【作者】 唐娜；

【导师】 黄玉明；

【作者基本信息】 西南大学 ， 环境科学， 2009， 硕士

【摘要】 潜流人工湿地具有保温性能好、有机物去除率高等优点而广泛用于生活污水、工业废水、农业用水等的处理。废水中有机物处理效果一直是研究工作关注的重点,且不同地域的湿地中有机物去除的关键调控因素对于充分发挥人工湿地效能具有重要意义。二甲基硫(DMS)是一种典型的挥发性有机硫化物,对全球硫循环、气候变化和臭味产生等过程有着重要的影响。在湖泊、河流等淡水生态系统中的DMS主要是通过硫化物的甲基化产生,潜流型人工湿地中产生的DMS量少,但是由于其嗅阈值低,对环境的影响不容忽视。设计参数以及运行参数对人工湿地中有机物去除的影响研究是人们关注的重点,但研究人工湿地中各参数之间关系的工作较少,特别是缺乏有关参数对有机物(COD)去除效果的影响。而有机物中重要的组成部分——可溶性有机物(DOM),由于具有复杂的结构组成以及重要的环境影响,已成为重要的研究对象,但潜流型人工湿地中DOM对DMS的影响研究尚未开展,鉴于此,本研究主要涉及以下内容:1.以中试规模的人工湿地水处理系统为对象,通过长期监测人工湿地进出口水中有机物浓度及其他物质的浓度,对监测数据进行统计处理、分析;评估人工湿地系统对有机物的处理效果,分析人工湿地中有机物去除的影响因素;2.研究DOM对人工湿地中DMS形成的影响。通过实验及分析,得到以下主要的结果:1.中试规模的潜流人工湿地废水处理系统能有效地去除水中的有机物,通过探讨总悬浮物(TSS)、总有机碳(TOC)、总碳(TC)等对有机物(COD)去除的影响,发现进水COD、TSS、BOD、TOC和TC浓度对潜流湿地系统中COD的去除有显著影响,沿程样品的分析表明,有机物的去除主要发生在湿地的前半部。2.以潜流型人工湿地中基质的表面附着物(污泥)为对象,研究了厌氧条件下,溶解有机物中的甲醇、乙醇及乙酸对DMS生成的影响,初步试验结果表明:(1)人工湿地中的DMS主要是通过无机硫的生物甲基化过程形成,在无机硫浓度足够高的情况下,也有可能通过化学过程形成。(2)添加甲醇、乙醇及乙酸能够显著降低DMS的生成量,三种物质对DMS生成的影响表现出一致的规律,它们对DMS生成的影响机制也可能是一致的。(3)无机硫化物是DMS形成过程中主要的硫供体,而甲硫醇可能是DMS形成过程中的重要中间体。在潜流型人工湿地这种厌氧环境下,微生物作用下硫化物的甲基化是DMS产生的主要机理。更多还原

【Abstract】 The subsurface flow constructed wetland is widely used in domestic sewage,industrial wastewater and agricultural wastewater treatment because of its good performance for heat preservation and high removal rate of organic pollutants.Removal of organic matter has been considered as an emphasis of research works.The key factor for controlling the performance of organic matter removal in constructed wetland has important significance on the complete utilization of the constructed wetland.Dimethyl sulfide(DMS),as one of the important volatile organic sulfur compounds,has an important impact on the global sulfur cycle,climate change,odor occurrence processes.In lakes,rivers,wetlands and other freshwater ecosystems,DMS is mainly produced through the process of methylation of sulfide. Although DMS amount generated in subsurface flow constructed wetlands is minor,its effect on environmental is not be ignored due to its very low odor threshold.Currently,major studies concerning the constructed wetlands are concentrated on the effect of design and operation parameters on removal of organic matters.It is rare to study the relationship among various parameters in the constructed wetlands for waste water treatment system,especially the effect of other parameters on COD removal.Due to the complex structure and important significance of the environmental impact,dissolved organic matter(DOM) has become an important subject in many researches.However,there is no report on the effect of DOM on DMS formation in constructed wetland. This master thesis focused on the following two aspects:1.Performance evaluation of constructed wetlands system by statistical analysis of data obtained by long term monitoring of organic matter and other substances in the influent and effluent;2.Study on the effect of DOM on the formation of DMS.The major conclusions are summarized as follows: 1.The removal of organic matters(COD) in a pilot-scale subsurface flow constructed wetland system was studied in the present study.Factors such as influent COD concentration,total suspended solids,BOD, total organic carbon,total carbon affecting COD removal were investigated.The results indicated that the concentrations of influent COD,TSS,BOD,TOC and TC had significant effect on COD removal.A survey of COD profiles along the wetland length revealed that COD removal was mainly occurred in the area located in the middle of the constructed wetland;2.The effect of DOM such as methanol,ethanol,and acetic acid on formation of DMS using sludge from substrate in the subsurface flow constructed wetland under anaerobic conditions was investigated. The experimental results showed that(1) DMS formation is mainly from the bio-methlation of inorganic sulfur,and also from the chem-methlation of inorganic sulfur in the presence of excess inorganic sulfur;(2) Addition of methanol,ethanol,and acetic acid could significantly decrease the formation of DMS.The effect of methanol,ethanol,and acetic acid on DMS formation showed the same trend,probably indicating the same mechanism of their effect on DMS formation;(3) Inorganic sulfur is major sulfur donor for DMS formation,and methanethiol is probably major intermediate for DMS formation.The bio-methylation of sulfur in the presence of microbial is major mechanism of DMS formation.更多还原