The rapid industrialization in the Chalawa Industrial Estate, Kano, Nigeria, has led to continuous discharge of untreated textile effluents into the Chalawa River, this effluent discharge polluted the surface water quality with adverse effects on the environment, in semi-arid regions where rivers serve as vital sources of domestic, agricultural, and ecological water supply this threat is significant and should be addressed. This paper study the environmental impact of a textile industry discharged into the River, Physicochemical parameters including pH, BOD5, COD, TSS, Total Nitrogen (TN), and Total Phosphorus (TP), river flow rate, and velocity were analyzed using the Streeter–Phelps model to evaluate oxygen depletion and re-aeration processes along the river reach. The model was applied to determine oxygen deficit, critical deficit location, and the self-purification capacity of the river system. Results indicate substantial oxygen depletion downstream of the effluent discharge point due to high organic pollution, a gradual recovery observed further downstream as natural re-aeration occurs. The DO curve revealed sections where dissolved oxygen concentrations fall below recommended environmental standards, indicating ecological stress and potential risks to aquatic life. Results were compared with Nigeria’s National Environmental Standards and Regulations Enforcement Agency (NESREA) discharge limits. Result analysis has shown a very significant exceedance of regulatory standards, which results to oxygen depletion and eutrophication risk. Bioremediation approaches such as constructed wetlands, bio augmentation, phytoremediation and microbial treatment are proposed to enhance natural purification processes and improve water quality restoration.
Abdulfatah et al. (Sat,) studied this question.