Experimental Study On Enhanced Denitrification By SBR Process With Staged Inflow

With the vigorous promotion of ecological civilization construction in China,environmental supervision has been strengthened,and relevant sewage discharge standards have become increasingly stringent.Due to the limitations of traditional biological denitrification process and the influent characteristics of low C/N ratio,it is difficult for the existing municipal sewage treatment plants to achieve efficient denitrification.Therefore,it is urgent to develop enhanced biological denitrification wastewater treatment process.This study will be segmented into the water and the SBR(Sequencing Batch Reactor)method to build A new type of enhanced biological denitrification process,on the basis of the theoretical derivation,system to study the Hydraulic retention time(Hydraulic retention time,HRT),the number of segments,the A/O(anaerobic/aerobic)longer than inflow discharge distribution ratio of process parameters on the pollutant removal effect,optimization of process operation,low carbon nitrogen ratio of sewage for practical engineering provides the theory basis for efficient nitrogen.The main research contents and results are as follows:(1)When the A/O time ratio is 1:2,the effect of hydraulic retention time on pollutant removal efficiency is investigated under the three different HRT operating conditions of 6 h,7.5h and 9 h.It is found that different HRT has little effect on the removal efficiency of COD and NH₄⁺-N,but great effect on TN.When the HRT is 9 h,TN removal efficiency is the best.(2)Theory is derived the optimal segmentation number for the 3 cases,in HRT for 9 h,time of A/O ratio of 1:2 condition analysis compares the pollutants removal in paragraph 1,2,3,is found that:with the improvement of block number,the final in three period of TN removal effect is best,because in the actual operation of oxygen shorter incomplete inflow denitrification carbon source utilization rate is low,the system actual TN removal efficiency have not reached the theoretical value.(3)In section 3,HRT for 9 h,flow distribution ratio of 6:3:1 running conditions,through the optimization of A/O time than found that by extending completely anoxic period is not only beneficial to denitrification process,and to strengthen the simultaneous nitrification denitrification to improve the effect of TN removal,2:1 ratio of A/O time,TN removal effect is best,on the basis of adjusting paragraphs feed water flow is found that reasonable distribution of each section of the water volume can improve the effective utilization rate of anoxic period of carbon source,the flow distribution ratio of 5:3:2,TN removal effect is best.Finally,the optimal working conditions are obtained as follows:the number of segments is 3,HRT is 9h,A/O time ratio is 2:1,and flow distribution ratio is 5:3:2.Under the optimal operating conditions,the degradation of COD and NH₄⁺-N conforms to the first-order reaction kinetics equation,and the rate of nitrification and denitrification in the system is related to the number of microorganisms.