Abstract

A new, highly advanced kind of natural wastewater treatment (WWT) has been developed. Engineered bioreactors (EBs) evolved from subsurface flow (SSF) constructed wetlands (CWs) but now differ greatly from them. EBs are semipassive attached growth systems in which design, morphology, operating methods, substrates, flows, and/or other process conditions are manipulated and controlled to allow superior performance. There are several varieties of EBs, including aerobic and anaerobic versions. EBs usually form the secondary (2°) WWT component of more comprehensive engineered bioreactor systems (EB systems), which can also include primary (1°) WWT components (e.g., lagoons, cascades, filters, dosing equipment) and tertiary (3°) WWT components (e.g., ponds, CWs, phosphorus removal equipment, disinfection). The environmental/biological technology (ecotechnology) of EB systems allows the treatment of wastewaters containing even the most recalcitrant pollutants to high levels of removals in in-ground basins which can operate almost unattended at high efficiencies whatever the ambient water and air temperatures. Most aspects of the EB ecotechnology are fully developed and proven.