Pollution Evaluation of Industrial Effluents from Consolidated Breweries: A Case Study from Benue State, Nigeria

Abstract

Industrial effluent discharged into surface water is an environmental concern, as it affects the esthetics, water quality as well as microbial and aquatic flora. Brewery effluents were analyzed for physicochemical parameters (pH, temperature, conductivity, turbidity, total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), nitrate, and sulfate, chloride) and heavy metals (As, Cd, Co, Cr, Fe, Mn, Ni, Pb, and Zn). Atomic absorption spectrophotometer was used to characterize heavy metals using standard analytical methods and compared with WHO standards. The result showed that pH (6.2–6.98), conductivity (137–273 μS/cm), chloride (31–53 mg/l), nitrate (7.53–10.72 mg/l), BOD, and DO were within the WHO limit. However, turbidity, sulfate, and phosphate were above the WHO limit. Heavy metal concentrations Cr, Ni, Pb, Mn, As, and Cd were higher than the WHO limit and vice versa for Fe, Zn, and Co. Ecological risk assessment revealed that effluent samples pose low to moderate ecological risk, for As, Pb, and Ni. Therefore, there is a need for proper treatment and continual monitoring before discharge into the environment.