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Abstract : |
The present study monitored the water quality of Hudiara drain using 72 water samples from three sampling points on a fortnightly basis and analysing for a range of water quality parameters. Large variations were found in almost all water quality indices with most of the lower values being observed during the monsoon season (July to September). Mean dissolved oxygen (DO) was below 1 mg L‾1 at all sampling points. Mean biochemical oxygen demand (BOD, 104-115 mg L‾1) and chemical oxygen demand (COD, 255-276 mg L‾1) values exceeded the Pakistan National Environmental Quality Standards (NEQS) for industrial effluents. Although mean total dissolved solids (TDS) and metal concentrations (Cd, Cr, Cu, Li and Pb) of the drain’s water were below the limits set for industrial effluents (NEQS), concentration of most of these indices (e.g. TDS, Cd and Cu) was above the acceptable limits of irrigation water. Between points, the TDS values were found lower at point 1 and the converse was the case for most of the metals at that point. E. coli were found above 200 MPN 100‾1 ml at all sampling points. The daily contribution of pollution load of Hudiara Drain to the River Ravi in terms of TDS, BOD and COD was 354, 45, 111 tons respectively. Prolonged use of water of the Hudiara drain for irrigation may be harmful to soils due to high TDS. Similarly, long term use of the drain’s water for irrigation may cause accumulation of Cd, Cu and Mn above the limits known to cause soil pollution. With an annual discharge of approximately 180 cusecs, Hudiara drain is one of the main causes of both chemical and biological contamination in the River Ravi. Poor water quality and stress on aquatic life in the River Ravi, especially during low flow may be largely attributed to Hudiara drain. , The present study monitored the water quality of Hudiara drain using 72 water samples from three sampling points on a fortnightly basis and analysing for a range of water quality parameters. Large variations were found in almost all water quality indices with most of the lower values being observed during the monsoon season (July to September). Mean dissolved oxygen (DO) was below 1 mg Lأƒآ¢أ‚€أ‚آ¾1 at all sampling points. Mean biochemical oxygen demand (BOD, 104-115 mg Lأƒآ¢أ‚€أ‚آ¾1) and chemical oxygen demand (COD, 255-276 mg Lأƒآ¢أ‚€أ‚آ¾1) values exceeded the Pakistan National Environmental Quality Standards (NEQS) for industrial effluents. Although mean total dissolved solids (TDS) and metal concentrations (Cd, Cr, Cu, Li and Pb) of the drainأƒآ¢أ‚€أ‚â„¢s water were below the limits set for industrial effluents (NEQS), concentration of most of these indices (e.g. TDS, Cd and Cu) was above the acceptable limits of irrigation water. Between points, the TDS values were found lower at point 1 and the converse was the case for most of the metals at that point. E. coli were found above 200 MPN 100أƒآ¢أ‚€أ‚آ¾1 ml at all sampling points. The daily contribution of pollution load of Hudiara Drain to the River Ravi in terms of TDS, BOD and COD was 354, 45, 111 tons respectively. Prolonged use of water of the Hudiara drain for irrigation may be harmful to soils due to high TDS. Similarly, long term use of the drainأƒآ¢أ‚€أ‚â„¢s water for irrigation may cause accumulation of Cd, Cu and Mn above the limits known to cause soil pollution. With an annual discharge of approximately 180 cusecs, Hudiara drain is one of the main causes of both chemical and biological contamination in the River Ravi. Poor water quality and stress on aquatic life in the River Ravi, especially during low flow may be largely attributed to Hudiara drain., |
