MEMBRANE BIOREACTOR APPLIED TO THE TREATMENT OF A FRUIT PROCESSING INDUSTRY WASTEWATER IN NORTHEAST BRAZIL

Abstract

The market for Membrane Bioreactors (MBR) technology has recently grown due to increasingly strict standards for effluent discharge and the need for alternative water sources. The high quality of the effluent produced, enabling the possibility of reuse is one of the most attractive characteristics of this technology. The objective of this article was to evaluate the treatment efficiency of a pilot-scale MBR plant in a fruit processing industry, including an analysis of the possibilities for effluent reuse. The pilot plant comprised a MBR with approximately 5000L in capacity, with porous type ultrafiltration grade polyethersulfone membranes. Other details for the membranes were: submerged configuration, flat plate type geometry, pore diameter ranging from 0.035 to 0.1 μm and total area of 25m². The industrial effluent came from fruits processing, floors and machinery washing, and was characterized by physical, chemical and bacteriological parameters. Results showed that permeability decreased about 50% during the monitoring, indicating the need of membrane cleaning. The removal efficiency for COD, BOD 5 , total nitrogen and total phosphorus, was 97.1%, 98.7%; 95.7 % and 53.5%, respectively. There was an absence of both total coliform and E. Coli at the inlet and outlet of the system. The permeate fits into agricultural, urban, environmental, industrial and aquaculture reuse modalities.