chapter  68
Role of Solid-Liquid Separation in the Removal of Zinc by Chemical Precipitation
Pages 6

Presence of heavy metals in the effluent streams from chemical and metal plating industries have been a major concern to communities and municipalities. Above certain limits each of these metals has a toxic effect on human and aquatic life. Moreover, as industrial discharges combine with the sanitary sewer streams for ultimate disposal, they pose added threat to the municipal wastewater treatment, since they severely interfere with microbiological processes, e.g., activated sludge, trickling filter, RBC treatment, etc., EPA and the regulatory agencies of individual states have set limits on the concentrations of all the metals commonly encountered in industrial wastewater streams. This requires the industries to treat their effluents in-house in order to reduce the levels of metals in the discharge streams within stipulated limits and fulfil the requirements to obtain discharge permits.