盐碱化改良区农田排水沟水体与底泥界面微环境特征分析
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

国家自然科学基金资助项目(51709144);江西省教育厅科研项目(GJJ170981);江西省自然科学基金项目(20202BABL204068)


Characteristics analysis of micro-environment of sediment-water interface in drainage ditches in reclamation areas
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    深入探究农田排水沟水体与底泥界面微环境对界面间物质交换和迁移转化具有重要意义,为了明确不同水力联系的排水沟界面微环境特征,该研究利用微电极测量系统对陕西卤泊滩盐碱化改良区和盐荒地2种水力条件差异较大的排水沟水体与底泥界面微环境进行了研究。结果表明:改良区与盐荒地排水沟水体水质指标和底泥含水率、有机质、硫酸盐含量等方面均存在不同程度的差异,底泥含水率自表层向下逐渐减小;改良区与盐荒地底泥氧气最大渗透深度分别为10.2和2.6 mm,扩散边界层厚度分别为0.4~0.8 mm和0.2~0.4 mm;改良区排水沟底泥硫化氢浓度小于10 μmol/L,而盐荒地高至178 μmol/L。研究结果可为研究区及类似地区利用排水沟渠湿地控制和治理农业面源污染、改善农田生态环境提供参考。

    Abstract:

    Abstract: Substance exchange and transfer depend mainly on the micro-environment of the interface between the water body and the underlying sediment in drainage ditches in Reclamation areas. In this study, the sediments were taken separately from two ditches that drain reclaimed and non-reclaimed fields in a salt impacted agricultural area in Shaanxi, China. A laboratory experiment was conducted to monitor physical and chemical properties at the sediment and water body interface using the Unisense micro-electrode system. The system consisted of microelectrode, four-channel host, motor controller, microelectrode thruster, the sensor trace PRO software, and lab support LS18. The tip diameter of Unisense DO microelectrode was 25 μm, and the polarization voltage of DO microelectrode was -0.8 V, where the pre-polarization signal value was stable. Five parallel samples were set to separately measure DO values, and the average value was calculated. Each group in experiments was repeated three times. The measurement interval was 100μm, each DO concentration profile was measured for 30 min, and 120 DO profiles were observed. The Uniense H2S microelectrode was a miniaturized picoamperometric microelectrode with a tip diameter of 25 μm and a pre-polarization voltage of +0.08 V, including three electrodes for the measurement, protection, and reference. The pre-polarized signal was corrected after stabilizing. The temperature of the calibration solution was consistent with the test sample, and the calibration test was conducted in the same environment as the measurement. The measurement depth of H2S profile was limited by the electrode length, where the maximum measurement depth was about 40 mm at 50 μm measurement step. The measurement time was about 60 min for each setup of H2S concentration profiles, and a total of 24 H2S profiles were observed. The monitoring results showed that the maximum depth of oxygen penetration was 10.2 and 2.6 mm for sediment samples taken from the reclaimed and the non-reclaimed fields, whereas, the diffusion boundary-layer thicknesses were 0.4-0.8 mm and 0.2-0.4 mm, respectively. The observation results showed that the water content in the sediment decreased with the depth of sampling, due mainly to the compaction at the ditch bottom. Specifically, the measured water content ranged from 54% to 78% in the ditches of reclaimed field, and from 73% to 87% in ditch sediment of non-reclaimed field. The Electrical Conductivity (EC) was between 3.64 and 4.12 mS/cm in the ditch of the reclaimed field, while it ranged from 10.74 to 13.22 mS/cm in the ditch sediment of non-reclaimed field. There was a large difference (of 4 times) in EC between the two different sampling sites, indicating the salt accumulation in the drainage ditch from the non-reclaimed fields. The measured DO value remained stable at 8 mg/L for sediments from the ditch of the reclaimed field, while it varied from 3.21 mg/L to 5.44 mg/L in the ditch sediment of the non-reclaimed field. The concentration of hydrogen sulfide in the ditch sediment of reclaimed field less than 10 μmol/L, while it was as high as 178 μmol/L in the ditch sediment of non-reclaimed field. The findings can provide a sound reference for the design and application of ditches, and thereby to improving the ecological environment of farmland in similar areas.

    参考文献
    相似文献
    引证文献
引用本文

潘延鑫,冯绍元,井思媛,罗纨,贾忠华.盐碱化改良区农田排水沟水体与底泥界面微环境特征分析[J].农业工程学报,2021,37(2):258-267. DOI:10.11975/j. issn.1002-6819.2021.2.030

Pan Yanxin, Feng Shaoyuan, Jing Siyuan, Luo Wan, Jia Zhonghua. Characteristics analysis of micro-environment of sediment-water interface in drainage ditches in reclamation areas[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE),2021,37(2):258-267. DOI:10.11975/j. issn.1002-6819.2021.2.030

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2020-08-19
  • 最后修改日期:2021-01-03
  • 录用日期:
  • 在线发布日期: 2021-02-09
  • 出版日期:
文章二维码
您是第位访问者
ICP:京ICP备06025802号-3
农业工程学报 ® 2024 版权所有
技术支持:北京勤云科技发展有限公司