A/O与SBR工艺处理猪场废水厌氧消化液对比研究

Comparative study on A/O and SBR processes for the treatment of digested effluent of swine wastewater

缺氧/好氧工艺(A/O)与序批式活性污泥法(SBR)是应用最为广泛的猪场废水厌氧消化液好氧处理工艺,但两者的处理性能孰优孰劣,目前尚无定论。基于此,本研究对比了实验室规模的A/O与SBR工艺处理猪场废水厌氧消化液的性能。结果表明:两种工艺直接处理猪场废水厌氧消化液,出水pH值下降至6以下,平均NH_(4)^(+)-N去除率均低于50%,但SBR的NH_(4)^(+)-N去除率略高于A/O。补充碱度后,4个氮负荷(0.02,0.04,0.06,0.08 kg∙kg^(-1)∙d^(-1))下,两种工艺的NH_(4)^(+)-N去除率提高到99%以上,但对COD、TN和TP去除的改善不明显,并且A/O与SBR对COD、NH_(4)^(+)-N、TN、TP去除效果无显著差异。活性试验表明,SBR的氨氧化活性和厌氧氨氧化活性高于A/O,但是反硝化活性要显著低于A/O。Stover–Kincannon模型与试验数据拟合良好(R^(2)>0.9),A/O和SBR对COD、TN、NH_(4)^(+)-N的最大去除负荷(U_(max))分别为7.62、0.28、48.8 g∙L^(-1)·d^(-1)和7.18、0.13、65.4 g∙L^(-1)·d^(-1),说明SBR有利于NH_(4)^(+)-N转化,而A/O有利于COD与TN去除。

The anoxic/oxic(A/O)process and sequencing batch reactor(SBR)process are popular aerobic biological processes for the treatment of digested effluent of swine wastewater.However,it is unclear which process has better performance.Therefore,laboratory-scale A/O and SBR processes were applied to compare their performance for the treatment of digested effluent of swine wastewater.The results showed that when the A/O and SBR processes were used to treat the digested effluent directly,the pH decreased to less than 6,thereby resulting in an average NH_(4)^(+)-N removal efficiency of less than 50%.However,the NH_(4)^(+)-N removal efficiency in the SBR process was slightly higher than that in the A/O process.After the digested effluent was supplemented with alkalinity,the NH_(4)^(+)-N removal efficiency in the two processes was improved to more than 99%.However,the improvement of the removal efficiencies of chemical oxygen demand(COD),total nitrogen(TN),and total phosphorus(TP)was not clear.There was no significant difference between the A/O and SBR processes in removing COD,NH_(4)^(+)-N,TN,and TP.Higher NH_(4)^(+) oxidation and anammox activities were observed in the SBR process than in the A/O process,whereas the denitrification activity in the SBR process was much lower than that in the A/O process.The modified Stover-Kincannon model best fit the experimental data(R^(2)>0.9).The _(max)imum COD,TN,and NH_(4)^(+)-N utilization rates were 7.62,0.28,and 48.80 g∙L^(-1)·d^(-1) in the A/O process,and 7.18,0.13,and 65.4 g∙L^(-1)·d^(-1) in the SBR process,respectively.The results suggest that the SBR process is more favorable for NH_(4)^(+)-N conversion,whereas the A/O process is more favorable for COD and TN removal.