(300h) Investigation of the Degradation of Endocrine Disrupting Compounds in a Membrane Bioreactor
The presence of endocrine disrupting compounds (EDCs) and pharmaceutically active compounds (PHAC) in sewage, industrial, and domestic waters is becoming a major health and environmental concern. The traditional activated sludge process is designed to eliminate solids, organic carbon and nitrogen loadings from wastewaters, but not trace contaminants such as EDCs. Membrane bioreactors (MBR) have become a preferred method for treating municipal and other industrials wastewaters. The objective of this study is to use advanced membrane technologies to develop wastewater treatment processes for removal of EDCs in order to recover and reuse wastewater to augment drinking water supplies. A set of model EDCs including acetaminophen, amoxicillin, atrazine, estrone, and triclosan were selected to study the removal by membrane bioreactor to represent different classes of compounds. Lab-scale MBR operated with real wastewater was tested under various operating conditions, such as retention time and volatile suspended solids concentrations to remove the spiked EDCs. The MBR was operated in two configurations batch and semi-continuous. In both operating modes, the module MBR can reach desired chemical oxygen demand (COD < 30 ppm), total ammonia nitrogen (TAN <5 ppm), and nitrate nitrogen (NO3-N< 5 ppm) in different retention times. Concentrations of the targeted EDCs and PHAC in the influent, effluent, and mixed liquor suspended solids of the two reactors at different retention time were determined in the period of operation. Different modes of removal mechanisms for these EDCs were identified.