School of Energy and Environment, Southeast University, Nanjing, 210096, China; State Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing, Jiangsu, 210096, China.
School of Energy and Environment, Southeast University, Nanjing, 210096, China; Huatian Engineering & Technology Corporation, Nanjing, Jiangsu, 210019, China.
Environ Res. 2020 Oct;189:109937. doi: 10.1016/j.envres.2020.109937. Epub 2020 Jul 15.
A three-dimensional biofilm-electrode reactor (3D-BER) was constructed to facilitate the tertiary denitrification of the secondary effluent of wastewater treatment plants (SEWTP) under 12 mA and in the absence of a carbon source. The TN removal efficiency was 63.8%. The path of the formation and transformation of nitrogen, the relationship between the TN and COD removal rate and the relative concentration and composition of organic matter in the influent and effluent were analyzed to clarify the possible pathways of N and C transformation in the 3D-BER system. Under the action of an electric current, 4.4 mg NH-N·L and 17.7 mg COD·L accumulated in the 3D-BER system, and the removal rates of TN and COD were strongly and positively correlated (R = 0.9353). The microorganisms in the 3D-BER system under the action of electric current secreted organic matter, some of which (humic acid and microbial metabolites) could be further electrolyzed by microorganisms into bioavailable organic matter for heterotrophic denitrification. Partially dissolved organic matter (DOM, tryptophan aromatic protein, humic acid and microbial metabolites) in the SEWTP could be hydrolyzed under the action of the electric current in the 3D-BER system and consisted of bioavailable organic matter for heterotrophic denitrification. The contribution of heterotrophic denitrification to TN removal was greater than 11.7%. Therefore, the 3D-BER system removed a portion of DOM through microbial electrohydrolysis and promoted the coupling of hydrogen autotrophic denitrification and heterotrophic denitrification to enhance the effectiveness of nitrogen removal in SEWTP. Overall, this technique is effective for enhancing tertiary denitrification in SEWTP.
构建了三维生物膜-电极反应器（3D-BER），以促进在 12 mA 且不存在碳源的情况下处理废水处理厂（SEWTP）二级出水的三级反硝化。TN 去除效率为 63.8%。分析了氮的形成和转化途径、TN 和 COD 去除率之间的关系以及进水和出水有机物质的相对浓度和组成，以阐明 3D-BER 系统中氮和碳转化的可能途径。在电流的作用下，4.4 mg NH-N·L 和 17.7 mg COD·L 在 3D-BER 系统中积累，TN 和 COD 的去除率呈强正相关（R=0.9353）。电流作用下的 3D-BER 系统中的微生物分泌有机物质，其中一些（腐殖酸和微生物代谢物）可以被微生物进一步电解成可用于异养反硝化的生物可利用有机物质。SEWTP 中的部分溶解有机物质（DOM、色氨酸芳香蛋白、腐殖酸和微生物代谢物）可以在 3D-BER 系统中的电流作用下被水解，形成可用于异养反硝化的生物可利用有机物质。异养反硝化对 TN 去除的贡献大于 11.7%。因此，3D-BER 系统通过微生物电水解去除了一部分 DOM，并促进了氢自养反硝化和异养反硝化的耦合，从而增强了 SEWTP 中氮去除的效果。总体而言，该技术有效增强了 SEWTP 的三级反硝化。
