Mass Transfer-Promoted Fe^(2+)/Fe^(3+)Circulation Steered by 3D Flow-Through Co-Catalyst System Toward Sustainable Advanced Oxidation Processes

Realizing fast and continuous generation of reactive oxygen species(ROSs)via iron-based advanced oxidation processes(AOPs)is significant in the environmental and biological fields.However,current AOPs assisted by co-catalysts still suffer from the poor mass/electron transfer and non-durable promotion effect,giving rise to the sluggish Fe^(2+)/Fe^(3+)cycle and low dynamic concentration of Fe^(2+)for ROS production.Herein,we present a three-dimensional(3D)macroscale co-catalyst functionalized with molybdenum disulfide(MoS_(2))to achieve ultra-efficient Fe^(2+)regeneration(equilibrium Fe^(2+)ratio of 82.4%)and remarkable stability(more than 20 cycles)via a circulating flow-through process.Unlike the conventional batch-type reactor,experiments and computational fluid dynamics simulations demonstrate that the optimal utilization of the 3D active area under the flow-through mode,initiated by the convectionenhanced mass/charge transfer for Fe^(2+)reduction and then strengthened by MoS_(2)-induced flow rotation for sufficient reactant mixing,is crucial for oxidant activation and subsequent ROS generation.Strikingly,the flow-through co-catalytic system with superwetting capabilities can even tackle the intricate oily wastewater stabilized by different surfactants without the loss of pollutant degradation efficiency.Our findings highlight an innovative co-catalyst system design to expand the applicability of AOPs based technology,especially in large-scale complex wastewater treatment.

Advanced Treatment of Biologically Treated Chemical Comprehensive Wastewater by Nano-TiO2 Photocatalytic Oxidation

Nano-TiO2 photocatalytic oxidation was used to perform the advanced treatment of biologically treated chemical comprehensive wastewater. The effects of reaction time,nano-TiO2 dosage and initial p H of the wastewater on the removal rate of COD were tested. The GC/MS and EEM techniques were used to qualitatively analyze organic compounds in the wastewater before and after treatment. The result showed that after the biologically treated chemical comprehensive wastewater was treated by nano-TiO2 photocatalytic oxidation under the conditions of reaction time 3 h,nano-TiO2 dosage 8 g/L,and pH 8. 0,the effluent COD was 61. 9 mg/L and its removal rate was 63. 8%. Additionally,the species of organic pollutants reduced from 12 to 6. Meanwhile,the content of humic-like and fulvic-like substances dropped dramatically.

Effect of the chloride ion on advanced oxidation processes catalyzed by Fe-based metallic glass for wastewater treatment

Fe-based metallic glasses (Fe–MGs) are potential candidate catalysts for advanced oxidation processes(AOPs) for recalcitrant organic pollutant degradation. However, industrial wastewater and natural contaminated sites usually contain abundant inorganic ions, like the chloride ion (Cl−), which significantly affectAOPs, but their influence on MG-activated AOPs still remains unclear. Through the study of three commonly used oxidants, hydrogen peroxide (H_(2)O_(2)), peroxydisulfate (PDS), and peroxymonosulfate (PMS), theeffect of Cl− on the FeSiB-catalyzed process of degradation of the typical azo dye Orange Ⅱ was investigated. Evidence indicates that the addition of Cl− resulted in the monotonous inhibition of the degradation process when the H_(2)O_(2)/FeSiB and PDS/FeSiB systems were employed, but promoted effect wasdetected with the PMS/FeSiB system, which is different from the previously observed dual effect of Cl−.It is closely relative with FeSiB induced unique variety of degradation pathways, including radicals, nonradicals (^(1)O_(2)), and direct reduction degradation. Moreover, the presence of Cl− significantly affected thesystems’ absorbable organic halogen content and the amount of Fe leached into the solution. The resultsof this work will provide essential references for Fe-based MG used as AOP catalysts in field applicationsand the development of advanced MGs with excellent adaptability to complex environments.

Advanced Oxidation Process for DNAN Using UV/H2O2

2,4-Dinitroanisole(DNAN)is an important component of insensitive munitions that is anticipated to replace 2,4,6-trinitrotoluene(TNT)in munitions formulations.Photocatalyzed hydrogen peroxide(H2O2)oxidation experiments and chemical analyses were conducted to study the effect of initial pH and H2O2 dosage on the kinetics of DNAN decomposition and the reaction pathways.The results show that DNAN degradation followed zero-order kinetics when a 250 ppm DNAN solution was treated with ultraviolet(UV)light and 1500–4500 ppm H2O2 in an initial pH range of 4–7.However,when the H2O2 concentration was 750 ppm,DNAN degradation followed pseudo-first-order kinetics.The results indicate that DNAN can easily be oxidized by UV/H2O2 treatment.When the H2O2 dosage was 1500 ppm and the initial pH was 7,DNAN was reduced from 250 ppm to less than 1 ppm in 3 h.However,the total organic carbon(TOC)and total carbon(TC)concentrations were reduced slowly from 100 to less than 70 ppm carbon(C)in 3 h,and decreased to about 5 ppm after 9 h of treatment,suggesting the formation of other organic compounds.Those reaction intermediates were oxidized to carbon dioxide(CO2)at a slower rate than the oxidation of DNAN.CO2 was emitted from the solution because the solution pH decreased rapidly to about 3 during the UV/H2O2 oxidation.Most of the nitrogen in DNAN was converted to nitrate by UV/H2O2 oxidation after 9 h of treatment.The research results indicate that UV/H2O2 oxidation is a promising technique for the treatment of DNAN in wastewater.

Recent advances in H_(2)O_(2)-based advanced oxidation processes for removal of antibiotics from wastewater

As important emerging contaminants, antibiotics have caused potential hazards to the ecological environment and human health due to their extensive production and consumption. Among various techniques for removing antibiotics from wastewater, H_(2)O_(2)-based advanced oxidation processes(AOPs) have received increasing attention due to their fast reaction rate and strong oxidation capability. Hence this review critically discusses:(i) Recent research progress of AOPs with the addition of H_(2)O_(2) for antibiotics removal through different methods of H_(2)O_(2) activation;(ii) recent advances in AOPs that can in-situ generate and activate H_(2)O_(2) for antibiotics removal;(iii) H_(2)O_(2)-based AOPs as a combination with other techniques for the degradation and mineralization of antibiotics in wastewater. Future perspectives about H_(2)O_(2)-based AOPs are also presented to grasp the future research trend in the area.

Performance of a polymerization-based electrochemically assisted persulfate process on a real coking wastewater treatment

Industrial wastewater should be treated with caution due to its potential environmental risks.In this study,a polymerization-based cathode/Fe^(3+)/peroxydisulfate(PDS)process was employed for the first time to treat a raw coking wastewater,which can achieve simulta-neous organics abatement and recovery by converting organic contaminants into separable solid organic-polymers.The results confirm that several dominant organic contaminants in coking wastewater such as phenol,cresols,quinoline and indole can be induced to poly-merize by self-coupling or cross-coupling.The total chemical oxygen demand(COD)abate-ment from coking wastewater is 46.8%and the separable organic-polymer formed from or-ganic contaminants accounts for 62.8%of the abated COD.Dissolved organic carbon(DOC)abatement of 41.9%is achieved with about 89%less PDS consumption than conventional degradation-based process.Operating conditions such as PDS concentration,Fe3+concen-tration and current density can affect the COD/DOC abatement and organic-polymer yield by regulating the generation of reactive radicals.ESI-MS result shows that some organic-polymers are substituted by inorganic ions such as Cl^(-),Br^(-),I^(-),NH_(4)^(+),SCN^(-)and CN^(-),suggest-ing that these inorganic ionsmay be involved in the polymerization.The specific consump-tion of this coking wastewater treatment is 27 kWh/kg COD and 95 kWh/kg DOC.The values are much lower than those of the degradation-based processes in treating the same coking wastewater,and also are lower than those of most processes previously reported for coking wastewater treatment.

Catalytic applications of amorphous alloys in wastewater treatment: A review on mechanisms, recent trends, challenges and future directions

Amorphous alloys,with unique atomic structures and metastable nature,are treated as superior candi-dates for environmental wastewater remediation due to their superior catalytic capabilities.Given the strong demand for environmental protection,the field of amorphous alloys in wastewater treatment has great development prospects,and numerous research results have been published in recent years.As a promising catalyst,it was demonstrated that amorphous alloys could exhibit many excellent proper-ties in wastewater treatment,such as high catalytic efficiency,easily adjustable parameters and reliable sustainability.This paper aims to summarize recent research trends regarding amorphous alloys in the field of catalysis,focusing on the preparation methods,physical performance,catalytic mechanisms and environmental application.Meanwhile,this review also investigates the challenges encountered and fu-ture perspectives of amorphous alloys,offering new research opportunities to enlarge their applicability spectra.

Advancements in adsorption and photodegradation technologies for Rhodamine B dye wastewater treatment:fundamentals,applications,and future directions

Organic dye pollutants present in wastewater pose a significant global challenge.Among pollutants,the synthetic dye Rhodamine B(RB)stands out due to its non-biodegradable nature and associated neurotoxic,carcinogenic,and respiratory irritant properties.Extensive research has been conducted on the efficacy of adsorption and photodegradation techniques for the removal of RB from wastewater.While adsorption and advanced oxidation processes(AOPs)have gained considerable attention for their effectiveness in recent years,the underlying behaviors and mechanisms of these technologies remain incompletely understood.Therefore,a comprehensive of recent research progress in this domain is imperative to clarify the basics and present the up-to-date achievements.This review provides an in-depth exploration of the fundamentals,advancements,and future trajectories of RB wastewater treatment technologies,mainly encompassing adsorption and photodegradation.This work starts with a general introduction of outlining the sources,toxicity,and diverse applicable removal strategies.Subsequently,it thoroughly examines crucial techniques within non-photochemical,photochemical,and adsorption technologies,such as UV light assisted AOP,catalyst assisted AOP,ozonation,Fenton system,electrochemical AOP,and adsorption technology.The primary objective is to furnish a broad overview of these techniques,elucidating their effectiveness,limitations,and applicability.Following this,the review encapsulates state-of-theart computational simulations pertaining to RB adsorption and interactions with clays and other adsorbents.Lastly,it delves into column adsorption of RB dye,and elucidates various influencing factors,including bed height,feed concentration,pollutant(RB)feeding or flow rate,and column regeneration.This panoramic review aims to provide valuable insights into suitable techniques,research gaps,and the applicability of nonphotochemical,photochemical,and adsorption technologies in the treatment of wastewater containing RB dye.

Review on reactive species in water treatment using electrical discharge plasma:formation, measurement, mechanisms and mass transfer

In the electrical discharge plasma process, various chemical and physical processes can participate in the removal of contaminants. In this paper, the chemical and physical processes that occur as a result of the electrical discharge plasma are reviewed, and their possible roles in the degradation of contaminants are discussed. Measurement methods for the quantification of important reactive species and their advantages and shortcomings are presented. Approaches on how to enhance the diffusion of the reactive species in solution are examined. In addition, the formation of typical reactive species in different electrical discharge plasma is compared.

Study on the removal of urea in wastewater using Fenton reagent

The great amount of NH3-N produced in biological hydrolysis process of high concentration urea can inhibit the growth of microorganisms. In allusion to this problem,the Fenton reagent was used to treat high concentration urea wastewater. And the optimum conditions of this experiment were employed as follows: Fe(Ⅱ)-H2O2mole ratio was 1/3.53,H2O2 was 4 mL (corresponding to 35.30 mmol),pH was 3.0-3.5. Then the experiment shows that the urea concentration decreases from 500 mg/L to less than 2 mg/L,or is even not detected; under the same dose of H2O2,repetitious addition does better than one-off addition; the reaction time within one minute or to be prolonged has little influence on removal effect. The results verify feasibility of this method.

Removal of sulfonamide antibiotics from wastewater by gamma irradiation in presence of iron ions

The presence of sulfonamide antibiotics in aquatic environments has received increasing attention in recent years.Sulfadiazine(SD),a widely used heterocyclic sulfonamide pharmaceutical,has entered into the receiving water body.In this paper,gamma rays are used to irradiate samples of sulfadiazine antibiotics-containing wastewater.The results demonstrate that SD can be effectively degraded by irradiation,but the mineralization degree of SD(in terms of TOC) is not as efficient as the SD degradation.The addition of Fe^(2+) can significantly enhance the SD degradation and mineralization through the generation of hydroxyl radical by catalytic decomposition of H_2O_2 from water radiolysis.Ion chromatography analysis indicates that sulfate ions(SO_4^(2-)) and formate(HCOO^-) are the main intermediate products.Gamma irradiation is a promising technology for removing low-concentration antibiotics from water and wastewater.

大蒜加工废水处理研究进展

我国是世界上最大的大蒜生产国和出口国,蒜片是主要的出口品种之一。每生产1 t蒜片会产生20 t以上的大蒜加工废水。大蒜加工废水具有强烈的杀菌作用,给其生物法处理带来了困难。文章围绕大蒜加工废水的特点和组成、大蒜素抑菌机理、大蒜加工废水的生物法处理、膜分离、高级氧化等工艺展开综述,以期为改进现有大蒜加工废水处理工艺提供借鉴。

零价铁活化过氧乙酸降解水中双酚A的效果与机制

双酚A(BPA)是含酚工业废水中代表性污染物,采用零价铁(ZVI)活化过氧乙酸(PAA)去除水中BPA,探究了ZVI和PAA投量、pH以及工业废水中典型共存阴离子对PAA活化和BPA降解的影响,并通过探究反应活性物种和活性位点解析了ZVI活化PAA的反应机制。在投加50 mg/L ZVI,1.00 mmol/L PAA和初始pH为3.4的最优工艺条件下,ZVI/PAA体系反应30 min可去除水中99.24%的BPA;HCO_(3)^(-)和SO_(4)^(2-)对BPA降解具有抑制作用,Cl^(-)(0~20.0 mmol/L)则加速BPA降解。反应中ZVI及其表面氧化层分别释放溶解性Fe(Ⅱ)和Fe(Ⅲ),溶出的Fe(Ⅱ)活化PAA贡献26.46%的BPA降解,非均相ZVI活化PAA对BPA降解起主要作用;淬灭实验表明,ZVI/PAA体系存在CH_(3)C(O)OO·、CH_(3)C(O)O·、·OH和FeⅣO^(2+),其中CH_(3)C(O)OO·和FeⅣO^(2+)是降解BPA的主要活性物种。本研究可为工业废水中双酚A的有效去除提供理论和数据支撑。

供排水系统中全氟和多氟烷基化合物(PFAS)的检测与去除研究进展

随着工业的发展,全氟和多氟烷基化合物(PFAS)在日常生活和生产中的应用日益广泛,对水环境的影响呈加剧趋势。由于PFAS良好的水溶性,其可以随着水循环在环境中迁移转化,最终对人体健康产生不利影响。因此,中国和欧美国家已着手制定相关标准和法律法规,以限制PFAS的使用。在系统性总结水环境中PFAS的来源、浓度和转化过程的基础上,文章对比了色谱法、总可氧化前体(TOP)法和传感器等检测方法以及传统物化生方法、高级氧化技术以及焚烧工艺等去除技术,旨在为PFAS的监测与控制提供理论支持。结果表明,饮用水中PFAS质量浓度普遍超过0.1 ng/L,且PFAS在供排水处理过程中的去除存在两大局限:一是检测技术仅能覆盖少数PFAS类型;二是目前的去除方法无法彻底消除PFAS风险,或导致去除率差,或转化为短链氟化物,引发更多潜在环境风险。

废水中离子液体高级氧化降解研究进展

离子液体(ionic liquids,ILs)是一类具有特殊性质的新兴材料,但其在水中的溶解度相对较高,容易通过废水排放进入水生系统并在环境中积累,且其结构非常稳定,难以被生物降解,具有潜在的生物毒性,因此被认为是一类持久污染物。高级氧化技术(advanced oxidation processes,AOPs)是一种高效降解难降解有机污染物的新技术,已被用于降解废水中的离子液体。文中综述芬顿和类芬顿氧化、阳极氧化、电芬顿氧化、光氧化、光催化氧化、光芬顿氧化及电光芬顿氧化等高级氧化技术降解处理废水中离子液体的研究进展;着重讨论各种氧化技术的降解动力学、降解机理、降解途径和优缺点,以及操作条件、离子液体的阴阳离子、侧链长度等因素对降解反应的影响规律,总结目前存在的问题,并对高级氧化技术降解处理离子液体的未来的研究方向及其前景进行了展望。

水合四价铁氧化特性与生成机制的研究进展

兼具强氧化能力和选择氧化特性的水合四价铁非自由基活性组分在高级氧化水处理体系中的关键作用得到了广泛关注。文章首先综述了水合四价铁的物理化学特性、氧化动力学和氧化机制,梳理总结了以原位光谱表征、化学探针法、同位素示踪技术等为代表的水合四价铁活性组分鉴别技术,并进一步探讨了水合四价铁非自由基活性组分在亚铁/过氧化氢、亚铁/过一硫酸盐、亚铁/过二硫酸盐、亚铁/次氯酸、亚铁/高碘酸和亚铁/过氧乙酸等高级氧化体系中的生成机制。最后,结合最新的研究成果及当前研究的不足,对水合四价铁工程化应用前景进行了展望,以期为水合四价铁的相关研究和运用提供理论依据和实践指导。

催化氧化-膜工艺处理有机废水研究进展

有机废水中难降解有机物控制不当,将严重影响生态环境和人类健康。有机废水深度处理技术的开发已成为水处理领域的研究热点。催化氧化-膜分离技术作为一种可同时兼具物理分离与化学氧化于一体的深度净水技术备受关注。催化膜耦合高级氧化技术(AOPs)不仅可以通过提高氧化性能促进污染物去除,还能通过强化自由基生成抑制膜污染,实现“自清洁”。文中结合国内外最新研究进展,全面总结了催化膜的制备方法,并重点讨论其与光催化、Fenton氧化、过硫酸盐活化、臭氧氧化及电催化氧化过程耦合的性能与机制。同时,针对催化膜耦合氧化过程的影响因素、优势及其存在的问题进行系统比较。最后,基于催化氧化-膜技术的未来发展方向及研究挑战提出建议和展望。

高级氧化技术在废水处理中应用进展

随着全球经济发展、人口增长和消费模式的转变,用水资源的紧张和排放标准的提高以及工业用水回用需求量的增加,高级氧化工艺凭借其极强的氧化能力成为处理自然界中顽固污染物的新兴方法之一,该过程通过添加强氧化剂可降解不同来源产生的污染物。本文综述了不同类型的高级氧化工艺在理论和实践中的处理效果,对比分析其优缺点,为今后的研究提供新思路。

臭氧催化氧化深度处理酚氰废水的正交试验研究

设计正交试验,利用臭氧催化氧化工艺对焦化酚氰废水进行深度处理,研究不同的臭氧投加量、进水含泥量、进水pH、停留时间4个因素对出水色度、COD的影响。结果表明:进水色度为50度,COD为100 mg/L的条件下,4个因素对出水色度影响程度由大到小顺序为:进水pH>进水含泥量>臭氧投加量>停留时间。4个因素对出水COD影响程度由大到小顺序为:臭氧投加量>进水pH>进水含泥量>停留时间。在臭氧投加量为200 mg/L、进水含泥量低于5 mg/L、进水pH在7.5~8.0之间、停留时间20 min的条件下,出水色度为5度,去除率在90%。在臭氧投加量为400mg/L、进水含泥量低于5mg/L、进水pH在7.5~8.0之间、停留时间30min的条件下,出水COD低于20 mg/L,去除率在80%以上。

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。