Enhancement of anaerobic digestive efficiency by the use of exchange resin to remove cations in sewage sludge

Abstract

<p>Hydrolysis is considered as the rate-limiting stage of anaerobic digestion which is one of the most applied stabilization processes in the disposition of sludge. It is urgent to accelerate the hydrolysis of the sludge particles and improve its biodegradability. This study utilized cation-exchange resin (CER) to adsorb divalent cations in the supernatant of activated sludge with the purpose of making the sludge floc disintegrated. The results showed that the biopolymers incorporated in the tightly bound extracellular polymeric substances can be released to the bulk using CER to remove cations. However, the lack of essential elements led to a much lower methane yield of treated sludge than that of activated sludge. The treated sludge got a higher methane production rate constants after added Fe²⁺. It is necessary to add Fe²⁺ or regenerated liquid of resin-containing essential elements in order to maintain the activities of microbial life.</p