【作者】 邢美燕；

【导师】 杨健；

【作者基本信息】 同济大学 ， 市政工程， 2008， 博士

【摘要】 基于目前我国小城镇经济发展水平及水污染治理的要求,高效、节能、生态平衡和环境友好的污水处理工艺成为研究的热点。新型蚯蚓生物滤池组合工艺在污水生物处理反应器中引入蚯蚓等物种,延长和扩展了原有的微生物代谢链,丰富了系统的微生物多样性,在污水处理过程中同步实现污泥的减量化和稳定化,适宜用于小城镇的污水处理。本文以蚯蚓生物滤池为主要研究对象,“厌氧水解-高负荷生物滤池”作为其处理城市污水的预处理,在中试试验（处理污水量100m³/d）的基础上,分别考察了以石英砂和陶粒为滤料的蚯蚓生物滤池处理城镇合流污水的工艺性能。主要研究内容包括蚯蚓生物滤池在污水-污泥同步处理的过程中实现的水质净化效果和污泥处理效果及其影响因素;运用PCR-SSCP（聚合酶链式反应-单链构象多态性）技术分析了蚯蚓生物滤池内的微生物的多样性及其功能微生物种群;从蚯蚓对污泥有机质的消化量及其体内的SOD（超氧化物歧化酶）和CAT（过氧化氢酶）含量变化,考察蚯蚓对生物滤池的适应性;最后,与常规活性污泥法工艺进行技术经济比较。试验结果表明:1.在进水水温7～28.6℃,有机负荷为0.46～0.93kgBOD₅·m^-3·d^-1,有机物、SS和氨氮进水平均浓度分别为58.57～78.30mg/L,29.60～38.40mg/L,24.31～36.19mg/L,18.62～24.21mg/L的条件下,石英砂蚯蚓生物滤池和陶粒蚯蚓生物滤池对“厌氧水解-高负荷生物滤池”预处理的城市合流污水的出水具有较好的有机物、SS和氨氮去除效果。2.石英砂蚯蚓生物滤池对COD、BOD₅、SS及氨氮最终出水水质及去除率范围分别为28.94～32.87mg/L,47.26%～57.55%;12.80～15.60mg/L,54.78%～59.29%;7.47～9.10mg/L,62.06%～77.90%;11.29～14.69mg/L,21.01%～52.58%。3.陶粒蚯蚓生物滤池对COD、BOD₅、SS及氨氮最终出水水质及去除率范围分别为21.17～28.66mg/L,50.64%～64.73%;10.4～15.0mg/L,55.99%～66.36%;7.2～9.77mg/L,57.18%～76.25%;7.64～11.30mg/L,35.53%～67.67%。4.陶粒蚯蚓生物滤池对COD、BOD₅及氨氮的去除率比石英砂蚯蚓生物滤池分别高约15.07%,7.39%和49.70%;对SS的去除率约低6.39%。二者对TN和TP的去除效果均不明显。5.试验中,蚯蚓生物滤池的有机负荷为0.46～0.93kgBOD₅·m^-3·d^-1,是普通生物滤池的4～7倍,这主要归因于蚯蚓生物滤池中,蚯蚓直接对有机物的降解作用,较大的滤料比表面积保持的高额的微生物量以及由于蚯蚓的存在而使系统微生物活性的提高。根据计算蚯蚓生物滤池中生物膜量为14.67kg/（m³石英砂）,是普通生物滤池的2～4倍。所用的石英砂和陶粒两种滤料的的比表面积分别是普通生物滤池滤料的5.25×10⁴和9.84×10⁴倍。6.在有机负荷为0.46～0.93kgBOD₅·m^-3·d^-1的条件下,蚯蚓生物滤池处理城市污水的有机负荷对有机物和SS去除效果的影响均呈线性负相关关系;对氨氮去除率的影响均呈二项式分布。有机负荷对TN和TP的影响不显著。试验结果表明,石英砂蚯蚓生物滤池适宜的有机负荷范围为0.78～0.90kgBOD₅/m³·d,陶粒蚯蚓生物滤池适宜的有机负荷范围为0.85～0.93kgBOD₅/m³·d。7.在水力负荷2.4～6.72m³·m^-2·d^-1条件下,蚯蚓生物滤池水力负荷对有机物和SS去除效果的影响均呈线性负相关关系;对氨氮去除率的影响均呈二项式分布。水力负荷对TN和TP的影响不显著。试验结果表明,石英砂蚯蚓生物滤池最佳水力负荷范围为4.8～6.0m³·m^-2·d^-1,陶粒最佳的水力负荷范围为4.8～5.5m³·m^-2·d^-1。8.温度对蚯蚓生物滤池有机物的去除符合二项式分布;对氨氮去除符合Sigmoidal方程式,石英砂和陶粒滤池氨氮去除速率最小和最大分别为34.852和83.273;26.705和58.570。温度对TN和TP的影响不显著。综合试验结果,石英砂滤床的最佳温度范围为15～24℃左右,陶粒滤床的最佳温度范围为18～26℃左右。在极端气温条件下,陶粒滤料较石英砂滤料具有较好的缓冲作用,利于蚯蚓的生长繁殖。9.蚯蚓生物滤池在净化污水的过程中具有同步处理污泥的功能,对污泥具有一定的减量化和稳定化作用。试验条件下,石英砂蚯蚓生物滤池对污泥减量率分别为43.4%、44.7%、39.5%、38.2%和39.2%。陶粒蚯蚓生物滤池污泥减量率分别为45.8%、48.2%、41.2%、40.5%和42.2%,分别高出石英砂蚯蚓生物滤池5.5%,7.8%,4.3%,6.0%,7.6%。10.试验条件下,蚯蚓生物滤池进泥为生物膜污泥,其平均VSS/SS值为58.2%～63.3%,石英砂滤池中VSS/SS值与VSS总减量率分别为44.8%～48.1%和48.9%～60.9%。陶粒滤池出泥的VSS/SS值与VSS总减量率分别为42.1%～46.1%和52.9%～65.5%,可以看出,蚯蚓生物滤池对生物膜污泥具有较好的污泥稳定化作用,可达到常规污泥好氧消化15天后的效果。比较得出,陶粒蚯蚓生物滤池对生物膜污泥的稳定化程度略高于石英砂蚯蚓生物滤池。对蚯蚓生物滤池进出泥的VFA含量、SVI值的变化及放置实验变化趋势也同样证明了上述结论。11.PCR-SSCP的试验结果表明,蚯蚓滤池系统中出现频率较高的微生物多为芽孢杆菌,约占43.3%,且多数为不可培养菌,这些菌对环境的适应能力较强,是系统中的功能微生物。12.蚯蚓的对污泥中有机质的消化量是影响污泥减量化和稳定化的关键参数。各工况条件下,石英砂滤池和陶粒滤池中,蚯蚓的有机消化量（OM）变化范围分别为（1.41～5.26）mgOM/g蚯蚓和（2.51～8.48）mgOM/g蚯蚓,陶粒中蚯蚓的消化量显著高于石英砂中蚯蚓的消化量。在相同摄食量前提下陶粒中蚯蚓能够有效利用污泥中的有机质成分,用以自身生物量的合成以及呼吸、生殖等一系列的生命活动。13.随着水力负荷由2.4m³·m^-2·d^-1增大到6.72m³·m^-2·d^-1,蚯蚓通过体内的SOD和CAT酶的协调作用来抵御外界环境胁迫而仍能发挥较好的作用。对蚯蚓生物滤池中的蚯蚓与生长在牛粪中的人工养殖蚯蚓相比,蚯蚓生物滤池中蚯蚓体壁组织结构会受到较大程度的损伤。在滤池相同的工况条件（进水水质、水力负荷、外界温度、湿度、光照强度）下,陶粒滤料中蚯蚓体壁的角质层、表皮层及环肌层所受的损伤程度都要比石英砂中的小。14.与常规活性污泥法相比,蚯蚓生物滤池组合工艺处理城市废水工程投资可节约36%左右,处理成本可节约41.33%左右,具有工程造价低、运行成本低、管理要求低和资源化程度高的特点,适宜于我国南方小城镇经济发展的现状及污水处理的要求。更多还原

【Abstract】 Over the years,along with the rapid urbanization in China,the sustainable wastewater control technologies have attracted more and more attentions.The research of high-efficient,energy-saving,environment-friendly,decentralized and onsite wastewater systems is one of popular topics.Vermi-biofilter system is this kind of new technology to meet the special requestment of the wastewater treatment in small towns,and have a high potential for application in developing countries. Vermi-biofilter is an ecology system that the earthworm（vermes）is introduced into the conventional biofilter according to modern ecological design conception,which has expanded the original biological chain and enriched the biodiversity of the system.It,should be noted that sewage and sludge synchronous treatment is achieved in the vermin-biofilter system.Accordingly,the performances of the Vermi-biofilter system with the quartz sand and ceramisite grain as the filter medium,respectively,used for the municipal wastewater treatment in small towns were investigated in a pilot plant.The dissertation discussed the processes of municipal wastewater treatment and synchroneously the sludge reduction and stabilization,and described the influence factors on the sewage and sludge treatment.Then,the diversity and functional populations in the vermi-biofilter was analyzed using PCR-SSCP technology.Later, the physiological characteristics adaptation of the earthworm in the vermi-biofilter system,such as the digesting quantity of the organics,the content change of the SOD and CAT was discussed,too.Finally,the cost-effectiveness comparison of the vermi-biofilter with the conventional activated sludge process（CAS）was performed.The principal conclusions were obtained as follows.1.Better organics,SS and NH₄-N removal were achieved using vermi-biofilter for municipal wastewater treatment,when the COD_cr,BOD₅,SS and NH₄-N influent concentrations were in the range of 58.57～78.30 mg/L,29.60～38.40 mg/L,24.31～36.19 mg/L,18.62～24.21 mg/L.respectively,at the organic loadings from 0.46 to 0.93 kgBOD₅·m^-3·d^-1,the wastewater temperature ranged from 7 to 28.6℃.2.The effluent and the removal efficiency of COD,BOD₅,SS and NH₄-N were in the range of 28.94～32.87mg/L,47.26%～57.55%;12.80～15.60mg/L,54.78%～59.29%;7.47～9.10mg/L,62.06%～77.90%;11.29～14.69mg/L,21.01%～52.58%, respectively,in the quartz sand vermi-biofilter system under the experimental conditions.3.The effluent and the removal efficiency of COD,BOD₅,SS and NH₄-N were in the range of 21.17～28.66mg/L,50.64%～64.73%;10.4～15.0mg/L,55.99%～66.36%;7.2～9.77mg/L,57.18%～76.25%;7.64～11.30mg/L,35.53%～67.67%, respectively,in the ceramisite grain vermi-biofilter system under the experimental conditions。4.The removal efficiencies of COD,BOD₅ and NH₄-N by the ceramisite grain vermi-biofilter system were 15.07%,7.39%and 49.70%higher than that by sand quartz vermi-biofilter system.And the removal efficiencies SS was 6.39%lower than that by the quartz sand vermi-biofilter system.No obvious removals on TN and TP were detected.5.The experimental organic loading was in the range of 0.46～0.93 kgBOD₅·m^-3·d^-1which was 4～7 times as that of the conventional biofilter.The reasons can be interpreted in 3 aspects,including the direct digestion on organics by earthworms,higher microorganism quantity due to higher specific surface of the filter medium,the enhancement of the microorganism activity.The quantity of the biofilm in the vermi-biofilter was calculated as 14.67kg/（m³sand quartz）,which was 2～4 times as that of conventional biofilter.The specific surfaces of the experimental sand quana and ceramisite grain were 5.25×10⁴ and 9.84×10⁴times as that of conventional biofilter.6.At the organic loading of 0.46～0.93 kgBOD₅·m^-3·d^-1,the influences of the organic loading on the removal of organics,and SS were negative linear correlation. That on the removal of NH₄-N was binomial distribution.No obvious influence was detected on the removal of TN and TP.The experimental results also indicated that the optimal organic loading of the quartz sand vermi-biofilter and the ceramisite grain vermi-biofilter were in the range of 0.78～0.90kgBOD₅/m³·d and 0.85～ demonstrated the conclusion.11.The functional microbial in the vermi-biofilter is Bacillaceae,accounting for about 43.3%,most of which is uncultured with strong adaptation.12.The digestion on the sludge organics is a key factor for the sludge reduction and stabilization.The digestion quantity in the experiment in the quartz sand vermi-biofilter and ceramisite grain vermifiltraion were（1.41～5.26）mgOM/（g earthworm）and（2.51～8.48）mg OM/（g earthworm）.The results indicated that the earthworms in the ceramisite grain vermifiltraion can utilize more the organics in the sludge for their vital movements,such as synthesis,respiration and reproduction etc.13.With the increase of the hydraulic loadings from 2.4 m³·m^-2·d^-1to 6.72 m³·m^-2·d^-1,the earthworms can exist well in the vermi-biofilter due to the regulation of the SOD and CAT enzyme to resist the environmental menaces.Compared with the earthworms bred in the cattle excrement,the somatopleure of the earthworms in the vermi-biofilter suffered some damages to some extent.Under the same experimental conditions,the damages in the ceramic grain bed were less than that in the quartz sand bed.14.Compared with CAS process,the vermi-biofilter process is of less investment,less operation cost,simple management.It can be concluded that the total investment was averagely 36%lower and the operation cost was averagely 41.33% less than that of CAS process.Consequently,the vermi-biofilter was more appropriate for the wastewater treatment of the small towns in southern China.更多还原