COMBINING BIOLOGICAL AND PHYSICAL PROCESSES FOR COMPLETE TREATMENT OFOILY WASTEWATERS

A novel process system for wastewater treatment has been developed tha t combines the use of biological and physical processes. This system, called the membrane biological reactor (MBR) system, consists of a sus pended growth biological reactor combined with a membrane ultrafiltrat ion unit process. The MBR system is particularly attractive when appli ed in situations where long biological solids retention times are nece ssary, and physical retention and subsequent hydrolysis are critical t o achieving biological degradation of pollutants. In order to develop full scale process and design information, field pilot studies were co nducted for several months. These pilot studies involved assessing sys tem performance and developing system design information in the treatm ent of wastewaters from metalworking automotive plants. The results of the pilot studies provided the basis for the design of a full scale d emonstration MBR system for treatment of industrial oily wastewaters. Information is presented on system design as well as operation and per formance. Despite certain design issues, to date the system has met or exceeded performance expectations.