Impact assessment of wastewater discharge from a textile industry in Lagos, Nigeria

Abstract

The quality of effluent from a wool and synthetic textile manufacturing company in Nigeria was examined by obtaining triplicate samples per week over a 6-week period. This was done to measure the waste-load and volume from the textile industry. Obtained samples were analyzed for 18 physicochemical parameters such as pH, color, turbidity, total suspended solids, total dissolved solids (TSS), conductivity, dissolved oxygen, biochemical oxygen demand (BOD), chemical oxygen demand (COD), chloride, nitrates, phosphates, some heavy metals and odor. Heavy metals, phosphate, and color were analyzed using spectrophotometer while dissolved oxygen and BOD were analyzed using azide modification method. The effluents were found to pass the national standard for the effluent limit for 13 parameters but exceeded specified limits for pH in one sample and, COD, TSS, color, turbidity and odor in all samples. Turbidity was found to exceed national limits by 100 to 300%; COD exceeded limits by 20% to 500%; TSS exceeded limits by 10% to 110% in 5 out of 6 samples analyzed. All obtained samples were dark colored and exceeded prescribed limits by 2,000 to 3,000% in all samples. Likewise, all six samples had an offensive odor. It was recommended that strict compliance with stipulated standards was necessary for the protection of public health and the environment.