The Use Of High Concentration Ozone For Water Treatment

The use of high concentration ozone (HCO) in potable water treatment has been examined at laboratory scale with a gaseous concentration of 19% w/w. This has been compared with conventionally generated ozone at 1.5% w/w. The results of the study have shown that greater transfer efficiencies and higher ozone residuals are possible with HCO. In addition, faster rates of atrazine removal and significantly greater reductions in color and trihalomethane formation potential (THMFP) were observed with HCO.     

Experiences with Ozone Treatment Of Drinking Water in Yugoslavia

Ozone currently is being used in several drinking water treatment plants in Yugoslavia. The new Belgrade water treatment plant “Makis” is the largest one with 42 kg/h of installed ozone generating capacity and has been in operation since 1987. This paper describes the main features of ozone application in drinking water treatment. The experimental results of “Makis” pilot-plant investigations and a few examples of ozone application in Yugoslavia are presented.     

Rationales for Multiple Stage Ozonation in Drinking Water Treatment Plants

Starting in the early 1970s, the application of ozone for drinking water treatment began to evolve from primarily single-purpose, single-stage use for disinfection, taste and odor control or iron and manganese oxidation, to multipurpose uses of ozone. As a result, most of the newer drinking water treatment plants have installed two- and even three-stages of ozonation. in order to maximize the technological benefits of ozone and to minimize the costs involved.     

Worldwide Ozone Capacity for Treatment of Drinking Water and Wastewater: A Review

One question often raised when ozone professionals gather is “How much ozone capacity is installed?” Although the use of ozone for industrial purposes is growing, the largest use for ozone resides in the use of treatment of municipal drinking and wastewater. It is very difficult to summarize ozone capacity for industrial applications as much data are kept confidential. A number of reports have been published over the years on installed ozone capacity. Ozone capacity estimation is a moving target as plants are built and others removed from service for a number of reasons. This paper summarizes, using data available, ozone capacity for drinking water and wastewater. Focus is on the United States, Canada, Europe and Japan. IOA members and member companies are encouraged to submit additional data to enable this summary to be as accurate and relevant as possible.     

Destruction of Volatile Organic Contaminants in Drinking Water by Ozone Treatment

Controlled, pilot-plant ozone treatment tests were conducted on twenty-nine volatile organic contaminants in distilled water and groundwater. Results show that aromatic compounds and alkenes are well removed by ozone treatment, but that alkanes are poorly removed. Also, efficiency of destruction improved for the alkenes and aromatic compounds with increasing applied ozone dosage and, for some alkanes, with increasing pH. For most compounds, the efficacy of ozone was not severely affected by the background water matrix. Generally, information gathered from the literature regarding rate constants for the ozone treatment of compounds in the gaseous phase or in organic solution predicted, to a useful degree, the effectiveness of ozone in treating aqueous solutions in the present study.

Several of the test conditions selected for this preliminary study may be similar to those found in drinking water treatment plants. Consequently the findings of this research may help guide utilities in their choice of alternative treatments to meet Maximum Contaminant Levels for volatile organic contaminants such as trichloroethylene and benzene.     

Gas-Phase Ozone Oxidation of Hydrogen Sulfide for Odor Treatment in Water Reclamation Plants

Gas-phase O₃ oxidation is effective to treat H₂S emitted from wastewater treatment processes. The reaction is fast for full-scale applications. In most cases, 67–96% of total H₂S removed in 40-s reaction time was achieved within the first 8 s of reaction time. The initial [O₃]/[H₂S] ratio of 8 was sufficient to reduce H₂S from up to 8 ppmv to less than 0.5 ppmv in 40-s reaction time. The reaction stoichiometry ratio of [O₃]/[H₂S] ranged from 2.0 to 3.7, depending on the initial [O₃]/[H₂S] ratio. The moisture content, dimethyl sulfide, and dimethyl disulfide in the odorous air influence H₂S removal.     

臭氧—生物活性炭技术在饮用水深度处理中的应用进展

介绍了臭氧化活性炭技术在生活饮用水深度处理中的应用进展,通过研究国内外臭氧—生物活性炭工艺的发展现状和应用实践,综述了臭氧化—生物活性炭联用技术的作用机理及在水处理中的应用研究,分析了此项技术在应用中存在的问题,并介绍提高此项技术的应用措施。     

臭氧-生物活性炭技术在饮用水深度处理的应用

随着饮用水源污染的日益加剧和饮用水质标准的提高,采用饮用水深度处理工艺显得越来越有必要。文章系统介绍了臭氧-生物活性炭技术在国内外的应用情况、工作原理和安全性问题,并对臭氧-生物活性炭水质安全问题的解决方案进行了探讨。     

The Installation of GAC and Ozone Surface Water Treatment Plants In Anglian Water,UK

The surface water treatment plants in Anglian Water are being upgraded in order to more reliably meet the requirements of the EEC Drinking Water Directive. Ozone and additional GAC filtration capacity are being installed at 11 waterworks treating river and reservoir water, with capacities ranging from 11 to 360 ML/d. The installations and reasons for the plant designs are discussed.     

管道直饮水系统的设计

以工程实例从用水定额、管道设计秒流量、工艺流程、管网设计、管材等方面谈谈管道直饮水的设计,同时对管道直饮水的经济效益进行了分析。     

Ozone Treatment of Surface Water to Provide High Quality Cooling Water and Process Water

The characteristic feature of this cooling tower water treatment is the intermittent addition of ozone for several days.     

Influence of Carbonate on the Ozone/Hydrogen Peroxide Based Advanced Oxidation Process for Drinking Water Treatment

The influence of carbonate on the ozone/hydrogen peroxide process has been investigated. Carbonate radicals, which are formed from the reaction of bicarbonate/carbonate with OH radicals, act as a chain carrier for ozone decomposition due to their reaction with hydrogen peroxide. The efficiency of bicarbonate/carbonate as a promoter for the radical-based chain reaction in presence of hydrogen peroxide has been calibrated and compared to a well-known chain promoter (methanol) and an inhibitor (tert-butanol). Relative to tert-butanol, the hydrogen peroxide induced ozone decomposition is accelerated by bicarbonate/carbonate. Relative to methanol, bicarbonate/carbonate in presence of hydrogen peroxide is less effective as a promoter under comparable experimental conditions.     

高浓度含砷废水处理回用工程

介绍了黄金冶炼及烟气制酸等排放的高浓度含砷废水的水质，分析了处理该废水的原理．根据处理后的废水要全部回用，按污水水质和出水要求，提出用石灰—铁盐共沉淀法除去废水中砷、氟及重金属等，阐述了工艺流程及工艺参数的控制，指出该处理方法具有流程短、布置紧凑、投资少等特点。     

GAC—UF处理工艺生产优质饮用水的试验研究

本研究就活性炭吸附和超滤膜分离联用技术生产优质饮用水进行试验。试验结果表明、工艺流程自动化程度高、运行稳定、出水水质满足饮用净水标准（DB31／197－1997）的水质标准。PAN超滤膜及其工艺系统不仅能有效地去除细菌、浊度、对有机物也有较好的去除效果。本处理系统对铁的去除效果较好,但对锰的去除效果较差。     

The Efficacy of Ozone/BAC Treatment on Non-Steroidal Anti-Inflammatory Drug Removal from Drinking Water and Surface Water

Three non-steroidal anti-inflammatory drugs (NSAIDs)—ketoprofen, naproxen and piroxicam—in both deionized (DI) water and surface lake water (SW) (Tallahassee, FL), were exposed to varying ozone treatment regimes or H₂O₂/O₃ advanced oxidation on the laboratory bench. Recently used biofilm-supporting granular activated carbon (BAC) was sampled from a municipal drinking water treatment facility (Tampa, FL, USA), and employed to determine the bio-availability of chemical intermediates formed in ozonated water. Advanced chemical analysis was used to identify oxidation by-products formed and combined with a bioanalytical tool to assess non-specific toxicity (Microtox assay). All 3 target pharmaceuticals were efficiently removed by different processes, with a lower NSAIDs removal yield observed in lake water compared to DI water experiments. The removal yields of ketoprofen, naproxen, and piroxicam improved with increasing ozone dose, H₂O₂/O₃ ratio and empty bed contact time (EBCT) with BAC. Ozonation with BAC filtration had a positive impact by reducing the initial ozone dose required to achieve > 90% removal of all 3 pharmaceuticals (when an initial ozone dose < 1 mg L^-1 was combined with EBCT < 15 min). The toxicity evolution of the treated samples was monitored by Microtox bioassay. Ozone doses higher than 2 mg L^-1 for 2 min contact time were optimal to reach the lower water samples toxicity with NSAIDs removal yields ranging from 95.5 to 99.0% in DI water and from 77 to 90% in SW. Also, higher ozone doses were not shown to remove the residual toxicity. In contrast, the BAC filtration hardly decreases the sample toxicity when an EBCT of 15 min was chosen despite a NSAIDs removal yield equal or higher than 90% in SW.     

Cooling Water Treatment with Ozone

Small scale tests oruan open recirculating cooling system with a cooling water flow of 10 m³/h conducted for a period of two years have shown that ozone could be a viable alternative to chlorine and other commonly used biocides. An average ozone dosage of 0.05 mg/L was applied continuously to the cooling water. Corrosion rates of copper alloy samples immersed in ozonized water were lower than the rates of samples in non-ozonized water. No corrosion was detected for the Cr-Ni steel alloys DIN 1.4306 and DIN 1.4404 as well as for titanium either in the presence or absence of ozone in water. This is ascribed to the formation of a thin protective layer in both cases.

A pilot plant has been set up at the EVS Heilbronn coal-fired power station in West Germany in order to confirm the results obtained on small scale. The open recirculating cooling system has a cooling water flow of 1,000 m³/h and is fed by conditioned Neckar river water. An air-fed ozone generator is used to ozonize a 10% side stream of the cooling water. A bubble diffuser contactor is used to introduce ozone into the water and an air heater is operated to decompose excess ozone leaving the contactor. The plant can be run to yield either a constant ozone residual concentration in the water or a constant ozone dosage to the water leaving the contactor. All relevant data are registered continuously and the plant presently is operated automatically with a constant ozone dosage in the side stream. Corrosion experiments are performed using laboratory heat exchangers, and all physical, chemical, and microbiological data of the cooling water are acquired. The operation started February 1, 1989 and is scheduled to be terminated by the end of 1990.     

An Assessment of the Benefits Afforded by the Continuous Versus Intermittent Operation of Ozone for Drinking Water Treatment

Stricter regulation by OFWAT has encouraged water companies to optimize all stages of the water treatment process. This work reviews the ozonation process, in order to evaluate the benefits and disadvantages of continuous versus intermittent ozone operation. Two Advanced Water Treatment Works (AWTW) were surveyed, Farmoor AWTW, Which involves traditional (chemical) treatment processes, and Kempton Park AWTW, which incorporates slow sand filter sandwich? beds. Both reviews indicated that continuous ozone operation would result in an optimized solution based on dependability of ozone plant, reliability of water quality and cost efficiency.     

O_3-内电解组合工艺处理高浓蜡染废水

采用O3-内电解组合工艺处理实际高浓蜡染废水,探讨了臭氧协同内电解处理蜡染废水中臭氧量、铁碳比、反应时间、p H值等因素对反应的影响。结果表明当臭氧量为12 g/L,p H值为5,铁碳体积比为1∶2,反应时间为60 min时,废水的色度去除率达到95%,COD去除率达到了75%。     

Are the Results of Ozonation of Model Compounds at High Concentrations Transferable to the Conditions of Drinking Water Treatment With Ozone?

Organic compounds of the different classes of substances (isobarbituric acid, citraconic acid and o-chlorophenol) were ozonized while varying their initial concentrations (c = 10^-3 to 10^-5 mol/L) at pH 7. In the case of isobarbituric acid at 10-3 mol/L, formyloxaluric acid, oxaluric acid, and formic acid were identified. At an initial concentration of 10^-3 mol/L, alloxanic acid and oxalic acid were formed in addition to oxaluric acid and formic acid. In both cases, the rates of elimination are similar.After ozonation of citraconic acid (c = 10^-5 mol/L, pH 7), the following oxidation products were identified: glyoxylic, acetic, formic, oxalic, pyruvic, and hydroxypyruvic acids.