Pilot-scale multi-level biological contact oxidation system on the treatment of high concentration poultry manure wastewater

Abstract

Abstract A pilot-scale (5 m3/d) study was applied for the treatment of a high-strength poultry manure wastewater by using a multi-level biological contact oxidation tanks system with novel carriers. Firstly, four kinds of carriers including porous block carriers, sponge globoid carriers, fiber ball carriers, and suspend plastic carriers were compared at lab-scale experiment to choose the best performed carriers for the further application in pilot scale experiment. Then, the performance of the pollutants elimination during the whole pilot-scale reactor as well as the contribution efficiency of each tank under different influent pollutants loads were investigated. Finally, the biomass evaluation on the carriers and the mechanism of nitrogen removal were also explored. The conclusion showed that the effluent quality could satisfy the discharge standard of pollutants for livestock and poultry breeding industry (GB 18596-2001) when the influent organic load was less than 3.64 kg CODcr/(m3 d) during the pilot-scale system placed with the porous block carriers. The contact oxidation tank I dominated the average contribution efficiency of CODcr (89.2%), ammonia (69.6%), and the total nitrogen (57.3%) during the three-level biological contact oxidation tanks. The step-feed operational model was suggested to further increase the pollutants removal capacity of the following Tank II and Tank III. The oxygen-deficient environment of the biofilm and the proper three-dimensional spiral structure of the carriers were suitable for the happening of the simultaneous nitrification and denitrification occurred in the pilot-scale aerobic reactor.