The gills are directly in contact with water. Therefore, the concentration of pesticides in gills reflects their concentration in water where the fish live, whereas the concentrations in liver represent storage of pesticides in the water [12]. Sediments are important sinks for various pollutants like pesticides and also play a significant role in the remobilization of contaminants in aquatic systems under favorable conditions and in interactions between water and sediment. Fish samples can be considered as one of the most significant indicators in fresh water systems for the estimation of pesticides pollution level [10]. The region of accumulation of pesticides within fish varies with the route of uptake. Their potential use as bio monitors is therefore significant in the assessment of bioaccumulation and bio magnifications of contaminants within the ecosystem [12].Many dangerous chemical elements, if released into the environment, accumulate in the soil and sediments of water bodies. The lower aquatic organisms absorb and transfer them through the food chain to higher trophic levels, including fish. Under acidic conditions, the free divalent ions of many metals may be absorbed by fish gills directly from the water [12]. Hence, concentrations of pesticides in the organs of fish are determined primarily by the level of…show more content…
70 mm) to remove debris and suspended materials and then poured into a 2 liter separatory funnel. For the first LLE, the mixture of 100 ml n-hexane and dichloromethane (1:1 v/v) was added and shaken vigorously for 2 min before two phase separation. The water-phase was drained from the separatory funnel into a 1000 ml beaker. The organic-phase was carefully poured into a glass funnel containing 20 g of anhydrous sodium sulfate through a 200 ml concentrator tube. Following the second and third LLE, the water-phase was poured back into the separatory funnel to re-extract with 50 ml of the same solvent mixture. The extract was concentrated to the volume of 2 ml under a gentle stream of nitrogen using rotary evaporator and then analyzed with Gas Chromatography with micro Electron Capture Detector (GC-ìECD)

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