An Experimental Study On Nitrogen And Phosphorus Removal Of The Sequencing Biofilm Batch Reactor

The issue of eutrophication in the water body caused by the emission of the nitrogen and phosphorus wastewater under standard is increasingly serious,with the stricter and higher of the water quality indicator system,the problems of removal nitrogen and phosphorus in the wasterwater becomes a hot topic in the water pollution control.This paper proposed a sequencing batch biomembrane reactor (SBBR) to treat the anaerobic digestive juice from the piggery wastewater,basing on a comprehensive understanding of the latest research results about the removal of nitrogen and phosphorus in domestic and abroad.This article studied the rule of hanging of the biomembrane,and had determined the best operating condition,then run the best conditions to deal with the anaerobic digestive juice from the piggery wastewater which is high in NH₄⁺-N concentrations and low biodegradability,and discussed effects of the elements to nitrogen and phosphorus removal performance in the SBBR reactor,the main conclusions of the study are as follows:1) This research cultivated and domesticated the biomembrane through the ways of stuffy insolation and aeration in intermittent,the removal rates of COD,NH₄⁺-N, TP achieved respectively 85%,90%,87%after the mature of domesticated biomembrane.2) It determined the operating condition of SBBR:time of entering water, anaerobic,aerobic,precipitation,drainage,idle,discharging sludge is respectively 0.25h,3h,7h,0.5h,0.25,1h,7day.3) The experiment using the SBBR reactor to treat the anaerobic effluent of the piggery wastewater to eliminate the nitrogen and phosphorus indicated that:the pollutant elimination effect is bad when the SBBR reactor directly deal with anaerobic digestive juice.The removal rate of COD is only about 10%,effluent COD is about 1000mg/L,the removal rate of NH₄⁺-N is above 72.1%,the effluent NH₄⁺-N reaches above 115mg/L,the total average removal rate of phosphorus achieves 73.7%.4) Towards the problem which the carbon source is insufficient regarding the anaerobic effluent of the piggery wastewater,the test result indicated that:Increasing the partial raw waters in the anaerobic digesting juice,the pollutant elimination efficiency enhances distinctly,the removal rate of COD is higher than 83%,the effluent COD falls to 233.72～305.85mg/L;The removal rate of NH₄⁺-N is higher than 96%,the effluent NH₄⁺-N is smaller than 35mg/L;In the reactor,nitration reaction is prominent by the sub-nitration reaction(the ratio that NO₂^--N accounts for the nitric nitrogen is 64.7%);The removal rate of TN increases to 52.16%～58.13%;the removal rate of TP increased 81.21%～82.97%,the stability of the system has also been enhanced.5)The impact of factors about anaerobic digestive juice of piggery wastewater of nitrogen and phosphorus removal experimental study showed that:the lower the ratio of water distribution,the effluent NH₄⁺-N concentration increased sooner,the greater the range;the addition proportion of raw wastewater must be more than 30%to ensure normal operation of aerobic treatment of anaerobic digestive juice;an increase in the concentration of ammonia in entering water will inhibit the reaction,and the greater the concentration,the more obvious,the removal rate of the total nigtrogen and the total phosphorus reduced;at the same time pH should be controlled between 6.0～8.5;In addition,the reactor to achieve a good effect of nitrogen removal,there must ensure that the system has a certain amount of carbon,that is,a suitably COD concentration in influent water.The results of the research which will provide the scientific guides for the project practice to treat the anaerobic digestive juice from piggery wastewater,are of great guiding significance.