Abstract

It is an everyday norm for tanners and textile industries to discharge untreated tannery wastewater to receiving water bodies, which can pose various environmental hazards due to its hazardous chemicals and dangerous microorganisms. The study evaluated the physicochemical and bacteriological quality of wastewater from tanning and allied industries at Kano State. A total of 10 wastewater samples were aseptically collected and analysed by standard physicochemical and microbiological methods. Physicochemical parameters such as pH, temperature, chromium, Biochemical Oxygen Demand, sulphide, Chemical Oxygen Demand and ammonium contents were analysed. The bacteriological quality of the wastewater was analysed using the total coliform Most Probable Number (MPN) technique. The physicochemical parameters analysed showed varying degrees of conformity and divergence to the National Environmental Regulatory Agency standards. The coliform analysis recorded the presence of Escherichia coli and Enterobacter aerogenes. Samples A, D, and E were found to be within the standards given by the Environmental Protection Agency. The total coliform counts ranged from 196 cfu/100ml to 1028 cfu/100mL, with the highest coliform count of 1028 cfu/100ml in sample B, which is relatively higher than the permissible value of the World Health Organization guideline limit of <1000 cfu/100ml for faecal coliform bacteria in wastewater ready for discharge to the environment. The study showed that physicochemical parameters are within statutory limits, with chromium recording hazardous potential (3.0−8.3mg/L). The wastewater collected could pose an environmental risk when let into receiving water bodies because of the high levels of chromium. Also, Escherichia coli shows the possibility of other bacterial pathogens causing water-borne and foodborne diseases within the study area since the wastewater is often used for irrigation.