【作者】 白永刚；

【导师】 吴浩汀；

【作者基本信息】 东南大学 ， 环境工程， 2005， 硕士

【摘要】 近年来随着工业排放点源污染的有效治理,太湖的富营养化程度已有所下降,但是太湖流域内的面源污染仍比较突出,且区域内氮、磷污染严重,因此太湖流域内水环境的治理已到了刻不容缓的地步。本研究课题属于863项目的农村生活污水处理技术及示范性工程专题,要求结合农村的实际情况,为治理太湖流域内的农村生活污水提供行之有效的先进处理工艺及技术,并在试验运行的基础上,获得最佳的运行条件,为后续的治理工作提供实践经验。基于此,设计了滴滤池-人工湿地组合工艺处理农村生活污水,并在实际的运行过程中得出以下结论:1.滴滤池内的溶解氧水平与滤池外气温、污水水温相关,滤池内水温对滤池出水溶解氧的影响较大,而气、水温差对其仅有微弱影响。2.滴滤池处理效果受到工艺负荷、水力负荷、回流比等方面的影响,且在COD容积负荷小于0.5kgCOD/m³·d,水力负荷为4.0m³/m²·d,回流比为200%时,滴滤池获得最佳的处理效果;滴滤池内的硝化作用与水温紧密相关,低温会引起亚硝酸盐的累积。3.通过对滴滤池内的生物相的分析发现,滴滤池内细菌数量处于1012cells/g生物膜水平,沿滤层高度呈现先减少后增加的分层分布现象。亚硝酸菌和硝酸菌在整个滴滤池内分布较均衡,滴滤池内硝化作用的效果与滤池中下部保持稳定的硝化菌数量呈正相关。4.对建立的滴滤池简化模型进行试验数据回归,结果表明,对于生活污水,有机物浓度以COD计,滤料为珍珠岩矿渣,滤层高度为2.5m,其反应速率常数k20为1.354d-1,常数n为0.77,温度系数θ为1.021。5.人工湿地对COD、NH₄⁺-N均具有较好的去除效果。湿地系统除氮的主要机制在于微生物的作用,随停留时间的延长湿地系统对氮的去除效率增加,且该作用与波形水流状态所形成的溶解氧交替变化有关。湿地系统除磷的主要机制是介质的吸附沉淀作用,且pH值的沿程降低将不利于磷与石膏介质的吸附沉淀作用。更多还原

【Abstract】 The eutrophic degree of Lake Taihu has descended after the effectual treatment of industry effluence point pollution in the recent years.But the non-point pollution in Taihu Lake area has been the most important one for the pollution contribution with the serious pollution of nitrogen and phosphorus.So the disposition of water circumstance in Taihu Lake area has become the most imperative thing that will be done. This full-scale experimental study belongs to the subject about technology and demonstrative engineering for rural domestic wastewater treatment which is one part of the 863 tasks. Combined with the rural fact complexion,the advanced treatment progress and technology which can treat rural domestic sewage in Taihu Lake area effectively will be provided.With the experimental data,the optimal running conditions are obtained which can provide the experiences for continued treatment tasks.Based on these,the trickling filter-constructed wetland combined processes for treating rural domestic wastewater are designed.The following conclusions can be arrived at during the practice:1.The DO concentration in trickling filter has correlation to both the exterior air temperature and sewage temperature,the sewage temperature effects the DO in TF effluent remarkably while the gap between the air and water temperature has almost no effect to the DO in TF effluent.2.The loads of process,hydraulic load and circumfluence ratio influence the treatment effect of TF,the best treatment effect can be obtained at the following level:COD cubage load≤0.5kgCOD/m3·d, hydraulic load is 4.0m~3/m~2·d, circumfluence ratio is 200%.The nitration action has close correlation to the water temperature,and the low temperature can bring out the cumulation of nitrite.3.The analysis through the microorganisms inside TF indicate that bacteria data in TF is at 1012cells/g biofilm level and the delamination distribution cases which reduced first while increased later.The nitrosomonases and nitrobacters are distributing equably within the whole TF.The effect of nitration in TF has a positive correlation with the amounts of nitrifying bacterias in the middle and nether parts within TF.4.The data regression done according to the simple model for TF through the full-scale test indicate that the reaction velocity constant k20 is 1.354 d-1,constant n is 0.77, temperature coeffifientθis 1.021 when using COD as the organic matter concentration and the condition is that the filtration mediums are perlite slags as well as the height of which is 2.5 metres.5.The constructed wetland has perfect effect for removal of COD and NH4+-N.The main mechanism of nitrogen in wetland systems is the action of microorganisms,while the removal efficiency will increase with the protraction of HRT(hydraulic resort time)in wetland,and also the action has a close relationship with the alternant changes of DO formed by the undee flowing.The main mechanism of phosphorus removal is the adsorption and sedimentation by the reaction of wetland bed medium with phosphate in wastewater,and the debasement of pH along the length of wetland will make against the action of phosphate’reaction with the gypsum.更多还原