By the time sewage has arrived at a wastewater treatment plant, it is in the form of a thin liquid which contains food materials, human waste, detergents, fats, oils and greases, sand clay, paper fibres as well as other waste chemicals and debris.
United States Office of Water December 1989 Environmental Protection (WH-552) EPA 800/B-89/001 Agency (EN-336) Aluminum, Copper, And Nonferrous Metals Forming And Metal Powders Pretreatment Standards A Guidance Manual
Heavy Metal Wastewater Treatment - oberlinfilter.com
Effluent Guidelines are national standards for industrial wastewater discharges to surface waters and publicly owned treatment works (municipal sewage treatment plants). We issue Effluent Guidelines for categories of existing sources and new sources under Title III of the Clean Water Act.