水厂排泥水浓缩试验之负荷研究

进行了水厂排泥水的现场中试水力负荷和固体负荷试验研究。结果表明,投加PAM可提高斜板浓缩池抗击负荷的能力,投加PAM＋快速搅拌可进一步提高斜板浓缩池抗击负荷的能力。     

自来水厂排泥水的静沉及浓缩试验研究

对自来水厂排泥水分别进行了静沉和动态浓缩试验,以便为高效斜板浓缩池的设计和运行提供依据和指导。结果表明,慢速搅拌可显著提高泥水的静态沉降速度;对于含固率 >0. 2%的排泥水,当固体负荷为 3. 2~3. 4kg/(m2·h)时经浓缩后底泥的含固率 >2. 6%;当浓缩池进泥含固率<0. 17%时浓缩效率会明显降低,要达到 2%的出泥含固率则固体负荷需降到 1. 9kg/(m2·h)以下。斜板浓缩池在以固体负荷为设计参数的同时,还应采用水力负荷来校核,以保证上清液的水质达到排放标准,如要求上清液SS<70mg/L,则水力负荷应控制在 3. 7m3 /(m2·h)以下。     

浓缩时间对污泥浓缩效果、磷释放及去除的影响

针对城市污水厂剩余污泥浓缩过程中浓缩时间对浓缩效果、磷释放及去除的影响进行试验研究。结果表明:对已建有重力浓缩池的城市污水处理厂且污水厂处理能力存有一定富余时,可适当延长浓缩池的污泥浓缩时间,这既可大大提高浓缩池出泥的含固率,又可大部保留污泥中的含磷量,且不会对污水厂除磷产生不良影响。     

水厂污泥水沉淀试验负荷分析

为解决自来水厂中污泥水的污染问题,同时尽可能地压缩成本,用中试试验模型对武汉白鹤嘴自来水厂污泥水处理过程中的斜板沉淀池相关负荷数据进行总结和分析,以便更好地解决自来水厂污泥水的沉淀效率和成本问题.通过水厂污泥水现场中试研究,其结果表明,投加PAM可提高斜板沉淀池抗击负荷的能力;投加PAM+快速搅拌可进一步提高斜板沉淀池抗击负荷的能力.     

污泥浓缩池中磷的释放及其强化去除措施

城市污水处理厂污泥浓缩池上清液和脱水机滤液重新回流入污水处理系统会增加系统的磷负荷。针对污水处理厂剩余污泥浓缩过程中浓缩时间、投加聚合氯化铝(PAC)以及曝气对磷释放的影响进行了研究。结果表明,污泥浓缩池中的剩余污泥静置4 h后,释磷速率显著加快。在污泥浓缩池投加0.1 g/g干泥的PAC不仅将快速释磷时间延迟至8 h,还可以显著降低上清液中的磷酸盐浓度。对污泥浓缩池曝气30 min且溶解氧达到3 mg/L以上时,上清液中磷酸盐浓度降低了77.7%。通过合理控制剩余污泥在浓缩池中的停留时间、投加PAC以及曝气等,可以降低浓缩池上清液磷浓度,有效提高系统的除磷效果。     

搅拌对给水厂污泥浓缩的影响

通过试验研究了搅拌对给水厂污泥浓缩的影响,并分别探讨了快速搅拌和慢速搅拌对沉降效果的影响,结果表明:适当的慢速搅拌可以在一定程度上提高浓缩效果,建议最佳搅拌的速度梯度为1.4 s-1。     

滗水器在污泥调节池中的应用

武汉市南太子湖污水处理厂的进水污染物浓度较高,而脱水机效率不高,导致大量污泥无法及时排出,氧化沟的污泥浓度长期维持在7 000 mg/L左右,运行费用较高.经分析,造成脱水机效率不高的主要原因是在无浓缩池的情况下,污泥调节池中的污泥浓度不高所致.拟将现仅为一个搅拌区的调节池分为搅拌区及沉淀区,在沉淀区利用滗水器连续滗出清水,以提高调节池的污泥浓度.通过在污泥调节池上增设沉淀区和加装滗水器后,大幅提高了脱水污泥量,降低了氧化沟的污泥浓度及电耗.该方法具有投资少、见效快、维护管理简便、出水水质好等优势,具有推广价值.     

基于在线污泥浓度计的污泥浓缩脱水运行优化

随着污泥处理与处置成本的升高,以及絮凝剂的极高成本,使得污泥浓缩优化和机械脱水优化的重要性日益显现,为生化法污水处理厂节约成本提供了可能。污泥浓缩过程可以通过在重力浓缩池中使用可悬浮颗粒物传感器实时监测污泥排放来得到改进,从而保证浓缩后的污泥都是高浓度污泥。通过监测脱水设备的进泥负荷和离心分离机中的污泥浓度可以重新制定絮凝剂的投加方案,从而减少脱水前化学处理的絮凝剂用量和费用。     

膨胀污泥沉降性能的恢复试验研究

在前期已进行的污泥负荷对丝状菌污泥膨胀影响的研究基础上。对低污泥负荷下发生的污泥膨胀进行了污泥沉降性能恢复的试验研究。结果表明，恢复高污泥负荷运行能使膨胀污泥的沉降性能得以恢复，而恢复时间及恢复速率与膨胀程度均呈正相关关系；溶解氧是影响膨胀污泥沉降性能恢复的重要因素，在溶解氧不足时提高污泥负荷不但不能使污泥膨胀得到控制。反而却加剧了污泥膨胀。     

逆向流斜板沉降器的改进设计及其性能研究

介绍了一种改进型逆向流斜板沉降器的设计原理，通过试验，与相同几何尺寸的传统型逆向流斜板沉降器的固液分离性能进行了比较。结果表明，在处理流量为0．2m^3／h和0．25m^3／h的正常水力负荷下，改进型斜板沉降器的整体出水浊度较传统型的分别低39．95％和47、52％，且其各出水分区的水质较传统型的均匀、稳定；在处理流量为0、35m^3／h的超常水力负荷下，传统型斜板沉降器不能正常运行，而改进型斜板沉降器可正常运行；在临界流量下，改进型斜板沉降器的表面负荷较传统型的高出28．13％。斜板沉降器的改进设计解决了其在工程应用中出现的排泥困难、出水水质不均匀、抗冲击负荷能力差等问题。     

德国某污水厂浓缩工艺选型案例分析

为了研究最佳的污泥浓缩工艺,德国某污水厂对螺旋式、转鼓式、离心式、带式等7种不同的污泥浓缩机进行了运行性能和费用的对比试验.结果表明,在浓缩机最小处理量为30m3/h、每天24 h连续运行、出泥含固率控制在5%～6%、固体回收率>90%的前提下,某带式浓缩机运行效果好且费用低,是最适合该污水厂的污泥浓缩机;该带式浓缩机的处理量为100 m3/h,药耗约为2.5 g/kgDS,电耗约为0.12 kW·h/m3.     

宝钢长材坯料生产污泥处理系统的设计

采用调节池/混凝反应槽/絮凝反应池/污泥浓缩池/带式压滤机工艺处理电炉和连铸机净循环旁滤过滤器反冲洗排泥、连铸浊循环水系统斜板除油沉淀器排泥及VOD浊循环水系统斜板沉淀器排泥等的混合钢铁污泥。该系统自2007年9月初调试正常以来,运行良好,泥饼含固率为30%。     

Gravity drainage of activated sludge: new experimental method and considerations of settling velocity, specific cake resistance and cake compressibility

A laboratory scale setup was used for characterization of gravitational drainage of waste activated sludge. The aim of the study was to assess how time of drainage and cake dry matter depended on volumetric load, SS content and sludge floc properties. It was demonstrated that activated sludge forms compressible cakes, even at the low pressures found in gravitational drainage. The values of specific cake resistance were two to three orders of magnitude lower than those obtained in pressure filtration. Despite the compressible nature of sludge, key macroscopic parameters such as time of drainage and cake solid content showed simple functional dependency of the volumetric load and SS of a given sludge. This suggests that the proposed method may be applied for design purposes without the use of extensive numerical modeling. The possibilities for application of this new technique are, among others, the estimation of sludge drainability prior to mechanical dewatering on a belt filter, or the application of surplus sludge on reed beds, as well as adjustments of sludge loading, concentration or sludge pre-treatment in order to optimize the drainage process.     

Effect of sludge retention time on inclined plate function,treatment performance and sludge characteristics of inclined plate membrane bioreactors treating municipal wastewater

Two identical bench scale inclined plate membrane bioreactors (ip‐MBRs) were operated for the treatment of real municipal wastewater for 1 year. Sludge retention time (SRT) was varied over the course of operation to investigate the effects on inclined plate function, treatment performance and sludge characteristic. Removal rates of chemical oxygen demand and ammonia over 90% and of total nitrogen (TN) more than 70% were achieved when ip‐MBRs were operated under SRTs between infinite and 40 days while short SRT (20 days) negatively affected TN removal. When the sludge concentration in anoxic tank exceeded 15 g/L, the failure of the inclined plate function was observed, resulting in no difference in sludge concentrations between aerobic and anoxic tanks. To avoid severe effects on inclined plate function and treatment performance, an SRT range of 40–80 days was recommended for ip‐MBRs. Moreover, sludge floc size under prolonged SRT became smaller than that under short SRT due to increased attrition among the sludge floc particles caused by strong aeration needed for keeping a sufficient dissolved oxygen level.     

V形斜板强化接触絮凝沉淀设备的研发与应用

V形斜板强化接触絮凝沉淀技术利用设备的流体上升流道截面差造成水流沿重力方向的速度差,使斜板沉淀单元内部形成一定厚度的具有自我更新能力的絮体动态悬浮层,同时通过增设的垂直板来增加絮体悬浮层厚度,实现强化接触絮凝、提高絮体沉淀分离性能的目的.中试结果表明,当斜板长为850 mm、斜板间距为25 mm、直板长为150 mm时,沉淀设备达到最佳性能;在处理水量超过设计负荷的20%时,设备仍运行效果良好.在水厂改造项目中,V形斜板沉淀设备的出水浊度稳定在0.4 NTU以下,低于原设备的出水浊度(1.63 NTU),同时节省了49%的投药量.     

钢厂热轧污泥脱水系统的设计与设备选型

介绍了钢厂热轧污泥的组成、特点及热轧污泥处理系统的设计、设备选型及调试运行情况。长期运行实践表明，以全自动悬梁式板框压滤机为主体设备的热轧污泥重力浓缩、加药调理、机械脱水处理工艺系统运行稳定，污泥脱水效果良好，泥饼含固率〉70％且成型较好。     

Optimization of alum recovery from water treatment sludge‐case study: Samannoud water treatment plant,Egypt

Alum recovery from water treatment sludge is a promising technique applied for reducing the virgin coagulant demand and the sludge volume and safe disposal of the sludge. The aim of the current study is to optimize alum recovery process from alum sludge in Samannoud water treatment plant, Egypt by acidification technique using sulphuric acid and evaluate the effect of total solids (TS) content in the sludge on alum recovery process. Results showed that the optimal mixing time for alum recovery was 60 min for clariflocculator sludge, whereas 15 min for thickener sludge. Optimum pH value was 1.50 for alum recovery from different sludge types. At optimum conditions, acidification experiments showed that alum recovery percent and sludge volume reduction for clariflocculator sludge were 83 and 91.2%, respectively, versus 35.9 and 45%, respectively, for thickener sludge. Besides, alum recovery and sludge reduction decreased with the increase in TS content in the sludge.