农村生活污水治理长效管理机制研究

近年来,随着杭州农村生活污水治理工程的全面实施,设施的日常管理维护,保证正常稳定运行、长期发挥应有作用日益成为关注重点.本文在对杭州地区农村生活污水治理现状调研基础上,分析了现有治理工程在规划设计、工程质量、设施运行、日常管理及资金等方面存在的问题,提出了从组织体系、工程项目体系、政策保障体系、资金筹措体系、考核评价体系等方面构建农村生活污水治理长效管理机制.     

Measuring disaster recovery: bouncing back or reaching the counterfactual state?

How should one measure the recovery of a locale from a disaster? The measurement is crucial from a public policy and administration standpoint to determine which places should receive disaster assistance, and it affects the performance evaluation of disaster recovery programmes. This paper compares two approaches to measuring recovery: (i) bouncing back to pre‐disaster conditions; and (ii) attaining the counterfactual state. The former centres on returning to normalcy following disaster‐induced losses, whereas the latter focuses on attaining the state, using quasi‐experimental design, which would have existed if the disaster had not occurred. Both are employed here to assess two housing recovery indicators (total new units and their valuations) in Hurricane Katrina‐affected counties (rural and urban). The examination reveals significantly different outcomes for the two approaches: counties have not returned to their pre‐disaster housing conditions, but they do exhibit counterfactual recovery. Moreover, rural counties may not be as vulnerable as assumed in the disaster recovery literature.     

村镇公共安全评价体系研究——以河北省沧州市南大港一分区为例

将环境承载力评价理论引入到农村公共安全研究中,根据农村公共安全环境承载力指标体系的构建原则,选取一级指标5个,二级指标10个,基于鱼骨图分析法建立村镇公共安全体系。结合统计软件SPSS,采用主成分分析法(PCA),对村镇公共安全体系进行排序,找出影响村镇公共安全水平的重要因子,为改善村庄公共安全风险提供了重要参考价值。结果表明:一分区各村公共安全承载能力差异较大,且基础设施承载因子和土地承载因子是影响村庄公共安全承载能力最重要因子,加大公共安全基础设施的投入、有效利用闲置土地,可以较好地提高村镇公共安全承载能力。     

关于农村环境问题及解决对策浅析

本文通过全面解析当前我国农村环境所面临的主要问题,提出解决我国农村环境问题的方法和改善农村生态环境的对策,为国家行政决策和环境保护提供参考。     

沼气建设对促进农村经济发展效益分析

针对河南省9个县(市)中9个乡(镇)的农户沼气使用情况,按比例选择不同生态模式,入户调查了沼气建设前后农户各类能源消耗情况,农业生产投入与产出等80多项指标,定量对比分析了沼气户与非沼气户在能源消耗量及消耗成本、种植业和养殖业发展以及主要气体污染物减排等情况。结果表明沼气建设项目的实施大大降低了传统能源消耗量和消耗成本,促进了种植业和养殖业的发展,减少了污染物的排放,改善了农户居住环境,提高了作物产量,增加了农民收入,具有明显的能源效益、经济效益、环境效益和社会效益。     

日光型厌氧好氧-体化技术在农村生活污水处理中的应用

根据天津农村生活污水的特点,采用日光型厌氧好氧一体化技术,在宁河县大北涧沽村建设污水处理站。运行结果表明:平均出水ρ(COD)<60.3mg/L,ρ(BOD)<20mg/L,ρ(NH3-N)<32.75mg/L,ρ(TN)<33.5mg/L,粪大肠菌群数<30个/100mL。出水可用于农业灌溉。工程运行实践表明:该工艺对农村生活污水处理效果较好,其中COD和BOD的平均去除率均达70%以上,粪大肠菌群的平均去除率达95%。NH3-N和TN经处理后达到排放标准,但处理效果有待改进,平均去除率分别为26.87%和38.25%。     

MBBR-A2O/MBR处理农村生活污水动力学研究

采用MBBR-A2O/MBR(又称BCO-MBR)工艺,对水质特征呈现低碳源高氮磷、水质波动大和日变化系数大等特点的农村生活污水进行研究。对比MBBR-A2O/MBR工艺在5种不同水力停留时间下的(0.42 d、0.50 d、0.75 d、1.25 d、1.50 d)运行状况,挑选出最佳的水力停留时间,并利用Lawrence-McCarty模型构建该工艺的污染物降解动力学方程。结果表明,随着水力停留时间(HRT)的延长,MBBR-A2O/MBR工艺对污染物的去除效果逐渐提升。当HRT为1.25d,CODCr、NH3H、TN、TP平均进水质量浓度分别280.67mg/L、36.88 mg/L、50.59 mg/L、2.51 mg/L时,平均出水质量浓度分别为34.33 mg/L、3.19 mg/L、5.13 mg/L、0.63 mg/L,平均去除率分别可达87.86%、89.92%、89.85%、74.95%。CODCr、NH3H、TN出水质量浓度在城镇污水排放标准一级A限值以下,TP出水质量浓度达到一级B标准,因此确定最佳的HRT为1.25 d。污染物降解动力学计算所得模拟值与实际出水质量浓度测量值拟合度良好,其中CODCr模拟值与平均测量值一致性最高,相对误差在0.02~0.14,NH3H与TN的相对误差分别在0.19~0.60和0.1~0.33。这表明污染物降解动力学方程可以较好地模拟工艺出水的污染物质量浓度。CODCr降解动力学方程常数为Vmax=0.19 d-1,KS=82.97 mg/L;NH3H降解动力学方程常数为Vmax=0.02d-1,KS=8.49 mg/L;TN降解动力学方程常数为Vmax=0.024 d-1,KS=8.10 mg/L。研究的动力学常数与传统活性污泥法动力学常数相比,KS较高,而Vmax较低,导致Vmax较低的主要原因可能是测定的污泥质量浓度高于实际有效的质量浓度。研究对利用MBBR-A2O/MBR工艺处理农村生活污水和传统活性污泥工艺提标改造具有一定的应用参考价值。     

不同区域农村生活污水处理技术层次分析——以新疆维吾尔自治区为例

在对新疆维吾尔自治区(以下简称“新疆”)农村生活污水排污特点、处理现状和常见处理工艺进行调研的基础上,根据新疆农村生活污水处理排放标准要求,筛选了满足标准要求的5种组合处理技术。根据自然环境条件、人口规模和聚集程度、居民生活习惯、经济发展水平、污水收集方式、处理规模和排水水质要求等,将新疆农村分成3类区域。综合考虑排放去向、处理规模、处理效果、处理方式、投资运行成本5个主要影响因素,分区域对5种组合处理技术进行了层次分析,得出3类区域的农村生活污水处理模式优选顺序,以此可为新疆农村生活污水处理规范化管理和技术选择提供参考。     

An innovative integrated oxidation ditch with vertical circle (IODVC) for wastewater treatment

The oxidation ditch process is economic and efficient for wastewater treatment, but its application is limited in case where land is costly due to its large land area required. An innovative integrated oxidation ditch with vertical circle(IODVC) system was developed to treat domestic and industrial wastewater aiming to save land area. The new system consists of a single-channel divided into two ditches(the top one and the bottom one by a plate), a brush,and an innovative integral clarifier. Different from the horizontal circle of the conventional oxidation ditch, the flow of IODVC system recycles from the top zone to the bottom zone in the vertical circle as the brush is running, and then the IODVC saved land area required by about 50% compared with a conventional oxidation ditch with an intrachannel clarifier. The innovative integral clarifier is effective for separation of liquid and solids, and is preferably positioned at the opposite end of the brush in the ditch. It does not affect the hydrodynamic characteristics of the mixed liquor in the ditch, and the sludge can automatically return to the down ditch without any pump. In this study, experiments of domestic and dye wastewater treatment were carried out in bench scale and in full scale, respectively. Results clearly showed that the IODVC efficiently removed pollutants in the wastewaters, i.e., the average of COD removals for domestic and dye wastewater treatment were 95 % and 90%, respectively, and that the IODVC process may provide a cost effective way for full scale dye wastewater treatment.     

复合式厌氧反应器处理生活污水运行特性研究

本文对复合式折流板厌氧反应器处理生活污水的运行特性进行了研究,并作了灵敏度分析。结果表明:HABR反应器因其特殊的结构而具有很好的耐冲击负荷能力及很好的去除效果;当进水的CODCr在300mg/L左右,温度在16 3～30 5℃时,水力停留时间采用6h,容积负荷为1 2kgCOD/m3·d左右,COD去除率可保持在70%以上,出水CODCr可小于100mg/L,出水SS浓度在27～64mg/L之间;各操作参数对HABR反应器CODCr去除率的影响有显著性不同;HRT是系统运行过程中需严格控制的关键因素。