Removals of Nutrients and Organic Matter in Swine Manure Using a Lab-scale Sequencing Batch Reactor

摘要

The disposal of swine wastewater poses a considerable challenge for both farmers and the environment. Simultaneous biological nitrogen and phosphorus removals from solids separated swine wastewater with high organic matter were investigated in a lab-scale anaerobic-anoxic-anaerobic-anoxic/aerobic sequencing batch reactor ((AO)2SBR). The SBR was operated with three cycles per day, temperature at 20°C, sludge retention time (SRT) at around 22 days and hydraulic retention time (HRT) at three days. Under the periodical circulation with different oxidation-reduction status, the biological process of nitrification-denitrification contributed to the overall nitrogen removal up to 99.1%, compared to total nitrogen in the feeding influent. The biological removal of phosphorus that is believed to be the work of phosphorus-accumulating organisms could reach the ranges of 97.7%o to 99.3%ofor total phosphorus (TP) and 69.7%> to 98.1%) for soluble phosphorus (SP), depending on the ratio of BOD5 to phosphorus inthe feeding wastewater. The (AO^SBR system showed a stable organic matter removal performance. The average removal efficiencies of COD were over 93.9% while nearly 100% of BOD5 was broken down after one cycle of SBR operation. The acetate added along with the primary influent feeding would be more beneficial to improve the nutrients/organic matter removal rates as well as the quality of effluent