Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences
National Natural Science Foundation of China (No. 52070179); The Science and Technology Service Network Program of Chinese Academy of Sciences (STS Program)(No. KFJ-STS-QYZD-162)
针对传统的填充床硫自养反硝化工艺填料用量大、水头损失严重以及反应器易堵塞等问题，采用硫涂层接触反硝化工艺进行模拟污水脱氮研究，主要考察了反应器内部的填料填充比、温度以及水力停留时间（HRT）对其脱氮性能的影响。结果表明，在进水NO3--N浓度为50 mg·L-1，温度为（25±1）℃，HRT=19.5h时，将填料填充比由1/10增大到1/5，NO3--N的去除效果明显提升，由56.77%提升至78.26%；温度的变化对反应器脱氮有很大的影响，当填料填充比为1/5，HRT=19.5h时，在（25±1）℃和（30±1）℃条件下，NO3--N的平均去除率分别为71.05%和98.38%；此外，当HRT降低至9.7h时，NO3--N的平均去除率为89.29%。整个反应过程中，出水NO2--N浓度均很低，保持在0.4 mg·L-1以内，并且反应器出水pH值保持在6.8-8.3之间，满足微生物生长所需的pH条件。硫涂层接触反硝化系统的硫自养反硝化优势菌属是Thiothrixs、Thiomonas和Sulfuritalea，其占比分别为2.89%、1.55%和1.35%。微生物功能预测结果表明，硫氮代谢对系统脱氮起着关键作用。
For the traditional packed bed sulfur autotrophic denitrification process has the problems of large filling dosage, serious head loss, easy blockage of the reactor and so on, the nitrogen removal of simulated wastewater by contact denitrification process with sulfur coating was studied. The effects of filler filling ratio, temperature and hydraulic retention time (HRT) on the denitrification performance of the reactor were investigated. The results showed that with influent of NO3--N 50 mg·L-1, the temperature was (25±1)℃, and HRT=19.5h, the NO3--N removal efficiency was significantly improved with the filler filling ratio increased from 1/10 to 1/5 and the NO3--N removal rate increased from 56.77% to 78.26%. Temperature has a great influence on the denitrification in the reactor. When the filler filling ratio was 1/5 and HRT=19.5h, the average NO3--N removal rates were 71.05% and 98.38% at (25±1 )℃ and (30±1)℃, respectively. Moreover, when HRT was reduced to 9.7h, the average NO3--N removal rate was 89.29%. During the whole reaction process, the effluent NO2--N concentration was very low, kept within 0.4 mg·L-1. And the effluent pH value of the reactor was maintained between 6.8 and 8.3, which met the pH conditions required for microbial growth. The sulfur autotrophic denitrification?dominant bacteria of sulfur coating contact denitrification system were Thiothrixs、Thiomonas and Sulfuritalea, with the proportions of 2.89%、1.55% and 1.35%, respectively. The result of microbial function prediction showed that sulfur and nitrogen metabolism plays a key role in denitrification of the system.