Technical Note 8 - Applicability of support medium based of polyurethane foam for systems used to post-treatment of anaerobic effluents

Abstract

Several technologies have been applied to post-treat anaerobic effluents. For most of those, a rigorous sludge management is needed. In this case, the use of sponge-based packing media in biofilm systems tends to significantly contribute to the minimization of sludge production and effluent quality improvement. Endogenous respiration and predation are important mechanistic processes explaining such improvements, which is related with the increase of the sludge retention time by the retention of biomass within the sponge. Depending on the operational condition, nitrogen removal is also observed in addition to the notorious performance for organic matter removal. Considering the advances for the post-treatment of anaerobic effluents with the use of sponge-based biofilm systems, this Technical Note aim to present: (i) fundamentals of biofilm systems using polyurethane sponge as support media; (ii) full-scale experiences with emerging sponge-based technologies; (iii) performance of sponge-based biofilm systems and operational conditions usually practiced; (iv) a preliminary critical analysis regarding implementation and operational costs; (v) advantages and disadvantages. The potential and limitations regarding the use of sponge-based reactors as post-treatment of anaerobic effluents are finally remarked.