磁化学技术在水处理中的应用

对近年来磁化学技术在水处理中的应用做了比较全面的综述。介绍了磁化学技术的发展、磁分离技术的原理和分类及磁种强化处理废水，并对磁化学技术的应用领域进行了详细讨论。     

磁化学技术在水处理中的应用

对近年来磁化学技术在水处理中的应用做了比较全面的综述。介绍了磁化学技术的发展、磁分离技术的原理和分类及磁种强化处理废水 ,并对磁化学技术的应用领域进行了详细讨论。     

微量臭氧催化氧化深度处理煤气化废水

采取固定床连续式水处理方式,实验研究了在固体催化剂作用下微量臭氧催化氧化深度处理地下煤气化废水的效果.结果表明,当处理COD为300 mg,/L左右的该类型废水时,加入微量臭氧,水处理装置COD去除率提高了45％,平均1 mg的臭氧处理了2.4 mg有机物;当废水COD为200 mg/L左右,进水速度为1 L/h时,最佳臭氧投加量为每升废水20 mg左右的臭氧,此时气水比为15:1左右;同时实验发现,不同COD的废水色度均可以被有效去除.通过与其他类似的实验研究比较发现,微量臭氧催化氧化技术具有成本优势.     

臭氧水处理技术的进展

臭氧氧化技术是高级氧化技术的一种，在水处理中已有百年的历史。近年来由于对微污染物和难降解有机废水的关注，臭氧处理技术有了新的发展。本文总结了臭氧的应用和三种臭氧氧化技术，指出了臭氧技术发展的方向。     

水产养殖废水处理技术及应用

主要综述了国内外水产养殖废水的物理化学处理和生物处理2方面的技术，并总结了水产养殖废水循环使用的水处理工艺流程和生物工程在水产养殖废水处理中的应用，表明了水产养殖废水的综合利用和无害化排放技术为今后发展方向。     

电催化臭氧氧化技术深度净化纳滤膜浓水

纳滤膜浓水高效无害化处置是膜法污水深度处理值得关注的问题,传统臭氧氧化技术对膜浓水处置存在处理效率较低、氧化能力有限等问题。针对实际再生水深度净化工艺,构建并评估了电催化臭氧氧化技术对纳滤膜浓水净化效果。电催化臭氧氧化处理180 min可以去除膜浓水中72%的COD和71%的TOC,其一级反应速率常数是单独电催化氧化的14倍、单独臭氧氧化的1.5倍。进一步利用斜生栅藻生长抑制率指标评价了3种氧化过程对膜浓水处理时的毒性削减效果,单独臭氧氧化对膜浓水处理后的斜生栅藻生长抑制率达24.6%,而电催化臭氧氧化深度处理后斜生栅藻生长抑制率仅16.0%,电催化臭氧氧化技术处理后膜浓水的残存生物毒性显著降低。     

臭氧/ 生物活性炭深度处理循环养殖废水

随着工厂化循环水养殖的不断发展,高浓度循环养殖废水对环境污染日益严重.为实现环境友好和资源节约,采用臭氧/生物活性炭对循环养殖废水进行深度处理中试研究.实验结果表明,臭氧化臭氧最佳投加量为4 mg/L,显著增强水体的可生化性,使TOC(总有机碳)/UV254(在波长为254 nm处的单位比色皿光程下的紫外吸光度)提高80%.臭氧/生物活性炭对循环养殖废水中的有机物和氨氮具有良好的去除效果.臭氧/生物活性炭对TOC、高锰酸盐指数和UV254的最终去除率比生物活性炭分别高11.9%、13.4%和6.5%.臭氧/生物活性炭和生物活性炭对氨氮的最终去除率分别为96.0%、90.7%.     

磁化处理对活性污泥胶体颗粒表面的zeta电位的影响

污水处理过程中,二沉池的泥水分离影响整套工艺的效果,用投加混凝剂来降低活性污泥胶体颗粒表面的zeta电位(以下简写活性污泥zeta电位),增加了运行成本.通过磁场磁化可以降低活性污泥zeta电位,达到节省药剂的目的.研究了磁感应强度、磁化时间、磁场位型以及搅拌速率对氧化沟活性污泥zeta电位的影响规律.研究表明,磁化处理能降低活性污泥zeta电位,在磁场中心磁感应强度为0.40 T左右及反应器与磁场平行静置磁化时,zeta电位降低幅度最大,平均在46.5%～51.4%.     

臭氧技术及其在水处理中的应用

近年来，由于氯消毒副产物，微污染物，难降解或有毒有机废水的治理缺乏有效的方法，以及臭氧发生设备性能的提高，臭氧技术已在饮用水和废水处理中重新受到关注且得到了新发展。臭氧技术已由最初经碱催化的直接氧化发展发展形成催化，多相催化氧化；在水处理方面，由原来的单独使用发展形成与其它方法联合作用，臭氧处理单元自身也有很大的发展。     

国外污泥处理技术进展

简要介绍了国外污泥处理技术的一些新进展,包括超声处理,臭氧处理,蚯蚓处理,污泥制油,涡流熔炉技术,污泥的资源化再生利用是一个重要的发展方向。     

炼油厂含油冷却水处理回用技术研究

开展了O3 氧化和强碱性阴离子交换组合工艺用于炼油厂含油冷却水回用处理的实验研究。结果表明 ,O3 氧化过程中的最佳pH值约为 10 .5 ,O3 氧化的除油效率为 86 .7% (紫外法测定 ) ,去除 1mg石油类约需消耗 5 .7mgO3 ,O3 氧化后产物以乙酸和丙酸等挥发性脂肪酸为主。离子交换处理后油的含量达到未检出的水平。研究结果表明 ,O3 氧化和离子交换组合处理技术能使炼油厂含油冷却水达到回用水水质标准。     

Kinetics of simazine advanced oxidation in water

Comparison of the effects and kinetics of UV photolysis and four advanced oxidation systems (ozone, ozone/hydrogen peroxide, ozone/UV radiation and UV radiation/hydrogen peroxide) for the removal of simazine from water has been investigated. At the conditions applied, the order of reactivity was ozone < ozone/hydrogen peroxide < UV radiation < ozone/UV radiation and UV radiation/hydrogen peroxide. Rate constants of the reactions between ozone and simazine and hydroxyl radical and simazine were found to be 8.7 M-1s-1 and 2.1 x 10(9) M-1s-1, respectively. Also, a quantum yield of 0.06 mol.photon-1 was found for simazine at 254 nm UV radiation. The high value of the quantum yield corroborated the importance of the direct photolysis process. Percentage contributions of direct reaction with ozone, reaction with hydroxyl radicals and direct photolysis were also quantified.     

Oxidation of artificial sweetener sucralose by advanced oxidation processes: a review

Sucralose, a chlorinated carbohydrate, has shown its increased use as an artificial sweetener and persistently exists in wastewater treatment plant effluents and aquatic environment. This paper aims to review possible degradation of sucralose and related carbohydrates by biological, electrochemical, chemical, and advanced oxidation processes. Biodegradation of sucralose in waterworks did not occur significantly. Electrochemical oxidation of carbohydrates may be applied to seek degradation of sucralose. The kinetics of the oxidation of sucralose and the related carbohydrates by different oxidative species is compared. Free chlorine, ozone, and ferrate did not show any potential to degrade sucralose in water. Advanced oxidation processes, generating highly strong oxidizing agent hydroxyl radicals (^?OH), have demonstrated effectiveness in transforming sucralose in water. The mechanism of oxidation of sucralose by ^?OH is briefly discussed.     

Sensitivity of urban ozone formation to chlorine emission estimates

Recent evidence has demonstrated that chlorine radical chemistry can enhance tropospheric volatile organic compound oxidation and has the potential to enhance ozone formation in urban areas. In order to investigate the regional impacts of chlorine chemistry in southeastern Texas, preliminary estimates of atmospheric releases of atomic chlorine precursors from industrial point sources, cooling towers, water and wastewater treatment, swimming pools, tap water, reactions of chlorides in sea salt aerosols, and reactions of chlorinated organics were developed. To assess the potential implications of these estimated emissions on urban ozone formation, a series of photochemical modeling studies was conducted to examine the spatial and temporal sensitivity of ozone and a unique marker species for chlorine chemistry, 1-Chloro-3-methyl-3-butene-2-one (CMBO), to molecular chlorine emissions estimates. Based on current estimates of molecular chlorine emissions in southeastern Texas, chlorine chemistry has the potential to enhance ozone mixing ratios by up to 11–16 ppbv. Impacts varied temporally, with emissions from cooling towers primarily responsible for a morning enhancement in ozone mixing ratios and emissions from residential swimming pools for an afternoon enhancement. Maximum enhancement in CMBO mixing ratios ranged from 59 to 69 pptv.     

铝合金极板表面涂覆Mn催化剂及其对臭氧的分解

静电式空气净化器工作时会产生臭氧,因此,可通过在极板表面涂覆臭氧分解催化剂以实现对臭氧的原位分解。研究了6061型铝合金极板表面涂覆Mn基催化剂时,活性组分、粘结剂、反应时间和环境条件等因素对催化分解臭氧性能的影响。结果表明：在实际应用相适应的条件下,臭氧可实现原位高效分解;催化剂构成是影响臭氧分解的关键因素,Ag修饰可使MnO₂催化分解臭氧效率提高约50%,但粘结剂的存在会导致催化分解臭氧效率下降;臭氧分解效率随入口臭氧浓度升高或空气湿度增大略有下降。本研究结果可为静电式空气净化器同时实现除尘提效与臭氧控制提供参考。     

Kinetics of simazine advanced oxidation in water

Abstract

Comparison of the effects and kinetics of UV photolysis and four advanced oxidation systems (ozone, ozone/hydrogen peroxide, ozone/UV radiation and UV radiation/hydrogen peroxide) for the removal of simazine from water has been investigated. At the conditions applied, the order of reactivity was ozone < ozone/hydrogen peroxide < UV radiation < ozone/UV radiation and UV radiation/hydrogen peroxide. Rate constants of the reactions between ozone and simazine and hydroxyl radical and simazine were found to be 8.7 M^‐1s^‐1 and 2.1x10⁹ M^‐1s^‐1, respectively. Also, a quantum yield of 0.06 mol.photon^‐1 was found for simazine at 254 nm UV radiation. The high value of the quantum yield corroborated the importance of the direct photolysis process. Percentage contributions of direct reaction with ozone, reaction with hydroxyl radicals and direct photolysis were also quantified.     

Application of ozone for the removal of bisphenol A from water and wastewater – A review

The extensive use of Bisphenol A (BPA) in the plastics industry has led to increasing reports of its presence in the aquatic environment, with concentrations of ng L^?1 to μg L^?1. Various advanced oxidation processes, including ozonation, have been shown to effectively degrade BPA. This paper reviews the current advancements in using ozone to remove BPA from water and wastewater.Most of the published work on the oxidation of BPA by ozone has focused on the efficiency of BPA removal in terms of the disappearance of BPA, and the effect of various operational parameters such as ozone feed rate, contact time and pH; some information is available on the estrogenic activity of the treated water. Due to increasing operational reliability and cost effectiveness, there is great potential for industrial scale application of ozone for the treatment of BPA. However, there is a significant lack of information on the formation of oxidation by-products and their toxicities, particularly in more complex matrices such as wastewater, and further investigation is needed for a better understanding of the environmental fate of BPA.     

An advanced integral model for cooling tower plume dispersion

An advanced integral model is developed for predicting cooling tower plume rise from single natural draft cooling towers. The theoretical formulation of the model is aimed at avoiding many of the pitfalls and unnecessary assumptions of existing models. The model is based on a careful integration of the three-dimensional partial differential equations of conservation across the plume cross-section; radial profiles of temperature, velocity, and total water are assumed to be Gaussian in shape. The model includes a treatment of plume thermodynamics and tower downwash effects. The model has been calibrated with a wide range of laboratory data. Verification of the model with single-tower field data from Chalk Point, Paradise, Lünen, Gardanne and Philippsburg reveals good results.     

Degradation of PCDD, PCDF, PAH, PCB and chlorinated phenols during the destruction-treatment of landfill seepage water in laboratory model reactor (UV, Ozone, and UV/Ozone)

Seepage water of toxic waste landfills is polluted with high concentrations of toxic organic compounds. The concentrations in the seepage water we applied for chlorinated phenols are between 2 μg/1 and 1 mg/l, for PCB between 800 pg/l and 250 ng/l, for PAH between 200 ng/l and 12 μg/l and for PCDD and PCDF between 20 pg/l and 1 ng/l. Usual purification methods produce highly contaminated residues, which have to be treated by pyrolysis or are deposited again at a landfill. A better way is to destruct these contaminants by UV/ozone treatment. The treatment of seepage water by UV-irradiation, ozone and UV/ozone is compared. Results show no significant effect during all treatments for PCB and PCDD/PCDF. The chlorinated phenols and PAH were mostly destroyed by UV/ozone treatment more than 90 %. The pH value has no influence on the UV/ozone treatment of seepage water.