污泥处理技术发展

综述目前污泥处理技术的发展概况,介绍污泥减量化和资源化技术,分别从超声波破解、微型动物捕食、臭氧氧化和污泥解偶联等方面介绍了污泥减量化的最新工艺技术;从利用剩余污泥做碳源、建材、肥料及制油等方面总结了污泥资源化的最新成果。     

生物捕食污泥减量化系统的污泥特性

通过中试分析了以减量化为目的的微型动物捕食系统中活性污泥的特性.结果表明,细菌分散培养段的悬浮污泥浓度比原生动物捕食段约高15%,比大型微型动物捕食段约高40%;微型动物的捕食作用在减少剩余污泥产率的同时,可以提高悬浮污泥的沉降性能约36%,轮虫可作为该系统污泥沉降性能的指示生物;低底物浓度下,大型微型动物的捕食活动可以增强污泥的活性.     

臭氧氧化剩余污泥的影响因素分析及应用初探

通过小试得出臭氧氧化剩余污泥的最佳作用条件,并将该作用条件应用于实际废水的剩余污泥减量化中,进行能耗分析。在臭氧氧化污泥过程中,采用单因素分析法分别考察臭氧投加量、剩余污泥浓度、碱解以及热解预处理对污泥减量的影响。在小试基础上,结合实际情况,对某污水处理厂污泥进行了不同污泥浓度下的减量试验,验证了小试结果,得出针对该种污泥MLSS=8.287kg/m3,臭氧最佳投加量在0.038gO3/gMLSS左右,所需能耗为0.589kW.h/kgMLSS。     

采用脱氢酶进行AB工艺A段细菌增殖及污泥产生规律的研究

采用测定活性污泥脱氢酶含量变化的方法对AB法A段细菌增殖及剩余污泥产生规律进行研究。结果表明 :A段细菌比生长速率 μ为 0 .0 5 9～ 0 .0 84h- 1;细菌世代时间为 7.9～ 11.7h ;A段剩余污泥量中 ,增殖的活细菌质量占 6 .89%～ 10 .99% ,未转化的SS占 89%～ 93.12 % ;A段细菌的高速增殖不是产泥量大的根本原因 ,不设初沉池 ,造成大量SS随污水进入反应器才是A段污泥产量大的真正原因 ;得出了污泥产率系数YBOD为 0 .0 6 38～ 0 .10 15kg微生物 /kgBOD ,进水SS造成的污泥增量系数YSS为 0 .84 5～ 0 .893kgMLSS/kgSS ,此外 ,得出了A段剩余污泥量计算式 ,并分析探讨了A段污泥的减量途径及方法     

污泥减量技术

介绍了目前国内外一些污泥减量的技术和工艺 ,如 :原生动物和后生动物摄食细菌法 ,能减少污泥产量 60 %以上 ,对于固定式淹没生物膜法甚至没有剩余污泥产生 ;微生物强化法 ,利用外投优化菌种减少污泥排放量 1 6% ;投加酶法 ,将难溶解的大分子有机污染物分解为易于微生物吸收和利用的小分子溶解性有机物 ,既有利于有机污染物的降解 ,又能促进细菌的增殖 ,能减少污泥产量50 % ;此外还介绍了超声波技术、臭氧氧化、Cambi工艺和生物细胞溶解系统等一系列方法。     

剩余污泥减量化技术研究进展与发展趋势

按照物理、化学、生物及组合工艺的分类对污泥减量技术的研究发展状况进行了分析,并 通过污水处理效果来评价各污泥减量工艺。总结出污泥减量化的两个发展趋势:通过调整反应器和 工艺参数实现在污泥产生过程中减少污泥产量;在污泥回流过程中通过细胞溶解实现在污泥产生后 减少污泥外排量。     

剩余污泥水解酸化释放有机物的效果及影响因素研究

在常压、不调节pH条件下,探讨了不同温度和水力停留时间下城市污水处理厂剩余污泥在水解酸化过程中CODCr、挥发性有机酸(volatile fatty acids,VFA)和总氮(TN)的释放量和释放速度,同时考察了剩余污泥减量效果,在此基础上探讨了剩余污泥水解酸化释放有机物用于反硝化碳源和实现减量化的最优控制条件。结果表明:MLSS为30 000 mg/L的污泥,50℃下水解酸化24 h,达到有机物的最佳释放效果,上清液CODCr浓度为8 349 mg/L,VFA(以CODCr计)浓度为2 490 mg/L;总氮释放量相对较低,CODCr/TN为10.3∶1。同时MLSS削减了22.5%,较高效率地实现了剩余污泥减量。     

臭氧处理对剩余污泥减量化、资源化与无害化的影响研究进展

臭氧作为强氧化剂和杀菌剂,此前被广泛应用于污水处理系统以改善污水出水水质,近年来在剩余污泥原位减量方面得到了广泛的关注.首先,总结了臭氧处理对剩余污泥原位减量和脱水性能的影响;其次,归纳了臭氧联合厌氧消化技术对污泥资源化的促进作用;接着,从无害化角度总结了臭氧处理对污泥中痕量有机物降解的影响;最后,对臭氧处理污泥技术的...     

化学一级强化污泥中温厌氧消化工艺的研究

采用中温厌氧消化对化学一级强化污泥进行减量化、稳定化处理是一种技术上、经济上合理可行的方法。     

利用污泥发电试验研究

污泥发电是污泥合理开发利用的技术措施之一 ,是污泥减量化、无害化、资源化的良好方式 ,该课题研究探索出一条生态兴业的可供借鉴的技术途径。     

超临界水氧化技术在城市污泥处理中的应用

综述了超临界水氧化(SCWO)技术的基本原理和工艺、在城市污泥处理中应用的国内外研究进展,并就SCWO处理城市污泥的前景作了展望。SCWO技术处理城市污泥,污泥中有机物的去除率可达99.9%以上,污泥氧化后的最终残余固体产物的容积仅为浓缩污泥容积的1.2%左右,反应后剩余收集液的COD质量浓度小于10 mg/L,处理后的残留固体还可以进行磷酸盐和重金属回收。     

Organic matter release in low temperature thermal treatment of biological sludge for reduction of excess sludge production.

Thermal treatment applied in association with a biological system allows for a significant reduction in excess sludge production (approximately 50%). In general, heat treatment is described as a sludge disintegration technique. This paper offers a thorough study on the impact of heat treatment, at temperatures below 100 degrees C, on the solubilisation of the sludge COD and its biodegradability. Discontinuous heating experiments were performed on activated and digested sludge. At all temperatures tested the released COD for digested sludge was systematically higher than that for activated sludge (15 and 40%, respectively, at 95 degrees C for 40 min of contact time). For the first 30 min, a 1st order kinetic, with respect to the residual COD, was systematically found. In the range of 40-95 degrees C, digested sludge had a lower activation energy than activated sludge (26 kcal/mol compared to 70-160 kcal/mol). COD solubilisation is thus more positively influenced by temperature in the case of activated sludge. This may be due to the significant difference in the ratio of protein/carbohydrate in digested and activated sludge (1-5 and 0.2-0.7, respectively). The increase in the COD/TKN ratio in the solubilised fraction after thermal treatment of activated sludge suggests a preferential solubilisation of proteins over carbohydrates. Respirometric tests performed on the solubilised COD showed that whatever the sludge origin, only 40-50% of released COD is biodegradable at a conventional hydraulic retention time (i.e., 24 h). Hence, heat treatment would act more through organic matter solubilisation rather than by a biodegradability increase.     

Evaluating the stabilisation degree of digested sewage sludge: investigations at four municipal wastewater treatment plants.

Further reduction of volatile suspended solids (VSS) during a post-stabilisation step was applied to evaluate the stabilisation degree of digested sewage sludge. For this purpose digested sludge was collected at four municipal wastewater treatment plants (WWTPs) and further stabilised in lab-scale chemostat reactors either under anaerobic or aerobic conditions. Experimental results showed that even in adequately digested sludge a consistent amount of VSS was degraded during aerobic post-stabilisation. It seems that aerobic conditions play a significant role during degradation of residual VSS. Additionally, specific VSS production (gVSS/peCOD110.d) as well as specific oxygen uptake rate were shown to be suitable parameters to assess the degree of sludge stabilisation at WWTPs. Fourier transform infrared spectroscopy was used to reveal changes in the sludge composition. Spectra of treated and untreated sludge samples indicated that the major component of residual VSS in stabilised sludge for instance consisted of biomass, while cellulose was absent.     

混合液污泥浓度与污泥回流系统控制策略研究

生物反应池中的混合液污泥浓度(MISS)是活性污泥系统重要的设计与运行参数.在城市污水处理厂日常运行中,应根据运行条件的变化,如进水水质水量的波动、污泥沉降性能的改变等,实施一定的污泥回流控制策略,以保证生物反应池中合理的活性污泥数量,促进系统的稳定高效运行.     

Experience with phosphorus removal and sludge handling and disposal in Flanders.

The way excess sludge must be disposed of is a key factor in the choice of the appropriate phosphorus removal technique at municipal wastewater treatment plants. In Europe the ongoing trend of tightening the sludge spreading rules called for a serious reduction of its agricultural utilisation and the expansion of the (co-)incineration disposal route, which led to a shift towards more sophisticated sludge handling techniques. This paper illustrates the impact of different sludge handling techniques on the performance of chemical and enhanced biological phosphorus removal at municipal WWTPs. The main conclusion is that although enhanced biological phosphorus removal is particularly sensitive to the problem of return liquors from sludge treatment processes indirect dewatering and anaerobic stabilisation cannot be discarded altogether when considering its implementation.     

Sludge as source of energy and revenue.

Sludge is a residue/product from wastewater treatment plants and contains most of the contaminants released during human activities. Some stringent environmental regulations on sludge treatment and disposal exist in many countries. This has resulted in increasing interest in sludge treatment methods that encourage sludge reduction and improvement in biogas production during anaerobic digestion processes. This work demonstrates the first exploitation of valuable energy from homogenised sludge at technical scale with mass reduction. The optimal combination of sludge homogenisation at relatively low pressures using a modified high-pressure homogeniser led to the success of this unique project. Results showed that about 30% more energy could be obtained from thickened and disrupted sludge than from untreated samples. The energy produced was higher than that invested during disruption and digestion processes. About 23% sludge reduction was also observed with no increase in chemical oxygen demand. This new process can produce extra energy for local electrification and heating the digester while the sludge reduction provides economic benefits. Concentration of sludge causes reduction in investment cost on digester as well as reduction in operational time for sludge dewatering.     

Process performance and change in sludge characteristics during anaerobic digestion of sewage sludge with ozonation.

A new process configuration combining anaerobic digestion with ozonation, and operated at long SRT, was studied with the objective of on-site reduction in sludge quantity and improving biogas recovery. The process performance with respect to solid reduction efficiency and other important process parameters like accumulation of inorganic solids, changes in sludge viscosity and dewatering characteristics were evaluated from the data of long term pilot scale continuous experiments conducted using a mixture of primary and secondary municipal sewage sludge. Due to sludge ozonation and long SRT, high VSS degradation efficiency of approximately 80% was achieved at a reactor solid concentration of 6.5%. A high fraction of inorganic solid (>50%) consisting mainly of acid insoluble and iron compounds was found to accumulate in the reactor. The high inorganic content accumulated in the digested sludge did not, however, contribute to the observed increase in sludge viscosity at high solid concentration. The sludge viscosity was largely found to depend on the organic solid concentration rather than the total solid content. Moreover, higher inorganic content in the digested sludge resulted in better sludge dewaterability. For a quick assessment of the economic feasibility of the new process, an economic index based on the unit cost of digested sludge disposal to unit electric cost is proposed.     

Reduction of excess sludge production using mechanical disintegration devices.

The usability of mechanical disintegration techniques for the reduction of excess sludge production in the activated sludge process was investigated. Using three different disintegration devices (ultrasonic homogeniser, stirred media mill, high pressure homogeniser) and different operational parameters of the disintegration, the effect of mechanical disintegration on the excess sludge production and on the effluent quality was studied within a continuously operated, laboratory scale wastewater treatment system with pre-denitrification. Depending on the operational conditions and the disintegration device used, a reduction of excess sludge production of up to 70% was achieved. A combination of mechanical disintegration with a membrane bioreactor process with high sludge age is more energy effective concerning reduction of sludge production than with a conventional activated sludge process at lower sludge ages. Depending on the disintegration parameters, the disintegration has no, or only minor, negative effect on the soluble effluent COD and on the COD-removal capacity of the activated sludge process. Nitrogen-removal was slightly deteriorated by the disintegration, whereas the system used was not optimised for nitrogen removal before disintegration was implemented.     

Impact of sewage sludge applications on the biogeochemistry of soils

This report describes an investigation into the bioavailability and fate of trace metals and their subsequent impact on important soil microbiological functions such as nitrification, denitrification and methane oxidation in low and high Cu containing soils in the presence and absence of residual organic matter from sewage sludge additions made 10 years earlier. The soils being studied are part of long term sewage sludge trials and include a low Cu soil (13.3 mg Cu/kg soil, 4.18 LOI %), left un-amended to serve as a control soil, soil amended with a high Cu sewage sludge (278.3 mg Cu/kg soil, 6.52 LOI %) and soil amended with a low Cu sewage sludge (46.3 mg Cu/kg soil, 6.18 LOI %). Soil was also amended with inorganic metal salts (273.4 mg Cu/kg soil, 4.52 LOI %) to further investigate the impact of Cu in the absence of additional organic matter contained in applied sewage sludge. Data from the first two years of a project are presented which has included field-based studies at long term sewage sludge trials based in Watlington, Oxford, UK and laboratory based studies at the Institute of Grassland & Environmental Research, North Wyke, Devon, UK.