College of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China; Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou 730070, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Bioresour Technol. 2022 Aug;357:127318. doi: 10.1016/j.biortech.2022.127318. Epub 2022 May 21.
Sponge iron (SI) can serve as an indirect electron donor to provide Fe(II) for the nitrate-dependent ferrous oxidation (NDFO) process, producing OH and magnetite. The SI-NDFO system mainly uses Fe(OH) as an electron donor, achieving a TN reduction rate of 0.42 mg-TN/(gVSS·h) for a period of at least 90 days. The enrichment of iron-oxidizing bacteria and the competition of iron-carbon micro-electrolysis for reaction sites on the surface of SI are the main reasons for the improvement of total nitrogen removal efficiency (TNRE). With an influent NO-N concentration of 50 mg/L and a SI concentration of 50 g/L (at pH 5.0 and 30 °C), the TNRE reached a maximum level of 38.28%. In addition, reducing the pH environment was found to improve the denitrification efficiency of the SI-NDFO system, although denitrification stability was also reduced as a result. Overall, the SI-mediated NDFO process is a promising technique.
海绵铁 (SI) 可作为间接电子供体，为硝酸盐依赖亚铁氧化 (NDFO) 过程提供 Fe(II)，从而产生 OH 和磁铁矿。SI-NDFO 系统主要利用 Fe(OH)作为电子供体，在至少 90 天的时间内实现了 0.42 mg-TN/(gVSS·h)的 TN 去除率。铁氧化菌的富集和铁碳微电解对 SI 表面反应位点的竞争是总氮去除效率 (TNRE) 提高的主要原因。在进水 NO-N 浓度为 50mg/L 和 SI 浓度为 50g/L（在 pH 值为 5.0 和 30°C 的条件下）时，TNRE 达到了 38.28%的最高水平。此外，降低 pH 值环境被发现可以提高 SI-NDFO 系统的反硝化效率，尽管这也导致了反硝化稳定性的降低。总的来说，SI 介导的 NDFO 工艺是一种很有前途的技术。
