MOVING-BED BIOFILM REACTORS AND CHEMICAL PRECIPITATION FOR HIGH-EFFICIENCY TREATMENT OF WASTE-WATER FROM SMALL COMMUNITIES

A new Moving Bed Biofilm Reactor (MBBR) has been developed, where the biomass is attached to small plastic elements that move freely along w ith the water in the reactors. Several small biological/chemical waste water treatment plants are now using the MBBR process. Official contro l samples have shown that these plants are very reliable. The average effluent concentrations from the plants surveyed, three retrofits and two originally designed with the MBBR process, were as low as 11 mg BO D7/l(similar to 9 mg BOD5/l), 11 mg SS/l and 0.26 mg total P/l. Approx imately 2 man hours per week were needed for operation of a plant orig inally designed with the MBBR process. (C) 1997 IAWQ. Published by Els evier Science Ltd.