用城市污水处理厂剩余污泥制备脱硝催化剂

以城市污水处理厂剩余污泥为原料,采用氧化锌和硝酸铁化学浸渍、高温热解制备脱除NOx的催化剂。用微型气固相催化反血装置考察了该催化剂在NH3选择性催化还原NO中的应用效果及寿命。实验结果表明：存350～450℃时的催化活性较高,在400℃时NO的最大转化率可达98．3％;催化剂的活性良好,经660min的活性测试,催化剂的活性只降低了约3％。对该催化刹进行了X射线衍射、热重和扫描电镜分析,分析结果表明,该催化剂含有丰富的金属元素及碳元袤,具有丰富的孔结构和晶体结构,而且表面及孔隙间负载的活性粒子较多,这些特征也表叫该催化刺具订良好的催化忡能。     

层柱粘土催化剂在SCR烟气脱硝中的应用

电站锅炉排放的氮氧化物（NOx）是大气污染的主要来源之一,对人类的健康构成了极大的威胁。在我国燃煤电站中,大多采用低NOx燃烧技术,而脱硝效率较高的选择性催化还原（SCR）技术则应用较少。随着我国NOx排放标准的日益严格,SCR技术将会在我国获得较大的发展。在SCR技术的应用过程中,催化剂的制备生产是其中最重要的组成部分,其催化性能直接影响到SCR系统的整体脱硝效果。层柱粘土（Pillared Interlayer Clays,PILC）催化剂,是近年来国际上正在大力研究开发的一种新型催化材料,具备非常优异的催化性能。我国拥有丰富的膨润土资源,它是制备层柱粘土的主要原料。研究层柱粘土催化剂对于我国的环保产业及非金属矿业的发展具有重要意义。     

Electroreductive dechlorination of chlorophenols with Pd catalyst supported on solid electrode

Electroreductive dechlorination of chlorophenols with Pd catalyst supported on solidelectrode was studied. As solid electrodes, carbon cloth (CC), carbon felt (CF) and titanium mesh were used, and palladium was plated on solid electrodes by either electrolytic or electroless method. On each electrode with Pd, chlorophenols were qualitatively dechlorinated to phenol, while they were entirely intact on electrodes without Pd. Moreover, neither base electrode nor plating method significantly affected the activity of Pd as far as it was sufficiently loaded on the electrode. Based on the results in the experiments using one electrode repeatedly, Pd catalyst proved to possess a satisfactory duarability under the present condition. It was suggested that the reactive species responsinble for the dechlorination of chlorophenols could be formed during preliminary electrolysis. Thus, (Pd)_x-H resulting from the adsorption of electrogenerated hydrogen on metallic Pd might be assumed most probable.     

燃煤发电厂SCR脱硝技术原理及催化剂的选择

阐述了SCR反应的基本原理,SCR高含尘布置系统主要构成以及选择催化剂应注意的要素。     

H2O2预氧化对负载铁制备污泥炭基催化剂效能的影响

以城市污水厂二沉池污泥为原料,考察了不同H_2O_2投加量下污泥预氧化对铁负载污泥形成前驱体及其热解后制得炭基催化剂性能的影响,研究了污泥预氧化对强化铁负载制备均一分散型污泥炭基催化剂的机理.结果表明,污泥预氧化促进了污泥细胞破解,降低了絮体颗粒粒径和表面Zeta电位,使铁负载量增加、铁活性位点在污泥载体上的分散性明显增强,形成炭基催化剂保持着高催化活性,其稳定性显著增加.对模拟含铬黑T染料废水的多相芬顿降解试验说明,当污泥预氧化H_2O_2投加量为2.25%时制备的炭基催化剂,其反应120 min后铬黑T的降解率为91%,略低于未预氧化时污泥炭基催化剂的降解效率(96%);但未预氧化炭基催化剂其反应后溶液中铁离子的溶出量(18.9%)远高于预氧化后形成的催化剂(2.5%),且后者循环3次对铬黑T的降解率仍可达到86%,表现出较强的稳定性.     

低温等离子体氧化甲烷的实验研究

采用电容耦合等离子体对干空气中的甲烷进行氧化实验,对甲烷的分解效率、反应产物进行了分析。并且和放置催化剂时进行对比,结果表明放置催化剂后,甲烷的分解效率明显提高,反应产物中CO2 的选择性增加。甲烷的最终氧化产物都为CO、CO2 和H2 O。     

贫燃条件Ag-Rh/CeO_2-ZrO_2-Al_2O_3协同催化C_3H_6选择性还原NO的原位红外研究

将Ag-Rh浸渍到共沉淀法合成的Ce-Zr-Al上,制备出Ag(0.04)-Rh(x)/Ce0.5Zr0.5O2-75%Al2O3系列催化剂,采用BET比表面积、X射线衍射光谱(XRD)和原位漫反射傅里叶变换红外光谱(DRIFTS)对催化剂进行表征,并探讨催化剂在贫燃条件下选择性还原NO的活性和反应机理.结果表明,Ag-Rh双组分催化剂的活性较单组分Ag、Rh催化剂的高.Rh负载量为0.7%(质量分数)时,NO转化率达最佳(90.3%),且反应的起燃温度低、活性温度范围宽(300～500℃).DRIFTS结果显示,Rh的添加不仅有利于催化剂表面NO的吸附,而且能促进Ag催化生成关键反应中间体—CO—NH—,进而显著提高NO的转化率.     

半导体光催化氧化有机物的研究现状及发展趋势

就半导体光催化氧化法的机理,光催化对有机物的氧化能力,提高光催化剂催化活性的途径及固定相光催化的进展等几面进行了较为全面的概述,并提出了光催化氧化法今后的研究方向。可以预见,光催化氧化将会成为新型有效的水处理手段。     

A review on sustainable reuse applications of Fenton sludge during wastewater treatment

• The sustainable approaches related to Fenton sludge reuse systems are summarized. • Degradation mechanism of Fenton sludge heterogeneous catalyst is deeply discussed. • The efficient utilization directions of Fenton sludge are proposed. The classical Fenton oxidation process (CFOP) is a versatile and effective application that is generally applied for recalcitrant pollutant removal. However, excess iron sludge production largely restricts its widespread application. Fenton sludge is a hazardous solid waste, which is a complex heterogeneous mixture with Fe(OH)₃, organic matter, heavy metals, microorganisms, sediment impurities, and moisture. Although studies have aimed to utilize specific Fenton sludge resources based on their iron-rich characteristics, few reports have fully reviewed the utilization of Fenton sludge. As such, this review details current sustainable Fenton sludge reuse systems that are applied during wastewater treatment. Specifically, coagulant preparation, the reuse of Fenton sludge as an iron source in the Fenton process and as a synthetic heterogeneous catalyst/adsorbent, as well as the application of the Fenton sludge reuse system as a heterogeneous catalyst for resource utilization. This is the first review article to comprehensively summarize the utilization of Fenton sludge. In addition, this review suggests future research ideas to enhance the cost-effectiveness, environmental sustainability, and large-scale feasibility of Fenton sludge applications.     

单原子环境催化研究进展

单原子催化剂不仅实现了对金属原子最大化利用,而且具有较高催化活性和选择性,还是理想的催化理论研究位点,近年来引起了广泛关注。环境催化在环境保护和污染修复中扮演着重要的角色。单原子催化剂在环境催化领域越来越受关注并有望应用于解决环境问题。单原子催化剂研究的重点和难点集中在单原子催化剂可控合成和催化位点分析表征。为推进单原子催化剂在环境催化领域中的应用,本文综述了单原子的主要制备方法和常规表征手段以及单原子催化剂在环境催化中应用的典型案例,并对单原子催化剂在环境催化中的应用将面临的挑战进行了展望。