| 生态沟渠对农田面源污染的消减机理及其影响因子分析 |
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| 引用本文： | 程浩淼,季书,葛恒军,朱腾义,冯绍元.生态沟渠对农田面源污染的消减机理及其影响因子分析[J].农业工程学报,2022,38(21):42-52. |
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| 作者姓名： | 程浩淼 季书 葛恒军 朱腾义 冯绍元 |
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| 作者单位： | 1. 扬州大学环境科学与工程学院，扬州 225127; 2. 扬州大学水利科学与工程学院，扬州 225127;;3. 扬州市勘测设计研究院有限公司，扬州 225007; |
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| 基金项目： | 国家自然科学基金资助项目（42177365、51809226）；江苏省农业科技自主创新资金项目（CX(21)3071） |
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| 摘 要： | 农业生产过程中肥料和农药的大量施用，造成农田面源污染问题日益突出，开发农田面源污染的减控技术对生态修复具有重要的意义。生态沟渠不仅兼具农田排水沟的过水功能，同时是有效消减面源污染且适合中国农情的重要生态措施之一。该研究阐述了生态沟渠对农田面源污染的消减机理（底泥吸附及植物阻抗作用、植物/微生物吸收作用、降解去除作用）；通过整理分析559组生态沟渠野外观测试验数据，剖析了污染物初始浓度、水力停留时间、植物种类、生物量这4个主要影响因子对农田排水中N、P及农药去除率的影响；进而采用多元线性回归模型将多因子影响与N、P及农药去除率之间建立定量关系。结果表明总氮和总磷的去除率随单一因子污染物初始浓度、水力停留时间或生物量增大而增大，但与植物种类没有显著关系（P>0.05）；且多元线性回归模型结果表明污染物初始浓度的对总氮/总磷去除率的贡献大于生物量。农药的去除率随水力停留时间、生物量增大而增大，随污染物初始浓度增大而减小，与植物种类没有显著关系（P>0.05）。研究可为生态沟渠的合理构建和设计提供理论和技术支撑。
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| 关 键 词： | 生物量 氮 磷 生态沟渠 去除率 初始浓度 水力停留时间 |
| 收稿时间： | 2022/5/12 0:00:00 |
| 修稿时间： | 2022/8/10 0:00:00 |
Dissipation mechanisms of ecological ditch on agricultural non-point source pollution and their influencing factors |
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| Cheng Haomiao,Ji Shu,Ge Hengjun,Zhu Tengyi,Feng Shaoyuan.Dissipation mechanisms of ecological ditch on agricultural non-point source pollution and their influencing factors[J].Transactions of the Chinese Society of Agricultural Engineering,2022,38(21):42-52. |
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| Authors: | Cheng Haomiao Ji Shu Ge Hengjun Zhu Tengyi Feng Shaoyuan |
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| Institution: | 1. School of Environmental Science and Engineering, Yangzhou University, Yangzhou 225127, China; 2. School of Hydraulic Science and Engineering, Yangzhou University, Yangzhou 225127, China;;3. Yangzhou Survey Design Research Institute Co., Ltd., Yangzhou 225007, China; |
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| Abstract: | Agricultural Non-Point Source Pollution (ANSP) has posed a great challenge in modern agriculture worldwide, due mainly to the massive application of fertilizers and pesticides in fields. It is of great significance to develop ecological restoration technologies to mitigate the ANSP. Among them, an ecological ditch can function as a farmland drainage ditch and constructed wetland in recent years. Most previous studies have focused on the dissipation mechanisms of nitrogen (N) and phosphorus (P). However, it is still lacking in the pesticide removal in the ecological ditch. Meanwhile, it is a high demand for the multiple factors analysis rather than the commonly-used single factor analysis, because the dissipation mechanisms of the ecological ditch were influenced by the interaction of multiple factors. In this review, a literature survey was performed on the field experiments of ecological ditches using the ISI Web of Science and CNKI databases from 2001 to 2022. The dissipation mechanisms of ANSP included sediment sorption and plant resistance, as well as plant/microorganism absorption and degradation. The search criteria involved field experiment, ecological ditch or drainage ditch, and ANSP. A total of 559 groups of field experimental data were analyzed to explore the removal rates of total nitrogen, ammonia nitrogen, nitrate nitrogen, total phosphorus, orthophosphate, and pesticides. Four influencing factors were taken into account, i.e., the Initial Contaminant Concentration (IC), Hydraulic Retention Time (HRT), Plant Species (PS), and Plant Biomass (BM). Other influencing factors were also discussed, such as the temperature, hydraulic load, rainfall, and alternate wetting and drying. Both single and multiple factors analysis were carried out using correlation analysis and Multiple Linear Regression Model (MLR), respectively. The results indicated that both total nitrogen and total phosphorus increased as the IC, HRT and BM increased (P<0.01), while the PS had no significant correlation with total nitrogen and total phosphorus (P>0.05). The reason was that the sorption and uptake processes were stimulated by the higher IC, HRT and BM, whereas, the resuspension was inhibited by the higher HRT and BM in the ecological ditch. The MLR analysis demonstrated that the coefficient of determination (R2) was 0.80 and 0.92 for the total nitrogen and total phosphorus, respectively. Both the IC and BM showed a positive correlation with the total nitrogen and total phosphorus (P<0.05). Therefore, the high IC and BM greatly contributed to the high total nitrogen and total phosphorus. Particularly, the contribution ratio of IC was higher than that of BM in the MLR equations for the total nitrogen and total phosphorus. The high concentration gradient was attributed to the contribution of the ecological ditch. The diffusion of nutrients was promoted from the overlying water to pore water in the sediment. As such, more favorable absorption conditions were provided for the sediment microorganisms and plants. The single-factor analysis indicated that the pesticide declined as the IC raised (P<0.05), in terms of pesticides. The toxicity of pesticides might inhibit the pesticide-degradation ability of the microorganisms and plants in high IC condition, further weakening the metabolic activity of microorganisms and the absorption of plants. The pesticides raised significantly, as the HRT increased (P<0.05), indicating the longer microbial reaction for the higher pesticide removal rate. Besides, the MLR equation for the pesticides showed reliable statistical parameters in the training set with the R2=0.56. The pesticides in the MLR were negatively correlated with the IC (P<0.05), but positively correlated with the HRT (P<0.05), which were consistent with the single-factor analysis. Therefore, it is very necessary to supplement the experimental research on the interaction of multiple factors in the future. It is also of great significance to investigate the other hydrologic and environmental factors on the removal efficiencies of ecological ditches. Future research can also explore the effects of pesticide structures and microbiological mechanisms on pesticide removal in ecological ditches. |
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| Keywords: | biomass nitrogen phosphorus ecological ditch removal rate initial concentration hydraulic retention time |
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