城市污泥无害化处置的研究

考虑到污泥处理的紧迫性和复杂性,结合工程的经济性原则,重点介绍了无害化处理城市污泥的系统方案——污泥干化焚烧.该系统采用空心桨叶污泥干燥机对污泥进行干燥、循环流化床炉对污泥进行焚烧,再利用余热锅炉吸收烟气热能产生蒸汽用于污泥干燥机对污泥进行干燥,实现了整个废弃物能源利用的最大化,降低了系统整体的运行费用.经过处理后的污...     

湿污泥循环流化床干化焚烧一体化研究

为高效处理污泥并回收热量,提出湿污泥干化焚烧一体化工艺.在0.15 MW循环流化床试验台上对湿污泥干化焚烧一体化工艺进行验证性试验.利用循环流化床焚烧产生的热灰在外置式流化床干化器内对湿污泥先进行干化,再送回炉膛燃烧,结果表明通过调节湿污泥给料速率、循环热灰调节阀开度和辅助给煤量可以实现焚烧炉内温度和干化器内料层温度的运行稳定,干化后污泥颗粒粒径分布比较均匀,水分在20%左右,焚烧后烟气排放在环境允许的范围内.     

污泥在流化床中的焚烧特性研究

本文研究了高水分、低热值的污泥在流化床中的结团特性、着火特性。考察了床温、污泥水分、辅助燃料、给料粒径、流化风速对污泥结团的影响，比较了多种不同污泥的结团情况，并运用中间相理论对污泥结团机理作了初步分析。试验结果对于污泥流化床焚烧的基础理论和应用研究都有着重要意义。     

基于高温空气燃烧技术的污泥掺煤焚烧系统设计

采用高温空气层燃炉焚烧系统处理高水分污泥,计算得出处理1 kg水分为90%的高水分污泥,最佳的过量空气系数为1.65,氧气浓度为13%,一二次风配比为7:3,一燃室停留时间为7 218 s,排烟温度为182℃,所需耗煤量0.15 kg/kg,为高水分污泥处理提供一种新颖、高效、低成本的处理方式。     

50 t/d市政污泥干化系统及特点

介绍了50t/d市政污泥干化系统的湿污泥接收储存及输送、污泥干化机、干污泥输送、蒸汽供应及凝结水回收、尾气处理、臭气收集输送等装置设备及设计,对市政污泥干化系统的研发和优化具有借鉴意义。     

基于料位模型的污泥柱塞泵自校正体积流量软测量研究

由于湿污泥流动性差且不稳定，无法建立稳定流场，国内外目前没有成熟可用的流量测量技术。通过基于湿污泥仓料位模型建立了污泥柱塞泵自校正体积流量软测量方法，测量湿污泥仓的料位变化量推算出对应时间段柱塞泵泵出的污泥体积量，通过两者的数学关系建模和实时自校准，根据柱塞泵的运行周期，计算得到可用的污泥柱塞泵瞬时流量。实际应用的案例分析表明，基于料位模型的污泥柱塞泵自校正体积流量软测量方法有效，可供同类工艺系统借鉴。     

污泥焚烧处理系统

污泥处理与处置的目的与其他废弃物的处理与处置一样，都是以减量化、资源化、无害化为原则。目前在世界各国，填埋、农用和焚烧是污泥处置的几种主要方法。近几年来，污泥焚烧技术已经成为处理污泥的主流。     

污泥独立干化焚烧系统关键参数节能优化

本文以某污泥独立干化焚烧项目为研究对象,对该系统中不同污泥外热(干化机)及内热(焚烧炉内干化)的比例进行热平衡计算,并结合安全、物料输送等方面进行综合分析.研究发现:系统外部所需蒸汽量随热干化机污泥出口含水率升高而降低.提高热干化机出口污泥含水率,有助于污泥独立干化项目节省蒸汽,但同时需要考虑焚烧炉入炉污泥允许最高含水率及污泥输送粘度等问题.     

深度脱水污泥输送系统问题研究

污泥处理处置是我国建设无废城市最关注的问题之一。其中燃煤耦合污泥发电是目前国内主流的污泥处理工艺,主要是利用电厂内低品位蒸汽对含水率为60%～80%的污泥干化至含水率为30%～40%后与燃煤掺烧处理。无论采用何种技术对污泥进行处理处置,都不可避免地需要对污泥进行输送,选择合适的污泥输送技术及输送工艺系统的合理设计对于整个污泥处理系统的稳定运行至关重要。本文通过某燃煤电厂污泥输送系统的设计选型及运行情况进行分析,以期为同类项目的设计提供参考。     

市政下水污泥焚烧处置装置

污水处理厂下水污泥一般含水率为80％,其余的20％中含有各种有害物质,焚烧是最彻底的无害化处理方法。鼓泡流化床焚烧炉成为主要的污泥焚烧装置。不添加煤等辅助燃料才能保证焚烧处理的环保性使烟气中的污染物不被稀释。烘干后含水率达到～62％,应用基低位热值达到650kcal／kg以上的污泥才能达到焚烧条件。焚烧系统由污泥进料系统、鼓泡流化床焚烧炉、送风系统、排渣及砂循环系统四个单元构成。污泥进料系统中料斗的形状应能防止斗内污泥搭桥、堵塞。鼓泡流化床焚烧炉应保证q3、q4损失接近于0。送风系统中一、二次风机抽气口设置在污泥池内来避免臭气外泄。并设置高温空气预热器使热风温度最高达到500℃。排渣及砂循环系统应保证炉膛密封。     

上海市竹园污泥干化焚烧系统的能量平衡分析

结合上海市竹园污泥处理工程,根据竹园污泥干化焚烧工程的设计方案,研究了污泥干化焚烧系统的能量平衡模型。根据所建立模型的计算结果,上海竹园污泥处理工程焚烧系统可产生47×106kJ的能量,而干化机所需的能量约为57.2×106kJ,焚烧系统产生的能量不足以提供污泥干化系统所需的全部能量。     

Decentralized drying-gasification scheme of sewage sludge with torrefied biomass as auxiliary feedstock

A drying-autothermal gasification scheme with torrefied biomass as auxiliary feedstock was proposed for the first time in order to realize the decentralized treatment of sewage sludge in wastewater treatment plant. Thermodynamic equilibrium and energy flow balance for the proposed system were evaluated. A non-stoichiometric thermodynamic equilibrium model was applied to evaluate the effect of adding ratio of torrefied biomass on the autothermal gasification performance. A novel dual-check algorithm was developed to determine the molar numbers of syngas components and the injected air. The energy utilization ratio for the whole process was introduced to measure the ratio of the energy used in the whole system to the total input energy. High adding ratio of torrefied biomass was favor of lifting the cold gas efficiency, but it would lead to low energy utilization ratio in terms of sewage sludge treatment.     

入炉污泥含水率对污泥干化焚烧工艺影响研究

以上海某污水处理厂为例,通过理论计算和工程设计分析,研究了入炉污泥含水率(质量分数)对污泥干化焚烧工艺的影响.结果表明,随着干化程度的提高,对干燥机处理能力的要求提高,对干燥机型式的选择余地缩小,对焚烧炉、余热锅炉等设备的要求也将提高,对设备材质、系统安装、运行管理的要求也将相应提高.随着污泥干化程度的降低,进料量和烟气量增大,导致焚烧和烟气处理设备体积庞大.由于污泥泥质特性随时间变化大,在污泥热值整体偏低的地区,采用60%入炉污泥含水率存在一定的风险.污泥入炉含水率对污泥焚烧处理工程中的工艺选择及布置影响较大,工程设计中不应简单照搬国内外类似工程,而应根据当地污泥泥质特性、热值、辅助热源等实际情况,合理选择入炉污泥含水率.     

Enhanced microbial oil production by activated sludge microorganisms from sugarcane bagasse hydrolyzate

The use of sugarcane bagasse hydrolyzate as a carbon source for enhanced oil production by activated sludge microbial cultures was investigated. Cultivation of raw activated sludge inoculum using pure xylose as carbon source was necessary prior to bagasse hydrolyzate feeding for microbial acclimation to this pentose sugar, the major component of the hydrolyzate. Lipid contents from 40 to 47% (dry cell weight) were achieved under high C:N ratio following bagasse hydrolyzate feeding; however nutrient supplementation was found to be necessary in order to maintain viable cell biomass levels (>10 g/L) to achieve a high lipid titer (7.62 g/L). Hence, a process involving sequential batch feeding of hydrolyzate with and without nutrients was proposed and simulated using the Logistic and Luedeking–Piret models. Analysis of the product lipids showed up to 50% saponifiable fractions and dominance of C₁₆ and C₁₈ fatty acids, demonstrating their suitability as biofuel feedstock.     

Heat and energy requirements in thermophilic anaerobic sludge digestion

The heating requirements of the thermophilic anaerobic digestion process were studied. Biogas production was studied in laboratory experiments at retention times from 1 to 10 days. The data gathered in the experiments was then used to perform a heat and energy analysis. The source of heat was a conventional CHP unit system. The results showed that thermophilic digestion is much faster than mesophilic digestion and therefore produces more biogas in a shorter time or at smaller digester volumes. The major part of the heating requirements consisted of sludge heating. The heat losses of the digester were only 2–8% of the sludge heating requirements. The heating requirements in thermophilic digestion are about twice those of mesophilic digestion. Therefore a CHP unit system cannot cover all of the needs for successful operation of thermophilic digestion. Heat regeneration was introduced as a solution. Heat is regenerated from the sludge outflow at a temperature of 50–55 °C and transferred to the cold inflow sludge at a temperature of 11 °C. Enough heat is regenerated in a conventional counter flow heat exchanger to bring the thermophilic process to the same level as the mesophilic one. Considering the smaller digester volumes and the relatively small investment in the regenerative equipment, the construction of thermophilic digestion systems may be a very good alternative to conventional mesophilic sludge digestion systems.     

污水处理厂污泥处理处置现状分析及建议

城市污水污泥产量巨大且污泥成分复杂.若污泥处理处置不当,不仅会对环境造成二次污染,同时也是对资源的一种浪费.目前,污泥处理处置问题已成为全球环境保护面临的主要难题.在对上海市13个区48家污水处理厂污泥处理处置现状调研的基础上,分析了污水处理厂污泥处理和处置中存在的问题,进而针对存在问题提出了污泥处理和处置的建议,为上...     

Treatment of oily sludge by two-stage wet air oxidation

Oily sludge produced in petrochemical industries contains a large amount of toxic and hazardous substances. High oil sludge yield and high treatment cost have become major obstacles to the development of the petrochemical industry. In this study, the treatment and disposal of oily sludge using the wet oxidation method was investigated. Firstly, the orthogonal optimization experiment was designed to discuss the influence of reaction time, reaction temperature, oxidant amount, and emulsion splitter amount on the removal efficiency of oil and sludge volume. On this basis, a two-stage wet air oxidation method was employed to treat oily sludge. The results show that the two-stage oxidation method could remove 93.1% oil from the oil sludge and reduce the volume of oil sludge by 85.4%. Furthermore, the oil sludge treated with wet oxidation could be more easily separated from water, and the waste oil could be recycled. The proposed two-stage wet oxidation method shows excellent performance in treating oily sludge, from which resources can be recycled while reducing the amount of sludge.     

应用超声波技术处理污泥的现状分析

污水处理过程中产生大量的污泥,这些污泥的含水量高,并含有大量的微生物和病原体,需要进行有效的处理处置。简述了超声波作用于污泥的机理:通过超声空化作用产生的强有力水流喷射的剪切力对污泥发生作用;总结了超声波在污泥处理中的应用情况。重点阐述了超声波能促进污泥脱水,即超声能产生一种海绵效应使水分子更易在波面的通道传播,超声破坏菌胶团使内部水释放出来;超声波能促进污泥消化,缩短污泥发酵时间并能提高沼气的产率以及超声波能破解污泥等的研究状况。