水厂高藻期污泥量的确定与调节

依据沉淀池和排水池的排泥规律确定了日排泥水总量,采用物料平衡法、排泥现场测定法、排泥水处理系统参数监测法及公式法确定日总干污泥量.结果表明:排泥水处理系统监测法操作容易、设备简单且数据可靠.通过污泥量的确定,可调节排泥规律和排泥水处理系统的流量及浓度,并可降低排泥水对系统的冲击负荷,使水厂在高温高藻期达到稳定运行.     

气浮工艺应用于给水污泥浓缩的试验探索

针对太原市呼延水厂排泥水处理系统的实际问题,研究了冬季低温低浊条件下压力溶气气浮工艺对呼延水厂排-泥水浓缩处理的应用效果,最终使呼延水厂全年各季排泥水浓缩后浓度均能达到板框压滤机运行所要求的3%的进泥浓度,并且有良好的脱水效果.     

斜管沉淀池处理净水厂排泥水工艺优化研究

以净水厂排泥水为研究对象,考察了斜管沉淀池对排泥水的处理效果。结果表明,随着进泥负荷的不断增大,斜管沉淀池出水的上清液浊度和CODMn含量都逐渐升高,阴离子聚丙烯酰胺或聚合氯化铝与聚丙烯酰胺的联合投加都可以改善排泥水的沉降性能,且只要聚丙烯酰胺的投加量大于2 mg/L,就可以形成较大且密实的矾花;投加聚丙烯酰胺药剂后,可应对由于净水工艺进行沉淀池冲洗后排泥水性质的恶化,改善排泥水的沉降性能,降低出水浊度,提高出泥浓度。     

水厂排泥水处理系统优化运行研究

为解决水厂排泥水处理系统中高密度沉淀池斜管沉淀区出现的絮体上浮问题,对PAM投加量和污泥回流工艺进行了试验研究.结果表明:阴离子型PAM的投加量与排泥水浓度存在线性关系,在生产中可以根据沉降比快速估算排泥水浓度.回流污泥的浓度和性质受高密度沉淀池泥位影响,适宜的污泥回流比为1%～2%.     

大丰二水厂排泥水处理系统设施改造

以大丰市二水厂排泥水处理系统为例,针对在运行过程中综合排泥池存在严重淤积进而导致排泥水处理系统相关设备故障频发这一问题,对原排泥水处理系统设施进行改造,采取水力搅拌和冲刷、增设扰流搅拌设备、对综合排泥池及配管进行改造等措施,使得排泥水处理系统相关设备故障发生频率大幅降低,为安全生产提供了可靠保障。     

水力旋流器原位处理疏浚泥水研究

环保疏浚的关键在于疏浚泥水的妥善处理与处置。为解决异位处理存在的能耗高、占地面积大、容易引发二次污染以及工程投资效益低等问题,采用水力旋流器对疏浚泥水进行原位处理,探讨了疏浚泥水性质、操作条件和结构形式等对疏浚泥水固液分离效率的影响。结果表明,水力旋流器处理疏浚泥水具备运行负荷高、结构紧凑、占地面积小的显著特点,是疏浚泥水原位处理的适宜装备。试验条件下,当处理负荷为1.3 m~3/h时,分离效率可达75%以上,相应的水力停留时间仅为4~5 s;疏浚泥水中固体颗粒粒径越大、含固率越高,水力旋流器的分离效率也越高;水力旋流器的最佳处理负荷为1.3 m~3/h,最佳分流比为0.13~0.15;水力旋流器的最佳锥体锥角与处理负荷有关,当负荷为1.3 m~3/h时,最佳锥角为5°;适当增大溢流/底流管管径,有助于分离效率的提升。     

净水厂排泥水处理系统工艺设计

分析总结了净水厂排泥水污泥量确定原则、排水排泥池及脱水机械类型选择等工艺设计要点。以陕西省渭南市某水厂排泥水处理工程为例,重点介绍了排水排泥池、污泥均衡池以及污泥脱水间等排泥水处理系统建、构筑物的设计参数和工艺特点,以期为类似项目选择合适的排泥水处理模式提供借鉴。     

水厂排泥水处理系统工艺优化试验研究

针对南水北调引江水净水气浮工艺排泥水特点,进行了斜管混凝沉降浓缩性能、药剂投加量、水力负荷、固体负荷、排泥量和PAM絮凝浓缩脱水投加量、比阻的试验研究,并优化确定了工艺参数.结果表明,三氯化铁和活化硅酸组合混凝处理能显著改善斜管浓缩池排泥水的脱水性能,沉降斜管浓缩池最大水力负荷为3.0 m3/(m2·h),最大固体负荷...     

福州市西区水厂排泥水处理系统的改造设计

为减少排泥水对自然水体的污染,福州市西区水厂对排泥水处理系统进行改造。在设计中将沉淀池排泥水、滤池反冲洗水收集后经高密度浓缩池处理后,上清液达到《污水综合排放标准》(GB8978-1996)后排放至闽江,浓缩污泥经厢式隔膜压滤机脱水至60%后外运填埋。本文详细介绍了该工程排泥水处理的设计方案、设计参数及系统特点,为类似工程的应用提供更有效的设计参考。     

自来水厂排泥水的调质和浓缩

在整个排泥水处理工艺中,排泥水的调质和浓缩是关键。通过对现阶段自来水厂排泥水浓缩和调质的研究成果、技术方法和工程应用的总结分析,提出对于排泥水处理系统的合理设计、优化运行是非常必要的。     

谈污水处理厂污泥处理系统

主要论述了污水处理厂的污泥处理系统,从污泥处理的各个环节,包括排泥、污泥浓缩、污泥调理、污泥机械脱水和污泥处置等几方面进行了阐述,行之有效的控制污泥生产,以保证污水处理厂水质合格达标。     

山西省污水厂污泥处理技术路线分析

对山西省污水处理厂的污泥处理存在的疑难问题及关键性技术进行了分析,着重对污泥燃料化技术降低污泥含水率、提高热值,实现污泥资源化利用的技术内容进行了描述,提出了以污泥燃料化作为污泥综合利用技术路线的结论。     

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.     

Oxygen transfer and uptake, nutrient removal, and energy footprint of parallel full-scale IFAS and activated sludge processes

Integrated fixed-film activated sludge (IFAS) processes are becoming more popular for both secondary and sidestream treatment in wastewater facilities. These processes are a combination of biofilm reactors and activated sludge processes, achieved by introducing and retaining biofilm carrier media in activated sludge reactors. A full-scale train of three IFAS reactors equipped with AnoxKaldnes media and coarse-bubble aeration was tested using off-gas analysis. This was operated independently in parallel to an existing full-scale activated sludge process. Both processes achieved the same percent removal of COD and ammonia, despite the double oxygen demand on the IFAS reactors. In order to prevent kinetic limitations associated with DO diffusional gradients through the IFAS biofilm, this systems was operated at an elevated dissolved oxygen concentration, in line with the manufacturer’s recommendation. Also, to avoid media coalescence on the reactor surface and promote biofilm contact with the substrate, high mixing requirements are specified. Therefore, the air flux in the IFAS reactors was much higher than that of the parallel activated sludge reactors. However, the standardized oxygen transfer efficiency in process water was almost same for both processes. In theory, when the oxygen transfer efficiency is the same, the air used per unit load removed should be the same. However, due to the high DO and mixing requirements, the IFAS reactors were characterized by elevated air flux and air use per unit load treated. This directly reflected in the relative energy footprint for aeration, which in this case was much higher for the IFAS system than activated sludge.     

Accelerated carbonation of alkaline construction sludge by paper sludge ash-based stabilizer and carbon dioxide

Construction sludge frequently has high alkalinity after its generation or during the intermediate treatment process. The aim of this study is to experimentally investigate the potential of combining accelerated carbonation and a paper sludge ash-based stabilizer (PSAS) to neutralize the alkalinity of construction sludge in a short period and to improve its strength for use as a recycled material. The experimental results indicate that the addition of a PSAS significantly granulated the alkaline sludge, and once granulated, the PSAS successfully accelerated the pH neutralization of the alkaline sludge. It was also found that the decrease in dry density ρ_d and the degree of saturation S_r of the PSAS-treated sludge was able to reduce the period required for the pH neutralization, t_N. The decrease in ρ_d is thought to allow fresh CO₂ gas to penetrate the specimen more easily. However, if S_r is below a certain limit, it does not strongly facilitate the reduction of t_N. This implies that pH neutralization cannot be accelerated when the amount of water in the sludge is below a certain level. Moreover, it was found that mean particle diameter D₅₀ also affected t_N. The strength development of the PSAS-treated sludge was evaluated using a series of cone index tests. It was found that the strength of the alkaline sludge without the PSAS was significantly decreased by accelerated carbonation, but was significantly increased even after accelerated carbonation when the PSAS was present. Due to the porosities of the remaining PS ash particles, most of the contribution of the water absorption and retention performance of the PSAS to the strength development of the PSAS-treated sludge was secured after accelerated carbonation. In addition, the granulated particles of the PSAS-treated sludge retained their granular shape to some extent. Therefore, it is presumed that the friction and interlocking of the particles did not decrease significantly. It was also found that, after carbonation, the q_c of the PSAS-treated sludge increased more rapidly than that of the alkaline sludge without the PSAS. A further detailed examination of the test results showed that under air-curing conditions, the q_c of the treated sludge with accelerated carbonation increased relatively gradually compared to that of the treated sludge without accelerated carbonation.     

Prediction of thickening capacity using diluted sludge volume index

Knowledge of the secondary clarifier's capacity to produce an adequately thickened underflow stream is essential for successful design and control of the activated sludge process. Accurate prediction of thickening capacity is possible using settling flux theory, but establishment of the required functional relationship between settling velocity and suspended solids concentration is a lengthy and tedious procedure. In this study, parameters characterizing such relationships are shown to be well correlated with an easily measured index of sludge settleability, the diluted sludge volume index (SVI^*). It is therefore possible to predict, using settling flux theory, limiting values of solids loading as a function of SVI^* and underflow velocity. This technique has numerous potential applications in activated sludge process control and design.     

Micro-profiles of activated sludge floc determined using microelectrodes

The microbial activity within activated sludge floc is a key factor in the performance of the activated sludge process. In this study, the microenvironment of activated sludge flocs from two wastewater treatment plants (Mill Creek Wastewater Treatment Plant and Muddy Creek Wastewater Treatment Plant, with aeration tank influent CODs of 60-120 and 15-35 mg/L, respectively) were studied by using microelectrodes. Due to microbial oxygen utilization, the aerobic region in the activated sludge floc was limited to the surface layer (0.1-0.2mm) of the sludge aggregate at the Mill Creek plant. The presence of an anoxic zone inside the sludge floc under aerobic conditions was confirmed in this study. When the dissolved oxygen (DO) in the bulk liquid was higher than 4.0mg/L, the anoxic zone inside the activated sludge floc disappeared, which is helpful for biodegradation. At the Muddy Creek plant, with its lower wastewater pollutant concentrations, the redox potential and DO inside the sludge aggregates were higher than those at the Mill Creek plant. The contaminant concentration in the bulk wastewater correlates with the oxygen utilization rate, which directly influences the oxygen penetration inside the activated sludge floc, and results in redox potential changes within the floc. The measured microprofiles revealed the continuous decrease of nitrate concentration inside the activated sludge floc, even though significant nitrification was observed in the bulk wastewater. The oxygen consumption and nitrification rate analyses reveal that the increase of ammonia flux under aerobic conditions correlates with nitrification. Due to the metabolic mechanisms of the microorganisms in activated sludge floc, which varies from one treatment plant to another, the oxygen flux inside the sludge floc changes accordingly.     

南方地区典型水厂排泥水水质特性研究

选择南方某城市3座具有典型自来水和排泥水处理工艺的水厂,从物理、化学、生物安全性三个方面对排泥水、砂滤和炭滤池反冲洗水、排水池和排泥池上清液的水质特征进行了系统研究,并考察了原水水质、工艺选择和控制、排泥水收集和处理模式等因素对排泥水水质的影响。