Chemical Pollution Profile of Rehri Creek Area, Karachi (Sindh)

Abstract

The present investigation focuses on environmental issues along Rehri Creek area, which is an imperative creek of economic importance. During the study, a total of 30 samples of wastewater (industrial waste, Cattle colony waste and domestic waste) and seawater (infront of Rehri Goth and Lat Basti) from five sites along Rehri Creek area were collected for physical (pH and TSS), chemical (BOD5, COD, salinity, phosphate, TKN, oil & grease and organic matter) and heavy metals (Cr, Cu, Pb, Ni, As and Zn) analysis. Results of the physicochemical analysis revealed that effluent from Cattle Colony (Site 4) is the major source of marine water pollution along Rehri Creek area as it has high levels of all parameter except pH. Other two important sources are industrial effluent (Site 1) and domestic sewer drains (Site 2). Except pH and oil and grease concentration at Site 2, the levels of all the parameters in industrial and domestic drains are not within permissible limit. Heavy metal analysis reveals that the concentration of heavy metals along the Creek is higher than previously estimated. The study showed that marine water quality of Rehri Creek is grossly contaminated with the industrial and cattle colony effluents, which are dumped into the sea without any treatment and would create an alarming situation in future. The continued accumulation of pollutant is also responsible for ecological imbalances and biodiversity losses in the area.