Treatment of Anaerobically Digested Cattle Manure Wastewater by Tubular Ultrafiltration Membrane.

A resurgent interest in anaerobic treatment of organic wastes intrigues the subsequent wastewater purification and nutrient recovery. This study investigated the feasibility of tubular ultrafiltration to treat anaerobically digested wastewater (AnDW) in the pilot-scale. Due to the gel-layer filtration mechanism, which primarily governed the AnDW wastewater passing through the membrane module, the change of operating pressure in the experimental conditions showed a minor effect on the permeate flux, while the cross-flow tangential velocity showed a significant effect on the permeate flux. A permeate flux on average of 22 l m−2 h−1was obtained when the feed superficial-velocity was up to 2 m s−1. The permeate flux decreased with increasing suspended solid concentration, implying a potential advantage of preliminary solid-liquid separation such as mechanical centrifugation. Irrespective of the arranged order of the sequential cleaning, the fouled membrane can be successfully cleaned using specific cleaning agents, which included a weak acid, a detergent, and an oxidant, respectively. A commercial detergent, namely KLD II, exhibited the greatest contribution to the flux recovery during the sequential cleaning. [ABSTRACT FROM PUBLISHER]