Biological Pretreatment for Membrane Systems. Agreement No. 98-FC-81-0010. Desalination and Water Purification Research and Development Program Report No. 79.

摘要

Investigators at the Center for Biofilm Engineering proposed a technology to increase the biological stability of water to be further processed by reverse osmosis membrances. It was proposed to reduce membrance fouling by pretreating feed water using biological reactors to remove organic nutrients that support formation of fouling biofilms. The goal of the work was to determine if biological pretreatment can reduce fouling in membrane systems. Specific objects include: (1) determine if biological pretreatment using biologically active carbon and iron oxide coated sand as support media will reduce downstream fouling; (2) determine if chlorination as an oxidation step for feed water will influence downstream fouling; (3) determine if filtration of feed water will reduce downstream fouling; and (4) develop evaluation methods of these objections by developing and testing assays. The results of this work supported the acceptance of all objectives except the use of chlorination as an oxidation step for the organic amendment. The biological treatment coupled with filtration resulted in the best reduction in downstream fouling as measured by the assays employed. The reduction shown in biofilm cell numbers supported the assumptions made in the cost analysis.