【作者】 王云龙；

【导师】 陈英旭；

【作者基本信息】 浙江大学 ， 环境工程， 2008， 博士

【摘要】 近年来，卫生填埋作为城市生活垃圾广泛应用的最终处置方式日益暴露出局限性。卫生填埋场封场植被恢复缓慢，恶臭和温室气体污染以及景观生态破坏严重等问题，已成为影响我国城镇生态文明建设的制约因素之一。因此，本论文针对目前垃圾填埋场植被恢复缓慢所带来的若干问题，通过对杭州市天子岭垃圾填埋场植被调查和筛选，获得系列国内外首次报道的垃圾填埋场适生植物，在此基础上，构建了一种污泥或污泥堆肥强化覆土肥力适生植物适配种植的垃圾填埋场植被恢复技术，通过实验室模拟试验，探讨了填埋气体胁迫下适生植物白藜和高羊茅根际土壤微生物种群结构多样性及功能变化，阐明了填埋气体胁迫下污泥及堆肥污泥覆土改良及提升适生植物根际土壤甲烷氧化微生物分子生态学机理。研究结果为垃圾填埋场植被快速恢复和温室气体减排提供技术与理论依据。以杭州市天子岭垃圾填埋场为研究对象，运用植物分类学与植物生态学相结合的方法，调查分析了垃圾填埋场35科86种植物及其分布状况，发现填埋场植被自然恢复周期较长，约需7～8年，植被主要以耐干旱贫瘠，具有强侵占性和破坏性的草本植物为主，灌木次之，藤本植物和乔木的种类相当稀少，演替趋势符合废弃地植被演替的一般趋势。提出以人工控制天然草本植物的繁衍为基础，适当引入耐干旱贫瘠的抗性浅根系植物品种，通过强化填埋覆土肥力，促进植物生长，加速垃圾填埋场封场植被恢复进程的措施和建议。以垃圾填埋场植被调查为依据，结合生物多样性与景观生态设计原则，选取乔、灌木植物20种和草本植物9种，人工筛选获得女贞、湿地松、珊瑚朴、白藜、高羊茅等11种耐性适生植物，其中珊瑚朴、黄连木、大叶榉、红叶石楠、紫荆和白藜为国内外首次报道的垃圾填埋场适生植物。创建了以女贞、湿地松、珊瑚朴、红叶石楠、紫荆、高羊茅和画眉草等耐性适生植物为基础的“乔木+灌木+草本”组合适配填埋场覆土植被种植方案，自主研发了一套污泥强化覆土填埋场植被快速恢复技术，可缩短垃圾填埋场植被恢复时间2年以上。以垃圾填埋场适生植物白藜为试材，在实验室条件下，研究并探讨填埋气体胁迫下，适生植物白藜的生长发育对填埋覆土甲烷氧化活性和微生物种群结构多样性的影响及其相互关系。研究结果表明，白藜的种植可显著提高土壤中可培养细菌数量(P＜0．05)。在填埋气体胁迫下，自白藜生长的花期(90天)，覆土可培养甲烷氧化菌数量和甲烷氧化活性均显著高于未经填埋气体处理的对照土壤(P＜0．05)。在白藜生长发育进入果期(150天)时，填埋气体胁迫下白藜根际土壤甲烷氧化菌数量和甲烷氧化活性最高。变性梯度凝胶电泳(PCR-DGGE) -分子克隆的研究结果表明，填埋气体胁迫下白藜根际土壤细菌种群结构多样性与纯土、纯土种植白藜和纯土加填埋气体处理土壤存在显著性差异。甲基八叠球菌属(Methylosarcina)是填埋气体胁迫下白藜根际土壤优势甲烷氧化菌群，而甲基球菌属(Methylococcus)、甲基孢囊菌属(Methylocystis)、甲基弯曲菌属(Methylosinus)则是未种植白藜的填埋覆土的主要甲烷氧化菌群。因此，填埋气体胁迫下，白藜根际对优势甲烷氧化菌群具有选择性，白藜的种植可显著提高覆土的甲烷氧化活性和细菌种群结构及多样性。选取垃圾填埋场适生植物高羊茅为研究对象，研究探讨了填埋气体胁迫下污泥和堆肥污泥等覆土添加剂对植物生长、光合性能、根际土壤甲烷氧化活性、根际土壤微生物种群结构多样性的影响及其相互关系。研究结果表明，填埋气体胁迫下，污泥或堆肥污泥的添加，可显著提高植物叶片叶绿素含量和光合特性，促进植物生长。末端限制性片段长度多态性分析(T-RFLP)技术分析结果表明，填埋气体胁迫下，污泥和堆肥污泥的添加可改变适生植物高羊茅根际土壤细菌种群结构多样性。添加污泥和污泥堆肥可显著提高根际土壤可培养甲烷氧化菌数量及其甲烷氧化活性(P＜0．05)，相比之下，堆肥污泥添加效果更为明显。PCR-DGGE-分子克隆分析表明，添加污泥和堆肥污泥可显著提升高羊茅根际土壤甲烷氧化菌生物多样性，并使Ⅱ型甲烷氧化菌成为了其中的优势甲烷氧化菌。填埋气体处理与植物种植前，填埋覆甲烷氧化菌主要以Ⅰ型甲烷氧菌甲基球菌属(Methylococcus)和甲基杆菌属(Methylobacter)微生物为优势。在填埋气体胁迫下，添加堆肥污泥处理的高羊茅根际土壤甲烷氧化微生物甲基球菌属(Methylococcus)、甲基暖菌属(Methylocaldum)和甲基孢囊菌属(Methylocystis)为优势，且Ⅰ型甲烷氧化菌的丰度比Ⅱ型甲烷氧化菌更高；而添加污泥处理的高羊茅根际土壤甲烷氧化菌则以甲基暖菌属(Methylocaldum)、甲基孢囊菌属(Methylocystis)和甲基弯曲菌属(Methylosinus)为优势，根际土壤甲烷氧化菌群种类明显低于堆肥污泥处理，并以Ⅱ型甲烷氧化菌为主。显然，不同的填埋覆土改良剂对填埋气体胁迫下，适生植物根际土壤甲烷氧化微生物多样性的形成、数量及其活性的影响机制存在差异。尽管如此，添加污泥或堆肥污泥提升高羊茅根际土壤甲烷氧化活性的机理可能是由于养分促生，覆土孔隙度改善以及根系氧压增加的结果；填埋气体胁迫下，高羊茅根际土壤甲烷氧化菌群结构多样性差异是导致不同覆土改良剂作用下高羊茅根际土壤甲烷氧化活性存在显著性差异的重要因素。更多还原

【Abstract】 Sanitary landfill technique of Municipal Solid Waste （MSW） disposal plays an important role, but faces more and more challenges. Retardation of revegetation, ever escalating water and air pollution caused by landfill and the degradation of land resource and landscape Scenary are becoming the major issues to be addressed in conserving the city ecology. According to the investigations on vegetation of Tianziling landfill, several tolerant plants under the stress of landfill gases were the frist time to be selected by us. Based on these findings, a novel technique for landfill revegetation was designed using municipal sewage sludge to enhance the landfill cover soil. The variation of the composition of microbial community in rhizosphere soil of tolerant plants: Chenopodium album L. （C. album） and Festuca ovina under the stress of landfill gas （LFG） was studied at laboratory level. Microbial molecular ecology of the methanotrophic bacteria community in rhizosphere soil of tolerant plants, enhanced by the addition of sewage sludge and compost to the landfill cover was investigated under the stress of LFG.The survey carried out in and around the Tianziling landfill of Hangzhou city, to understand the composition of vegetation, revealed that there are 86 species of plants belonging to 35 families, inside the landfill. The results show that it needs 7-8 years to cover the whole landfill by natural vegetation, and the dominant plants are herbs mainly composed of wild weeds, while plants belong to arbor and frutex are very rare in the landfill. The evolving trend is fit to the trends of general disused sites. However, the natural wild weeds play a destructive role in landfill revegetation. The effective strategy to enhance landfill revegetation is therefore first, to control the unlimited extension of wild weeds in the landfill and then, to select tolerant plants to the landfill amended with the landfill cover soil with biosolid and other nutrients.Based on the investigation of vegetation and the principles of landscape reclamation in landfill, 20 species of arbor and frutex plants and 9 species of herbs were used for the vegetation study in the Tianziling landfill site. It is found that Pinus elliottii, Ligustrum lucidum, Cercis chinensis, Festuca ovina, Eragrostis pilosa and Chenopdium album L （C. album） ect, are more tolerant to the landfill conditions. Celtis julianae、Zelkova schneideriana、Pistacia Chinese、Photinia serrulata、Cercis chinensis and Chenopdium album L. were selected for the first time as the tolerant plants used for landfill revegetation. These tolerant plants were seclected to be planted in the landfill according to the "Arbor + Frutex + Herb" principle, and a successful field demonstration was done to provide the novel landfill revegetation techniques of using municipal sewage sludge to enrich the landfill cover soil. The revegetation time of a landfill is expected to be shortening at least by two years with this technique.The effect of a LFG tolerant plant: C. album on methane oxidation activity （MOA） and bacterial community composition in landfill cover soil was investigated at field level. Soil samples from four simulated lysimeters with and without LFG and plant vegetation were taken at 4 stages during the development cycle of the plant. Results showed that the total number of culturable bacteria in soil could significantly be increased （P < 0.05） by the growth of C. album. The total number of methanotrophs and MOA in soils with LFG was significantly higher （P < 0.05） than in soils without LFG on the sampling days of 90, 150 and 210. Further, the total number of methanotrophs and MOA in lysimeters with LFG, increased in the presence of C. album when the plant entered the seed setting stage. Polymerase chain reaction and denaturing gradient gel electrophoresis （PCR-DGGE） gel patterns of 16S rDNA gene fragment and band sequencing analyses apparently differed among soil bacterial communities in the presence of LFG and plant vegetation. Members of the genus Methylosarcina were found to be the most active and dominant methanotrophs in rhizosphere soil of C. album with LFG, while Methylococcus, Methylocystis, and Methylosinus were the primary methanotroph genera in LFG soil without C. album. Thus, C. album appears to be methanotrophic bacteria specific, in the presence of LFG. Soil MOA and microbial diversity can also be affected significantly by the presence of this plant. The inclusion of plants that are capable of tolerating LFG and specific on active methanotrophs may be critical in controling CH₄ emissions from landfills.Traditional cultivation and the rolling tube method combined with modern molecular microbiological techniques including the Terminal Fragment Length Polymorphism （T-RFLP） Analysis, PCR-DGGE and Clone techques were used to detect the Festuca ovina rhizosphere soil bacterial community compostion, the soil culturable methanotrphic bacteria and the soil methanotrphic bacteria community compostion under the landfill cover soil amended with sewage suldge and sewage sludge compost. The results showed that the biomass, chlorophyll content and photo-physiological characteristics of Festuca ovina were significantly increased by the LFG under the landfill cover soil amended with sewage suldge and sewage sludge compost（P<0.05）. The T-RFLP anaysis showed that, the addition of sewage sludge or sewage sludge compost to the landfill cover plays an important role in improving the soil bacterial community compositon. The total number of methanotrophs and MOA in soils stressed by LFG could significantly be increased （P < 0.05） by using sewage sludge and sewage sludge compost. The results of PCR-DGGE combined 16S rDNA phylogenetic analysis showed that the methanotrophic bacterial community and composition of rhizosphere are obviously influenced by the stress of LFG and the addition of sewage sludge or sewage sludge compost to landfill cover. Type II methanotrophic bacteria also became one of the dominant microbes. The dominant methanotrophic bacteria in landfill cover soil, before the stress of LFG and with out the plantation of Festuca ovina were Methylococcus and Methylobactor which are type I methanotrophic bacteria. However, the dominant methanotrophic bacteria in rhizosphere soil of Festuca ovina amended with sewage sludge compost changed to Methylococcus, Methylocaldum and Methylocystis under the stress of LFG. Type I methanotrophic bacteria were more dominant than Type II methanotrophic bacteria under this situation. In contrast, when sewage sludge was used to amend the landfill cover soil, the dominant methanotrophic bacteria in rhizosphere soil of Festuca ovina turned to Methylocaldum, Methylocystis and Methylosinus under the stress of LFG, and Type II methanotrophic bacteria were more dominant under this situation. Consequently, the type of landfill cover has a significant influence on shaping the methanotrophic bacteria community composition and MOA in the rhizosphere soil of the tolerant plants, and the mechanisms may probably be different. The mechanisms attributable to this finding are: the improved availability of nutrients to the tolerant plants and the increased soil porosity, assuring increased supply of oxygen to the plant roots which can create niches for the colonization of methanotrophic bacteria. The variation of methanotrophic bacteria community composition in rhizosphere soil of tolerant plants among the different types of landfill cover is one of the key factors bringing about the significant differences of MOA in different kinds of landfill covers.更多还原