间甲酚臭氧化反应动力学研究

本文采用停流光谱仪研究了溶解臭氧和间甲酚在液相中的均相反应动力学,探讨了反应温度为298K和pH值在3～7范围内,间甲酚臭氧化反应的动力学参数。间甲酚臭氧化总的反应呈二级,对臭氧浓度和间甲酚浓度分别呈一级。臭氧化反应速率常数随溶液pH值的增大而增大,在T为298K时,当pH值从3变化到7,总的反应速率常数从6 28×103(mol L)-1·s-1增大到9 15×105(mol L)-1·s-1。     

对硝基苯酚臭氧化反应动力学研究

在T=298K,pH=2.1～6,采用停流光谱仪研究了对硝基苯酚与臭氧在水溶液中的臭氧化反应动力学。实验结果表明,对硝基苯酚臭氧化总的反应是2级,对臭氧浓度和对硝基苯酚浓度分别为1级。臭氧化反应速率常数随溶液pH值的增大而增大;T=298K时,当pH值从2.1变化到6,总的反应速率常数从5.88×104L(mol·s)-1增大到1.56×106L(mol·s)-1。为了验证其适用性,对臭氧在搅拌釜中在对硝基苯酚溶液中的吸收过程进行了模拟。采用MATLAB软件求解臭氧在搅拌釜中在对硝基苯酚溶液中吸收过程的质量平衡方程,模拟得到了吸收过程中臭氧和对硝基苯酚浓度的变化,并与实验值进行了比较。结果表明,在85%的对硝基苯酚降解之前,模拟值和实验值能很好地一致。在反应末期,模拟值和实验值出现了一定的偏差。     

Biodegradability Improvement of Aqueous 2,4-Dichlorophenol And Nitrobenzene Solutions By Means of Single Ozonation

The possibility of the integration of ozonation and biological processes as an economical way to treat biorecalcitrant organic compounds such as nitrobenzene and 2,4-dichlorophenol was investigated. In the pre-treatment step, stoichiometric coefficients and pseudo first-order kinetic constants were obtained. Biodegradability was monitored throughout the ozonation step, in order to evaluate the optimum ozone doses. The low TOC reduction after these ozone doses allowed much of the organic carbon to be removed in the biological stage. In the case of 2,4-dichlorophenol, the biodegradability improvement was checked in an aerobic bioreactor. By means of the combined ozonation-biological oxidation, up to 80% of the initial organic content was removed. Results presented in this study show the feasibility of using the combination of ozone and conventional biological treatments to treat wastewaters containing these pollutants.     

臭氧化法在水处理中的应用

臭氧具有极强的氧化能力，其综合处理技术应用在含有许多难降解有机物及有毒有害物废水的处理工艺中，具有特殊的功效。     

The Economics of Ozonation at Monroe

The economics of operating the ozonation system at the water works in Monroe, Michigan, are reviewed after four years of successful operations. Operating expenses and overhead are analyzed and combined to determine the ultimate cost of taste and odor treatment by this unique method. The reliability of the system, its undemanding ease of operation, and its unvarying total effectiveness in meeting design objectives are parallelled by a host of beneficial side effects that compound its usefulness while effecting savings in other areas.     

饮用水处理中的臭氧化技术

臭氧化技术是一种新型的消毒技术,与传统的消毒技术相比,该技术具有氧化能力强、杀菌效果好、接触时间短、受水中的pH值和氨氮影响小等优点。本文简述了臭氧的性质以及自来水的臭氧消毒工艺,并综述了臭氧与其他技术联用在饮用水处理中的应用,说明臭氧化技术存水处理中具有广泛的应用前景。     

Quantitative Investigation of the Synergistic Effect of Electrolysis Combined with Ozonation for Degradation of Nitrobenzene

The synergistic effect of electrolysis-ozonation was quantitatively studied in a divided cell for the degradation of nitrobenzene (NBz). The results showed that the synergistic effect of the cathodic compartment resulted from three pathways: the generation of ?O₃^¯ and ?O₂^¯, high pH near the cathode, and the generation of H₂O₂, in which their importance decreased sequentially. The synergistic mechanism of the anodic compartment was also discussed. This study is of great significance for the further development of electrolysis-ozonation.     

废水臭氧催化氧化深度处理试验研究

采用单独臭氧及三种不同催化剂对烟气脱硫含碱废水迚行臭氧催化氧化试验,试验结果表明,合适催化剂投加的条件下,可以大大提高臭氧氧化效率,减少臭氧投加量。COD去除率最高可达88%,BOD5、B/C分别提高了88、675倍,大大改善了废水的可生化性,有利于迚行废水深度处理。     

Ozonation Kinetics Of o-phenylphenol in Aqueous Solutions

This study investigated the oxidation and reaction kinetics of biocide o-phenylphenol (o-PP) during ozonation. The second-order rate constants for direct reaction of molecular ozone with o-PP were determined in homogenous system using classical and competition kinetics. Obtained values of the second-order rate at pH 2 are equal to (3.79 ± 0.23)?×?10² M^?1 s^?1 and (4.42 ± 0.64)?×?10² M^?1 s^?1, for the two methods, respectively. The rate constant for the dissociated form of o-PP was also determined. It was found that the rate constants for the reaction of o-PP with ozone increase significantly with increasing pH.     

硝基苯废水处理的微生物及工艺

从降解硝基苯的微生物和以微生物为核心的硝基苯废水生物处理工艺两个方面,综述了目前硝基苯废水微生物降解研究的进展,并对微生物处理硝基苯废水的发展提出了建议.     

硝基苯类废水处理研究进展(续前)

<正>(续2010年第3期第37页)3生物法国内外学者对于生物法降解硝基苯废水进行了大量研究,其中国外研究比较注重降解机理,对微生物的生长条件及工业化应用报道极少;而国内学者大都通过驯化活性污泥来降解硝基苯,     

Ozonation of activated sludge in the recycle stream

Intermittent ozonation of a part of the recycle sludge was performed two times a week for a laboratory‐scale reactor at an average ozone dose of 0.019 g O₃(gSS_ozonated)^?1. Under these conditions a decrease of about 50% in sludge growth was obtained for the ozone‐treated system, in comparison with the control. As a consequence less sludge had to be removed from the test reactor. Only a slight decrease in quality of effluent was noticed. A comparative cost calculation was made, based on these results, between an ozone‐treated activated sludge system and a traditional activated sludge system. © 2001 Society of Chemical Industry     

Rates of Ozonation of Cresol Isomers in Aqueous Solutions

This research used a stopped–flow spectrophotometer system to study the kinetics of the fast oxidation of cresols by ozone in aqueous solutions. The overall reaction between ozone and a cresol isotner is second order, with first order in each reactant. At the same operating condition, the ozonation rate of m–cresol is the fastest and that of o–cresol the slowest. For the oxidation of o–cresol in neutral solutions, the overall rate constant increases from 422,000 to 1,550,000 1/M–s as the temperature changes from 10 to 40°C. In aqueous solutions with the pH range of 2.4 to 9.0 at temperatures varying from 5 to 40°C, the ozonation rate of the cresols increases with temperature and pH.     

Catalytic Ozonation of Acid Red 88 from Aqueous Solutions

Degradation of Acid Red 88 (AR 88) azo dye in water was investigated in laboratory-scale experiments in presence of three metal oxide supported catalyst. Oxidation process was monitorized in terms of colour, chemical oxygen demand (COD) and total organic carbon (TOC) removals. Influence of catalysts type and aqueous solution pH were studied.     

Ozonation of alachlor catalyzed by Cu/Al2O3 in water

The Cu/Al₂O₃ catalyzed ozonation for degrading an endocrine disruptor—alachlor in water was investigated. The Cu/Al₂O₃ powders were coated on a cordierite honeycomb column, which was taken as the reactor of catalytic ozonation of alachlor. Additional uncatalyzed experiments were carried out and the results were compared to those of the catalytic runs.

The experimental results demonstrated that Cu/Al₂O₃ was a very effective catalyst for ozonation of alachlor. The removal rate of alachlor in total organic carbon (TOC) with ozonation in the absence of Cu/Al₂O₃ was only above 20% in 180 min, while the reduction of totle organic carbon (TOC) in the presence of Cu/Al₂O₃ was more than 60%. Correspondingly, more inorganic ions created and less by-products produced in the Cu/Al₂O₃ catalyzed ozonation than in the unanalyzed process. These results indicated that the use of Cu/Al₂O₃ substantially enhanced the mineralization of alachlor in ozonation. The EPR experiments verified that more √OH radicals generated in the Cu/Al₂O₃ catalyzed ozonation could bring on a higher alachlor removal rate.     

零价铁还原体系硝基苯初始浓度对还原过程的影响

为了考察在不同硝基苯初始浓度下,零价铁（zero-valentIron）还原硝基苯的反应动力学特性·分别配制初始浓度在15---400mg／L范围内的6种浓度的样品,通过液相色谱和气．质联用分析硝基苯和还原产物苯胺的浓度变化,以探讨初始浓度对零价铁还原硝基苯的影响。结果表明：pH为中性的条件下,对于不同初始浓度硝基苯,还原反应主要发生在前120mm,硝基苯的减少和苯胺的增加都里线性规律,零价铁还原硝基苯的反应过程符合假一级动力学模型：随着硝基苯初始浓度的升高,表观速率常数kobs值逐渐降低。120rain之后还原反应逐渐减慢,还原反应不符合假一级动力学模型。     

Ozonation And AOP Treatment Of Phenanthrene In Aqueous Solutions

Phenanthrene is considered to be a hazardous pollutant and is listed as a priority pollutant by the U.S. EPA. This laboratory study was designed to investigate the degradation of phenanthrene in water solutions by ozone, by ozone in combination with hydrogen peroxide and UV-radiation and by UV-radiation only, to compare the efficiency of different oxidation processes at different values of pH = 3, 7 and 9. On the basis of kinetic curves of phenanthrene destruction, the chemical reaction rate constants were calculated. The results obtained confirmed that phenanthrene oxidation proceeds mostly with molecular ozone and the best method for reducing its concentrations is an ozonation in neutral medium. The rate of phenanthrene autoxidation is rather slow and does not depend on pH nor H₂O₂ addition. UV-radiation alone is also unable to reduce phenanthrene concentration significantly.     

Aqueous Ozonation Of Surfactants: A Review

The aqueous ozonation reactions of surfactants have been reviewed, including the degree of reaction and ozonation byproduct identity. Compounds are classified into three groups: anionic, cationic and non-ionic surfactants. Experimental conditions for each study reviewed are summarized. Much work has been carried out under conditions unlikely to occur during drinking water treatment. Thus, most of the findings of the papers reviewed cannot be directly applied to potable water treatment. However this review can serve to indicate the likely reactivity of the individual surfactants towards ozone and the possible byproducts formed. This reactivity depends mainly upon the chemical structure of the surfactants. The removal of surfactants is pH dependent, with the best results being obtained in alkaline media. High ozone doses usually do not cause complete disruption of the surfactants, while smaller doses are sufficient to enhance their biodegradation.     

Aniline and Anilinium Ion Ozonation in Aqueous Solution

The ozonation of aniline and anilinium ion in aqueous solution is investigated by determining the product distributions at different degrees of ozonation. Results indicate that anilinium ion, although less reactive than aniline, still has a remarkable reactivity towards ozone. The high anilinium ion reactivity and the observed product distributions are explained by assuming a radical mechanism for anilinium ion ozonation, whereas the behavior of aniline appears to be regulated mainly by the electrophilic ozonolysis mechanism.     

硝基苯废水治理技术的研究进展

硝基苯具有高毒性、难降解性及在环境中的积累性,使得硝基苯污染问题越来越受到科学研究者的关注。硝基苯废水的主要处理方法有物理法、化学法和生物降解法,论述了近年来国内外对这3种处理方法的研究进展,并阐述了今后研究的重点和发展方向。