原位臭氧氧化对活性污泥系统硝化和反硝化作用的影响研究

摘要

将厌氧序批式间歇反应器(ASBR)和序批式间歇反应器(SBR)串联组成污泥减量新工艺,着重探讨了对SBR段进行原位臭氧投加时,臭氧氧化作用对系统硝化和反硝化能力的影响,并以不投加作为对照.结果表明,将臭氧原位投加到ASBR—SBR组合工艺的SBR段,臭氧投加量为0.027 g(以每克MLSS计),每隔3个周期再次投加、连续运行40 d,试验组SBR段臭氧投加当期出水COD去除率为86％,比对照组下降了9百分点,但臭氧氧化细胞内大量有机物进入混合液中,为反硝化作用提供了外加碳源,对污泥反硝化能力的提高起到了一定的促进作用；试验组部分硝化细菌由于臭氧的强氧化作用而失去活性,但是随着剩余污泥量的减少,系统的污泥龄延长,有利于硝化细菌的生长,使得系统的硝化能力基本未受影响；试验组臭氧投加当期SBR段出水NO2- -N平均浓度比对照组的高18.9％,但经过3个周期的运行后,其SBR段出水NO2- -N平均质量浓度降低至7.57 mg/L,基本与对照组持平；试验组臭氧投加当期SBR段出水NO3- -N的平均浓度高于对照组,但经过3个周期的运行后,试验组出水NO3- -N平均浓度低于对照组；试验组臭氧投加当期SBR段出水TN和对照组的出水TN平均去除率分别为65％和75％,但试验组再经过3个周期的运行后,出水TN平均去除率可以达到72％.可见,原位投加臭氧并未对SBR段的硝化和反硝化能力产生明显的影响.%The anaerobic sequencing batch reactor (ASBR) and SBR were combined to reduce the sludge production of activated sludge system. Two ASBR/SBR processes, with or without a sludge ozonation, were operated in parallel for 40 days. The effect of simultaneous sludge ozonation on nitrification and denitrification of ASBR/SBR process was investigated. In the test group (with sludge ozonation) ,ozone was added to the aeration stage of the SBR per 3 cycles with the dosage of 0. 027 g/g,the COD removal rate of SBR was 86% .which was 9 percent lower than control group (without sludge ozonation). While, because of the ozone oxidation, a large number of organic matter were released to the mixed liquor which provided a good carbon source for denitrification. Parts of nitrobacteria was deactivated due to the strong oxidation of ozone,but the decreasing excess sludge prolonged the system retention time which benefited the growth of nitrobacteria, so the nitrification capacity of combination process was not influenced. The average effluent NO^-N of test group was 18. 9% higher than that of control group,after 3 cycles of operation, the average effluent Nor-N was decreased to 7. 57 mg/L,which was flat to the control group. The effluent NO^-N of test group was first higher than that of control group, while it was less than the control group after 3 cycles of operation. The TN removal efficiency of test group and control group was 65% and 75% respectively,the TN removal efficiency of test group was increased to 72% after 3 cycles of operation. It was concluded that nitrification and denitrification in the SBR are not significantly influenced by simultaneous ozonation.