TESTING TWO DIFFERENT MEMBRANE BIOREACTOR CONFIGURATIONS ON INDUSTRIAL WASTE

Two different bench-scale membrane bioreactors (MBRs) were operated for a period of five months on high-strength process wastewater produced by fruit fly rearing operations. The two configurations tested included a flat-plate submerged MBR system by Enviroquip (Kubota membranes) and a hollow-fiber submerged MBR system by Zenon. The study consisted of four phases. In the last phase several processes (ozonation, hydrogen peroxide, potassium permanganate, granular activated carbon, and reverse osmosis) were evaluated for post MBR treatment to remove residual color and odor. It was found that the MBR treatment system is a viable option for treatment of the subject wastewater and further that it produces a very high quality effluent. Fortunately, this unique process wastewater did not immediately foul or blind the membranes and long-term stable operation seems feasible. There are differences between the two membrane systems examined and there will be differences between the bench-scale units tested and any actual full-scale units. Based upon the tests conducted here, it is apparent that either system would be suitable and final selection would be dependent upon a combination of capital cost and an analysis of differences in operational costs (electrical costs, membrane cleaning, membrane replacement) and operational ease/difficulty since staffing will be minimal.