Ma Jieting, Chen Yunlu, Luo Gang, Nie Jianxin, Guo Zhigang, Liu Yan, Ma Luming
Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China.
College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
AMB Express. 2017 Dec;7(1):3. doi: 10.1186/s13568-016-0309-6. Epub 2017 Jan 3.
The concentration of total nitrogen (TN) (between 40 and 60 mg/L, mainly nitrate) in the biological and catalytic ozonation treated dyeing and finishing wastewater needs to be reduced before discharge. The present study investigated the feasibility of using waste iron shavings as electron donor for nitrogen removal by biological denitrification. Two anoxic sequencing batch reactors (AnSBR) were continuously operated for more than 100 days. The results showed that the TN removal efficiency increased from 12% in the control reactor (AnSBR-C) to 20% in the reactor with waste iron shavings (AnSBR-Fe). The TN removal was mainly achieved by the reduction of nitrate by heterotrophic denitrification and autotrophic denitrification for AnSBR-Fe. The residual COD (38.4 mg/L) in the effluent of AnSBR-Fe was higher than that (22 mg/L) in the effluent of AnSBR-C, which could be due to that the bacteria preferred to use iron instead of the recalcitrant organics that present in the wastewater. Furthermore, 3DEEM, UHPLC-QTOF and GC-MS analysis were used to characterize the organics in the wastewater, and the results showed that the addition of waste iron shavings affected the degradation of organics during the biological denitrification process.
生物和催化臭氧化处理后的印染废水在排放前，需降低其总氮（TN）浓度（40至60毫克/升之间，主要为硝酸盐）。本研究考察了利用废铁屑作为电子供体通过生物反硝化进行脱氮的可行性。两个缺氧序批式反应器（AnSBR）连续运行了100多天。结果表明，总氮去除效率从对照反应器（AnSBR-C）中的12%提高到了添加废铁屑的反应器（AnSBR-Fe）中的20%。AnSBR-Fe中的总氮去除主要通过异养反硝化和自养反硝化还原硝酸盐来实现。AnSBR-Fe出水的残余化学需氧量（38.4毫克/升）高于AnSBR-C出水的（22毫克/升），这可能是由于细菌更倾向于利用铁而非废水中存在的难降解有机物。此外，采用三维荧光光谱（3DEEM）、超高效液相色谱-四极杆飞行时间质谱（UHPLC-QTOF）和气相色谱-质谱联用（GC-MS）分析对废水中的有机物进行了表征，结果表明添加废铁屑影响了生物反硝化过程中有机物的降解。
