Nitrogen And Phosphorus Removing Form Swine Wasterwater By Sbbr Reactor Based On Activated Carbon Fiber

Since1990s, the development of large-scale livestock industry had solved the livestock supply and promoted rural economic development. However, it had also brought to the increasingly serious environmental pollution problems. The swine wastewater contains very high concentrations of pollutants such as nitrogen, phosphorus and organic matter. Swine wastewater is the main source of pollution in China’s agricultural non-point source. The current swine wastewater is treated mainly by one or the combination processes of anaerobic, aerobic and land treatment method. However, the disadvantages that ineffective of a single process and high cost of combined process made that pollution of the swine wastewater was not effectively controlled. This paper tried to removing nitrogen and phosphorus simultaneously from swine wastewater by a sequencing batch biofilm reactor (SBBR). The major objectives of this study are to study the influencing factors of removing nitrogen and phosphorus simultaneously from swine wastewater using SBBR and obtain the process parameters of treating swine wastewater as well as verify the reliability of the long-term stable operation.By three months of microorganism cultivation and domestication, the system initially had the removal capacity to nitrogen and phosphorus of pig wastewater. Then the effects of anaerobic and aerobic hydraulic retention time, dissolved oxygen concentration, COD/TN ratio on nitrogen and phosphorus removal were studied in this article under the conditions of the replacement rate of wastewater20%, temperature25℃and anaerobic circulation8L·min-1throughout the experiment. The phosphorus accumulating bacteria substantially complete release of phosphorus after3hours of anaerobic and the effluent removal rates of COD, NH4+-N, TP, TN reached77.6%,84.6%,64.3%and66.2%, respectively after7hours of aerobic. The effluent NH4+-N and TN concentrations were the best16.7mg·L-1and47.9mg·L-1when the concentration of dissolved oxygen was controlled between3.5mg·L-1to3.95mg·L-1. Simultaneous nitrification and denitrification phenomenon was observed. The effluent TN concentration can be further reduced to around35mg·L-1by the method of the external carbon source to making the COD/TN ratio11.4:1, while the effluent COD, TP did not change significantly. The reactor was run for15consecutive weeks under the condition of the above and the system showed stable removal of organic matter and nitrogen and phosphorus. Scanning electron micrographs of activated carbon fiber filler showed that the surface of the filler has a complex structure biological membrane. The material regeneration performance test showed that carbon fiber material had good regenerative performance and had a long service life. This means the activated carbon fiber filler has a good performance in forming biofilm and can be used as filler of SBBR system.