A preliminary pollution appraisal of western backwater at Karachi Coastal area

Abstract

Abstract This study aims at preliminary analysis of pollution profile of western backwater. The site is very important from the ecological perspective. The mangrove ecosystem of the study area is of prime significance, whilst the study area is receiving heavy pollution load from Lyari River. The water samples were collected from the pre-designated locations and analyzed for physical and biochemical characteristics. The BOD and COD concentrations of the samples were extremely higher from the environmental and ecological viewpoint. The heavy inorganic and organic load is coming from the domestic and industrial effluents coming from Lyari River. Oil and grease concentrations were also extremely higher in all these sites indicating the hampering of natural purification system of water. The concentration of phenol also indicates the emptying of industrial effluent at the Lyari River outfall. The heavy influx of the nutrients in the form of nitrogen and phosphate represents the problem of eutrophication at the study area. Out of all 7 sites, L-7 was most polluted as it was closed to the Lyari River outfall. The extent of pollution is at the following order L-7 > L-5 > L-6 > L-4 > L-3 > L-2 > L-1.

Keywords

• Untreated effluent
• Western backwater
• Pollution
• Karachi