Abstract
Centralized wastewater treatment plants remove nutrients prior to discharge. Recently, technologies have become available to manage nutrients at different scales (individual buildings, neighborhoods/communities, or large centralized plants). Nutrient-recovery technologies applied upstream of the centralized treatment plant may affect both the wastewater flow rates and the nutrient fluxes reaching the plant. This study evaluates how the introduction of such upstream technologies affects the treatment efficiency and economics of nutrient management across a sewershed. Employing treatment technologies upstream from the centralized plant that receives highly loaded municipal wastewater could reduce nitrogen loading to the mainstream treatment train by over 50%, which generally reduces treatment plant effluent concentrations and saves money. In extreme cases, excessive upstream removal of nutrients can negatively affect biological treatment processes at the centralized treatment plant. Treatment of sidestreams at the centralized plant would likely be effective in reducing phosphorus loading, but not nitrogen loading, to the mainstream process.
