| In recent years,China’s rising of groundwater nitrate pollution of groundwater in excessive amounts of nitrate on human health and the natural environment caused great threat,so how to safe and efficient nitrogen has become the research focus of modern water treatment technologies,including sulfur autotrophic denitrification denitrification technology because it has no additional carbon source,and low sludge production quantity is gradually widely used.The traditional packing used in sulfur autotrophic denitrification is made by mixing elemental sulfur and limestone particles according to a certain volume ratio.The diameter of the particles is small and not the same.The mixing way of the diameter of the filler cannot be controlled and the volume ratio cannot be used as the accurate standard to measure the total amount of substance.In order to solve this problem,a variety of new packing methods were tried in this subject,and the quality ratio was taken as the new mixing standard.On this basis,influences of various factors on the reactor efficiency were explored,and the sulfur autotrophic denitrification process was further improved.In this paper,two new ideas were proposed for making packing method,respectively normal temperature solidification method and high temperature melting method,and the feasibility of the latter method in the process of sulfur autotrophic denitrification was proved by experiments.Then on the basis of the use of artificial simulated wastewater sludge inoculation and domestication,the reactor starts successfully,follow the principle of control experiment,to explore the three kinds of quality of sulfur/limestone than(3:2,3:1,2:1)influence on reactor treatment effect,found that when sulfur/limestone quality ratio of 2:1,in different HRT and fill the NO3--N of the reactor at concentration,the removal rate of NO3--N was the highest,and the initial growth rate of microorganisms in the system was faster,among which NO3--N was higher than HRT at 4h removal rate can be maintained above 70%basically.After determining that the optimum mass ratio of sulphur/limestone in the filler is 2:1,the effect of reflux on the experimental effect is explored,and three water NO3--N are set in the experiment concentration was 50mg/L,100mg/L and 150mg/L respectively,and four refl ux ratios were preliminarily set as 100%,200%,300%and 400%.It was found in the experiment that the treatment performance of the reactor was greatly improved by setting reflux,and the lifting effect was high water NO3--N concentration and high reflux ratio are more significant,but when the reflux ratio reaches 400%,the water load of the reactor reaches its limit,NO3--N removal rate began to decline,accompanied by sludge loss.Are the major factors affecting sulfur autotrophic denitrification process of stuffing diameter,dissolved oxygen,temperature,HRT,pH,this topic on the above-mentioned five kinds of influence factors in the control of political reform were analyzed one by one,to explore,find the appropriate to reduce the diameter of packing and dissolved oxygen are conducive to the denitrification process,lower HRT to cause a decline in reactor treatment effect,and determine the optimal denitrification of the system temperature is 35℃,the optimal denitrifying pH of 7.On this basis,multi-factor optimization analysis was carried out by using the corresponding surface method,and a BBD test model was established for the reactor effluent NO3--N The peak value of removal rate was predicted,and the interaction effects of three variables including temperature,HRT and pH were further explored through 2D contour map and 3D curved surface map,and the optimal process parameters of the reactor were obtained. |
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