Study Progress Analysis of Effluent Quality Prediction in Activated Sludge Process Based on CiteSpace

In this paper, CiteSpace, a bibliometrics software, was adopted to collect research papers published on the Web of Science, which are relevant to biological model and effluent quality prediction in activated sludge process in the wastewater treatment. By the way of trend map, keyword knowledge map, and co-cited knowledge map, specific visualization analysis and identification of the authors, institutions and regions were concluded. Furthermore, the topics and hotspots of water quality prediction in activated sludge process through the literature-co-citation-based cluster analysis and literature citation burst analysis were also determined, which not only reflected the historical evolution progress to a certain extent, but also provided the direction and insight of the knowledge structure of water quality prediction and activated sludge process for future research.

Intercross real-time control strategy in alternating activated sludge process for short-cut biological nitrogen removal treating domestic wastewater

To develop technically feasible and economically favorable dynamic process control(DPC)strategies for an alternating activated sludge(AAS)system,a bench-scale continuous-flow alternating aerobic and anoxic reactor,performing short-cut nitrogen removal from real domestic wastewater was operated under different control strategies for more than five months.A fixed-time control(FTC) study showed that bending-points on pH and oxidation-reduction potential(ORP)profiles accurately coincided with the major biologic...

Enhanced biological nutrient removal in modified carbon source division anaerobic anoxic oxic process with return activated sludge pre-concentration

A pilot-scale modified carbon source division anaerobic anoxic oxic(AAO) process with pre-concentration of returned activated sludge(RAS) was proposed in this study for the enhanced biological nutrient removal(BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60% and 50%, respectively, with an inner recycling ratio of 100% under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L-1with a removal efficiency of 63% and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.

Comparison of heavy metal removal efficiencies in four activated sludge processes

The removal efficiencies of heavy metals(As, Cr, Cu, Ni, Pb and Zn) were investigated in the 17 operating municipal wastewater treatment plants(WWTPs) and compared with those in four main activated sludge processes. Significant differences of heavy metal removal efficiencies were observed among four activated sludge processes. The removal efficiency for As(75.5%) in the oxidation ditch(OD) process is significantly higher than that in the conventional activated sludge(CAS) process(38.6%) or sequencing batch reactor(SBR) process(51.4%). The mean removal efficiencies for Cu and Ni in the OD process are 90.5% and 46.7%, respectively, while low mean removal efficiencies are observed for Cu(69.9%) and Ni(16.5%), respectively, in the SBR process. The removal efficiencies for Cu and Ni in the OD process are significantly higher than those in the anaerobic-anoxic-oxic(A2-O) process. These results highlight the differences of removal efficiencies for heavy metals in different processes and should be considered when selecting a wastewater treatment process.

Stoichiometric deduction of activated sludge process for organic carbon and nitrogen removal

The activated sludge process （ASP） is the most generally applied biological wastewater treatment method. The ASP for the removal of organic carbon and nitrogen can be looked as the combination of eight processes. In order to set up an ASP model, the stoichiometric coefficients should be deduced so that the stoichiometric matrix can be presented. The important assumptions and simplifications behind the model for ASP are enumerated. Using the matrix, mass balance equation and consistent units, the stoichiometric coefficients in the eight processes are exclusively deduced one by one.

Combined process of sequencing batch reactor activated sludge process and constructed wetland for domestic wastewater treatment

By combining sequencing batch reactor (SBR) activated sludge process and constructed wetland (CW), this study is to achieve the domestic wastewater treatment. Our purpose was to determine the optimum operating parameters of the combined process. The process involved advantages and shortages of SBR and CW. Under normal temperature, the 3rd cycle (SBR’s operation cycle is 8 h: inflow for 1 h, limited aeration for 3 h, sediment for 1 h, outflow for 1 h, and idling for 2 h; CW’s hydraulic retention time (HRT) is 24.8 h and hydraulic loading is 24.5 m3/m2 d) was the best cyclic mode. The effluents can meet the standard GB/T18921-2002: "The reuse of urban recycling water: water quality standard for scenic environment use". In the 3rd cycle, the efficiency of CW was the maximum, and energy consumption of SBR was the minimum. Under the condition of low dissolved oxygen, the removing efficiency of chemical oxygen demand (COD) and ammonia was not affected obviously. Simultaneously, nitrification and denitrification phenomena occured and phosphorus was absorbed obviously.

Comparative study of two biological nitrogen removal processes:A/O process and step-feeding process

Two biological nitrogen removal processes are compared in the aspect of nitrogen removal, process operation and energy saving. Results show that when the returned sludge ratio is 50% of the inflow rate, the step-feeding process achieves over 80% total nitrogen （TN） removal efficiency, but the TN removal efficiency of the A/O process is only 40%. Moreover, filamentous sludge bulking can be well restrained in the step-feeding process. Given the conditions of a returned sludge ratio of 100% and a nitrifying liquor recycle ratio of 200%, the TN removal efficiency is 78.32% in the A/O process, but the sludge volume index （SVI） value increases to 143 mL/g. In the step-feeding process, the SVI is only 94.4 mL/g when the TN removal efficiency reaches 81. 1%. The step-feeding process has distinct advantages over the A/O process in the aspects of practicability, nitrogen removal and operating stability.

Kinetics of aerobically activated sludge on terylene artificial silk printing and dyeing wastewater treatment

Aerobically activated sludge processing was carried out to treat terylene artificial silk printing and dyeing wastewater (TPD wastewater) in a lab-scale experiment, focusing on the kinetics of the COD removal. The kinetics pa-rameters determined from experiment were applied to evaluate the biological treatability of wastewater. Experiments showed that COD removal could be divided into two stages, in which the ratio BOD/COD (B/C) was the key factor for stage division. At the rapid-removal stage with B/C>0.1, COD removal could be described by a zero order reaction. At the mod-erate-removal stage with B/C<0.1, COD removal could be described by a first order reaction. Then Monod equation was introduced to indicate COD removal. The reaction rate constant (K) and half saturation constant (KS) were 0.0208-0.0642 L/(gMLSS)h and 0.44-0.59 (gCOD)/L respectively at 20 C-35 C. Activation energy (Ea) was 6.05104 J/mol. By comparison of kinetic parameters, the biological treatability of TPD wastewater was superior to that of traditional textile wastewater. But COD removal from TPD-wastewater was much more difficult than that from domestic and industrial wastewater, such as papermaking, beer, phenol wastewater, etc. The expected effluent quality strongly related to un-biodegradable COD and kinetics rather than total COD. The results provide useful basis for further scaling up and efficient operation of TPD wastewater treatment.

Slaughterhouse Wastewater Characterization and Treatment: An Economic and Public Health Necessity of the Meat Processing Industry in Ontario, Canada

The characteristics of the slaughterhouse effluents and current wastewater treatment practices in the province of Ontario, Canada are analyzed. Meat processing plants are found to produce large amounts of wastewater due to the slaughtering process and cleaning of their facilities. Furthermore, the composition of the wastewater varies according to the type and number of animals slaughtered and the water requirements of the process. However, the slaughterhouse wastewater usually contains high levels of organics and nutrients. Several slaughterhouses in Ontario discharge their wastewater into the municipal sewer system after primary pretreatment at the meat processing plant. Therefore, due to the high-strength characteristics of the slaughterhouse effluents, an extensive treatment for a safe discharge into the environment is required. Thus, the combination of biological processes and advanced oxidation technologies for slaughterhouse wastewater treatment is evaluated in this study. Results show that the application of combined biological and advanced oxidation processes is recommended for on-site slaughterhouse wastewater treatment.

城市污水处理过程污泥膨胀识别与抑制综述

污泥膨胀是活性污泥法污水处理过程中常见的一类异常工况,且具有严重危害性,研究污泥膨胀的识别和抑制方法对城市污水处理过程正常运行意义重大.本文主要针对城市污水处理过程中污泥膨胀的识别和抑制方法进行综述.首先,文章概述了城市污水处理过程,介绍了污泥膨胀的概念、主要特点、类型和成因;其次,概述了基于微生物生理特征、机理模型、图像识别和数据驱动的污泥膨胀识别方法,分析其发展现状并指出优缺点;然后,概述了基于过程调控和机理特征的污泥膨胀抑制方法,分析其发展现状并对比优缺点;最后,总结全文,指出了城市污水处理过程污泥膨胀识别和抑制面临的主要问题,并对其研究趋势进行了展望.

高效包埋好氧颗粒污泥在农药废水处理中的应用研究

为了高效处理有毒有害的农药废水,研究了包埋好氧颗粒污泥对实际农药废水的处理效果,并对比了包埋好氧颗粒污泥、市政好氧污泥及两者混合体系在实际农药废水活性污泥法处理中的表现。结果表明:在实际农药废水处理中,市政好氧污泥的硝化速率和COD降解速率分别为0.67 mg[N]/(g[SS]·h)和3.54 mg[COD]/(g[SS]·h),两者混合体系的平均硝化速率和COD降解速率分别为5.0 mg[N]/(g[包埋颗粒]·h)和49.05 mg[COD]/(g[包埋颗粒]·h),而包埋好氧颗粒污泥的平均COD降解速率为91.14 mg[COD]/(g[包埋颗粒]·h),并且具有更好的硝化性能,平均硝化速率为18.8 mg[N]/(g[SS]·h)。包埋好氧颗粒污泥对农药废水表现出较强的耐冲击负荷能力,说明了包埋好氧颗粒污泥的投加对提高农药废水氨氮降解效果显著。

铁炭内电解-CASS工艺处理模拟印染废水实验研究

印染废水具有水质水量变化大,COD、色度高,可生化性差等特点,属于难处理工业废水之一。采用铁炭内电解预处理以及CASS工艺处理模拟印染废水,试验结果表明:当铁炭床的铁炭质量比为3:1,停留时间为80 min,pH为6,曝气量为0.3 m3/h及CASS反应器曝气量为0.375～0.5 m3/h,排水比为0.3,运行周期6 h,其中,进水曝气5.0 h,沉淀20 min,排水30 min,闲置10 min时,废水处理效果最佳,其COD去除率可达88%～92%,BOD5去除率可达90%～94%,脱色率可达92%～95%。预处理段可以破坏废水中的难降解物质,提高废水的可生化性,且增加的铁离子含量可以改善后续CASS工艺活性污泥的沉降性能,提高废水COD的处理效果。

CASS工艺微生物抵抗含Cu^(2+)、Ni^(2+)锻造添加剂废水毒性的效果

工(产)业园区内企业在紧急情况下排放的污水中,有毒物质会影响污水处理厂活性污泥微生物的活性,甚至导致微生物的死亡。基于此,利用CASS工艺的特点检验微生物系统抗冲击毒性的能力,通过不同的配比浓度调整试验水样中Cu2+、Ni2+的质量浓度,监测CASS系统进出水的Cu2+、Ni2+、CODcr指标,用以判断微生物系统是否受到影响,进而确定CASS微生物系统抗毒性冲击的临界点。结果表明:Cu2+质量浓度小于3.0mg·L-1,Ni2+质量浓度小于5.0mg·L-1时,CASS工艺微生物抵抗含Cu2+、Ni2+锻造添加剂废水的毒性能力较强,对Cu2+、Ni2+、CODcr的去除率均可以达到80%;当Cu2+质量浓度大于3.0mg·L-1,Ni2+质量浓度大于5.0mg·L-1时,CASS工艺微生物对毒性抵抗能力显著降低,活性受到严重破坏,对Cu2+、Ni2+、CODcr去除率下降至60%以下。所以可以确定CASS工艺微生物抵抗含Cu2+、Ni2+锻造添加剂废水毒性的最高质量浓度限值,Cu2+为3.0mg·L-1,Ni2+为5.0mg·L-1。为污水处理厂实际运行工程中避免活性污泥微生物系统受毒性冲击而导致运行瘫痪提供参考依据。

活性污泥法污水处理技术在上海的早期传入与实践

20世纪初,上海公共租界工部局为了解决抽水马桶带来的水环境问题,邀请英国化学家福勒来沪进行考察,提出结合活性污泥法的处理方案。文章以活性污泥法污水处理技术传入上海的过程为重点,分析了福勒提出活性污泥法方案的过程,梳理了工程师前往美国、加拿大考察并评估该技术在上海的适用性,探讨了活性污泥法落地上海,建造污水处理实验室的情况。这是活性污泥法首次进入上海,也是第一次传入中国,促进了近代上海的城市现代化建设。活性污泥法在上海的传入,反应了技术移植过程中的常规程序,即提出方案、调研与选择、探索实践模式。活性污泥法的引入,是近代技术进入中国的典型案例。

预处理+EGSB+CASS+气浮处理木糖废水工程实例

介绍了河南某木糖生产企业的废水处理工程。该工程采用污污分流,经"预处理+EGSB+CASS+气浮"工艺处理高浓度硫酸盐木糖废水。运行实践表明,工艺运行稳定,经济可行。当综合进水COD<4 000 mg/L、BOD5<1 500mg/L、硫酸盐<1 200 mg/L时,出水可达到《污水综合排放标准》(GB 8978—1996)的二级标准。

3株高效石油降解菌对SBR处理含油废水的强化作用

研究了3株不同高效石油降解菌株用于序批式活性污泥法(SBR)处理含油废水的效果。结果表明,投加菌液苍白杆菌FP1、假单胞菌X1、红平红球菌KB1的SBR,COD平均去除率分别为90.8%、92.8%、98.2%;石油类物质平均去除率分别为79.1%、80.0%、92.8%;NH_(4)^(+)-N平均去除率分别为87.5%、91.4%、94.7%;TP平均去除率分别为23.8%、30.9%、44.4%。与未投加石油降解菌相比,投加石油降解菌株能显著提高SBR对含油废水中各污染物的去除效率,同时系统运行稳定,耐冲击负荷能力高。实验结果还表明在SBR中投加Fe Cl3利用化学除磷协助生物除磷可提高系统对TP的去除率,同时提高活性污泥的絮凝沉降性能,增加系统内活性生物量。该研究为生物强化SBR处理含油废水的工艺设计与设备运行提供了参考,石油降解菌强化SBR技术有望应用于含油废水生物处理。

CASS法工艺在某高校生活污水处理中的应用

采用地埋式水解调节池———CASS法处理某高校新区二期工程生活污水。利用调节池的工作特性,在部分空间分段设置生物填料,利用污泥无动力回流,强化污水的水解与除磷。池顶绿化,无地面构筑物。整个系统采用PLC集中控制自动运行,无人值守。经技术经济分析,污水处理成本 0 452元 /m3,投资指标 860元 /m3。此外,还考虑了处理系统的扩容、污泥和尾气处理、噪声控制、消毒和回用方案。

基于CASS工艺的污水处理自控系统设计

为提高设备厂家及自控专业人员远在故障现场时处理及解决问题的效率,在CASS(Cyclic Activated Sludge System)工艺的污水处理自控系统中设计并实现了超远程监控与维护功能模式。依据CASS工艺的特点,开发了一套稳定可靠的污水处理自控系统,详细阐述了该控制系统中上/下位机的设计方案、网络拓朴结构等内容,并在下位机编程过程中提出了一种基于状态转移图的编程方法;给出了利用Dame Ware软件在污水处理控制系统中实现超远程监控与维护的操作方法。投运效果表明,自控系统性能稳定,运行可靠,尤其是超远程监控与维护功能的设计有效降低了故障诊断与解决的时间,达到了设计的目标及要求。

HABR-CASS组合工艺处理棉机织物印染废水的研究

采用HABR-CASS组合工艺进行棉机织物印染废水处理的中试研究。结果表明,在HABR厌氧池、CASS反应池的水力停留时间分别为24、12 h的条件下,系统对CODCr、BOD5、氨氮、SS的总去除率分别为90.4%、95.5%、87.0%、87.5%,各污染物出水平均质量浓度分别为67.5、13.8、6.9、38.0 mg/L,出水色度为33.0倍,总去除率为95.0%,均低于DB 44/26—2001《广东省水污染排放限值》第Ⅱ时段一级排放标准限值。

污水生化处理工艺发展阶段化技术特征及未来趋势

百余年来,伴随人类社会和科技日新月异,污水生化处理技术也在实现快速发展与不断迭代,新工艺与新反应器、新功能微生物与新生化代谢途径不断被提出、发现和解析,并进一步推动了污水处理技术的进步与升级。回顾了过去百余年污水生化处理技术发展历程,就典型污水生化工艺,结合技术研发进展、技术成熟度及案例应用情况,给出了不同生化处理工艺代际划分与技术发展期“S曲线”,分析了近些年来新涌现出的一些革新性污水生化处理工艺的技术原理、技术特征,结合实际案例分析了工艺技术特征、技术优势与总体效能,从工艺强化、绿色低碳与集约高效等方面总结了未来污水处理发展的技术趋势,以期为“双碳背景”下排水系统提质增效工作、未来国内前瞻性污水厂工艺设计与运行提供参考和借鉴。