【作者】 曹笑笑；

【导师】 吕宪国；

【作者基本信息】 中国科学院研究生院(东北地理与农业生态研究所) ， 环境工程， 2013， 硕士

【摘要】 农田退水是农业面源污染的主要输出途径之一，水量较大，该污染源较稳定。大量的农田退水未经处理直接排入接纳水体，不仅浪费了水资源，而且污染了接纳水体环境。人工湿地污水处理技术是一种新型的生态方法，具有显著的生态环境效益。本文以东北农田退水为例，根据农田退水的水质和水量特征，结合出水水质要求，设计了一种净化农田退水水质的复合人工潜流湿地系统，构建了实验室模拟装置，通过对设计参数筛选，设计了实际工程运用中的人工湿地污水处理工艺流程与参数，给出了工艺系统构筑物布置图。通过研究得出以下结论：1、从人工湿地类型上看。该工艺中的人工湿地处理部分是由厌氧潜流人工湿地和好氧潜流人工湿地组成，好氧潜流人工湿地中的流态又分为垂直流和水平潜流。厌氧潜流人工湿地可将水温提升3℃左右，利于好氧部分对污染物的去除，而且湿地的占地面积可再利用。好氧潜流人工湿地充分利用了垂直流和水平潜流的优点，优于单一人工湿地模式。2、从人工湿地基质上看。选择填料的种类，包括：土壤、沸石、蛭石、炉渣、砾石。涉及到的设计参数为基质粒径、孔隙度和基质填充厚度。3、从人工湿地植物上看。好氧部分选择了芦苇。芦苇是湿地中典型的植物，生命力旺盛，利用价值较高。涉及到的设计参数为芦苇种植密度。4、从人工湿地设计构建参数上看。首先通过模型公式计算出各设计参数：水力停留时间、水力负荷、湿地几何尺寸、湿地水位和坡度，然后利用通过国内外潜流人工湿地数据训练好的人工神经网络模型优化人工湿地水力负荷参数，得到2个水力负荷值：0.03~0.037m3/（m2·d）和0.078~0.083m3/（m2·d）。利用试验验证人工湿地处理效果并确定构建工程的水力负荷为0.078~0.083m3/（m2·d）。5、从工艺主要构筑物上看。该工艺包括：格栅、调节池和人工湿地部分。利用中格栅以去除农田退水进入系统前所携带的固体悬浮物，避免系统堵塞。调节池的使用是用来调节水量变化较大的农田退水，减小系统所受的冲击负荷。6、从工程实践上看。该人工湿地工艺系统较适合温度偏低和水量变化较大的东北农田退水。对人工湿地工艺系统各个处理单元进行模拟实践设计，包括：选定设计参数、详细计算各参数值，绘制流程高程布置图。通过这次设计，为我国农田退水净化处理工程提供技术指导和参考。更多还原

【Abstract】 Farmland drainage is one of the main output way for agriculturalnon-point source pollution. It is of high quantity, and is a stable pollutionsource. Large amounts of farmland drainage without any purificationdirectly discharge into receiving waters, It not only wastes waterresources, but also makes receiving waters pollution. Constructed wetlandis a new ecological method to purify wastewater, and is of significantenvironmental benefits. The northeast farmland drainage was chosen tostudy. Based on the characteristics of water quality and water quantity offarmland drainage, combined with the effluent quality requirements, ahybrid subsurface flow constructed wetland was designed. Devices in thelaboratory were built. Through filtering design parameters, the processand parameters of constructed wetland sewage treatment were designed,and a layout of the structures was drawn. The main conclusions wereshown as follows:1. From types of constructed wetlands: The part constructed wetlandwas composed of aerobic and anaerobic subsurface-flow constructedwetlands. The subsurface flow pattern of aerobic subsurface-flowconstructed wetland is divided into vertical flow and horizontal flow. Anaerobic constructed wetland can raise water temperatures of3℃,which is beneficial to removal of contaminants. The wetland area can bereused. Aerobic constructed wetland takes full advantage of the benefitsof vertical and horizontal subsurface flows that is better than a single flowpattern of constructed wetlands.2. From substrates in the constructed wetlands: Constructed wetlandbeds are filled with several materials: soil, zeolite, vermiculite, slag andgravel. Grain size, porosity and thickness of materials are designed.3. From plants in the constructed wetland: Aerobic subsurface flowconstructed wetland planted Phragmites. It is typical of wetland plants,strong vitality, and high using value. A design parameter for Phragmitesis planting density.4. From parameters of constructed wetlands: Design parameters arecalculated by model and formula. Then the optimization of hydraulicloading is worked with the artificial neural network that is trained bydates of domestic and international subsurface constructed wetlands. Theresult is two hydraulic loadings:0.03~0.037m3/(m2·d) and0.078~0.083m3/(m2·d). Finally, validation of the constructed wetlandsand determining0.078~0.083m3/(m2·d) as a hydraulic parameter valueengineered is by experiment.5. From the main structures: The constructed wetland process includes:grille, regulating reservoir and constructed wetland. The constructed wetland is integrated anaerobic subsurface flow with aerobic subsurfaceflow that is composed of horizontal subsurface flow and vertical flow.6. From engineered: The constructed wetland system is more suitablefor Northeast farmland drainage featured by low water temperature andobviously varies water quantity. Each part was engineered, which mainlyincludes: selecting and calculating design parameters, mapping a relevantprocess elevation plan. It aims to provide a technical guidance andreference for drainage purification projects.更多还原