Effluent management for a metal finishing industry aiming zero discharge conditions

Technical applicability of zero discharge conditions is evaluated for the specific case of a large metal finishing industry located within the protection zone of a surface water body designated as a potential source for domestic water supply. Within the context of a sound water management strategy, a detailed process profile of the plant is established with relevant balance between water demand and wastewater generation. Quality restrictions for various water uses are identified. Wastewater flows are segregated depending on significant quality parameters. A comprehensive treatment scheme is defined for optimum wastewater recycle and reuse. Source allocation is made for the reuse of different streams of recycled wastewater. The study indicates that wastewater reuse can only be implemented with an efficiency of around 85-90% for the selected industry.