EPA (Environmental Protection Agency) Design Information Report: Sidestreams in Wastewater Treatment Plants

摘要

Performance problems at publicly-owned treatment works are often attributed to the recycling of sidestreams generated in the wastewater treatment and sludge handling systems. Although the volumes of these sidestreams are generally small compared to plant influent flows, sidestreams can contain significant concentrations of organic and inorganic materials, either in solution or suspended solids form. These recycle loads can be considerably stronger and have characteristics different from the plant influent. Recycle of these sidestreams within the treatment plant without regard to their effects can cause process upsets, violation of discharge limits, release of odors, and increased operation and maintenance costs. The impacts of recycles can be reduced if sidestreams are adequately defined and accomodated in treatment plant design and operation. This report addresses handling of recycle flows and loads, sources and characteristics of sidestreams, potential adverse impacts of sidestreams on plant performance, design and operation procedures that can reduce sidestream impacts, and use of a mass balance to assess sidestream impacts. (Copyright (c) J. Water Pollution Control Federation, 59(1):54-59, January 1987.)