Wastewater treatment

摘要

Today, some 15,000 companies in the United States perform electroplating and metal finishing operations. These firms discharge their spent process wastewaters either directly to rivers and streams, or indirectly to Publicly Owned Treatment Works (POTWs). Metal finishing, by far, comprises more individual wastewater discharges than any other industrial category. Typically, pollutants contained in metal finishing process waters are potentially hazardous, therefore, to comply with Clean Water Act requirements, the wastewaters must be treated, or contamination otherwise removed, before being discharged to waterways or POTWs. Regulations, in general, require oxidation of cyanides, reduction of hexavalent Chromium, removal of heavy metals, and pH control.