Sheng Xiao-Lin, Cui Can-Can, Wang Jia-de, Liu Rui, Xu Feng, Chen Lü-Jun
Zhejiang Provincial Key Laboratory of Water Science and Technology, Department of Environment in Yangtze Delta Region Institute of Tsinghua University, Jiaxing 314006, China.
College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
Huan Jing Ke Xue. 2018 Apr 8;39(4):1697-1703. doi: 10.13227/j.hjkx.201706191.
Nitrifying activated sludge (NAS) was enriched in a membrane bioreactor (MBR) with pre-treated municipal wastewater and additional ammonium sulfate as the culture medium. The influences of temperature, dissolved oxygen (DO), ammonia nitrogen volumetric load, free ammonia (FA), and free nitrite (FNA) on the enrichment of NAS were investigated, the cost of the process was evaluated, and then NAS's application in enhancing a wastewater biological treatment system against ammonia shocking loads was attempted. The results showed that after 182 days of cultivation in an MBR, NAS had a nitrification activity of 98.41 mg·(L·h), which was 30-times higher than that of the seeding sludge. The yield of NAS was 14.96 mg·(L·d), costing 3.52 Yuan for 1 kg. Temperature was found to be a key factor affecting the sludge nitrification activity. The sludge nitrification activity was decreased to 1/3 of the maximum value at temperatures below 15.0℃, while lowering the ammonium volumetric load retarded the decrease in the sludge nitrification activity to some extent. In addition, dissolved oxygen deficiency resulted in nitrite accumulation, and thereby slowed down the NAS enrichment rate. The enriched NAS was then applied to a wastewater biological treatment pilot equipment, which had just been exposed to an ammonium shocking load. The removal rate of ammonia nitrogen in the biological system increased from 29.4% to 88.4% after 2.0% of NAS was inoculated. The enhanced biological system retained ammonia removal rates of as high as 99.0%, even as the temperature dropped to 13.3℃±1.6℃ afterwards. The above pilot-experiment results suggested that enriched nitrifying sludge is suitable for quickly increasing the start-up or recovery rates of the nitrifying function in a biological system.
以预处理后的城市污水和额外的硫酸铵为培养基，在膜生物反应器（MBR）中富集硝化活性污泥（NAS）。研究了温度、溶解氧（DO）、氨氮体积负荷、游离氨（FA）和游离亚硝酸盐（FNA）对NAS富集的影响，评估了该过程的成本，然后尝试将NAS应用于增强废水生物处理系统以应对氨冲击负荷。结果表明，在MBR中培养182天后，NAS的硝化活性为98.41 mg·(L·h)，比接种污泥高30倍。NAS的产量为14.96 mg·(L·d)，每千克成本为3.52元。发现温度是影响污泥硝化活性的关键因素。在温度低于15.0℃时，污泥硝化活性降至最大值的1/3，而降低铵体积负荷在一定程度上减缓了污泥硝化活性的下降。此外，溶解氧不足导致亚硝酸盐积累，从而减缓了NAS的富集速率。然后将富集的NAS应用于刚遭受氨冲击负荷的废水生物处理中试设备。接种2.0%的NAS后，生物系统中氨氮的去除率从29.4%提高到88.4%。即使随后温度降至13.3℃±1.6℃，强化生物系统仍保持高达99.0%的氨去除率。上述中试实验结果表明，富集的硝化污泥适用于快速提高生物系统中硝化功能的启动或恢复速率。
