青岛麦岛污水处理厂污泥消化及热电联产运行管理经验

污泥厌氧消化/热电联产是一项重要节能工艺技术,对于提高资源和能源利用效率意义重大。完善的管理是保证污泥消化及热电联产系统稳定高效运行的关键环节。麦岛污水处理厂将Multiflo~?Trio初沉污泥与生物滤池剩余污泥进行混合,形成沼气产率较高的混合污泥,并进行中温厌氧消化,所产沼气进入热电联产系统用于发电及沼气锅炉,回收余热作为污泥消化及厂区采暖热源。10余年来,麦岛污水处理厂的污泥消化及热电联产系统实现了安全、稳定、高效的运行,保证了污泥的资源化、减量化、无害化处理及利用。介绍了青岛麦岛污水处理厂污泥厌氧消化及热电联产的运行情况,探讨如何在污泥消化及热电联产间做好运行管理和调控,使之形成良性循环。     

某再生水厂沼气系统设计探讨

城市污水处理厂污泥处理的思路是对其进行减量化、稳定化、无害化和资源化。污泥在消化过程中产生沼气,其中可作为燃料的甲烷气体约占2/3。污泥消化与沼气发电是城市污水厂节能降耗,降低运行成本,实现污泥资源化的重要措施。消化池产生的沼气,需要通过沼气净化、存储及输送系统,安全稳定地输送至发电机、锅炉房等利用点。以北京某新建再生水厂为例,对新建沼气收集及净化系统的设计进行分析讨论。     

亚洲最大的预应力蛋形消化池在济南建成

随着经济建设的发展和生活质量的提高,环境工程已越来越引起人们的重视,其中污水处理工程被视为现代城市环境质量的一种标志及文明的象征。 在整个污水处理过程中,污泥消化是重要环节之一。通过污泥消化达到无害化、减少污泥容积和获得沼气。在这方面,蛋形消化池有其独特的优点: a.池型符合流体形态,用较少的能量可获得充分的混合搅拌;     

瑞典Laholm沼气厂的运行实践

瑞典沼气的总产量约为1400GW·h,约有60%产自200多家市政污水处理厂的污泥消化池,垃圾填埋场的产量占30%,剩余的10%主要来源于工业废水处理厂和混合消化厂。一般情况下,沼气用作热源和发电,也可以作为汽车燃料。有机废物转化成沼气的同时还产生了消化残余物,可用作生物肥料。在瑞典有机废物填埋要课以重税,并且自2005年开始该国已严禁有机物的填埋处理,所以人们逐渐开始了对有机物混合消化的重视和研究。目前瑞典约有10家沼气厂利用厌氧消化处理收集来的各种有机废料,总处理能力>20×104t/a。多数沼气厂将牲畜粪便作为主要原料,再辅以其他…     

污泥消化池气提筒式沼气搅拌器的研讨

污泥消化池气提筒式沼气搅拌器的研讨①陈双星胡振苓（天津市污水处理研究所）朱雁伯（天津市排水管理处）林荣忱（天津大学）污泥混合搅拌是影响污泥消化的重要因素。有资料报道，在英国４８例消化池事故中有４３例和搅拌系统有关；加拿大有关部门曾经考察安大略的１０家...     

白龙港污水处理厂污泥厌氧消化系统的设计和调试

白龙港污泥处理工程主要处理白龙港污水处理厂200×104 m3/d污水处理产生的污泥,采用浓缩、中温厌氧消化、污泥脱水和部分脱水污泥干化处理工艺,消化产生的沼气用于加热消化池污泥,多余的沼气作为能源干化脱水污泥。干化处理后冷凝水的余热回收辅助用于污泥消化系统供热。介绍了污泥厌氧消化系统的设计参数、工艺特点及调试情况,可供设计人员参考。     

污水处理厂沼气发电的经济性分析

介绍了法国2006年颁布的沼气利用政府法令以及沼气发电的价格体系,并以法国南部某污水处理厂为例,分析了污水处理厂利用污泥厌氧消化产生的沼气进行发电的技术经济可行性.研究表明,沼气发电在经济上完全可行,可在3年左右收回投资成本;选择适当功率的发电机,沼气发电后的余热还能保证消化池的正常运行,每处理1 m3污水产生的电能达0.191 kW·h.此外,结合我国现有沼气发电的成功经验,指出污水处理厂的污泥采取厌氧消化、沼气发电进行综合利用,具有良好的发展前景.     

污泥常温厌氧消化和运行操作的规律

1 概述 天津市纪庄子污水处理厂采用比较完善的污泥处理和处置工艺,全部污泥经厌氧消化处理.消化后的污泥经压虑机脱水后农用、填埋,产生的沼气用于沼气搅拌及沼气发电,运行十几年来取得了宝贵的经验.为保持污泥中温消化温度,利用锅炉(燃煤)提供的热水经热交换器为污泥加热,以保证污泥温度保持在(30～35℃),为达到这一恒定温度,无论从能源消耗及工艺管理方面都提出了较高的要求.     

海口市污水处理厂污泥消化的运行分析

白沙门污水处理厂(30×104m3/d)是海口市利用德国政府软贷款兴建的第一座城市污水处理厂,处理工艺为高负荷生物处理加深海排放。2005年以前,该厂污泥仅经重力浓缩后直接离心脱水。在消化池投入运行后,污泥利用厌氧消化进行稳定处理及离心脱水,产生的沼气用来发电,其废热用于加热消化池污泥。从消化对污泥脱水、污泥量及其经济效益和环境影响等方面进行对比分析,阐明消化作为稳定工艺的必要性。在运行中应加强对沼气脱硫塔的维护,避免由于磷酸铵镁(MAP)的形成而堵塞污泥管道,同时还应积累对沼气发电机组的操作及其维护的经验。     

污泥消化沼气的净化利用系统设计

为了利用污泥消化产生的沼气 ,发挥其高效热能 ,减小环境污染 ,结合工程实例 ,通过对沼气采取过滤、脱硫等净化措施 ,保护沼气锅炉及沼气发动机的正常运行 ,延长设备的使用期 ,降低沼气燃烧时二氧化硫的排放量 ,并利用沼气燃烧时产生的热量加热污泥 ,产生良好的经济效益和环境效益     

Effect of linear alkylbenzene sulphonates (LAS) on the anaerobic digestion of sewage sludge

Batch anaerobic biodegradation tests with different alkylbenzene sulphonates (LAS) at increasing concentrations were performed in order to investigate the effect of LAS homologues on the anaerobic digestion process of sewage sludge. Addition of LAS homologues to the anaerobic digesters increased the biogas production at surfactant concentrations 5-10 g/kg dry sludge and gave rise to a partial or total inhibition of the methanogenic activity at higher surfactant loads. Therefore, at the usual LAS concentration range in sewage sludge, no adverse effects on the anaerobic digesters functioning of a wastewater treatment plant (WWTP) can be expected. The increase of biogas production at low surfactant concentrations was attributed to an increase of the bioavailability and subsequent biodegradation of organic pollutants associated with the sludge, promoted by the surfactant adsorption at the solid/liquid interface. When the available surfactant fraction in the aqueous phase instead of the nominal surfactant concentration was used to evaluate the toxicity of LAS homologues, a highly significant relationship between toxicity and alkyl chain length was obtained. Taking into account the homologue distribution of commercial LAS in the liquid phase of the anaerobic digesters of a WWTP, an EC(50) value of 14 mg/L can be considered for LAS toxicity on the anaerobic microorganisms.     

Conductive heating and microwave hydrolysis under identical heating profiles for advanced anaerobic digestion of municipal sludge

Microwave (2.45 GHz, 1200 W) and conventional heating (custom pressure vessel) pretreatments were applied to dewatered municipal waste sludge (18% total solids) using identical heating profiles that span a wide range of temperatures (80–160 °C). Fourteen lab-scale semi-continuous digesters were set up to optimize the energy (methane) output and sludge retention time (SRT) requirements of untreated (control) and thermally pretreated anaerobic digesters operated under mesophilic and thermophilic temperatures. Both pretreatment methods indicated that in the pretreatment range of 80–160 °C, temperature was a statistically significant factor (p-value < 0.05) for increasing solubilization of chemical oxygen demand and biopolymers (proteins, sugars, humic acids) of the waste sludge. However, the type of pretreatment method, i.e. microwave versus conventional heating, had no statistically significant effect (p-value >0.05) on sludge solubilization. With the exception of the control digesters at a 5-d SRT, all control and pretreated digesters achieved steady state at all three SRTs, corresponding to volumetric organic loading rates of 1.74–6.96 g chemical oxygen demand/L/d. At an SRT of 5 d, both mesophilic and thermophilic controls stopped producing biogas after 20 d of operation with total volatile fatty acids concentrations exceeding 1818 mg/L at pH <5.64 for mesophilic and 2853 mg/L at pH <7.02 for thermophilic controls, while the pretreated digesters continued producing biogas. Furthermore, relative (to control) organic removal efficiencies dramatically increased as SRT was shortened from 20 to 10 and then 5 d, indicating that the control digesters were challenged as the organic loading rate was increased. Energy analysis showed that, at an elevated temperature of 160 °C, the amount of methane recovered was not enough to compensate for the energy input. Among the digesters with positive net energy productions, control and pretreated digesters at 80 °C were more favorable at an SRT of 10 d.     

Effect of ultrasound pretreatment in mesophilic and thermophilic anaerobic digestion with emphasis on naphthalene and pyrene removal

In many anaerobic digestion processes for the treatment of the sludge produced in wastewater treatment plants, the hydrolysis of the organic matter has been identified as the rate limiting step. This study is focused on the effect of ultrasonic pretreatment of raw sewage sludge before being fed to the mesophilic and the thermophilic anaerobic digestion. From particle size reduction, COD disintegration degree and biodegradability test, 11,000kJ/kg TS was estimated as the optimal specific energy in ultrasonic pretreatment. Moreover, the use of pretreated sludge improved significantly the COD removal efficiency and biogas production in lab-scale anaerobic digesters when compared with the performance without pretreatment, specially under mesophilic conditions. During ultrasonic pretreatment, the diffusion of polycyclic aromatic hydrocarbons (PAH) compounds to the aqueous phase was stated by a reduction in the pretreated sludge micropollutants content. With sonication, naphthalene was better removed than without this pretreatment, particularly in the mesophilic digester. However, pyrene removal remained at same efficiency level with and without ultrasonic pretreatment.     

Comparative evaluation of batch and continuous process biogas production from animal wastes

The production of biogas, an alternative source of energy from animal wastes, was investigated in the laboratory scale using the simple single-state digesters. In this study, a comparison between two feed processes, a batch feeding process and a continuous feeding process, both within mesophilic temperature ranges was carried out. The digesters were fed with mixture of cow dung and poultry droppings and operated at ambient temperature of 30°C as baseline and temperatures of 32?45°C for 30 days. In this study, the optimum temperature for biogas production from the blends of the animal wastes was determined as controlled heat was supplied to the digester. Results obtained indicate maximum biogas yield of 3.603 litres from the digestion of the animal wastes at temperature of 370°C in the continuous process while maximum biogas yield of 2.685 litres was obtained at temperature of 400°C for the batch process.     

德国汉堡污水处理厂污泥循环处理模式探讨

汉堡科勃兰霍夫污水处理厂采用污泥先浓缩，然后消化、脱水、干化，最后焚烧的处理工艺，实现污泥循环处理模式。该模式在污泥焚烧发电的同时，利用污泥焚烧的热量干化污泥，实现了外加燃料需求量为零的预期效果，并且提供了污水厂所需用电量和用热量的60％和100％，极大地提高了污泥处置的经济性，降低了运行成本。     

Mesophilic and thermophilic temperature co-phase anaerobic digestion compared with single-stage mesophilic- and thermophilic digestion of sewage sludge

The performance of thermophilic and mesophilic temperature co-phase anaerobic digestions for sewage sludge, using the exchange process of the digesting sludge between spatially separated mesophilic and thermophilic digesters, was examined, and compared to single-stage mesophilic and thermophilic anaerobic digestions. The reduction of volatile solids from the temperature co-phase anaerobic digestion system was dependent on the sludge exchange rate, but was 50.7-58.8%, which was much higher than 46.8% of single-stage thermophilic digestion, as well as 43.5% of the mesophilic digestion. The specific methane yield was 424-468 mL CH(4) per gram volatile solids removed, which was as good as that of single-stage mesophilic anaerobic digestion. The process stability and the effluent quality in terms of volatile fatty acids and soluble chemical oxygen demand of the temperature co-phase anaerobic digestion system were considerably better than those of the single-stage mesophilic anaerobic processes. The destruction of total coliform in the temperature co-phase system was 98.5-99.6%, which was similar to the single-stage thermophilic digestion. The higher performances on the volatile solid and pathogen reduction, and stable operation of the temperature co-phase anaerobic system might be attributable to the well-functioned thermophilic digester, sharing nutrients and intermediates for anaerobic microorganisms, and selection of higher substrate affinity anaerobic microorganisms in the co-phase system, as a result of the sludge exchange between the mesophilic and thermophilic digesters.     

Evaluation of continuous mesophilic anaerobic sludge digestion after high temperature microwave pretreatment

Effect of microwave pretreatment (MW) high temperature (175 °C) and MW intensity to waste activated sludge digested with acclimatized inoculum in single- and dual-stage semi-continuous mesophilic anaerobic digesters at different sludge retention times (SRTs) (20, 10 and 5 days) were investigated. MW pretreatment led to similar sludge stabilization at low SRTs (5 and 10 days). Although lowering MW intensity slightly improved sludge solubilization, it had a negative effect on digestion at low SRTs. Single-stage digesters with MW pretreatment surpass dual-stage digesters performances.     

Anaerobic codigestion of municipal solid waste and biosolids under various mixing conditions--I. Digester performance

The feasibility of codigestion of the organic fraction of municipal solid waste, primary sludge, and waste activated sludge was evaluated in mesophilic (37 degrees C), laboratory-scale digesters. In a first experiment, different startup strategies were compared using four digesters, operated under continuously mixed conditions. After two weeks, the experiment was continued under minimally mixed conditions. Results demonstrated that reducing the level of mixing improved digester performance. Therefore, in a second experiment, six digesters were operated to compare performance under continuous mixing and reduced mixing levels at various loading rates and solids levels. The continuously mixed digesters exhibited unstable performance at the higher loading rates, while the minimally mixed digesters performed well for all loading rates evaluated. In a third experiment, it was demonstrated that an unstable, continuously mixed digester was quickly stabilized by reducing the mixing level. These experiments confirmed that continuous mixing was not necessary for good performance and was inhibitory at higher loading rates. In addition, reduction of mixing levels may be used as an operational tool to stabilize unstable digesters.