UV-Based Advanced Oxidation Processes for Antibiotic Resistance Control: Efficiency, Influencing Factors, and Energy Consumption

Antibiotic resistant bacteria(ARB)with antibiotic resistance genes(ARGs)can reduce or eliminate the effectiveness of antibiotics and thus threaten human health.The United Nations Environment Programme considers antibiotic resistance the first of six emerging issues of concern.Advanced oxidation processes(AOPs)that combine ultraviolet(UV)irradiation and chemical oxidation(primarily chlorine,hydrogen peroxide,and persulfate)have attracted increasing interest as advanced water and wastewater treatment technologies.These integrated technologies have been reported to significantly elevate the efficiencies of ARB inactivation and ARG degradation compared with direct UV irradiation or chemical oxidation alone due to the generation of multiple reactive species.In this study,the performance and underlying mechanisms of UV/chlorine,UV/hydrogen peroxide,and UV/persulfate processes for controlling ARB and ARGs were reviewed based on recent studies.Factors affecting the process-specific efficiency in controlling ARB and ARGs were discussed,including biotic factors,oxidant dose,UV fluence,pH,and water matrix properties.In addition,the cost-effectiveness of the UV-based AOPs was evaluated using the concept of electrical energy per order.The UV/chlorine process exhibited a higher efficiency with lower energy consumption than other UV-based AOPs in the wastewater matrix,indicating its potential for ARB inactivation and ARG degradation in wastewater treatment.Further studies are required to address the trade-off between toxic byproduct formation and the energy efficiency of the UV/chlorine process in real wastewater to facilitate its optimization and application in the control of ARB and ARGs.

Recent advances on decomplexation mechanisms of heavy metal complexes in persulfate-based advanced oxidation processes

In some industrial wastewater,heavy metals combine with organic complexing agents to form heavy metal complexes(HMCs).These HMCs can be difficult to decompose and remove through conventional techniques due to their higher stability than free heavy metal ions.In recent years,persulfate based advanced oxidation processes(PS-based AOPs)have been recognized as a viable technique for HMCs degradation.Nevertheless,a comprehensive and in-depth understanding of the relevant HMCs decomplexation mechanisms in PS-based AOPs is still lacking.This review delineates the current progress of HMCs decomplexation in PS-based AOPs.We discuss the distinctions between the two widely used oxidant types in PS-based AOPs techniques.Moreover,we summarize and highlight the decomplexation mechanisms based on electron and energy transfer,and degradation pathways of HMCs.We also emphasize the effects of environmental water constituents,namely p H,inorganic ions,and natural organic matter(NOM),on HMCs decomplexation.Ultimately,we identify the existing challenges and perspectives that will steer the direction of advancing PS-based AOPs to remove HMCs.

Recent advances in persulfate-based advanced oxidation processes for organic wastewater treatment

In recent years,with the emergence of new pollutants,the effective treatment of wastewater has become very important.Persulfate-based advanced oxidation processes have been successfully applied to the treatment of wastewater,such as wastewater containing antibiotics,pharmaceuticals and personal care products,dyes,endocrine-disrupting chemicals,chlorinated organic pollutants,and phenolics,for the degradation of refractory organic contaminants.This paper summarizes the production of sulfate radicals,which can be generated by the activation of persulfate via conventional and emerging approaches.The existing problems of persulfate-based advanced oxidation processes were analyzed in detail,including residual sulfates,coexisting factors(coexisting inorganic anions and natural organic matter),and energy consumption.This paper proposes corresponding possible solutions to the problems mentioned above,and this paper could provide a reference for the application of persulfate-based advanced oxidation processes in actual wastewater treatment.

Oxidative treatment of aqueous monochlorobenzene with thermally-activated persulfate

The oxidation of aqueous monochlorobenzene （MCB） solutions using thermally- activated persulfate has been investigated. The influence of reaction temperature on the kinetics of MCB oxidation was examined, and the Arrenhius Equation rate constants at 20℃, 30℃, 40℃, 50℃, and 60℃ for MCB oxidation performance were calculated as 0, 0.001, 0.002, 0.015, 0.057 min-1, which indicates that elevated temperature accelerated the rate. The most efficient molar ratio ofpersulfate/MCB for MCB oxidation was determined to be 200 to 1 and an increase in the rate constants suggests that the oxidation process proceeded more rapidly with increasing persulfate/MCB molar ratios. In addition, the reactivity of persulfate in contaminated water is partly influenced by the presence of background ions such as CI-, HCO3, SO2 , and NO3. Importantly, a scavenging effect in rate constant was observed for both C1 and CO2- but not for other ions. The effective thermally activated persulfate oxidation of MCB in groundwater from a real contaminated site was achieved using both elevated reaction temperature and increased persulfate/MCB molar ratio.

Surfactant-assisted removal of 2,4-dichlorophenol from soil by zero-valent Fe/Cu activated persulfate

The organic compounds contaminated soil substantially threatens the growth of plants and food safety.In this study,we synthesis zero-valent bimetallic Fe/Cu catalysts for the degradation of 2,4-dichlorophenol(DCP)in soils with persulfate(PS)in combination of organic surfactants and exploring the main environmental impact factors.The kinetic experiments show that the 5%(mass)dosage of Fe/Cu exhibits a higher degradation efficiency(86%)of DCP in soils,and the degradation efficiency of DCP increases with the increase of the initial PS concentration.Acidic conditions are favorable for the DCP degradation in soils.More importantly,the addition of Tween-80,and Triton-100 can obviously desorb DCP from the soil surface,which enhances the degradation efficiency of DCP in soils by Fe/Cu and PS reaction system.Furthermore,the Quenching experiments demonstrate that SO_(4)^(-1)·and·OH are the predominant radicals for the degradation of DCP during the Fe/Cu and PS reaction system as well as non-radical also exist.The findings of this work provide an effective method for remediating DCP from soils.

Fabrication of pollution-free coal gangue-based catalytic material utilizing ferrous chloride as activator for efficient peroxymonosulfate activation

Novel coal gangue-based persulfate catalyst(CG-FeCl_(2))was successfully synthesized by the means of calcinating under nitrogen atmosphere with the addition of ferrous chloride tetrahydrate(FeCl_(2)·_(4)H_(2)O).The phase transformation of the prepared materials and gas products during the heating process are thoroughly investigated.It is suggested that ferrous chloride participated in the phase transformation and formed Si-O-Fe bonds.And the main gaseous products are H_(2)O,H_(2),and HCl during the heating process.Besides,the ability of CG-FeCl_(2) to activate peroxymonosulfate(PMS)for catalytic degradation of polycyclic aromatic hydrocarbons(PAHs)and phenol was deeply studied.More than 95%of naphthyl,phenanthrene and phenol were removed under optimizied conditions.In addition,1O_(2),·OH,and SO_(4)·−were involved in the CG-FeCl_(2)/PMS system from the free radical scavenging experiment,where 1O_(2) played a major role during the oxidation process.Furthermore,CG-FeCl_(2)/PMS system exhibited superior stability in a relatively wide pH range and the presence of common anion from related degradation experiments.Overall,the novel CG-FeCl_(2) is an efficient and environmentally friendly catalyst,displaying potential application prospect in the field of PAHs and phenol-contaminated wastewater treatment.

单原子催化剂在过硫酸盐氧化体系中的研究进展

近年来,大量研究表明过硫酸盐高级氧化技术(PS-AOPs)是处理污水中难生物降解有机污染物的有效策略.寻求高活性、高稳定性、低成本的催化剂是实现过硫酸盐高效活化降解新污染物的关键.相比于传统金属纳米颗粒催化剂,单原子催化剂(SAC)在PS-AOPs中表现出超快的反应速率、较低的金属负载量以及强金属与载体相互作用等优点.更重要的是,SAC具有原子级分布的活性中心,以便于从原子甚至电子层次下研究非均相催化体系中的构效关系和多种反应机制.然而,目前SAC在PS-AOPs中的研究尚处于起步阶段.本文重点综述了SAC活化过硫酸盐产生氧化活性物质的驱动机制,对结构调控与催化性能的相关性进行了系统总结,深入了解结构-性能关系,指出了精确调整催化剂活性位点的策略,并对相关研究领域未来的机遇和挑战提出了展望.

过硫酸盐高级氧化工艺降解水中嗅味物质的研究进展

近年来,由嗅味物质引发的水污染事件频发,高效去除水中嗅味物质已成为水处理行业面临的挑战之一。高级氧化工艺以其反应速率快和处理效果好,被广泛用于治理含嗅味物质的水体。文章首先阐述了水中嗅味物质的来源及特点,其后根据氧化降解水中嗅味物质过程中起主导作用的自由基种类,介绍了传统高级氧化和基于过硫酸盐的高级氧化工艺的优缺点,重点分析了基于不同活化方式的过硫酸盐高级氧化工艺的研究动态,并探讨了水中嗅味物质的降解特性和机理。最后对过硫酸盐高级氧化工艺去除嗅味物质的未来发展进行了总结和展望,以期为水中嗅味物质的深度处理提供一定的理论基础与技术参考。

碳质材料活化过硫酸盐去除水中微污染物的研究进展

过硫酸盐高级氧化体系(SR-AOPs)可有效去除微污染物(MPs),但对催化剂的要求较高。碳质材料(CMs)具有独特理化性质,可作为SR-AOPs体系的新型催化剂。综述了生物炭(BC)、石墨烯基材料(GBMs)、碳纳米管(CNTs)的制备方法及其协效SR-AOPs体系催化氧化的反应机理及其去除MPs的研究。杂原子掺杂、含氧官能团的引入是提高GBMs及CNTs催化性能的主要手段,在纳米尺度上精确控制杂化材料的结构可实现性能优化。在CMs/SR-AOP中引入膜技术、电化学技术和光催化技术等将有望推动净水技术的发展。

Engineering carbon nanocatalysts towards efficient degradation of emerging organic contaminants via persulfate activation:A review

The engineering of carbon nanocatalysts for the persulfate activated elimination of emerging organic contaminants(EOCs)demonstrates promising potential compared with metal-based counterparts due to their unique advantage of high stability and low toxicity.The early reviews introduced the theoretical background of persulfate activation together with a detailed summary of different mechanisms responsible for degradation of EOCs.To further unify the state of knowledge,identify the research gaps,and prompt new research in this area,we present a thorough review on current trends in research on metal-free carbon nanocatalysts(e.g.,0D nanodiamond,1D carbon nanotubes and carbon nanofibers,2D graphene and graphitic carbon nitride,and 3D carbon nanocatalysts),with emphasis on their applications in persulfate activation and EOCs decontamination.We also discuss the current challenges and future perspectives in practically relevant applications.Last,we highlight that the development of sustainable carbon nanocatalysts/persulfate systems lies at the interface of multiple disciplines,which calls for future in-depth interdisciplinary collaborations.

过硫酸盐高级氧化原位修复地下水中卤代烃污染研究进展

近年来,地下水卤代烃污染问题日益突出,在多种修复技术中,过硫酸盐(PS)高级氧化技术由于其氧化能力强、反应适用pH范围广、半衰期长且氧化范围广,在水处理界引起了广泛关注。本文先对地下水卤代烃的赋存类型进行了分类,指出国内污染场地检出的卤代烃大部分为重非水相液体(DNAPLs),然后对收集的155个污染地区的卤代烃检出类型和频次进行了统计。对于PS高级氧化技术对卤代烃的降解机制,本文作了详细的分析,大体上分为自由基途径和非自由基途径。由于单一的PS活性不高,因此需要将其活化才能起到较好的氧化效果。在此,总结了金属基催化剂和碳基催化剂的种类和特点。最后讨论了具体应用时PS浓度、无机阴离子、反应初始pH和地下水中天然有机物对反应的影响。与传统的地下水卤代烃修复技术相比,过硫酸盐高级氧化技术可以成为高效清洁的替代技术。

碳基催化剂活化过硫酸盐降解煤化工高盐废水工艺及再生研究

采用碳基催化剂活化过硫酸盐的高级氧化技术处理煤化工高盐有机废水,考察碳基催化剂的吸附性能,研究了不同种类氧化剂、停留时间(HRT)、过一硫酸盐(PMS)投加量、进水pH和反应温度等工艺参数对有机物降解效果的影响。将失活后的碳基催化剂进行原位再生,考察不同工艺条件对再生后催化剂性能的影响。结果表明,碳基催化剂吸附能力较强;PMS相较于过二硫酸盐(PDS)对有机物去除率更高,停留时间越长、反应温度越高PMS催化氧化有机物去除率越高;TOC去除率随PMS投加量增加先上升后下降,最佳投加量为5 g/L,pH为酸性条件更有利于PMS催化氧化反应进行。微波辅助比热循环辅助的催化剂再生效果略强但损耗率高,热循环辅助再生效果和PMS浓度、反应温度和循环流量呈正相关关系,循环时间为1.5 h再生效果最佳,催化剂再生后催化性能提升35%左右,且再生后循环稳定性较好。

催化膜活化过硫酸盐降解水中有机污染物研究进展

针对废水中难降解有机污染物具有持久性和毒害性的现状,对催化膜耦合过硫酸盐高级氧化技术在废水处理中的应用进行综述;根据不同的膜材料,简要总结常用的膜种类,介绍催化膜的制备方法,包括电纺法、相转换法、浸渍法和真空过滤法等,重点讨论催化膜耦合过硫酸盐高级氧化技术对水中抗生素、有机染料、内分泌干扰化合物等有机污染物的降解效果,探讨催化膜耦合过硫酸盐高级氧化技术在污水处理中存在的主要问题,并对其应用前景进行展望,指出该技术有望大规模应用于工业废水处理中。

高级氧化技术降解磺胺类抗生素的应用研究

磺胺嘧啶、磺胺吡啶、磺胺甲恶唑和磺胺二甲嘧啶是水体中检测到的4种高含量抗生素,水环境中磺胺类抗生素(SAs)的降解技术是近年来的热点问题,高级氧化工艺(AOPs)在基本机理及应用研究等方面均取得了快速进展,综述了AOPs中的臭氧、光、电、超声波及过硫酸盐等催化氧化技术在废水处理中的应用进展,分析了目前AOPs降解SAs的研究情况,并对未来技术发展方向进行了展望。

过硫酸盐高级氧化技术活化方式的研究进展

近年来,过硫酸盐高级氧化技术因具有反应速率快、氧化能力强、适用范围广、成本适宜等优点而被广泛应用在废水处理和地下水污染修复领域。尽管过硫酸盐是一种非常强大的氧化剂,但其与常见污染物的反应相对较慢,因此要以可接受的速率降解污染物通常须对过硫酸盐进行活化以产生具有强氧化性的硫酸根自由基。文章综述了活化过硫酸盐的常用方式,包括光活化、热活化、碳基材料活化、电活化、过渡金属活化和碱活化,分别介绍了其研究进展及应用实例,并对未来活化过硫酸盐技术的发展进行了展望。

基于自由基的高级氧化技术在处理印染废水处理中的研究现状

印染废水排放量大、色度高、毒性大、难生物降解,是工业废水中难处理的高浓度有机废水。本文综述了基于自由基的高级氧化技术,包括羟基自由基和硫酸根自由基两种氧化技术的原理,以及硫酸根自由基的活化方法。并介绍了这两种技术对印染废水及难降解有机污染物处理的研究,并对硫酸根自由基的高级氧化技术研究进行了展望。

Carbon-based single-atom catalysts in advanced oxidation reactions for water remediation:From materials to reaction pathways

Single-atom catalysts(SACs)have been widely recognized as state-of-the-art catalysts in environment remediation because of their exceptional performance,100%metal atomic utilization,almost no secondary pollution,and robust structures.Most recently,the activation of persulfate with carbon-based SACs in advanced oxidation processes(AOPs)raises tremendous interest in the degradation of emerging contaminants in wastewater,owning to its efficient and versatile reactive oxidant species(ROS)generation.However,the comprehensive and critical review unraveling the underlying relationship between structures of carbon-based SACs and the corresponding generated ROS is still rare.Herein,we systematically summarize the fundamental understandings and intrinsic mechanisms between single metal atom active sites and produced ROS during AOPs.The types of emerging contaminants are firstly elaborated,presenting the prior pollutants that need to be degraded.Then,the preparation and characterization methods of carbon-based SACs are overviewed.The underlying material structure–ROS type relationship in persulfate-based AOPs is discussed in depth to expound the catalytic mechanisms.Finally,we briefly conclude the current development of carbon-based SACs in AOPs and propose the prospects for rational design and synthesis of carbon-based SACs with on-demand catalytic performances in AOPs in future research.

金属基纳米材料在过硫酸盐高级氧化工艺中的应用进展

随着过硫酸盐高级氧化技术的迅速兴起,开发高效活化过硫酸盐的催化剂引起了国内外学者的高度关注。在过硫酸盐的非均相催化剂中,金属基纳米材料由于自身粒径小、比表面积大、比表面活化能高、磁学性能好等结构与性质特点而呈现出良好的催化特性、化学稳定性、重复利用性等优势,被认为是过硫酸盐活化剂的最佳选择之一,在环境污染控制领域彰显出巨大的应用前景。但是,单一金属纳米材料在反应过程中易发生颗粒团聚、自身氧化、金属离子释放等问题,一定程度上限制了金属纳米催化剂的广泛应用。针对以上问题,研究人员使用复合材料替代单一材料作为过硫酸盐的活化剂以净化环境污染物。例如在催化剂制备过程中,将金属纳米颗粒负载在各类载体材料上,在催化净化过程中不仅能达到协同处理的效果,还能减少金属离子的流失,同时提高催化剂的重复使用性能。此外,制备出结构独特的多种金属基纳米复合材料作为非均相催化剂,多种金属之间的协同效应进一步提升了催化剂的活化性能,使其对污染物的去除效果更强。近年来,国内外研究者在金属基纳米材料的制备与结构特性、活化过硫酸盐过程中自由基与非自由基的产生机制、净化污染物的效果与机理方面不断探索,积累了大量具有重要价值的研究成果。本文对以纳米零价金属、纳米金属氧化物负载型金属基纳米颗粒及纳米铁酸盐等作为催化剂活化过硫酸盐的理论和应用研究进行了全面地综述,围绕不同金属基纳米材料的制备方法与结构特点、活化过硫酸盐生成活性物种的反应机理等方面展开系统阐述,最后指出了该类材料在活化过硫酸盐的过程中存在催化稳定性不高、产生环境风险等亟待解决的问题,并对今后的研究方向进行展望,旨在为金属基纳米催化剂在过硫酸盐高级氧化技术中的安全、高效应用提供参考。

低温水热耦合亚铁离子活化过硫酸盐提高剩余污泥的脱水性能

含水率高的剩余污泥给污泥的无害化处理和资源化利用带来了挑战。本文采用低温水热耦合Fe^(2+)活化过硫酸盐提高剩余污泥的脱水性能。结果表明,在80℃、Fe^(2+)/S_(2)O_(8)^(2-)的摩尔比为1.25的条件下,加入0.75mmol/g DS的Fe^(2+)和0.6mmol/g DS的S_(2)O_(8)^(2-),污泥的毛细吸水时间(CST)由397.4s±7.9s下降到18.9s±0.4s。研究发现在低温水热耦合Fe^(2+)活化过硫酸盐提高污泥脱水性能的过程中,污泥的粒径先减小后增大,胞外聚合物(EPS)被降解和絮体结构遭到破坏。在热和Fe^(2+)的共同作用下加速了过硫酸盐的分解,生成的硫酸根自由基(SO_(4)^(·-))和羟基自由基(·OH)降解了EPS,促进结合水转化为自由水,有利于污泥的固液分离。这些研究可为低温水热耦合Fe^(2+)活化过硫酸盐对污泥进行脱水处理提供了理论基础。

高级氧化耦合絮凝沉淀对水中恩诺沙星的降解研究

本文采用过硫酸钠(PS)-零价铁(ZVI)体系通过高级氧化和絮凝沉淀联合作用降解恩诺沙星(ENR)水溶液。开展了一系列单因素实验(PS投加量、ZVI投加量、反应时间、搅拌转速、pH优化),通过对实验数据的分析探讨反应体系中的复杂竞争机制。实验证明PS-ZVI体系降解ENR的效果远超单独使用PS或ZVI,经过优化,当ENR浓度为0.2g·L^(-1)时,PS投加量0.4g·L^(-1),ZVI投加量7g·L^(-1),反应时间120min,转速700r·min^(-1),pH8.49的条件下能获得良好的处理效果,降解率达94.10%,COD清除率达83.42%。