Huang Zhenzhen, Gao Jingqing, Liu Lina, Mao Yanli, Kang Haiyan, Song Zhongxian, Cai Ming, Guo Pengcheng, Chen Kai
School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China; Faculty of Environmental and Municipal Engineering, Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China.
School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China.
J Environ Manage. 2024 Nov;370:123042. doi: 10.1016/j.jenvman.2024.123042. Epub 2024 Oct 28.
Sulfur autotrophic denitrification technology is a promising nitrogen removing process and is suitable for the tail water of sewage treatment plants with easy biodegradation and low C/N ratio. Nitrogen removal efficiency and along-path variation of related product concentrations in the sulfur-siderite autotrophic denitrification (SSAD) and sulfur-limestone autotrophic denitrification (SLAD) systems were comprehensively investigated in this work. The optimal denitrification conditions for SSAD and SLAD systems were pH of 7, HRT of 3 h, temperatures of 20-25 °C with NO-N removal rates of more than 99%. Although a greater capacity for alkalinity was provided by limestone than siderite, siderite can also meet the advanced nitrogen removal of SSAD system. A transient accumulation of NO-N in the SLAD system eventually decreased to 0.02 mg/L, while S concentration gradually increased relative to SSAD. It might be due to the fact that Fe promoted the nitrogen removal efficiency of SSAD system and further reduced the content of intermediates in the nitrogen removal process. The results obtained may provide the scientific basis and technical countermeasures for the application of sulfur autotrophic denitrification in actual low-C/N wastewater.
硫自养反硝化技术是一种很有前景的脱氮工艺，适用于易生物降解且碳氮比低的污水处理厂尾水。本研究全面考察了硫-菱铁矿自养反硝化（SSAD）和硫-石灰石自养反硝化（SLAD）系统中的脱氮效率以及相关产物浓度的沿程变化。SSAD和SLAD系统的最佳反硝化条件为pH值7、水力停留时间3小时、温度20-25℃，硝酸盐氮去除率超过99%。虽然石灰石提供的碱度能力比菱铁矿大，但菱铁矿也能满足SSAD系统的深度脱氮需求。SLAD系统中硝酸盐氮有短暂积累，最终降至0.02mg/L，而相对于SSAD，硫浓度逐渐增加。这可能是因为铁提高了SSAD系统的脱氮效率，并进一步降低了脱氮过程中中间产物的含量。所得结果可为硫自养反硝化在实际低碳氮比废水中的应用提供科学依据和技术对策。
