活性炭及其负载活性组分催化臭氧氧化机理

催化臭氧氧化技术是一种有前景的高级氧化技术,经过几十年的发展,该领域研究的热点已由催化剂的活性评价逐渐转为机理研究。文章对活性炭及其负载活性组分催化臭氧氧化的机理进行介绍,指出其存在的问题并展望了今后的研究方向。     

负载型臭氧氧化催化剂研究进展

多相催化臭氧化技术是一种高效的污水净化技术。其中负载型臭氧氧化催化剂因其催化效果好、易分离、重复率用率高等优点而成为研究热点之一。依据不同的载体类型,将负载型臭氧氧化催化剂进行归纳分类,并综述了不同载体的催化剂在催化臭氧氧化水处理中的最新应用。     

活性炭催化剂臭氧催化氧化处理废水的研究进展

介绍了近年来国内外活性炭催化剂臭氧催化氧化的研究结果,对活性炭及金属负载型活性炭催化剂的反应机理进行了总结。讨论了非均相臭氧催化氧化过程中活性炭的主要作用,活性炭催化剂的表面物化性质、pH值、温度在臭氧催化氧化过程中的影响规律。并提出活性炭催化剂的降解机理以及催化剂性质与有机污染物的化学结构之间的关系还需要进一步的研究。     

臭氧催化剂的制备及其应用研究进展

催化臭氧氧化技术在处理难降解有机废水领域具有很大应用前景,催化剂是实现催化臭氧氧化的关键材料。本文综述了近年来在臭氧催化剂的制备及其应用方面的进展。臭氧催化剂主要是以Mn、Fe、Co等过渡金属氧化物为活性组分,负载型催化剂的载体主要有氧化铝、分子筛、活性炭等。与金属氧化物催化剂相比,负载型催化剂和碳质材料催化剂具有较好的催化效果。催化剂应用性能研究大多为实验室单一成分的有机废水,面向实际复杂工业废水研究开发优良的催化剂,并与具有高效臭氧传质性能的反应器相结合,是未来催化臭氧化技术研究开发的趋势。     

负载型稀土臭氧氧化催化剂在水处理中的应用进展

非均相催化臭氧氧化技术是一种高效的水污染控制技术。负载型稀土臭氧氧化催化剂因稀土元素独特的电子构型,展现出优异的催化性能,不仅具有良好的稳定性和较长的使用寿命,还可有效解决催化剂流失及出水金属离子超标问题,被认为是最有前景的非均相臭氧氧化催化剂。本文着重从负载型稀土臭氧氧化催化剂的制备、催化反应机理以及单稀土、稀土-过渡金属、双稀土-过渡金属氧化物负载型臭氧氧化催化剂在近几年的污水处理领域中的应用进展进行概述与总结。多稀土复合型非均相臭氧氧化催化剂的开发,以及对催化氧化过程的作用机理的深入研究,是未来非均相催化臭氧氧化技术在水处理中的重点研究方向。     

金属催化臭氧化应用在水处理中的机理研究进展

概述了金属催化臭氧化应用在水处理中的机理研究,详细介绍了臭氧应用于水处理的历程和臭氧与水中污染物的作用机理,综述了金属催化臭氧化技术,包括以金属离子为催化剂的均相催化臭氧化以及使用固态金属、金属氧化物或负载在载体上的金属或金属氧化物作为催化剂的非均相催化臭氧化技术在水处理中的机理研究进展,指出了金属催化臭氧化的应用前景.     

臭氧氧化技术在水处理中的应用进展

臭氧氧化技术在水处理领域逐渐得到了广泛应用。介绍了臭氧的物理化学性质、单独臭氧氧化技术、催化臭氧氧化技术及其组合工艺技术,总结了各类催化臭氧氧化技术的催化剂和反应机理的研究进展,并展望了臭氧氧化技术在水处理方向的发展前景。     

天然矿物催化氧化水中难降解有机污染物研究进展

催化氧化技术具有氧化性强、矿化效率高等优点,是去除水中难降解有机污染物最有效的处理技术之一,催化剂的应用和研究是关注的热点,天然矿物催化剂储量大、价格低,在使用成本方面具有其他催化剂无可比拟的优势。本文综述了天然矿物催化剂在Fenton法、催化臭氧氧化法、活化过硫酸盐催化氧化法处理水中难降解有机污染物的研究进展和作用机理,分析了其反应条件、处理效果和催化活性位点等,指出含有丰富的金属元素的天然矿物可作为芬顿氧化和过硫酸盐氧化的催化剂,有些天然矿物可作为金属负载载体参与氧化反应,而存在表面羟基等活性位点的天然矿物可催化臭氧氧化和芬顿氧化反应,天然矿物催化剂能明显提高Fenton、臭氧、过硫酸盐氧化难降解有机物（ROCs）的能力,在污水处理方面具有应用前景。以期能够为今后天然矿物催化剂的开发和在水处理高级氧化技术中的应用提供有益参考。     

臭氧氧化技术及其在水处理领域的发展

在环保水处理领域,高级氧化技术在去除生物难降解有机物方面得到了从业人员的广泛关注。臭氧氧化法属于高级氧化技术的一种,已被广泛应用于水处理工艺的各个环节。目前对其的研究主要集中在臭氧催化氧化和臭氧组合其他工艺两个方面。臭氧催化氧化主要有均相催化剂和非均相催化剂两种,而臭氧组合工艺主要是将臭氧作为预处理和深度处理工艺与其他处理方法联用。对臭氧氧化的机理和应用进行研究,必然会给难降解有机废水的处理带来技术变革。     

催化臭氧氧化有机废气处理技术研究进展

气相催化臭氧氧化是一种能够使有机废气在低温下实现催化氧化的高级氧化技术。气相催化臭氧氧化的催化剂载体主要有氧化铝、二氧化硅、二氧化钛、沸石和分子筛SBA-16等,负载的活性组分主要集中在铜、钴、锰和镍等金属氧化物,研究较多的是MnOx/γ-Al₂O₃。综述国内外催化臭氧氧化技术的研究进展,并对催化臭氧氧化有机废气的研究方向进行展望。催化氧化影响因素研究主要集中在活性组分及负载量、反应温度、运行时间、副产物和湿度等。反应机理研究按反应过程拆分为臭氧分解和有机物氧化两部分,研究认为,实现有机物氧化的关键物为催化分解臭氧产生的活性氧或过氧化物物种O^*₂。今后研究需解决的问题有催化剂载体的吸附性能影响、避免催化剂失活的最佳反应温度和完整的气相催化氧化反应机理。     

催化臭氧氧化处理难降解石化废水技术的研究进展

介绍了催化臭氧氧化的主要类别,分述了均相与非均相催化臭氧氧化在难降解石化废水方面的已有应用和催化机理,探讨了非均相催化臭氧氧化中活性炭的主要作用;简述了pH值、温度、臭氧和催化剂投加方式与投加量、催化剂体系等因素在非均相催化臭氧氧化中的影响规律。在已有研究的基础上,提出了将催化臭氧氧化与生化处理相结合的建议并佐证了其可行性;预测了催化臭氧氧化未来的研究方向;针对活性炭在催化臭氧氧化处理难降解石化废水中存在的问题,提出应加强对活性炭的改性研究,同时对某些工艺进行深入研究,全面掌握可能存在的问题,为完善催化臭氧氧化的机理作出努力。     

Effect of Catalytic Ozonation Coupling with Activated Carbon Adsorption on Organic Compounds Removal Treating RO Concentrate from Coal Gasification Wastewater

This paper reports a novel system of catalytic ozonation coupling with activated carbon adsorption for removing the organic compounds treating in the RO concentrate from coal gasification wastewater. The effect of ozone dosage, catalyst dosage, reaction time, influence pH, and temperature on organic compounds removal were examined for the processes. In the catalytic ozonation process, increasing solution pH, dosages ozone, and catalyst were statistically significant for improving the performance. In addition, the high salinity with chloride concentration of 15 g/L could reduce the catalyst specific surface area by 18%. Thus, high salinity showed negative influence on the catalytic effect in TOC removal. Regarding activated carbon adsorption process, modified activated carbon by NaOH revealed advantages in adsorbing organic compounds treating catalytic ozonation effluent. With the ozone dosage of 120 mg/L, catalyst dosage of 2.0 g/L, catalytic ozonation reaction time of 1 h, and modified activated carbon adsorption time of 1 h, the average TOC removal efficiencies were maintained at the stable level of 58% with the TOC concentration of 26 mg/L.     

Urban Wastewater Treatment by Catalytic Ozonation

This study focuses on the catalytic ozonation of organic matter recalcitrant to usual water treatment technologies. Experiments aimed to investigate the efficiency of the process TOCCATA®, which uses a granular catalyst coupled with ozonation. Comparison was made between single ozonation, single adsorption onto the catalyst and catalytic ozonation. Adsorption was proven to contribute to decreased dissolved organic carbon. Catalytic ozonation enhanced organic matter removal and ozone transfer compared to single ozonation. Catalytic ozonation was modeled with global apparent first-order kinetics and single adsorption with pseudo–second-order sorption kinetics.     

活性炭负载Fe~(3+)催化臭氧氧化水中双酚A

采用浸渍法在活性炭上负载铁制备催化剂Fe/AC,用于催化臭氧氧化水中内分泌干扰物双酚A(BPA),研究了Fe/AC/O3体系的协同效应,探讨了Fe/AC投加浓度、臭氧浓度和BPA初始浓度等工艺参数的作用规律,并分析了Fe/AC/O3体系在不同pH值下的催化反应机制。结果表明,在Fe/AC/O3体系下,反应60 min后,BPA和COD的去除率分别为97.44%和69.47%,效果明显优于臭氧体系的70.15%、30.89%和活性炭体系的14.69%、7.53%之和,具有明显的协同作用;Fe/AC/O3体系降解BPA符合一级反应动力学,当Fe/AC的投加浓度为5.0 g/L,臭氧浓度为15.0 mg/L,BPA初始浓度为50.0 mg/L时,Fe/AC/O3体系降解BPA的反应速率常数为0.05972 min-1;其反应机制受溶液pH值的影响,在酸性条件下是吸附和臭氧直接氧化共同作用,而在碱性条件下以·OH间接氧化为主,活性炭上负载的Fe3+促进了·OH的生成,大大提高了BPA的反应效率和矿化率。     

Ozonation of Textile Effluents and Dye Solutions in the Presence of Activated Carbon under Continuous Operation

Abstract

Ozonation was found to be effective for the decolorization of solutions, but has only a slight effect on TOC removal. On the other hand, adsorption on activated carbon improves the TOC removal, but the progressive uptake of the organic contaminants during the adsorption process decreases its removal efficiency. Decolorization, mineralization, and ozone consumption of colored solutions were evaluated under continuous operation in a column by three different processes: ozonation, adsorption on a fixed activated carbon bed, and ozonation in the presence of the activated carbon bed. The introduction of an ozone flow in a fixed activated carbon bed enhances both the decolorization of the solutions and mainly the mineralization of the organic matter, even when the activated carbon was previously partially saturated. Activated carbon acts both as an adsorbent and as a catalyst in the ozonation of colored solutions. The column configuration plays an important role in the performance of this system. The configurations in series and with activated carbon in the upper part of the column showed the highest colour and TOC removal for dye solutions.

The results obtained clearly show that the combination of ozone and activated carbon is a promising technique for the final treatment of colored effluents. Practical applicability of this process was validated by treating two industrial textile effluents, collected after two different biological treatments.     

Degradation of Refractory Organic Pollutants by Catalytic Ozonation—Activated Carbon and Mn-Loaded Activated Carbon as Catalysts

A novel catalyst for the ozonation process was prepared by loading manganese on the granular activated carbon (GAC). Nitrobenzene was used as a model refractory organic micropollutant in this study. The catalytic activity of GAC and the Mn-loaded GAC were studied respectively. The removal efficiency of nitrobenzene by Mn-loaded GAC catalyzed ozonation could reach 34.2–49.9%, with the oxidation efficiency being about 1.5–2.0 times higher than that achieved in GAC catalyzed ozonation and 2.0–3.0 times higher than that achieved by ozonation alone. The effect of pH and the t -butanol on the GAC/ozone process was discussed. The optimum condition for preparing the catalyst was studied.     

微气泡臭氧催化氧化深度处理化工园区废水研究

以酸/碱改性和Cu负载活性炭为催化剂,采用微气泡催化臭氧氧化深度处理化工园区废水。结果表明,经该工艺处理后,出水COD降至20 mg/L以下,发光抑制率降至-1.2%~-7.3%,B/C升至0.29~0.37,消除了废水生物毒性,并提高了废水可生化性。硝酸改性并负载Cu组分活性炭具有更强的催化活性,COD去除率和去除负荷分别可达70.8%和0.478 kg/(m~3·d),臭氧利用率为97.5%,催化臭氧氧化反应效率为0.554 mg COD/mgO_3。     

Gallic acid water ozonation using activated carbon

The ozonation of gallic acid in water in the presence of activated carbon has been studied at pH 5. Hydrogen peroxide, ketomalonic and oxalic acids were identified as by-products. The process involves two main periods of reaction. The first period, up to complete disappearance of gallic acid, during which ozonation rates are slightly improved by the presence of activated carbon. The second one, during which activated carbon plays an important role as promoter, and total mineralization of the organic content of the water is achieved. The organic matter removal is due to the sum of contributions of ozone direct reactions and adsorption during the first period and to a free radical mechanism likely involving surface reactions of ozone and hydrogen peroxide on the carbon surface during the second period. There is a third transition period where by-products concentration reach maximum values and ozonation is likely due to both direct and free radical mechanisms involving ozone and adsorption. Discussion on the mechanism and kinetics of the process is also presented both for single ozonation and activated carbon ozonation.