多功能微生物制剂用于污泥减量的研究

目前如何减少剩余污泥的产量已成为污水处理的研究热点。为此，基于目前主要的污泥减量理论，在自然界中分离、筛选出一些特殊的微生物菌种，在特定培养工艺下研制一种多功能微生物制剂（MCMP）用于污泥的减量。采用该微生物制剂在重庆长寿污水处理厂进行中试：设3套相同装置，均采用常规活性污泥法且运行操作相同，其中两套装置分别投加所处理水量0．005％和0．01％的微生物制剂，一套不投加，对比其污泥减量效果。试验结果表明：投加MCMP的两套装置的污泥减量比例分别为81．76％和89．18％，3套装置的污泥增长速率分别为2．0％、1．5％和11．5％；投加MCMP能提高出水水质，3套装置出水的COD、NH3-N平均浓度分别为35．08、33．89、36．51mg／L和1．40、1．22、1．62mg／L。投加MCMP不用增设专用的处理单元，也不需改变原有的处理设施及运行方式。3套装置的曝气量相同，因而投加MCMP不会增加整个系统的动力消耗。该制剂具有良好的污泥减量效果，能减轻污水处理厂污泥处理、处置的负担。     

江苏省城镇污水厂污泥减量技术及适用性分析

随着城镇污水处理率的提高,污水处理厂的污泥减量化问题日益受到重视。介绍了污水处理厂在污泥减量技术方面的研究和实践,如工艺优化、低污泥产率工艺、OSA、投加菌剂等。通过技术原理和运行效果的分析,对技术的适用性进行了比较和讨论,探讨了适合南方地区的污水处理厂污泥减量化的技术路线。     

富阳八一污水厂污泥在热电厂焚烧的可行性分析

富阳八一污水处理厂95％的进水为附近40多家造纸厂排放的废水，针对污水厂污泥产量大（剩余污泥约5．2t／h，初沉污泥约16t／h）、填埋处理存在占地大且易产生二次污染的问题，分析了将污泥在热电厂进行焚烧的可行性，并探讨了污泥的输送和投加方式。结果表明，八一污水厂的剩余污泥可全部运到相邻的热电厂与煤进行混合焚烧，理论上每台流化床锅炉最多可以混合焚烧3．9t／h的剩余污泥，实际运行中应控制剩余污泥的投量为3．5t／h；建议污泥采用卡车和稠污泥泵共同输送的方式。污泥混合焚烧具有控制简单、污水厂和热电厂间协调工作较少的优点。     

南方污水处理厂污泥厌氧发酵制取碳源及投加策略

为应对污水厂出水总氮标准日益提升的要求,提高生化池的反硝化能力,减少对外加碳源的依赖,考察了利用南方某污水处理厂的剩余污泥厌氧发酵制取碳源的效能、影响因素和回用投加比例,分析了剩余污泥厌氧发酵制取碳源的可行性、污泥减量效果和经济效益。当控制初始MLSS约为15 000 mg/L时,厌氧发酵的ORP基本在-400 mV左右,有利于碳源的制取;可采用按比例更换新污泥的方式进行厌氧发酵,换泥比例为每天50%左右,折合SRT约为48 h;以2.5%厌氧发酵污泥结合75 mg/L复合碳源投加到缺氧系统中,可增强脱氮能力,且发酵污泥的总氮、总磷和重金属离子基本不会对生化系统造成不良影响。以折合SRT计算,厌氧发酵的污泥削减率约为7%;以10×10⁴m³/d的污水处理厂为例,采用厌氧发酵技术每年可节省运营成本约410.6万元。     

城镇污水处理厂剩余污泥处理与处置技术探讨

随着城镇污水处理率的提高,污水处理厂的污泥减量化和处理、处置等问题日益受到重视。介绍了近年来在无锡市芦村污水处理厂开展的多项污泥减量化和处理、处置研究,包括污泥厌氧消化、生物菌剂减量、好氧沉淀工艺减量、延时曝气减量、生物沥浸干化、剩余污泥制肥、剩余污泥合成PHAs等。通过对实际运行数据的整理和分析,对技术的处理效果和适用条件进行了比较和讨论,并探讨了适合无锡地区的污水处理厂污泥处理与处置的技术路线。     

污泥石灰干化工艺在北京小红门污水厂的应用

介绍了北京小红门污水处理厂污泥干化项目的工艺方案、实施情况和运行费用的影响因素.通过小红门污水处理厂污泥干化项目的运行及实验室检测数据,初步研究和分析了污泥原始含水率对处理后污泥含水率的影响以及石灰投加量对杀菌效果的影响.结果表明,针对小红门污水厂的污泥,仅需添加5%的石灰,即可将大肠杆菌的含量降至未检出水平.而为了使成品污泥含水率同样达到小于60%的效果,原始污泥含水率越低,所需投加的生石灰量越少,当原始污泥含水率为80%-85%时,需要的石灰投加量为20%-30%,而原始污泥含水率为77%-78%时,仅需投加13%的石灰.     

超声处理对系统剩余污泥减量效果的研究

在运行稳定的连续流活性污泥系统中采用超声处理剩余污泥并将其返回系统,考察声能密度、超声作用时间和超声污泥回流比对系统剩余污泥减量效果的影响.结果表明,当超声污泥回流比为1∶24、声能密度为0.4 W/mL、超声时间为5 min时,系统污泥日平均产量为13.6 mg/(L·d),减量效果达到95.81%,此时出水COD为73 mg/L、NH4+-N为7.99 mg/L、TN为18.67mg/L,达到<城镇污水处理厂污染物排放标准>(GB 18918-2002)的二级排放标准.此外,系统中污泥的沉降性能及其有机质含量并没有受到显著影响.     

EM和MCMP对粪便污泥厌氧消化产气特性的影响

以化粪池粪便污泥为研究对象,采用中温(35℃)厌氧消化,研究分别投加0.005%～1.00%的有效微生物(EM)和多功能复合微生物制剂(MCMP)对粪便污泥厌氧消化产气速率、累积产气量以及消化体系中NH4+-N和pH值的影响。结果表明:投加0.005%～1.00%的外源EM和MCMP均有利于粪便污泥厌氧消化产气量的增加;至第20天厌氧消化结束,E1～E6的产气速率和累积产气量分别比对照(CK)的高约(60.96%～215.13%)和(60.74%～214.70%);M1～M6的产气速率和累积产气量比CK的高约(50.99%～255.31%)和(50.78%～254.82%);两试验组分别以投加0.10%的EM和0.05%的MCMP的产气速率和累积产气量为最高。两试验组的氨氮含量均低于文献报道的抑制浓度(2 000 mg/L),且其pH值也基本介于产酸细菌和产甲烷菌共存所要求的pH值范围(7.0～7.6)。     

剩余污泥的好氧消化设计

介绍了某工程剩余污泥的好氧消化设计，实际的运行情况表明，对于小型污水处理厂（站）的污泥采用好氧消化处理是行之有效的。     

陕西省关中地区污水处理厂剩余污泥特性调研

剩余污泥大量产生是目前城市污水处理厂不容忽视的环境问题.立足于陕西省关中地区7个正在运行的污水处理厂进行实地调研,分别对剩余污泥的有机质、氮、磷、重金属及微量元素含量进行测定.结果表明:剩余污泥可作为一种潜在的氮肥,从磷素含量角度考虑,其肥效有限;该剩余污泥有机质含量高,可作为污水处理厂潜在的补充碳源.依照农用污泥中重金属控制标准,陕西省关中地区剩余污泥中Cd元素的超标率最高,其次是Cu和Zn元素.微量元素分析显示,剩余污泥中Mo元素含量在不同的污水处理厂差异较大,剩余污泥中Se含量远高于我国土壤中Se元素含量的平均值,因此可作为低硒带土壤硒水平调节的潜在硒肥.     

A new pushover procedure for two‐way asymmetric‐plan tall buildings under bidirectional earthquakes

Conventional pushover analyses despite of extensive applications are unable to estimate the general responses of asymmetric‐plan tall buildings because of ignoring the effects of higher modes and torsion. A consecutive modal pushover procedure is one of the recent nonlinear static pushover procedures that used to analyse the seismic response of one‐way asymmetric‐plan tall buildings under one‐directional seismic ground motions. In this paper, a modified consecutive modal pushover procedure (MCMP) has been proposed to estimate the seismic demands of two‐way asymmetric‐plan tall buildings under two horizontal components of earthquakes simultaneously. The accuracy of the MCMP procedure is evaluated using different buildings and comparing with the results of FEMA (Federal Emergency Management Agency) procedures, the practical modal pushover procedure and nonlinear time history analyses as an exact solution. The results show the proposed MCMP procedure is able to estimate the displacements and storey drifts accurately and introduces a great improvement in predicting the plastic hinge rotations. Copyright © 2013 John Wiley & Sons, Ltd.     

Assessment of modified consecutive modal pushover analysis for estimating the seismic demands of tall buildings with dual system considering steel concentrically braced frames

According to the previous researches, conventional nonlinear static procedure (NSP), which is limited to single mode response, cannot predict the seismic demands of tall buildings with reliable accuracy. To estimate the seismic demands in upper stories for tall buildings the effects of higher modes should be included. In the recent years, developing traditional pushover analysis to consider the effects of higher modes conducted researchers to propose several methods, such as N2, MPA and MMPA procedures, that have a specific approach to estimate seismic demands of structures but the accuracy of them is doubtable for estimating of hinge plastic rotations. Recently consecutive modal pushover (CMP) procedure was proposed to consider the effects of higher modes with acceptable accuracy especially in prediction of hinge plastic rotations. The CMP procedure was limited to include two or three modes, and use of higher modes might cause some inaccuracy at results of upper stories. In CMP procedure, estimation of modal participating factors is important and choosing inadequate modes may cause large errors. In this paper some changes have been applied to the CMP procedure to improve accuracy of the results and the modified method is proposed and named modified consecutive modal pushover (MCMP) procedure. In this modified method the contribution of mode is used of effective modal participating mass ratio. The comparison of MCMP procedure to exact values derived by nonlinear response history analysis (NL-RHA) demonstrated the reliable predictions and it can overcome the limitations of traditional pushover analysis.     

Progress and perspectives of sludge ozonation as a powerful pretreatment method for minimization of excess sludge production

The treatment and disposal of excess sludge represents a bottleneck in wastewater treatment plants (WWTP) worldwide, due to environmental, economic, social and legal factors. The ideal solution to the problem of sludge disposal is to combine sludge reduction with the removal of pollution at the source. This paper presents an overview of the potential of ozonation in sludge reduction. The full-scale application of ozonation in excess sludge reduction is presented. Improvements in the biodegradability of the ozonated sludge were confirmed. The introduction of ozonation into activated sludge did not significantly influence effluent quality but improved the settling properties of the sludge. An operation with a suitable sludge wasting ratio seems to be necessary to prevent accumulation of inorganic and inert particles for long-term operation. Sludge ozonation to reduce excess sludge production may be economical in WWTP which have high sludge disposal costs and operational problems such as sludge foaming and bulking. The recommended ozone dose ranges from 0.03 to 0.05 g O₃/g TSS, which is appropriate to achieve a balance between sludge reduction efficiency and cost. An effort to design and optimize an economic sludge reduction process is necessary.     

半干污泥焚烧工程设计分析及探讨

为减少污泥运输体积,减轻污泥运输对环境的影响,污水厂出厂污泥处理趋势逐渐由含水率80%的脱水污泥转变为含水率40%~50%左右的半干污泥。上海市石洞口污泥处理二期工程采用“脱水干化(石洞口本厂污泥)+焚烧及烟气处理(泰和及石洞口污泥)”工艺,是针对半干污泥的焚烧工程。半干污泥接收储运采用“接收坑+抓斗提升”的方式,半干污泥焚烧产生的系统富余热能用于加热污泥调蓄池内的污泥,改善污泥浓缩脱水效果。在此基础上,进一步探讨了选址相对独立的半干污泥焚烧项目需注意的污泥泥质控制、热能利用方式及炉温控制措施等相关因素。     

旁路微氧污泥减量效果及其影响因素

通过对旁路微氧污泥减量技术中好氧污泥在微氧池中的减量效果及其影响因素的研究,发现污泥减量效果与微氧池的污泥浓度(MLSS)、好氧污泥与厌氧污泥的比例(α)、微氧池的氧化还原电位(ORP)、微氧池的污泥停留时间有关。当微氧池的α=2∶8、MLSS为10 000 mg/L时,减量效果最佳;通过不同MLSS和不同α值两组试验,得出在最佳值时的减量率分别为19.15%和19.61%。低ORP值条件下微氧池污泥颗粒细碎,中位粒径为20.24μm,而好氧污泥的中位粒径为32.18μm。同时,混合液中溶解性大分子有机物含量明显增加。该工艺使污泥有更充分的时间进行内源呼吸和EPS的离解释放,从而实现了污泥减量。     

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。     

污泥龄对活性污泥絮体中磷形态与分布的影响

以污泥龄分别为4和20 d的两组SBR反应器为研究对象,利用SMT法测定活性污泥、细菌细胞和EPS中磷的形态与分布,探讨了污泥龄对活性污泥中磷形态和分布的影响。研究结果表明,高SRT污泥的TP含量约为低SRT污泥的1.56倍,这主要是由于前者较后者有更高的OP和AP含量。高SRT污泥中细菌细胞和EPS的TP含量均高于低SRT污泥中的,且高SRT污泥中EPS的OP含量远大于低SRT污泥中的。高SRT污泥的细菌细胞和EPS分别较低SRT污泥的细菌细胞和EPS有更大的厌氧释磷量和好氧吸磷量,前者厌氧释磷和好氧吸磷主要源自其OP含量的变化,后者则主要源自其IP含量的变化;在厌氧/好氧反应过程中,污泥中EPS的IP含量改变主要源自其NAIP含量的变化。     

A new reactor concept for sludge reduction using aquatic worms

Biological waste water treatment results in the production of waste sludge. The final treatment option in The Netherlands for this waste sludge is usually incineration. A biological approach to reduce the amount of waste sludge is through predation by aquatic worms. In this paper we test the applicability of a new reactor concept for sludge reduction by the aquatic worm Lumbriculus variegatus. In this reactor concept the worms are immobilized in a carrier material. In sequencing batch experiments, the sludge breakdown in the predation reactor is compared to sludge breakdown in a blank reactor (i.e. without worms). Predation by the worms results in a distinct sludge reduction, which is almost three times higher than in the blank experiment. The worm faeces that are produced after sludge predation have a sludge volume index (SVI) that is approximately half that of the initial waste sludge. Due to the configuration of the predation reactor, waste sludge, worm faeces and worms are separated, which is beneficial to further processing. The obtained results show that the proposed reactor concept has a high potential for use in large-scale sludge processing.     

城市污水处理厂污泥的好氧处理研究

为了实现污泥的稳定化、减量化和无害化,对城市污水处理厂的浓缩污泥和厌氧消化污泥进行了好氧处理试验研究.试验结果表明,污泥好氧处理使污泥中有机物质含量降低,臭味减小.厌氧污泥经好氧消化处理后,一方面使污泥得到稳定化和减量化;另一方面,可以把污泥中的致病菌杀死.污泥经好氧消化后沉降性能有明显提高,絮凝剂的加入使其脱水性能也得到一定的改善.