| 城镇生活污水处理厂出水硝酸盐浓度及同位素组成的影响因素 |
| 摘要点击 2819 全文点击 1005 投稿时间：2022-06-25 修订日期：2022-08-15 |
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| 中文关键词 城镇污水处理厂 氨盐 硝酸盐 氮转化 氮和氧同位素 |
| 英文关键词 waste water treatment plant ammonia nitrate nitrogen transfer nitrogen and oxygen isotopes |
| 作者 | 单位 | E-mail | | 张东 | 河南理工大学资源环境学院, 焦作 454000 | zhangdong@hpu.edu.cn | | 葛文彪 | 河南理工大学资源环境学院, 焦作 454000 | | | 赵爱萍 | 康达环保水务有限公司, 焦作 454000 | | | 高振朋 | 河南理工大学资源环境学院, 焦作 454000 | | | 陈昊 | 河南理工大学资源环境学院, 焦作 454000 | | | 张琮 | 河南理工大学资源环境学院, 焦作 454000 | | | 蒋浩 | 中国科学院武汉植物园, 武汉 430074 | | | 吴文阳 | 河南理工大学资源环境学院, 焦作 454000 | | | 廖琪 | 河南理工大学资源环境学院, 焦作 454000 | | | 李成杰 | 河南理工大学资源环境学院, 焦作 454000 | | | 黄兴宇 | 河南理工大学资源环境学院, 焦作 454000 | | | 麻冰涓 | 河南理工大学资源环境学院, 焦作 454000 | |
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| 中文摘要 |
| 城镇生活污水是地表水硝酸盐(NO-3)的重要来源,但其NO-3浓度和同位素组成(δ15 N-NO-3和δ18 O-NO-3)仍不明确,特别是污水处理工艺对出水NO-3浓度、δ15 N-NO-3和δ18 O-NO-3影响仍不清楚.选择焦作市污水处理厂作为研究载体,每隔8 h收集污水厂进水、二沉池出水以及总排口出水样品,连续收集3 d,分析NH+4浓度、NO-3浓度以及δ15 N-NO-3和δ18 O-NO-3组成变化,说明处理工艺对氮转化、出水NO-3浓度及δ15 N-NO-3和δ18 O-NO-3组成的影响过程.结果发现:① ρ(NH+4)均值在进水口为(22.86±2.16) mg·L-1,二沉池出水降低至(3.78±1.98) mg·L-1,总排口出水减小到(2.70±1.98) mg·L-1;进水ρ(NO-3)中间值为0.62 mg·L-1,二沉池出水ρ(NO-3)均值升高至(33.48±3.10) mg·L-1,总排口出水ρ(NO-3)均值增加到(37.20±4.34) mg·L-1;②进水δ15 N-NO-3和δ18 O-NO-3均值分别为(17.1±10.7)‰和(19.2±2.2)‰,二沉池出水δ15 N-NO-3和δ18 O-NO-3中间值分别为11.9‰和6.4‰,总排口出水δ15 N-NO-3和δ18 O-NO-3均值分别为(12.6±1.9)‰和(5.7±0.8)‰;③进水NH+4浓度与二沉池出水和总排口出水NH+4浓度存在显著差异(P<0.05),二沉池出水NH+4浓度降低与好氧处理工艺中NH+4发生硝化作用有关,二沉池出水NH+4浓度与总排口出水NH+4浓度不存在显著差异(P>0.05);④进水NO-3浓度与二沉池出水和总排口出水NO-3浓度存在显著差异(P<0.05),进水NO-3浓度极低,但δ15 N-NO-3和δ18 O-NO-3均值较高,可能与生活污水在管道运输过程中发生反硝化作用有关;二沉池和总排口出水NO-3浓度显著升高(P<0.05),但δ18 O-NO-3均值显著降低(P<0.05),与NH+4硝化过程中水的参与有关.研究结果说明污水处理厂好氧和厌氧处理过程对出水NO-3浓度和同位素组成的影响,为借助δ15 N-NO-3和δ18 O-NO-3均值辨识生活污水对地表水硝酸盐的贡献提供科学依据. |
| 英文摘要 |
| Urban domestic sewage is one of the important nitrate (NO-3) sources for surface water; however, their NO-3 concentrations and nitrogen and oxygen isotope values (δ15N-NO-3 and δ18O-NO-3) remain unclear, and the factors affecting NO-3 concentrations and δ15N-NO-3 and δ18O-NO-3 values of effluents in the waste water treatment plant (WWTP) are still unknown. Water samples in the Jiaozuo WWTP were collected to illustrate this question. Influents, clarified water in the secondary sedimentation tank (SST), and effluents of the WWTP were sampled every 8 h. The ammonia (NH+4) concentrations, NO-3 concentrations, and δ15N-NO-3 and δ18O-NO-3 values were analyzed to elucidate the nitrogen transfers through different treatment sections and illustrate the factors affecting the effluent NO-3 concentrations and isotope ratios. The results indicated that ① the mean NH+4 concentration was (22.86±2.16) mg·L-1 in the influent and decreased to (3.78±1.98) mg·L-1 in the SST and continuously reduced to (2.70±1.98) mg·L-1 in the effluent of the WWTP. The median NO-3 concentration was 0.62 mg·L-1 in the influent, and the average NO-3 concentration increased to (33.48±3.10) mg·L-1 in the SST and gradually increased to (37.20±4.34) mg·L-1 in the effluent of the WWTP. ② The mean values of δ15N-NO-3 and δ18O-NO-3 were (17.1±10.7)‰ and (19.2±2.2)‰ in the influent of the WWTP, the median values of δ15N-NO-3 and δ18O-NO-3 were 11.9‰ and 6.4‰ in the SST, and the average values were (12.6±1.9)‰ and (5.7±0.8)‰ in the effluent of the WWTP. ③ The NH+4 concentrations of influent had significant differences compared to those in the SST and the effluent (P<0.05). The reduction of NH+4 concentrations in the SST was due to the above nitrification during the aerobic treatment process, which transferred NH+4 to NO-3. The NH+4 concentrations in the SST had no significant differences with that in the effluent of the WWTP (P>0.05). ④ The NO-3 concentrations in the influent had significant differences with those in the SST and the effluent (P<0.05), and minor NO-3 concentrations but relatively high δ15N-NO-3 and δ18O-NO-3 values in the influent were probably due to denitrification during the pipe sewage transportation. The obviously increased NO-3 concentrations (P<0.05) but decreased δ18O-NO-3 values (P<0.05) in the SST and the effluent resulted from water oxygen incorporation during the nitrification. The above results confirmed the impacts of aerobic and anaerobic treatment processes on NO-3 concentrations and isotope ratios of effluent from the WWTP and provided scientific basis for the identification of sewage contributions to surface water nitrate via average δ15N-NO-3 and δ18O-NO-3 values. |
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