Lu Zhikun, Xu Yifeng, Liang Chuanzhou, Guo Wenshan, Ngo Huu Hao, Peng Lai
Key Laboratory of Green Utilization of Critical Non-metallic Mineral Resources, Ministry of Education, Wuhan University of Technology, Wuhan, 430070, China; Shenzhen Research Institute of Wuhan University of Technology, Shenzhen, 518000, Guangdong, China.
Key Laboratory of Green Utilization of Critical Non-metallic Mineral Resources, Ministry of Education, Wuhan University of Technology, Wuhan, 430070, China; Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, China.
Chemosphere. 2025 Feb;370:143915. doi: 10.1016/j.chemosphere.2024.143915. Epub 2024 Dec 13.
Sulfur autotrophic denitrification (SADN) is regarded as a cost-effective bioremediation technology for nitrate-contaminated water. Nevertheless, the low bioavailability of sulfur is a major challenge that hinders nitrogen removal efficiency. A sulfur autotrophic disproportionation (SADP) process was proposed to convert sulfur to biogenic sulfide, greatly increasing the availability of electron donors. Throughout the 201-day laboratory-scale test, it was observed that the SADP process achieved desirable performance with 198.87 ± 39.8 mg S/L biogenic sulfide production per day, which could provide sufficient electron donors for the SADN process in treatment of 671.22 ± 134.40 mg N/L/d nitrate. Microbial community analysis confirmed the presence and dominancy of sulfur-disproportionating bacteria (SDB) (e.g., Desulfocaspa sp. taking up to 8.27% of the entire microbial community), while Thiobacillus was the most dominant genus of sulfur oxidizing bacteria (SOB), accounting for 87.32% of the entire community. Further experiments revealed that the addition of chemical and biogenic sulfides enhanced the nitrate removal rate of the SADN process by a factor of 1.31 and 1.34, respectively. Additionally, biogenic sulfide was found to be the most effective nitrous oxide (NO) mitigator, reducing emission by 82% and 95% in denitrification and denitritation processes, respectively. The results demonstrated that the integrated SADP and SADN processes was a more effective and carbon-neutral alternative in treatment of nitrate-contaminated water.
硫自养反硝化（SADN）被认为是一种用于处理硝酸盐污染水体的具有成本效益的生物修复技术。然而，硫的生物可利用性低是阻碍脱氮效率的一个主要挑战。人们提出了一种硫自养歧化（SADP）工艺，将硫转化为生物源硫化物，大大提高了电子供体的可用性。在为期201天的实验室规模试验中，观察到SADP工艺表现良好，每天产生198.87±39.8 mg S/L的生物源硫化物，可为处理671.22±134.40 mg N/L/d硝酸盐的SADN工艺提供足够的电子供体。微生物群落分析证实了硫歧化细菌（SDB）的存在及其优势地位（例如，脱硫荚菌属占整个微生物群落的8.27%），而硫氧化细菌（SOB）中最主要的属是硫杆菌属，占整个群落的87.32%。进一步的实验表明，添加化学硫化物和生物源硫化物分别使SADN工艺的硝酸盐去除率提高了1.31倍和1.34倍。此外，发现生物源硫化物是最有效的一氧化二氮（N₂O）减排物质，在反硝化和反亚硝化过程中分别使排放减少了82%和95%。结果表明，SADP和SADN集成工艺是处理硝酸盐污染水体更有效且碳中和的替代方案。
