Evaluation of Waste Minimisation Strategies in the Nigerian Textile Wet Processing Industry

Textile wet processing operations, encompassing dyeing, printing, and finishing, generate substantial volumes of wastewater, chemical waste, and energy loss, making waste minimisation a critical operational and environmental priority. This study evaluates waste minimisation strategies implemented or available to textile wet processing plants in Kano and Kaduna states, North West Nigeria, with a focus on water consumption reduction, dye utilisation efficiency, and chemical waste generation. A comparative case study approach was used, involving detailed process audits at four wet processing facilities, complemented by mass balance analysis of water and chemical inputs against product output and effluent generation. Water consumption per kilogram of processed fabric, dye fixation efficiency, and auxiliary chemical consumption were quantified as key performance indicators. Results show that facilities employing liquor ratio optimisation techniques achieved water consumption of 80 to 100 litres per kilogram compared to the sector average of 150 to 200 litres per kilogram. Dye fixation efficiency averaged 72 percent for reactive dyes, with the remainder discharged in effluent as hydrolysed dye. Salt recovery through nanofiltration was assessed as technically feasible with potential to reduce salt purchase costs by up to 60 percent at one large-scale facility. Hot water recovery through heat exchangers offered projected energy savings of 18 to 25 percent for dyeing operations. The study recommends a sector-level waste minimisation programme for North West Nigerian textile wet processors, incorporating targeted investment incentives, shared infrastructure for salt and water recovery, and best practice training facilitated by the Manufacturers Association of Nigeria. Keywords: waste minimisation, textile wet processing, Kano, Kaduna, water consumption