Zero-Discharge Strategies for Sustainable Wastewater Management: A Case Review of a 300 MW Oil-Fired Power Plant in Bangladesh

Crude oil-fired power plants generate significant volumes of wastewater containing oily residues, chemical contaminants, and domestic effluents, posing serious environmental risks if discharged untreated. This study explores the implementation of a Zero Discharge Plan (ZDP) at the Summit Gazipur II Power Plant in Bangladesh aiming to eliminate liquid waste discharge through comprehensive treatment and reuse strategies. The research outlines a multi-stage Effluent Treatment Plant (ETP) process incorporating physicochemical separation, activated sludge treatment, and advanced filtration systems including multi-grade filters, carbon filters, and reverse osmosis (RO) units. Wastewater sources such as engine lubrication systems, cleaning operations, and other facilities were analyzed for key pollutants including Total Dissolved Solids (TDS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Oil and Grease etc. The treated water was successfully used for different purposes of cleaning, gardening other non-potable applications, aligning with 3R/4R principles and Department of Environment (DoE) regulations. To run this power plant, engine (Generator) and boiler require demineralized (DM) water for cooling and generating stream consecutively. Water treatment plant produces DM (demineralized) water and rejects 40% mineralized water which generally contains no pollutants. This study shows the proper strategy plant for reusing this rejected water as part of resource efficiency and no discharge to water bodies. The findings demonstrate that ZDP not only ensures regulatory compliance but also contributes to environmental sustainability and resource efficiency in power generation. This model offers a replicable framework for other industrial facilities seeking to minimize ecological footprints through integrated wastewater management.