农村非点源生活污水垂直流人工湿地处理系统甲烷排放控制研究

发布时间：2018-06-20 21:18

本文选题：甲烷排放控制 + 复合垂直流人工湿地　；参考：《四川农业大学》2015年硕士论文

【摘要】：中国环境普查公报显示农村非点源污染已成为中国第一大污染源,成为影响水体生态环境重要的因素。人工湿地作为目前应用较成熟的农村污水处理系统,却甲烷排放有一定的贡献,考虑到CH4对温室效应的贡献和对全球生态的影响,人工湿地甲烷排放控制的研究对全球气候和生态环境具有重要意义。本研究主要对农村非点源生活污水垂直流人工湿地处理系统甲烷的排放控制,在四川农业大学大佛寺实验基地构建了垂直流人工湿地处理系统,该系统分为进水池和出水池,人工湿地尺寸为3600mm×1200mm×1200mm,人工湿地植物为风车草,铺设三层介质(分别为粒径10-20mm,铺设厚度400mm；粒径20-30mm,铺设厚度400mm；粒径30-40mm,铺设厚度2501mm)。利用正交实验设计,采用来自农村非点源生活污水作为降解对象,通过研究不同水位、曝气强度、曝气时间、曝气间隔时间的控制工况,测定不同运行条件下人工湿地处理系统甲烷排放通量及对应水质指标,分析人工湿地处理系统甲烷排放的主要的影响因子,提出控制措施,以最大限度减少温室气体的排放,最大限度满足水环境和大气环境的要求,为减排提供依据。研究表明：(1)通过对垂直流人工湿地系统甲烷排放通量的连续监测,测得在实验周期内该垂直流人工湿地系统甲烷平均排放通量为1.34mol/m2/day,排放水平较高,是典型的甲烷排放源。(2)通过正交实验对各因素下甲烷排放通量进行分析,发现实验设定的曝气量大小是影响甲烷排放通量的重要因素,过大的曝气量和过小曝气量都会引起曝气效果不佳等状况导致甲烷排放控制效果不理想。通过对不同运行条件下甲烷的连续监测以及水质变化的监测发现,在控制系统水位为110cm,以6小时为一个周期,曝气时间为20min,曝气间隔时间为340min,曝气强度为3.9m3/h的运行控制条件下,垂直流人工湿地系统产生的甲烷量最小,排放量范围在0 - 0.97mol/m2/day之间,平均排放量为0.355mol/m2/day,此时的曝气量为6.5m3/6h。(3)通过对不同水位下甲烷排放通量的测定发现,空白试验时,甲烷排放通量范围在0.76-2.41mol/m2/day之间,平均甲烷排放通量为1.42mol/m2/day。而通过对曝气强度、曝气时间、曝气间隔时间和水位的控制,甲烷排放通量范围保持在0.11一1.40mol/m2/day之间,平均甲烷排放通量为0.66mol/m2/day,相比空白试验时甲烷排放通量减少了53.21%。(4)曝气能增加人工湿地中DO的含量,曝气后人工湿地内水的DO平均增加54.34%,在本研究发现,水位和曝气头安装位置对曝气效果影响很大。控制水位为1100mm、曝气头均匀安装在池底,可以提高曝气效果,在垂直方向上最大平均氧气传递效率达21.25%。另外,气体在传递过程中能量消耗较大,特别是气体从空压机经由气体管道到微孔曝气头过程中所产生的能量损失大,平均每个曝气头压力损失达到25.86pa。(5)人工湿地中,各水质指标对人工湿地甲烷排放通量的影响由大到小依次是：水温TOCTNTN溶解氧pH氧化还原电位TCTP电导率。
[Abstract]:China's environmental survey Bulletin shows that rural non-point source pollution has become the first major source of pollution in China, and has become an important factor affecting the ecological environment of the water body. As a mature rural sewage treatment system, artificial wetland has contributed to methane emission, taking into account the contribution of CH4 to the greenhouse effect and the impact on the global ecology. The study on the control of methane emission from industrial wetlands is of great significance to the global climate and the ecological environment. This study mainly deals with the control of methane emission from the vertical flow constructed wetland treatment system in rural non-point source sewage. The vertical flow wetland treatment system is constructed at the experimental base of the Grand Buddha Temple in Sichuan Agricultural Uniersity. The size of the constructed wetland is 3600mm * 1200mm x 1200mm. The artificial wetland plants are the windmill grass, laying three layers of medium (respectively, the size of 10-20mm, the thickness of 400mm, the diameter 20-30mm, the thickness of 400mm, the particle size 30-40mm, the thickness 2501mm). The orthogonal experiment design is used to use the rural non-point source domestic sewage as the degradation object. By studying the control conditions of different water level, aeration intensity, aeration time and aeration interval, the methane emission flux and corresponding water quality indexes of artificial wetland treatment system under different operating conditions are measured, and the main influencing factors of methane emission in the artificial wetland treatment system are analyzed, and the control measures are put forward to minimize the greenhouse gas. Emissions, to meet the requirements of water environment and atmospheric environment to the maximum, provide the basis for emission reduction. The study shows: (1) through continuous monitoring of methane emission flux in vertical flow constructed wetland system, the average emission of methane emission in this vertical flow constructed wetland system is 1.34mol/m2/day, and the emission level is high, which is a typical one. The source of alkane emission. (2) through the orthogonal experiment, the methane emission flux under various factors is analyzed. It is found that the size of the aeration set in the experiment is an important factor affecting the methane emission. The excessive aeration and the excessive aeration will cause the poor aeration effect, and the effect of the methane emission control is not ideal. Through the different operating strips, the effect of the methane emission control is not satisfactory. The continuous monitoring of methane and monitoring of the change of water quality have found that under the control system water level is 110cm, the aeration time is 20min, the aeration time is 340min, the aeration is 340min, the aeration intensity is 3.9m3/h, the methane production of the vertical flow constructed wetland system is the smallest, the emission range is 0 to 0.97mol/m2/d. Between ay, the average emission amount is 0.355mol/m2/day, and the aeration amount at this time is 6.5m3/6h. (3) through the determination of methane emission at different water levels. It is found that the methane emission flux range is between 0.76-2.41mol/m2/day and the average methane emission flux is 1.42mol/m2/ day. while the aeration intensity, aeration time and aeration interval are passed in the blank test. With the control of the water level and the water level, the methane emission flux is kept between 0.11 and 0.11, and the average methane emission flux is 0.66mol/m2/day. Compared with the blank test, the methane emission decreased by 53.21%. (4) and the aeration can increase the content of DO in the constructed wetland, and the average increase of the DO in the artificial wet ground water after aeration is 54.34%. In this study, the water is found to be water. The position and the installation position of the aeration head have great influence on the aeration effect. The control water level is 1100mm, the aeration head is installed at the bottom of the pool evenly, and the aeration effect can be improved. The maximum average oxygen transfer efficiency is up to 21.25%. in the vertical direction, and the gas is consumed in the process of transmission, especially the gas from the air compressor through the gas pipe to the microporous aeration. The energy loss generated in the process of gas, the average aeration head pressure loss reached 25.86pa. (5) in artificial wetland, the influence of water quality on the methane emission from wetlands from large to small in turn is: water temperature TOCTNTN dissolved oxygen pH redox potential TCTP conductivity.
【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X799.3

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