重金属迁移转化规律研究

通过对阜阳污水处理厂的进水、曝气沉砂池、出水分析检测,研究CASS工艺对城市污水中重金属的去除效果,得出了重金属的迁移转化规律,为进一步提高CASS工艺的污水处理效果提供了科学依据。     

Concentrations of nitrilotriacetate and certain metals in Canadian wastewaters and streams: 1971–1975

At 13 Ontario cities, representing a variety of populations and sewage treatment processes, grab samples were taken from the sewage treatment plant influent and effluent and from the receiving stream above and below the sewage outfall. The samples, taken once each month from November 1971 to March 1975 were analyzed for nitrilotriacetate (NTA), 9 metals, and phosphorus. From April 1971 to January 1973 household detergents in Canada contained an average of 6% NTA; after March 1973 they contained 15%. This increased usage of NTA was reflected in the NTA content of sewage influents, which rose from a median level of 1.3 mg l⁻¹ before the change to 3.2 mg l⁻¹ after the change. NTA levels in sewage effluent also increased somewhat, but much of the NTA disappeared in the sewage treatment processes. Even with the increased usage of NTA, the receiving streams below the sewage outfall contained only low levels of NTA: 97% of all samples during this period contained less than 0.5 mg l⁻¹, and the median concentration was 0.05 mg l⁻¹. Phosphorus concentrations in the sewages decreased at the time detergent compositions changed. Comparison of metal concentrations before and after the change, as well as metal-NTA correlation coefficients, failed to show clear evidence of an association between NTA concentration and metal concentration.     

Occurrence of several acidic drugs in sewage treatment plants in Switzerland and risk assessment

The occurrence and fate of five acidic drugs (Mefenamic acid, Ibuprofen, Ketoprofen, Diclofenac and Clofibric acid) were analysed in three sewage treatment plants (STP) over 4-7 consecutive days. The results point out that the five substances were persistent in wastewater effluents after municipal wastewater treatment. At the most, half of Mefenamic acid was eliminated. Ibuprofen was well removed (80%) by one sewage treatment plant. The removal of Ibuprofen is dependent on the residence time of wastewater in the STPs. A long raining period induce an important decrease of removal of Ibuprofen and Ketoprofen. Removal rates showed a great variability according to sewage treatment plants and types of treatments (e.g. biological, physico-chemical). The concentrations of Ibuprofen, Mefenamic acid and Diclofenac were relatively high in the effluents (150-2000 ng/l), showing a potential contamination of surface water. An environmental risk assessment is presented. Mefenamic acid seems to present a risk for the aquatic environment, with a ratio PEC/PNEC higher than one.     

对污水处理厂主要备用设备及闸门的养护

针对污水处理厂主要备用设备(进水泵、鼓风机)在备用期间常见的损坏问题,以及设施闸门的常见破坏情况进行了原因分析,同时结合污水处理厂的实际运营管理提出了明确的解决方法和防治措施.     

Removal of zeolite type a during primary sedimentation and its effect on metal removal

Using two pilot plants operated in parallel, treating settled sewage the removal of the detergent builder zeolite type A during primary sedimentation has been studied. With one zeolite free pilot plant acting as a control to the other it was also possible to determine the effect of zeolite on suspended solids and heavy metal removal over a range of hydraulic loadings. At both influent concentrations of zeolite studied (30 and 60 mg l⁻¹) zeolite removal was substantial under all conditions. No evidence of enhanced removal of suspended solids in the presence of zeolite was observed. Removals of lead, zinc, copper and chromium were slightly enhanced in some experiments. The observed improvements in metal removal appeared to be strongly influenced by the sewage matrix.     

OPERATIONAL EXPERIENCE FROM A SMALL FOOTPRINT LAMELLA AND BAFF PLANT IN ABERDEEN.

The city of Aberdeen has a population of 265,000 people, which was previously served by a preliminary sewage treatment facility, Including screening and grit removal prior to discharge to the North Sea.
The Nigg Waste Water Treatment Works (WwTW) was designed and built to treat the sewage from Aberdeen as part of a Private Finance Initiative (PFI) in order to achieve Urban Waste Water Treatment Directive (UWWTD) standards for BOD (25mg/l 95%ile) and COD (125mg/195%ile). A small footprint plant was required and involved lamella tube settlers for primary treatment followed by a Biological Aerated Flooded Filter (BAFF) plant for secondary treatment.
The plant received loads above the design and chemical closing was applied to increase the capacity for treatment. Constant monitoring through the plant was put in place in order to optimise the performance. This paper gives details of the performance of the plant over the first year of operation.     

Removal of indigenous rotaviruses during primary settling and activated-sludge treatment of raw sewage

An eight month study of indigenous rotavirus removal during primary settling and activated sludge treatment of raw sewage was made in a plant in Houston, Texas treating 1.5 million gal day⁻¹. An average reduction of 44–55% was obtained by primary settling and a 93–99% reduction was achieved in final chlorinated effluents. Composite sampling at 1 h intervals over a 24 h period indicated average removals of 85% compared to a misleading 6% indicated by one set of grab samples of raw sewage and effluent collected simultaneously. Quantification of rotaviruses was made by immunofluorescent foci counts 24 h after addition of sample concentrates to coverslip cultures of fetal rhesus kidney cells. Rotaviruses varied from 40–5101⁻¹ of raw sewage and from 0 to 25 in the final chlorinated effluent.     

邯郸市排水系统运行状况分析

从排水管网、排水泵站、污水处理设施三方面论述了邯郸城市排水系统运行中存在的问题。从污水管道渗漏、汛期道路和下穿立交桥下积水、雨污混流污染水体、污水漫溢污染环境、超标排放损害排水设施、污水排放量统计、污水厂升级改造、污水厂剩余污泥对周边居民生活环境影响以及再生水利用等方面进行了分析,并提出了相应的解决措施。     

某城镇污水处理厂工艺参数的优化

某城镇污水处理厂采用AAO工艺.为达到最佳的除磷脱氮效果,通过小试设备模拟污水厂的正常运行条件,反复试验得出混合液回流比为200%,污泥回流比为75 %,污泥停留时间为12 d时的除磷脱氮效果最好.该批参数应用于污水厂运行时,效果明显,氨氮和总磷指标均达标排放.     

某城镇污水处理厂工艺参数的优化

某城镇污水处理厂采用AAO工艺。为达到最佳的除磷脱氮效果,通过小试设备模拟污水厂的正常运行条件,反复试验得出混合液回流比为200%,污泥回流比为75%,污泥停留时间为12 d时的除磷脱氮效果最好。该批参数应用于污水厂运行时,效果明显,氨氮和总磷指标均达标排放。     

The influence of heat treatment on the metallic and polycyclic aromatic hydrocarbon content of sewage sludge: A pilot plant study

Heat treatment of sewage sludge facilitates its dewatering. The liquors produced inevitably contain a portion of the heavy metal and polycyclic aromatic hydrocarbon contaminants present in the sludges. Using a pilot plant, the influence of time and temperature of treatment on the concentrations of these pollutants in the liquors and treated sludges from three types of untreated sludge have been determined. Statistical analysis of the data has been used to identify significant effects of the treatment process. It is concluded that heat treatment would not produce significant increases in the concentrations of these contaminants in sewage effluents.     

The influence of nitrilotriacetic acid on heavy metal transfer in the activated sludge process-I. at constant loading

Removal of metals in the sewage treatment process is closely related to the chemical forms in which the metals exist. One critical factor controlling the forms of the metals in sewage is the chemical matrix of the sewage; as a consequence of their chelating capacity detergent builders are important in modifying the sewage matrix. Laboratory simulations of the activated sludge process have been studied to estimate the impact of the detergent builder nitrilotriacetic acid on the removal of heavy metals from sewage in this treatment process.The acclimation period for the biodegradation of nitrilotriacetic acid in a hard water synthetic sewage was found to vary from 16 to 31 days. In a soft water synthetic sewage, biodegradation was not observed even after 60 days. Hydrolysis of condensed phosphates in both hard and soft water synthetic sewages occurred within 3 h. Even when substantially biodegraded in hard water synthetic sewage, nitrilotriacetic acid appeared to be adversely affected by the absorption of cadmium, copper and zinc by the biological solids. The greatest absorption of heavy metals to the biological solids occurred when condensed phosphates were present. In soft water synthetic sewage metal absorption was minimal in the presence of nitrilotriacetic acid. In the presence of condensed phosphates absorption was considerably higher but not comparable with that achieved in hard water synthetic sewage.     

山西省污水厂污泥重金属处理技术

针对当前国内污泥处理现状及重金属污染防治难题进行了探讨,介绍了山西省污水厂污泥的特点,着重阐述了化学法、物理法、生物法处理污泥重金属的原理及特点,指出化学淋滤技术与生物淋滤技术可作为山西污水厂污泥重金属处理的主要技术路线。     

污水再生利用双膜法工艺浓水水质分析

分别对某生活污水处理厂及进水含有工业废水的混合污水处理厂的双膜工艺(CMF+RO)浓水水质进行了调查,结果表明:混合污水处理厂双膜工艺浓水中TDS、Mg2+、Ca2+、Cl-、SO42-、CODCr、TOC、BOD5、TP、NH3-N、TN均高于生活污水处理厂。对浓水中有机物组分的GC-MS分析表明,两个污水处理厂双膜工艺浓水中残存的有机物均属于难生物降解物质,以酚类和酯类为主,且混合污水处理厂双膜工艺浓水中残留有机物的组成较复杂。     

The physicochemical speciation of Cd, Pb, Cu, Fe and Mn in the final effluent of a sewage treatment works and its impact on speciation in the receiving river

A scheme for the speciation of metals in freshwaters has been applied to the analysis of the final effluent from a sewage treatment plant and to the receiving river upstream and downstream of the effluent outfall. The treatment plant was selected because of the high influent and effluent concentrations of Cd. The metal speciation patterns in the effluent are interpreted primarily in terms of organic interactions, which appear to be exerting a solubilizing effect on Cd and Cu, but not on the Pb and Fe which are principally associated with the particulate size fraction (> 12 μm). The influx of metals with the sewage effluent alters the speciation pattern in the river. A large part of the Cd is added to the smallest size fraction (< 0.015 μm). However, the major part of each metal, with the exception of Mn, is associated with the colloidal and particulate size fractions, thus minimising the immediate toxic significance to aquatic life.     

The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria

The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria were investigated in two large-scale municipal treatment plants during a period of six months. Total and relative numbers of resistant bacteria were determined in raw sewage, treated sewage and anaerobically digested sludge by bacteriological counts on media selective for coliforms (MacConkey agar) and Acinetobacter spp. (Baumann agar). In addition, the level of antimicrobial susceptibility was determined by the disc-diffusion method in 442 Acinetobacter isolates identified by colony hybridisation with a genus-specific DNA probe. Independent of the different antibiotics and media used, the total numbers of resistant bacteria in treated sewage were 10-1000 times lower than in raw sewage. Based on linear regression analysis of data on bacteriological counts, the prevalences of antimicrobial-resistant presumptive coliforms and Acinetobacter spp. in treated sewage and digested sludge were not significantly higher compared with raw sewage. On the contrary at one plant, statistically significant decreases were observed in the prevalence of ampicillin-resistant presumptive Acinetobacter spp. (p = 0.0188) following sewage treatment, and in the prevalence of either ampicillin-resistant presumptive Acinetobacter spp. (p = 0.0013) or ampicillin- and gentamicin-resistant presumptive coliforms (p = 0.0273 and p = 0.0186) following sludge treatment. The results obtained by bacteriological counts were confirmed by antimicrobial susceptibility testing of Acinetobacter isolates. Based on logistic regression analysis, isolates from treated sewage and digested sludge were generally not significantly more resistant compared with isolates from raw sewage. Based on these evidences, it was concluded that tertiary wastewater treatment did not result in a selection of antimicrobial resistant bacteria.     

上海城市污水厂污泥的农用处置方法研究

历时一年的调查显示，上海11家城市污水厂的污泥中含有大量的植物养分，但是在某些时期重金属含量会超过国家《农用污泥质量标准》，为此采用生物法和化学法对污泥中的重金属进行了沥滤试验。沥滤7d后的结果表明，采用生物法双用浓H2SO4酸化具更好的滤除效果；在生物法沥滤重金属的过程中还具有酸化法所没有的泥消化功能。     

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in sewage treatment plants

In this study, the concentrations of PFOS and PFOA in the biological units of various full-scale municipal sewage treatment plants were measured. Samples of influent, primary effluent, aeration tank effluent, final effluent and grab samples of primary, activated, secondary and anaerobically digested sludge were collected by 5 sampling events over one year. The two sewage treatment plants (STPs) selected for this study include plant A receiving 95% domestic wastewater and plant B receiving 60% industrial wastewater and 40% domestic wastewater. PFOS and PFOA were observed at higher concentration in aqueous and sludge samples in plant B than that of plant A. Mass flow of PFOS increased significantly (mean 94.6%) in conventional activated sludge process (CAS) of plant B, while it remained consistent after the secondary treatment in plant A. Mass flow of PFOA increased 41.6% (mean) in CAS of plants A and B and 76.6% in membrane biological reactor (MBR), while it remained unchanged after the treatment of liquid treatment module (LTM). Our results suggest that mass flow of these two compounds remains consistent after treatment of activated sludge process operating at short sludge retention time (SRT). Seasonal variations of PFOS in concentrations of raw sewage were found in plant A, while PFOA did not have significant seasonal variation in both plants A and B.     

河间束城污水处理厂工程投资效益分析

根据《"十二五"全国城镇污水处理及再生利用设施建设规划》,我国将在"十二五"期间大规模加大对污水处理厂的投资力度和建设力度,在此背景下,论文以河间束城污水处理厂工程为研究对象,对该污水处理厂的财务效益、社会效益和环境效益进行分析研究,从货币量化的角度分析该项目所带来的综合收益,为今后污水处理厂建设,特别是镇一级污水处理厂的建设提供借鉴。     

瑞士伯尔尼污水处理厂的管理模式及收费机制

基于对瑞士伯尔尼污水处理厂的概况、污水处理工艺、企业与员工架构情况的分析,介绍了其管理运营模式,并对该厂与中国典型污水处理厂的收费机制进行了探讨,以供参考。