pH对BF-MBR工艺处理高强度生活废水的影响

Effect of pH on the treatment of high strength domestic wastewater by BFMBR process

受控生态生保系统中生活废水污染强度大,生物转化后回用于植物培养是废水资源化的有效途径,但面临氮素稳定转化难、碱度消耗较大的问题。以BF-MBR工艺(生物膜耦合膜生物工艺,biofilm-membrane bioreactor)为研究对象,研究了不同pH条件下的好氧硝化性能及硝化动力学,并考察了硝化过程的碱度消耗情况。结果表明,在pH=6.0~7.2内,好氧生物反应器均能获得良好的氨氧化效果,而在pH=6.0~6.5的条件下更有利于全程硝化的维持;氨氧化速率随pH的增加而增大,而亚硝氧化速率在pH 6.6时达到最高;酸性条件下的碱度消耗量远低于碱性条件,而氢氧化钾作为碱液时的消耗量比碳酸氢钾低3.28 g·g^(-1)。从物料损耗和工艺处理效果综合考虑,硝化系统中最佳的pH可调控在6.4~6.5,此时全程硝化率可达97.8%。以上研究结果可为受控生态生保系统中生活废水处理系统的设计和运行提供参考。

The pollution of domestic wastewater in the controlled ecological life support system(CELSS)is serious.The reuse for plant culture after biological transformation of this domestic wastewater is considered an effective way to resource utilization.However,there are still challenges such as the stability of nitrogen transformation and high alkalinity consumption in the process.In the present study,the biofilm-membrane bioreactor(BF-MBR)process was used to investigate the performance of aerobic nitrification and nitrification kinetics under different pH conditions,and the alkalinity consumption in the nitrification process.The results demonstrated that the aerobic bioreactor had a good ammonia oxidation capability in the range of pH=6.0~7.2,and pH=6.0~6.5 was more conducive to the maintenance of full nitrification.The rate of ammonia oxidation rose as pH increased,while the rate of nitrite oxidation reached its maximum at pH=6.6.The consumption of alkalinity under acidic conditions was much lower than that under alkaline conditions,and the consumption of KOH as alkali liquor was 3.28 g·g^(-1) lower than that of KHCO_(3).The optimal pH for the aerobic nitrification system could be adjusted to the range of 6.4~6.5 based on the comprehensive analysis of material consumption and treatment effect by the process,then the full nitrification rate could reach 97.8%.The findings of the study can provide a reference for the design and operation of domestic wastewater treatment system in CELSS.