Industrial Waste Water Treatment Plant Design Assessment for a Textile Factory in Kano State

This research assesses the design adequacy and operational performance of the industrial wastewater treatment plant serving a textile dyeing and finishing factory in Kano State, North West Nigeria. Textile effluent contains high concentrations of dyes, detergents, heavy metals, and chemical oxygen demand constituents that pose significant risks to receiving water bodies and public health if inadequately treated. This study evaluates the plant's design parameters against effluent composition data collected through weekly sampling and laboratory analysis over sixteen weeks, benchmarking treated effluent quality against the National Environmental Standards and Regulations Enforcement Agency effluent discharge limits. Process performance indicators including biochemical oxygen demand removal efficiency, total dissolved solids reduction, and colour removal percentage are calculated for each treatment stage. Results reveal that the biological treatment stage is hydraulically overloaded, processing sixty-three percent above its design flow capacity due to factory expansion since the plant's original commissioning. Consequently, treated effluent consistently exceeds permissible biochemical oxygen demand and colour limits. The study recommends upgrading the biological treatment stage capacity through an additional aeration basin, installing a tertiary coagulation and flocculation stage for colour removal, and implementing an in-plant water recycling programme to reduce raw effluent volume. Keywords: wastewater treatment, textile effluent, NESREA, Kano State, biological treatment