CIESC Journal ›› 2024, Vol. 75 ›› Issue (5): 2036-2046.DOI: 10.11949/0438-1157.20231393

• Energy and environmental engineering • Previous Articles     Next Articles

Effect of Hg on nitrogen removal performance of wastewater treatment system in low-pressure conditions

Lei GAO1(), Wen DAI1, Zhonglian YANG1,2, Shuping LI2,3,4, Gangyin YAN2,3,4, Qi SUN1, Yongze LU1,4(), Guangcan ZHU1,2,4()   

  1. 1.School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, China
    2.Key Laboratory of Water Safety and Aquatic Ecosystem Health of Xizang, Xianyang 712082, Shaanxi, China
    3.College of Information Engineering, Xizang Minzu University, Xianyang 712082, Shaanxi, China
    4.Key Laboratory of Water Pollution Control and Ecological Restoration of Xizang, National Ethnic Affairs Commission, Xianyang 712082, Shaanxi, China
  • Received:2023-12-29 Revised:2024-02-26 Online:2024-06-25 Published:2024-05-25
  • Contact: Yongze LU, Guangcan ZHU

汞对低气压条件下污水处理系统脱氮性能的影响研究

高磊1(), 戴闻1, 杨忠莲1,2, 李淑萍2,3,4, 闫刚印2,3,4, 孙琪1, 陆勇泽1,4(), 朱光灿1,2,4()   

  1. 1.东南大学能源与环境学院,江苏 南京 210096
    2.西藏自治区水质安全与水环境健康重点实验室,陕西 咸阳 712082
    3.西藏民族大学信息工程学院,陕西 咸阳 712082
    4.西藏水污染控制与生态修复国家民委重点实验室,陕西 咸阳 712082
  • 通讯作者: 陆勇泽,朱光灿
  • 作者简介:高磊(1996—),男,博士研究生,gao_leiseu@163.com
  • 基金资助:
    西藏自治区科技厅自然科学基金项目(XZ202101ZR0092G);西藏自治区科技厅自然科学基金项目(XZ202101ZR0077G);国家自然科学基金项目(52160004)

Abstract:

The presence of mercury (Hg) in wastewater treatment systems in low-pressure areas can potentially reduce the efficiency of wastewater treatment. In a laboratory-scale study using a sequencing batch reactor (SBR), the impact of Hg under low-pressure conditions on wastewater treatment systems was investigated. It was found that Hg significantly lowered the removal rate of ammonia nitrogen (NH4+-N), particularly at high concentrations. The removal rate of NH4+-N decreased from 89.73% to 38.71% with increased Hg concentrations. Hg had a detrimental effect on the nitrogen transformation process within the SBR cycle. At an influent Hg concentration of 250 µg/L, the specific ammonium oxidation rate (SAOR) and the nitrite reduction rate (SNIR) decreased by 96.74% and 96.91%, respectively, and the activities of related functional enzymes decreased by 100.00% and 97.87%, respectively. Furthermore, Hg altered the morphology and structure of the activated sludge, leading to the disintegration of the overall sludge structure and changes in surface characteristics. It also inhibited the production of extracellular polymeric substances (EPS), particularly affecting the protein content. In terms of the microbial community, the addition of Hg significantly altered the structure of the activated sludge community, especially affecting functional genera related to the nitrification process, such as Nitrosomonas and Nitrospira. Therefore, attention needs to be paid to the impact of the presence of Hg in the sewage treatment system under low-pressure conditions.

Key words: mercury, low-pressure, wastewater, environment, microbial community, bioprocess

摘要:

汞(Hg)在低气压地区污水处理系统中的存在可能会降低污水处理效率。在实验室规模下以SBR为例,通过研究Hg对低气压条件下污水处理系统的影响发现,Hg显著降低了氨氮(NH4+-N)的去除率,尤其是高浓度Hg的影响更显著,NH4+-N去除率从89.73%下降至38.71%。Hg对SBR周期内的氮转化过程产生了负面影响,当进水Hg浓度为250 µg/L时,活性污泥氨氧化速率(SAOR)和亚硝酸盐还原速率(SNIR)分别下降96.74%和96.91%,与之相关的功能酶活性分别降低100.00%和97.87%。此外,Hg改变了活性污泥的形态和结构,导致污泥整体结构的瓦解和表面特征的变化,同时对EPS的生成产生抑制作用,特别是蛋白质含量受到影响。在微生物群落方面,Hg的加入使活性污泥群落结构发生了显著变化,尤其是和硝化过程相关的功能菌属NitrosomonasNitrospira。因此,低气压条件下需对污水处理系统中Hg存在带来的影响给予关注。

关键词: 汞, 低气压, 废水, 环境, 微生物群落, 生物过程

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