农田排水系统分布特征对水质净化效果的影响研究

Types of Drainage Network Impact Attenuation of Dissolved Contaminants

【目的】分析不同排水沟塘系统分布特点对农田排水污染物去除能力的影响。【方法】分别选择陕西省富平县卤泊滩和江苏省扬州市江都区为研究区,通过理论计算,比较了2种不同分布但农田面积比接近的排水沟塘系统的水质净化能力。【结果】①位于南方的江都研究区"小沟多塘"排水系统对于污染物的去除率比卤泊滩地区"大沟无塘"高出7%～36%;②在卤泊滩研究区,污染物降解的主要场所为排水农沟,而在江都研究区,则是面积较大的支沟和池塘;③2个研究区不同类型沟塘对污染物的去除效率都与其面积呈现良好的相关性。【结论】分布特征决定了沟塘水系的水力联系,"小沟多塘"类型分布的排水系统更有利于污染物的降解。

【Objective】The overarching objective of this paper is to experimentally examine the impact of drain age network types on attenuation of agricultural pollutants.【Method 】The comparative experiments were con-ducted at two sites: One was Lubotan at Fuping in Shaanxi province where the drainage system was ditches, and the other one was Jiangdu at Yangzhou in Jiangsu province where the drainage system was combination of ponds and a small number of small ditches.For each site, we analyzed the removal rate of agrochemical contaminants.【Result】The system at Jiangdu site was 7%~36% more efficient than that at Lubotan site in removing agrochemi cal pollutants.At Lubotan, the contaminants were mainly degraded in the ditches, while at Jiangdu, the contami-nation attenuation occurred in ponds and large ditches.On both sites, contamination attenuation was positively re-lated to the areas of the ditch and the ponds.【Conclusion】Drainage network types control retention time of pol-lutants, and those with more ponds and a number of small ditches are more efficient in degrading pollutants.