江西省城镇污泥处理处置现状及建议

近年来,随着城市化进程加快,生活水平不断提高,污泥产量和处理量呈上升趋势.为解决江西省城镇污泥处理问题,对省内城镇污水处理厂基本情况、城镇污泥产生和处置情况进行了调查分析,得出2017年和2020年江西省城镇污水处理厂污泥的年产生量分别为50.17万t和71.27万t,预计2025年将达到85万t.但目前省内污泥处置技术较为落后,主要以填埋和制砖为主,其原因是由于政府和污水厂早期对污泥的处理处置不够重视,法律监管体系不够完善以及污泥处置责任主体和最终处置路线不明确.为提高江西省污泥处理处置技术,对我国目前在污泥浓缩脱水、厌氧消化和好氧发酵后的土地利用、污泥建材利用、污泥焚烧协同处置等技术现状进行了分析,得出各地市污泥处理处置方式的选择需根据污泥量的规模和性质,建立能源和矿物质回收利用、土地利用、建材利用,以及与发电厂协同处置等多种路径互补的污泥资源化利用模式.     

晋城市污泥资源化分析

叙述了晋城市生活污泥的处理现状及存在问题,比较和研究了几种污泥处理和处置的方法,提出了采取农林利用及建材利用进行污泥处理处置及资源化的建议。     

污泥处理和处置技术在燃煤电厂的应用

为了实现污泥处理处置无害化、减量化、稳定化和资源化,诞生了多种污泥处理处置技术路线,其中利用电厂烟气余热将污泥干化后与电厂配煤焚烧相结合是比较经济且简单易行的技术路线。本文针对污泥处理处置的技术路线进行分析和总结,为污泥处理、处置技术的应用提供参考。     

上海石洞口干化污泥焚烧炉的调试

随着环境保护观念的深入,污泥作为一种可以利用的资源也逐渐得到人们的重视.目前,世界各国处理污泥的方法很多,根据上海市石洞口污水污泥干化焚烧炉的调试结果,认为污泥焚烧是一种可靠、可行的处理方式,能实现污泥处置的减量化、资源化和无害化.     

我国市政污泥处理处置现状研究

随着我国生态文明建设进程日益加快,污泥处理处置行业也得到快速发展。我国市政污泥处理处置技术呈现多样化发展趋势,焚烧、厌氧发酵、好氧堆肥、热解炭化等方式尤为常见。统计分析了国内385个典型污泥处理处置项目的处理规模、各技术占比、投资、运行成本等指标,并针对各污泥处理工艺碳排放情况进行综述,以期为未来污泥处理处置技术发展方向提供一定参考。数据显示,截至2022年3月,我国污泥项目建设总规模达4851.4万t/a,污泥无害化理论处置率达73.5%。污泥处理处置项目以焚烧、厌氧消化、好氧堆肥为主,分别占比65.41%、15.55%、9.61%。对污泥碳排放水平、处理成本、能源回收效率、资源化利用水平等因素的综合分析表明,污泥厌氧消化是当前较具潜力的处理技术。     

给水污泥特性及其资源化利用的研究

介绍了给水厂污泥的物理化学性质和常规处置现状,简要概括了几种常规处置方式的特点。同时,阐述了给水厂污泥在土壤资源化利用、建材资源化利用和吸附资源化利用的研究进展与应用,表明了给水厂污泥可作为一种环保新型材料,在水环境治理领域占有极其重要的地位和广阔的发展空间。     

城市污泥处理及资源化利用现状与建议

随着我国城镇化的快速发展,城市污水厂的数量和规模不断增加,大量的城市污泥给环境带来巨大压力。分析我国城市污泥的产生源与组成性质,概述目前国内外城市污泥处理处置的现状,指出我国城市污泥综合利用存在的问题,并在此基础上就我国污泥的处理处置和资源利用提出了相关建议。     

污泥热处理技术及应用进展

水处理中对污泥合理处置和利用一直是全球各地科研工作者所关注的课题。污泥作为污水处理的伴生物,成分非常复杂,不仅含有大量有机质,还夹杂有病原微生物及有害重金属等,长期堆放风险较大,进行处理与处置则需较高费用。对污泥热处理技术进行概述,介绍污泥热处理的内容以及城市污水厂剩余污泥热处理技术及应用。     

福建省城市 汗水处理厂污泥处理处置工艺研究

通过对福建省污水处理厂污泥处置工艺的探讨,分析污泥处理利用所存在问题,并提出相应的建议。     

污水处理厂脱水污泥填埋处置的研究进展

对污水处理厂脱水污泥性质、污泥处理处置相关政策标准进行综述,同时,总结了脱水污泥填埋处置的研究进展,指出污泥预处理后达到一定要求后进入填埋场填埋或者作为填埋场覆土是一种可行且经济的污泥处置方式,为脱水污泥填埋处置工作提供参考。     

Exergy analysis of methanol from the sewage sludge process

This paper concerns a new method of sewage sludge treatment that contributes more than traditional methods to the sustainable technology by achieving a higher rational efficiency of sludge processing. This is obtained by preserving the chemical exergy present in the sludge and transforming it into a chemical one––methanol. The proposed method combines a sludge gasification process and a modified methanol plant. The sludge gasification produces a synthetic gas mainly containing CO and H₂, which gas is next used as a reactant to make methanol.The plant, with a capacity of 50 000 tons (dry) solids per year, is simulated by a computer model using the flow-sheeting program Aspen Plus (Aspen Technology). The exergy analysis is performed for various operating conditions and the optimal values of these conditions are found. The irreversibilities of different plant segments: thermal dryer, gasifier, gas cleaning, compressors, methanol reactor, distillation column and purge gas combustion are evaluated. It is shown that the rational efficiency of the overall process is much higher than that of traditional plants of thermal sludge treatment.     

城市污泥制备成型衍生燃料技术综述

城市污泥的处理与处置问题是世界共同关注的问题之一,传统的污泥处理方式已难以满足日益严格的环保要求,污泥的燃料化利用是世界的共识。由于污泥的挥发分含量高、固定碳含量低,污泥难以直接稳定地焚烧,且污泥中淀粉类糊化和蛋白质类变性能够促进氢键和架桥作用,充分利用城市生活污水处理厂污泥制备成型燃料是目前污泥燃料化的新兴方式。本文详细阐述了现有的污泥成型技术,包括污泥干化成型、半干化成型和湿式成型技术等,重点阐明了其各自的优缺点,指出污泥干化成型是未来污泥成型的主要方式。     

城市污泥在林地施用的生态环境效应

叙述了发达国家将城市污泥施用于林地改善土壤的微生物活动和数量,提高土壤的可利用性,N,P,K,有机质的含量以及促进林木生长的研究状况及中国在这方面的研究现状,指出,污泥林地利用存在着污染地下水、增加土壤重金属和有害化学物质等环境风险,认为有必要开展对土地的承载能力、树木的敏感程度、食物链风险、树木需肥量等综合因素的研究。     

浅谈我国污水处理厂污泥的处理和处置

随着国家的社会经济和城市化的发展,城市的污水量在不断增长,伴随者处理污水所产生的污泥也不断的增长。如果未经一定处理处置的污泥直接进入环境后,将直接给环境造成二次污染,容易对生态环境和人类活动构成了严重威胁。因此如何合理地处理、处置污泥,已成为城市污水厂和相关部门必需引起重视的问题。     

Enhancement of hydrogen production in steam gasification of sewage sludge by reusing the calcium in lime-conditioned sludge

Gasification is a promising alternative process for sewage sludge energy utilization. CaO has been identified as an effective additive which can increase H₂ content of syngas produced by coal, biomass, and sludge gasification. Considering that lime (CaO) is a widely applied conditioner for sewage sludge dewatering in filter press, this study investigated the enhanced efficiency of syngas, especially regarding H₂ yield, in the catalytic steam gasification of dry dewatered sludge with physically mixed CaO and dry sludge dewatered with CaO as conditioner. The experiments were conducted in an electrically heated reactor at 873 K, 973 K and 1073 K, respectively. According to the results, conditioner CaO improved the H₂ and syngas production more remarkably than additive CaO. It was identified by XRD and SEM-EDX that conditioner CaO was completely converted into Ca(OH)₂ while additive CaO was still presented mainly as CaO. Furthermore, the Ca species of conditioner CaO was evenly distributed over the sludge matrix while Ca species of additive CaO maintained the original state with uneven distribution, both of which could increase the formation of H₂ through interacting with produced gas and catalyzing thermal cracking of tar to some extent. In addition, the pore structure tests and XPS analyses revealed that, comparing to additive CaO, conditioner CaO was more favorable for the formation of pores, and it had a greater potential to encourage partial cleavages of C–C bonds and C–H bonds, resulting in the decomposition of organic macromolecules into relative small molecules, which might be more easily converted to the gaseous products. These indicate that it is valuable to reuse the Ca in lime-conditioned sludge during gasification process.     

Sewage sludge-to-energy approaches based on anaerobic digestion and pyrolysis: Brief overview and energy efficiency assessment

Energy recovery from sewage sludge offers an opportunity for sustainable management of sewage sludge and energy. Anaerobic digestion and pyrolysis are among the most promising processes applicable for sewage sludge-to-energy conversion. Anaerobic digestion of sewage sludge forms methane-rich biogas, which can be utilized as fuel to offset heat and electricity consumption of the wastewater treatment sector. However, the digestion process has the limitation that it cannot sufficiently extract the energy in sewage sludge. The digested sludge is still energy profitable in that it contains considerable organic matter, but poor in biodegradability. Sludge pyrolysis is an innovative process that can convert both raw and digested sludge into useful bioenergy in the form of oil and gas, forming biochar as a byproduct that is environmentally resistant and holds potential for carbon sequestration and soil conditioning. It is expectable that sludge pyrolysis would step into practical deployment in the near future.This paper presents a brief overview of anaerobic digestion and pyrolysis in the application to bioenergy production from sewage sludge. An assessment of energy conversion efficiency of two parallel sludge-to-energy pathways is also presented. One pathway relies on an exclusive pyrolysis process (fed with raw sludge) while the other is based on anaerobic digestion followed by pyrolysis (fed with the digested sludge). The pathway via the combination of anaerobic digestion and pyrolysis could achieve higher energy efficiency compared to the pathway employing the pyrolysis alone.     

微波吸收剂与气氛对造纸污泥微波裂解效能影响

研究了近年来比较新颖的一种处置污泥方法——微波裂解法。主要探讨了在输入功率为1 800 W的微波下,同种气氛时对250 g干的造纸污泥添加不同微波吸收剂以及在相同的前提条件下通入CO2和N2两种气体时造纸污泥微波裂解的效能影响规律。研究发现:在CO2气氛下,对造纸污泥中分别添加了5%的水、活性炭、NaOH和ZnCl2微波吸收剂后污泥的裂解效果明显变好,且可以看出添加了5%的NaOH后污泥微波裂解效果最好,污泥温度达到331℃;在相同的前提条件下污泥的微波裂解效果在不同气氛下也明显不同:在不添加任何微波吸收剂对干污泥进行裂解时,污泥在CO2气氛下裂解的最终温度只有85℃左右,甚至没有达到100℃,造纸污泥在N2气氛下裂解效果较好些,但对污泥添加了5%的水和NaOH后,污泥在CO2气氛下裂解效果较好些。上述研究结果为造纸污泥进行微波裂解时的适宜条件提供了一定的参考价值。     

Investigation on gasification performance of sewage sludge using chemical looping gasification with iron ore oxygen carrier

Chemical looping gasification (CLG), with inherent characteristic of low pollutant emissions can realize the treatment and disposal principle of sewage sludge of harmlessness, reduction, stabilization and reutilization. This work attempted to investigate the feasibility of CLG of sewage sludge with hematite oxygen carrier. The role of hematite in CLG was firstly determined and it was used as gasification agent to provide the required oxygen for sludge conversion. Subsequently, the effect of various operating parameters on sludge CLG was discussed. An optimal mass ratio of sludge to hematite oxygen carrier was determined at 0.33 to achieve the high-efficient conversion of sludge. The reaction temperature of sludge gasification was set at 900 °C to avoid the excessive reduction of hematite. Suitable steam content was assigned to at 19.52%, where the sludge conversion attained the maximum. Ash deposited caused the decrease of specific surface area of hematite, but the accumulated mineral elements in sludge ash can improve the reactivity of oxygen carrier. Additionally, the ash accumulation also can prolong the gas mean residence time. Hence, the sludge conversion showed a slight uptrend with the cycle numbers. The phosphorus element of sludge was formed of CaH₂P₂O₇ and CaHPO₄ during the CLG. Although some sludge ash deposited on the surface of hematite particles, the new compounds were not observed in the reacted oxygen carrier. Additionally, sludge ash has a relatively high resistance trend for bed agglomeration and deposit formation due to the high content of Ca/Al elements. Consequently, the accumulation of sludge ash only reveals physical effects rather than chemical effects on the hematite particles. Thus, it is easy to separate the sludge ash from hematite particles according to the differences in density and size.     

UASB处理养猪废水条件下进水浓度对污泥颗粒化的影响

通过进行废水浓度变化对污泥颗粒化影响的试验,发现：颗粒直径随进水浓度的上升而增大,受传质过程所能进入颗粒内部的营养量所控制.应根据COD去除率的情况适时提高进水浓度,及时地随微生物数量的增加补充营养,促进污泥颗粒化;避免了浓度变化太快引起细菌生长过快,污泥结构松散,沉降性能下降及COD去除率和产气率降低.     

污泥掺烧方式对燃煤锅炉燃烧影响的模拟研究

为了确保燃煤锅炉掺烧污泥后炉内燃烧安全稳定并控制NO_x的生成,以国内某典型1 000 MW超超临界燃煤锅炉为研究对象,利用CFD软件计算研究了不同的污泥掺烧方式对锅炉温度场和NO_x生成的影响。结果表明：在燃煤锅炉不同层的燃烧器掺烧污泥,掺烧污泥的燃烧器对应高度均出现了温度的下降和NO_x排放浓度的降低;随着污泥分别由下往上在B,D,F层燃烧器进行掺烧,在炉膛出口处烟温升高,NO_x排放浓度降低;在保持F层燃烧器总热值不变的情况下进行掺烧时,能保证锅炉整体温度水平,掺烧污泥比例越高,炉膛出口烟温越低,NO_x生成量越少;在F层燃烧器掺烧污泥燃烧效果较好,有利于NO_x减排,是最适合污泥掺烧的燃烧器层。