生态环境学报 ›› 2023, Vol. 32 ›› Issue (5): 980-988.DOI: 10.16258/j.cnki.1674-5906.2023.05.015

• 研究论文 • 上一篇    下一篇

滨海含水层咸-淡水过渡带反硝化性能与控制因素研究

王云1(), 郑西来1,2,3,*(), 曹敏4, 李磊4, 宋晓冉4, 林晓宇4, 郭凯5   

  1. 1.中国海洋大学环境科学与工程学院,山东 青岛 266100
    2.中国海洋大学/山东省环境地质工程重点实验室,山东 青岛 266100
    3.中国海洋大学/海洋环境与生态教育部重点实验室,山东 青岛 266100
    4.青岛市水文中心,山东 青岛 266101
    5.诸城市建筑业发展中心,山东 诸城 262200
  • 收稿日期:2023-03-03 出版日期:2023-05-18 发布日期:2023-08-09
  • 通讯作者: *郑西来,Email:zhxilai@ouc.edu.cn
  • 作者简介:王云(1997年生),女,硕士研究生,研究方向为地下水污染控制。Email:YunW97@hotmail.com
  • 基金资助:
    国家自然科学基金-山东省联合基金项目(U1806210);国家自然科学基金重点项目(41731280)

Study on Denitrification Performance and Control Factors in Brackish-Freshwater Transition Zone of Coastal Aquifer

WANG Yun1(), ZHENG Xilai1,2,3,*(), CAO Min4, LI Lei4, SONG Xiaoran4, LIN Xiaolei4, GUO Kai5   

  1. 1. College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, P. R. China
    2. Key Laboratory of Environmental Geology and Engineering of Shandong Province/Ocean University of China, Qingdao 266100, P. R. China
    3. Key Laboratory of Marine Environment and Ecology, Ministry of Education/Ocean University of China, Qingdao 266100, P. R. China
    4. Qingdao Hydrological Bureau, Qingdao 266101, P. R. China
    5. Zhucheng Construction Industry Development Center, Zhucheng 266200, P. R. China
  • Received:2023-03-03 Online:2023-05-18 Published:2023-08-09

摘要:

滨海含水层受沿海人口规模、工农养殖业发展以及污染物排放等原因的影响,来自陆地的地下水常向沿海输入硝酸盐造成严重的硝酸盐污染问题,反硝化作为去除地下水中硝酸盐污染物的典型反应,探究其对滨海硝酸盐污染防治、生态系统稳定和生物多样性具有重要科学意义。以地下水和含水介质为原料,设计微生物培养试验,利用硝态氮(NO3--N)、溶解氧(DO)、酸碱度(pH)和溶解性有机碳(DOC)的变化综合评价研究区反硝化性能,并通过高通量测序揭示微生物培养试验过程中细菌群落结构组成和多样性变化,最后利用响应曲面法探究碳氮比(C/N)、电导率(EC)和DO的交互作用对硝酸盐反硝化性能的影响。结果表明:在微生物培养试验中,硝态氮去除率可达80%以上,pH值维持在7.0左右,DO值维持在6.0-6.5,DOC最大利用率可达65%;高通量测序发现,随着试验的运行,微生物丰富度下降、多样性降低,与反硝化有关的微生物以好氧反硝化菌(假单胞菌属,Pseudomonas;芽胞杆菌属,Bacillus)和有机碳分解菌(福格斯氏菌属,Vogesella)为主;根据响应曲面分析可得,硝态氮去除率随着C/N的升高呈先升高后降低的趋势,随着EC的升高呈下降趋势,随着DO的升高呈轻微下降趋势,3种环境因素对硝态氮去除率影响的显著性由大到小分别是:C/N>EC>DO。研究结果揭示了以大沽河下游咸水入侵区为主的滨海咸-淡水过渡带硝酸盐去除过程、理化性质变化趋势、细菌群落物种组成和多样性以及主要环境因素(C/N、EC、DO)对反硝化过程的影响程度,可为滨海反硝化提供一定的理论依据。

关键词: 滨海含水层, 硝酸盐污染, 反硝化, 环境因素, 微生物群落结构, 响应曲面分析

Abstract:

Coastal aquifers are affected by the size of coastal population, the development of industrial and agricultural aquaculture, and pollutant discharge, and groundwater from land often imports nitrate to the coast, causing serious nitrate pollution, and denitrification as a typical reaction to remove nitrate pollutants in groundwater is of great scientific significance for coastal nitrate pollution prevention, ecosystem stability and biodiversity. In this study, groundwater and aqueous medium were used as raw materials, and the denitrification performance of the study area was comprehensively evaluated by using the changes of nitrate nitrogen (NO3--N), Dissolved Oxygen (DO), pH and Dissolved Organic Carbon (DOC), and the changes of bacterial community structure composition and diversity during microbial culture experiments were revealed by high-throughput sequencing. Finally, the response surface method was used to explore the influence of the interaction among carbon-nitrogen ratio (C/N), Electrical Conductivity (EC) and DO on the denitrification performance of nitrate. The results showed that in the microbial culture test, the removal rate of nitrate nitrogen could reach more than 80%, the pH value was maintained at about 7.0, the DO value was maintained at 6.0-6.5, and the maximum utilization rate of DOC could reach 65%. High-throughput sequencing found that as the experiment proceeded, microbial richness and diversity decreased, and microorganisms associated with denitrification were aerobic denitrifying bacteria (Pseudomonas; Bacillus) and organic carbon-decomposing bacteria (Vogesella). According to the response surface analysis, the nitrate nitrogen removal rate first increased and then decreased with the increase of C/N; it showed a downward trend with the increase of EC, and the slight downward trend with the increase of DO. The significance of the influence of three environmental factors on the nitrate followed the order of C/N > EC > DO. The results revealed the nitrate removal process, the physicochemical property change trend, species composition and diversity of bacterial communities, and the influence of major environmental factors (C/N, EC, and DO) on denitrification in the saltwater invasion zone of the lower reaches of the Dagu River, which, to some extent, can provide a theoretical basis for coastal denitrification.

Key words: coastal aquifer, nitrate contamination, denitrification, environmental factors, microbial community structure, response surface analysis

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