污水处理厂除臭工程设计

采用植物提取液进行污水处理厂除臭。简要介绍了植物提取液除臭的机理:利用喷雾系统将提取液直接喷洒在臭气源附近,喷洒剂中的活性成分可使异味分子发生化学反应,从而达到除臭的目的。污水处理工程污水量5万m3/d,分成四个相对独立的控制区域,总控制面积2 500 m2。工程总投资200.5万元,运行费用9 773元/d。系统运行时,H2S和NH3均能达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)二级标准。     

中山市三乡镇污水处理厂工程设计

三乡镇污水处理厂设计规模2万m3/d,污水处理工艺采用改良CASS法,污泥处理采用浓缩-机械脱水工艺,臭气处理采用分散收集后生物法集中除臭的方法.具体介绍了改良CASS工艺的设计参数、工艺流程及设计特点,为改良CASS工艺克服选址及占地限制提供一定参考.     

南京市城北污水处理厂工程设计

南京市城北污水处理厂设计规模30万m~3/d,其污水处理工艺采用一体化活性污泥法,污泥处理工艺采用浓缩脱水带式一体机,臭气处理采用分散收集、化学法集中除臭。介绍了工程设计参数、处理工艺流程及其设计特点。并详细阐述了除臭工艺流程及相关运行参数,净化后去除率达99.2％。     

上海曲阳污水处理厂改造工艺及应用

针对上海曲阳污水处理厂达标改造工程的特点和要求,对污水处理工艺采用具有自主知识产权的双污泥脱氮除磷处理技术(PASF)、污泥处理和生物滤池臭气处理方案、工艺流程和设计参数进行介绍,对工程实施和运行情况进行分析,为全国污水处理厂达标改造提供参考.     

生物除臭在污水处理厂中的应用

介绍了污水处理厂臭气测定方法、气味物质浓度设计值及除臭需满足的标准,并重点说明了厌氧池除臭工艺选择及生物除臭系统工程设计,最后根据除臭系统运行情况总结了设计经验。     

炭质生物媒填料在污泥干化除臭系统改造工程中的应用

随着公众环保意识日益增强,臭气问题已经引起越来越多的关注。深圳市某污泥热干化工程利用炭质生物媒填料对现有的生物除臭系统进行了改造,提高了运行的稳定性和除臭效果。从工程设计、工艺流程、设备选型以及工程调试和运行几个方面对项目进行了论述和总结。     

垂直潜流生态湿地技术在市区外围住宅小区中的应用

在常州市外围片区孟河镇通江花园,借鉴了德国先进的生态技术,应用垂直潜流人工湿地技术进行分散式污水及污泥处理.介绍了工艺的流程、单元设计、运行情况并进行经济分析,同时通过多项技术改进和工艺优化,提高了污水处理效率,出水可达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级B标准,为城乡结合部和农村集中管网未覆盖地区的分散式污水处理提供了实用技术.     

城市污水处理厂污泥的生物除臭

主要研究了微生物对生污泥臭味的去除作用及除臭过程中速效有机碳的含量的变化及除臭菌的抗热性 ;并结合除臭试验做了日处理 30t(含水率 80 %生污泥 )污泥处理厂的设计及经济分析     

生物除臭系统在污水处理厂中的应用——以武汉市落步嘴污水处理厂为例

1．工程概况 落步嘴污水处理厂位于武汉市青山区洪山乡苏家嘴村的规划用地范围内，紧临新建的武汉火车站，近期规模为12万m^3／d，远期总规模为24万m^3／d，厂区近期控制占地面积约9．172公顷，远期总占地面积约6．793公顷。污水处理工艺为厌氧氧化沟工艺，二级污水处理。污水处理过程中产生的臭气经生物除臭系统处理后的排放气体符合《城镇污水处理厂污染物排放标准》（0818918—2002）中规定的二级标准。     

郑州马头岗污水处理厂污泥处理处置方案比选

郑州马头岗污水处理厂近期规模30万m3/d,采用UCT工艺,设计阶段进行了浓缩污泥单独消化脱水方案与三座污水处理厂浓缩脱水污泥集中堆肥的污泥处理处置方案比选.介绍了两种方案的设计参数、前期处理工程费用及运行费用等情况,并确定了污泥最终处理处置方式.     

城镇污水处理厂项目环境影响评价重点的研究

城镇污水处理厂作为一项环境保护工程,在发挥环境效益的同时,运行过程中排放的尾水、产生的恶臭和污泥等污染物对环境将产生不利影响。在进行污水处理厂项目环境影响评价时,应识别评价重点,目的是使环境影响预测和评价具有针对性,以发挥更大的环境效益。根据污水处理厂的工程特性,结合江门市江海污水处理厂工程环境影响评价的实践经验,提出污水处理厂环境影响评价应重点关注厂址环境合理性分析、污水处理工艺比选、尾水排放对水环境影响、恶臭对大气环境影响、污泥处置对环境影响等问题。     

Post-aeration of anaerobically digested sewage sludge for advanced COD and nitrogen removal: results and cost-benefit analysis at large-scale.

At a large Austrian municipal wastewater treatment plant enhanced stabilisation of anaerobically digested sewage sludge was required in order to get a permit for landfill disposal of the dewatered stabilized sludge. By implementing a post-aeration treatment after anaerobic digestion the organic content of the anaerobically well digested sludge can be decreased by 16%. Investigations at this plant showed that during digested sludge post-aeration anoxic phases are needed to provide stable process conditions. In this way the pH value can be kept in a more favourable range for micro-organisms and concrete structures. Additionally, under the process conditions applied nitrite accumulation would inhibit the stabilisation process if denitrification is not adequately applied. By optimising the aeration/pause ratio approximately 45% of total nitrogen in digested sludge can be removed. NH4-removal occurs through nitrification and denitrification with an efficiency of 98%. This significantly improves nitrogen removal efficiency at the wastewater treatment plant. The costs/benefit analysis shows that post-aeration of digested sludge results in an increase of total annual costs for wastewater treatment of only 0.84%, corresponding to 0.19 Euro/pe/a. Specific costs for nitrogen removal (0.32 Euro/kgN) are comparable with other biological processes for N-removal in reject water.     

Application of the flotation process to thicken the sludge from a DAF plant.

Dissolved air flotation (DAF) was evaluated for thickening of the sludges from a water treatment plant which uses DAF. Solid flux theory for gravity thickening was applied to the solid flux of DAF sludge. The higher the polymer dosage, at fixed solid concentration, the greater the rising velocity becomes. When applied with solid flux equations, a similar relationship to that of gravity thickening has been found. However, the values were much higher than in gravity thickening, because both the inflow solid concentration and the floating velocity were higher than for settled sludge. With this result, the proper dosage of polymer could be derived from the relationship between total solid flux and withdrawal velocity of DAF sludge.     

A combined process of non-thermal plasma with sludge stabilization for the simultaneous reduction of odor and organic waste

Odor emissions and sludge disposals have become most challenging issues in many sludge treatment plants, and separate chemical oxidation processes have been commonly employed for these problems. It is, therefore, necessary to develop a combined process that simultaneously reduces the odor emissions and the amount of waste sludge. In this study, a non-thermal plasma reactor using a dielectric barrier discharge type was employed to treat a gas stream contaminated with 10 ppm(v) of H(2)S, and then the ozone-laden gas stream was supplied to a sludge stabilizer to reduce the organic constituents. The specific energy input to the plasma was varied to investigate the performance of the combined process. When the specific energy inputs were 200, 260, and 360 J/L, the rates of ozone generation from the plasma reactor were 0.036, 0.070, 0.144 g-O(3)/h, respectively. At these experimental conditions, the removal efficiencies of H(2)S were 60, 75, and >99%, and total chemical oxygen demand (TCOD) reduction efficiencies of 33, 61 and 67% were observed. In addition, a soluble organic fraction of the sludge increased at ratios of 1.9, 8.9, and 10.7%, respectively. Consequently, the combined process effectively and simultaneously reduced the odor compounds as well as the organic constituents and particles in the waste sludge.     

The use of immersed membranes for upgrading wastewater treatment plants

Membranes can be installed in the clarifier (or aeration tank) of an existing activated sludge plant to enhance the biomass separation function of the system, thereby effectively overcoming any operating constraints associated with sludge settleability. The resulting upgraded plant can be operated at high biomass concentrations (10–20 gMLSS/L), leading to an increase in its treatment capacity. The membranes also ensure a treated water consistently free of suspended solids and a superior disinfection performance. The system offers an enhanced operating flexibility, and allows to operate at high sludge ages leading to a low excess sludge production.Such an immersed membrane activated sludge process (BIOSEP^®) has been developed and applied to the treatment of raw sewage. When treating screened raw sewage with this process, with a sludge concentration of 15 gMLSS/L and a volumetric loading of 1.2 kgCOD/m³/d, a 96% COD reduction and a 95% Total Kjeldahl Nitrogen (TKN) reduction have been obtained. The disinfection performance of the system was over 6 Log removal for fecal coliforms. The resulting production of sludge was 0.20 kgMLSS/kgCOD.Two desk case studies are given for 900 m³/day upgraded plants. In one case, the primary objective was to increase the treatment efficiency and develop nutrient removal for the original plant, while in the other case the primary objective was to increase the capacity of the original 460 m³/day plant.     

白龙港污水处理厂生物处理污泥产量分析与预测

准确了解城市污水处理厂的污泥产量,不仅对污水处理厂的运行管理有指导意义,也有利于后续污泥的处理与处置。对上海白龙港污水处理厂生物处理工艺污泥产量的设计值、实际运行值进行计算,分析不同污泥产量计算方法的特点。并对重新启用初沉池后污泥产量的变化进行了详细的测算和分析,结果表明,重新启用初沉池后污泥产量比超越初沉运行时有所减少,减轻了后续污泥处置负荷。     

QMRA (quantitative microbial risk assessment) and HACCP (hazard analysis and critical control points) for management of pathogens in wastewater and sewage sludge treatment and reuse.

Hazard Analysis and Critical Control Points (HACCP) was applied for identifying and controlling exposure to pathogenic microorganisms encountered during normal sludge and wastewater handling at a 12,500 m3/d treatment plant utilising tertiary wastewater treatment and mesophilic sludge digestion. The hazardous scenarios considered were human exposure during treatment, handling, soil application and crop consumption, and exposure via water at the wetland-area and recreational swimming. A quantitative microbial risk assessment (QMRA), including rotavirus, adenovirus, haemorrhagic E. coli, Salmonella, Giardia and Cryptosporidium, was performed in order to prioritise pathogen hazards for control purposes. Human exposures were treated as individual risks but also related to the endemic situation in the general population. The highest individual health risk from a single exposure was via aerosols for workers at the belt press for sludge dewatering (virus infection risk = 1). The largest impact on the community would arise if children ingested sludge at the unprotected storage site, although in the worst-case situation the largest number of infections would arise through vegetables fertilised with sludge and eaten raw (not allowed in Sweden). Acceptable risk for various hazardous scenarios, treatment and/or reuse strategies could be tested in the model.     

Application of heat shock protein assay and proteome assay to water from wastewater treatment plant.

In this study we applied bioassay using Chinese hamster ovary (CHO) cells with a heat shock protein (HSP) 47 promoter to the effluent of the wastewater treatment plants in Sapporo and we observed the statistically significant HSP production. This implied the effluent contained some organic matter which can stress the CHO cells. To investigate the possible causes of the toxicity of the effluent, we applied the assay to the rejected water from the sludge treatment plant, the mixtures of sewage and rejected water. The evolution of HSP production during the aerobic decay process and thickening process of sludge was also examined. These assay results showed that dissolved microbial products generated and/or released from activated sludge during its decay process in the aeration tank and during thickening and dewatering process in the sludge treatment train contributed to develop HSP production. The proteomics analysis was also applied to the effluent and detected the production of elongation factor 1beta. This result implies that the effluent from wastewater treatment plants may cause changes in cell proteins involved in allergic reaction.     

Enhanced sludge conditioning by enzyme pre-treatment: comparison of laboratory and pilot scale dewatering results.

The effect of enzyme pre-treatment on dewaterability of anaerobically digested sludge was investigated at both laboratory and pilot scale. Our results revealed a significant increase in cake solid content (27% cake solids compared to 18% without enzyme pre-treatment), using an enzyme dose of only 20 mg/L. In order to assess practical application, enzyme pre-treatment was applied at the Wilmington, Delaware (U.S.) wastewater treatment plant, using a pilot-scale centrifuge. However, the efficiency reached in laboratory scale could not be obtained in pilot scale, where the final cake solids content did not exceed 20%. Centrifuge and belt filter press (simulated by Crown Press) dewatering were compared in terms of the process efficiencies in the absence and presence of enzyme pre-treatment. Possible factors that might cause the differences were tested by experimental and statistical comparisons. Results indicated that the higher shear applied in centrifugation is responsible for the lack of improved cake solids. The network strength of sludge determined by rheological measurements revealed that enzymatic treatment weakens the gel structure of the sludge floc through the hydrolysis of extracellular polymeric substances; this allows improved dewatering by filtration processes, but leads to floc deterioration when subjected to high shear during centrifugation.