反应器型式对有机废水光催化氧化特性的影响

采用浆态光催化反应器对苯甲酰胺模拟废水光催化氧化特性进行了研究。探讨了催化剂的用量、污染物的初始浓度、反应时间、空气流量等操作参数对鼓泡式、循环式等形式的浆态光催化反应器内苯甲酰胺模拟废水光催化氧化特性和动力学的影响。结果表明,浆态光催化降解过程中污染物的浓度越低效果越好,催化剂的用量存在适当值;不同操作条件对不同形式浆态光催化反应器内苯甲酰胺模拟污染物光催化降解性能的影响不近相同。在所考察的污染物初始浓度、催化剂量和空气流量范围内,反应器中苯甲酰胺光催化氧化速率均符合拟一级动力学方程。与鼓泡式浆态光催化反应器相比,所开发的循环式浆态光催化反应器在空气作用下能更好地改善催化剂与气体和废水的混合效果,进而提高了光催化剂的利用效率,能更有效降解有机污染物;而且空气利用量小,能够大大降低浆态床光催化氧化处理废水的运行成本。     

Influence parameters in the ozonation of phenol wastewater treatment using bubble column reactor under continuous circulation

The ozonation of phenol wastewater treatment system has been investigated with effective mass transfer between gas and liquid phase in a bubble column reactor. The designed bubble column reactor was investigated for increasing the rate of mass transfer of ozone, the rate of oxidation of phenol in the solution, the solubility and decomposition rate of ozone in the distilled water were also studied at different flow rates. The decomposition rate constants were calculated based on pseudo first order kinetics. The oxidation of phenol was investigated in order to provide the overall reaction rate constant for the reaction between ozone and phenol at 25 °C. The influence of the operating parameters like initial phenol concentration, ozone flow rate and pH for the destruction of phenol by ozonation were studied. The pseudo first order rate constant was depending on the initial concentration of phenol solution. A comparison of TOC removal percentage between bubble column reactor and bubble diffuser using ozonation were reported.     

Design and Modeling of a Staged Downflow Bubble Reactor

A staged downflow bubble column for ozonation of drinking and wastewater was developed. Equations for the calculation of head loss, the mass transfer coefficient, and power dissipation were proposed For mathematical modeling, the stagewise backmixing model was used. The validity of the model was verified by experiments with raw lake water Ozone absorption in a staged downflow bubble column was shown to represent a high capacity process for ozone uptake in water and wastewater treatment.     

高级氧化技术在印染废水处理中应用的探讨

高级氧化技术是近年来备受人们关注的印染废水处理技术,本文分析了印染废水的基本特征,并就高级氧化技术中的超临界水氧化技术、湿式氧化技术、臭氧氧化技术、电化学氧化技术、Fenton氧化技术、超声波处理技术和光催化氧化技术在印染废水中的应用做了阐述,介绍了各技术的基本原理和应用中优缺点,为高级氧化技术在处理印染废水的实际应用提供了理论依据。     

臭氧催化氧化反应器模拟与分析

臭氧催化氧化法是一种高效的污水处理技术,是目前污水高级处理的主要手段之一。传统的建模方法无法研究反应器内污水浓度的时空分布和操作条件对反应器的影响,本研究利用计算流体力学（CFD）,耦合多孔介质流动与传质和化学反应动力学多物理场模型,研究臭氧催化氧化过程中目标污染物浓度随时间和空间的分布情况,计算结果与实验结果有良好的一致性。进一步研究臭氧浓度和流量、循环水流量、催化剂层高度、催化剂颗粒大小等对臭氧催化氧化处理废水效率的影响,评估出最优的实验方案。结果表明,在不改变当前反应器主体结构的情况下,最优的操作条件是：臭氧浓度30～40mg/L,臭氧进口流量40～60mL/min,循环水量200～250mL/min,催化剂层填充高度600～800mm,催化剂颗粒半径大小为2mm。该研究有助于理解、设计和优化污水处理反应器。     

臭氧微气泡处理有机废水的效果与机制

为解决臭氧氧化有机废水氧化效率差、臭氧利用率低这一问题,本文提出了臭氧微气泡处理有机废水的新技术。采用加压溶气法制备的臭氧微气泡处理苯酚配置的模拟废水,通过显微拍摄、动力学分析、紫外-可见吸收光谱、自由基屏蔽等手段对臭氧微气泡的形态大小、氧化效果、传质特性和氧化机制进行了研究,并对臭氧气泡直径和界面压力之间的关系进行了深入探讨。试验与数值计算表明,臭氧微气泡平均粒径为20.37μm,处理初始COD浓度为51.2mg/L的有机废水,COD去除速率分别是使用1μm曝气头和100μm曝气头曝气的1.59倍和3.61倍,臭氧利用率达到99.19%以上,氧化过程是自由基为主的间接氧化过程,污染物最终氧化产物为小分子烃和羧酸。微气泡影响下,臭氧分子传质速率和分解速率均有所提高,而臭氧微气泡表面较高的界面压力是其高效传质的原因之一。     

臭氧深度处理焦化废水尾水及臭氧尾气利用研究

以焦化废水尾水深度处理过程为例,考察不同反应时间和p H条件下臭氧对尾水中残余污染物的去除效果,并进行臭氧氧化焦化废水尾水和臭氧尾气利用研究。结果表明,经臭氧流化床反应器处理2 h后,尾水COD和色度的去除率分别为49.1%和82.6%,挥发酚、氰化物和硫化物的浓度均低于检测限,初始p H=10.33的尾水COD去除效果优于p H=7.18和p H=5.27的尾水,O3消耗量/COD去除量的值随反应时间的延长不断增大;利用臭氧尾气制得的聚合硫酸铁达到了国标要求。     

Investigation of a homogeneous activating ozonation method in the rinsing procedure of cotton fabric dyed with reactive dye

The textile dyeing process requires the consumption of large quantities of water, which includes huge amounts of coloured wastewater. Usually the rinsing of dyed fabric and the treating of the dyeing house wastewater are separated. The two independent processes not only increase the difficulty of wastewater treatment but also increase the costs of the treatment. In this paper, the ozone/tetraacetylethylenediamine active oxidation technology was employed to rinse dyed fabric and to decolorise the rinsing wastewater simultaneously. The effects of the rinsing conditions on the decolorisation ratio and the chemical oxygen demand Cr value of treated wastewater, and the K/S value, colour difference, tensile strength and fastness of dyed samples were investigated. The results indicated that the decolorisation ratio of the rinsing effluent was greater than 80% and the chemical oxygen demand Cr value decreased more than 58% by the ozone/tetraacetylethylenediamine rinsing process compared with that of traditional rinsing processes. Furthermore, the curve of decolorisation kinetics was in good agreement with a pseudo‐first‐order kinetic model. In addition, the decolorisation mechanism was also discussed after ultraviolet–visible and ultra performance liquid chromatograph–mass spectrometry analyses of the degraded dye molecule.     

高级氧化技术处理染料废水的研究进展

由于染料废水中含有高浓度难降解有机污染物,对其有效处理一直是个难题.综述了近几年国内外采用湿式氧化法、Fenton法、光化学与光催化氧化法、电化学法、臭氧氧化法、微波辅助氧化法和超声氧化法等高级氧化技术处理染料废水的进展情况,并指出了高级氧化技术在染料废水处理中的发展趋势.     

纳米TiO2光催化法和UV—Fenton法联合作用的应用研究

文章通过对不同浓度和不回种类羽印染废水进行、处理可知,UV-feton／纳米TiO2催化氧化法为处理染料废水提供了一种可广泛运用的方法。不同浓度的染料废水其降解效率会有不同,但是基本都可适甩。多数染料废水都可以适用于此实验方法。     

Effect of Chemical Reaction and Mass Transfer on Ozonation of the Azo Dyes Reactive Black 5 and Reactive Orange 96

Ozonation of wastewater containing azo dye has been studied to evaluate the enhancement of ozone mass transfer from O₂O₃ gas into water with the presence of chemical reactions in a bubble column reactor. Experiments were performed at different initial dye concentrations and at various gas flow rates. C.I. Reactive Black 5 (RB 5) and C.I. Reactive Orange 96 (RO 96) have been chosen as representative model substances being found in wastewater from textile-finishing wastewater. Results show that the rate of ozone mass transfer increases with increasing initial dye concentration and gas flow rate. Consequently, an enhancement factor E for ozone mass transfer with chemical reaction could be calculated which increases with dye concentration. The chemical reaction between ozone and dye enhanced the mass transfer within the liquid film of the gas liquid boundary. The greatest enhancement factor for wastewater containing RO 96 of 2050 mgL^?1 is E = 15.4 compared with E = 9.1 for RB 5 of 3800 mgL^?1, both for gas flow rates of 19 Lh^?1. For lower gas flow rates, higher enhancement factors were observed, particularly for RO 96.     

催化湿式氧化法处理高浓度吡唑甲醛肟生产废水的研究

在鼓泡式固定床反应器连续反应装置上对吡唑甲醛肟生产过程中产生的高浓度有机废水进行催化湿式氧化处理。实验表明制备的复合负载型催化剂CuO—MnO2-Cr2O3／ZrO2-CeO2在处理该废水时具有较好的催化活性。通过对反应温度、反应压力、反应空速、气液比和进水pH值等工艺条件的考察,得出最佳的工艺条件为：反应温度T=220℃,反应压力P=5．8MPa,空速=1．8h^-1,V（气）：V（水）=260：1,进水pH值=9,在此条件下CODer去除率达到95．2％。     

活性炭负载催化剂臭氧催化氧化处理印染废水研究

以堇青石蜂窝陶瓷、硅藻土、活性氧化铝和活性炭作为载体、金属氧化物(FexOy、CuO、NiO、MnxOy、BaO)作为催化活性组分,对臭氧催化氧化印染废水进行了试验对比,并对影响载铁型活性炭催化剂臭氧催化氧化印染废水的因素进行了研究。结果表明,载铁型的催化剂活性相对较高,当焙烧温度为750℃时,催化性能最好。利用载铁型活性炭催化剂,在臭氧质量浓度为10mg/L、pH值为6、反应时间为60min的条件下,催化氧化具有最佳的效果,COD去除率达86%;催化剂的重复利用性好,连续使用12次,COD的去除率仍可达64%。     

牛仔服洗水与浆染废水混合处理小试研究

佛山市某印染污水厂拟进行工艺改造。废水处理主体工艺计划采用"调节+混凝+水解酸化+接触氧化"组合工艺处理高浓度印染废水及洗水,并提出两个组合方案。通过分析8个不同进水(不同比例的印染废水和洗水混合)的模拟系统运行的效果得到:各处理系统的出水达标,酸化池、氧化池的HRT最佳值为10 h。氧化池处理效率随HRT的变化和酸化池类似。系统的处理效果在一定的有机负荷范围内随浆染废水比例增大而增强,单独处理水洗废水效果最差,最佳比例为1:1。说明系统能够承受较大的印染废水冲击。牛仔布漂洗废水及其他印染废水混合进行集中处理具有较高的可行性。     

Intensification of nitrous acid oxidation

An alternative solution to the reduction of a discharge of residual nitric oxide and nitrogen dioxide into atmosphere has been proposed. Instead of using methane or ammonia for SCR or gas absorption into alkali solutions, which are the most popular treatment methods of tail gases, now the use of powerful oxidant—ozone capable of transforming nitrous acid and nitric oxides into nitrogen of the highest oxidation level—could be employed for this purpose. As the intensive oxidation and ozonation of nitrous acid is the heterogeneous gas-liquid process, the solubility of oxygen and ozone in HNO₂/HNO₃ aqueous solution was necessary to be determined. Variations of reaction rates depending on temperature, ozone dose and nitrous and nitric acid concentrations were studied experimentally. The kinetic model of the reactions, 2HNO₂+O₂→2HNO₃ and HNO₂+O₃→O₂+HNO₃, were proposed and the kinetic parameters (rate constants and activation energies) were estimated on the basis of experimental data in semi-batch laboratory gas-liquid contactor with the liquid phase drawn from an absorption column in the nitric acid plant. The determined kinetic parameters were then used in designing and modeling of the oxidation of nitrous acid using ozone-oxygen mixture in a continuous bubble column. The model consists of mass transfer kinetic equations and material balance equations for the gas and liquid phases. The co-current flow of gas and liquid phases and the complex kinetics of chemical reaction in the liquid phase were taken into account. The variation of the following process conditions, flow rate, compositions of the gas and liquid phases, temperature, and pressure in the bubble column of different diameters and heights, were studied in numerical solutions of the proposed model.     

Fenton试剂氧化降解结晶紫的动力学研究

探讨了Fenton试剂在光照条件下对结晶紫模拟印染废水进行氧化处理的动力学规律,讨论了H2O2初始浓度、FeSO4初始浓度、反应温度及草酸的络合作用对结晶紫氧化降解的影响,确定了最佳降解条件,建立了Fenton试剂氧化降解结晶紫的动力学方程,为光照条件下利用Fenton试剂处理含结晶紫类的印染废水提供了依据.     

臭氧氧化深度处理煤化工废水的应用研究

臭氧氧化作为一种有效的深度处理技术,对有机废水具有良好的降解功效。介绍了臭氧的性质及氧化机理,分析了臭氧氧化法在处理纺织印染废水、造纸废水、垃圾渗滤液、炼油废水、焦化废水等难降解有机废水中的应用,指出了臭氧氧化存在的问题,并提出建议。     

臭氧催化氧化深度处理印染废水的效能与成本

印染废水经常规处理后,出水按照臭氧催化氧化和空塔氧化两种深度处理技术路线进行处理,以此对这两种印染废水深度处理技术进行效能和成本的评估与分析。结果表明两者均可使脱色达到排放标准。在投加臭氧催化剂的情况下,臭氧投加量为30ppm,其出水效果与空塔在臭氧投加量为40ppm时相当,节省了臭氧的消耗量,运行成本从0.45元／m^3下降到0．33元／m^3。每年可节省运行费用约105万元,增加臭氧催化剂的投资收回期小于2年。     

臭氧氧化活性染料及其降解产物毒性研究

在印染废水中,染料成分复杂、高浓度、高色度、难生物降解物质多,用常规的生物处理方法难以有效治理。高级氧化技术(AdvancedOxidationProcesses,简称AOPs)作为一种有效的废水处理手段,引起了越来越多的关注。以活性染料活性艳红KE-3B为对象,模拟印染废水的实际情况对染料进行臭氧氧化研究,探讨了该过程的动力学影响因素。研究发现在pH=10时,脱色速度快;随着臭氧投加量的增加,色度去除率也相应增加;Na2CO3作为自由基清除剂在一定程度上抑制了臭氧氧化,而NaCl对臭氧氧化的影响则较小;对比了组合工艺UV/O3/H2O2应用于活性染料的处理效果,发现UV/O3反应体系中加入少量的H2O2能够使脱色率增加。利用海洋性发光菌VibrioFischeri对臭氧氧化后的溶液进行了生物毒性监测与评价,结果显示,在氧化过程中溶液毒性明显升高;随氧化程度的进一步加深,毒性又趋于下降。     

Experimental study on the ozone absorption accompanied by instantaneous chemical reaction

This work deals with gas absorption accompanied by chemical reaction in a liquid phase. Ozone absorption in potassium indigotrisulfonate solution was investigated in a batch bubble column. Enhancement factor for absorption accompanied by instantaneous chemical reaction in the liquid phase was experimentally determined, as a ratio of the volumetric mass transfer coefficient for the absorption accompanied by reaction to that for pure physical absorption. The influence of (a) the initial concentration of the solute from liquid phase and (b) the ozone concentration in gas phase on the enhancement factor were experimentally examined. The absorption accompanied by instantaneous chemical reaction is a diffusion-controlled process, whose rate depends upon the diffusivities of the absorbing gas and the solute in liquid phase. The influence of these diffusivities was found to be more significant for lower values of the enhancement factor. The rate of ozone absorption was followed by the time change of the solution color, using new method based on the computer program SigmaScan Pro 5 (Systat Software, Inc., San Jose, CA, USA). This investigation is a contribution to the prediction of the ozone consumption in wastewater treatment, in cases when ozone instantaneously reacts with substances present in water.