Quality Characterization and Magnitude of Pollution Implication in Textile Mills Effluents

Effluents from textile industries contain different types of dyes, which because of high molecular weight and complex chemical structures, show low level of biodegradability. Hence, direct deposition of these effluents into sewage networks, produce disturbances in treatment processes and exert pollution load on water bodies. Effluents from nine major textile industries in Karachi industrial areas (Sindh Industrial Trading Estate, Korangi Industrial Area, Landhi Industrial Trading Estate, Federal B. Industrial Area and North Karachi Industrial Trading Estate) were characterized for proposed effluent characterization. Seven of the measured parameters exceeded the limit set by the Pakistan Environmental Protection Agency. pH concentration exceeded in all the samples excepted Textile 9, while temperature was as well higher than the recommended limit, while biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total dissolve solids (TDS), and sulfide (S2-) were higher by about 2-5 folds respectively. Oil and Grease detected in Textile 1, 2, 5 and Textile 7 samples higher than the limits, while in Textile 3, 6, 7 and 8 are within the limits. Ammonia (NH3) was detected in all the samples within the limit, exceeded only in Textile 4 7. Color intensity is higher in all the samples (Textile 1- 9) by about 350 folds on the average. Chromium (Crtotal) and Iron (Fetotal) were detected in 20% samples were exceeded the limits. Manganese (Mn) and Zinc (Zn) was detected in 88 % samples were within the limits. Mercury (Hg) was detected in 100 % sample within the limits; Cupper (Cu) was detected in 55 % samples higher than the limits, exceeded 3 folds on the average. The present study is focused on the pollution implications of effluents from textile industries in the city because of the risk of human exposure and environmental degradation by this massive discharge effluent.