首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
刘佳  史俊  付坤  丁超  龚思成  邓慧萍 《化学进展》2021,33(8):1311-1322
20世纪80年代至今,水处理技术中的高级氧化过程(AOP)已被广泛研究及应用。然而水体中的有机污染物仍因种类繁多和降解难易不同困扰着研究者们,因此对于AOP的机理过程需要更深入的分析认识,以利于技术的进一步发展及应用。AOP中的过硫酸盐氧化工艺近年来得到大量关注,其自由基机理的关键活性物种是·OH 和·SO4-。非自由基机理分为1O2氧化和PS直接氧化(也称电子转移),某些体系中高价态金属也直接或间接地参与氧化过程。但非自由基过程的发生机理及优势特点仍存在争议。本文综述了基于多相催化过硫酸盐高级氧化过程处理水中有机污染物的最新研究,阐述反应机理及其分析手段,并指出当前研究可能存在的问题。对于过硫酸盐高级氧化工艺中非自由基过程的未来研究方向及应用前景提出展望。  相似文献   

2.
以泡沫镍(NF)为基底,采用一步水热法制备了主晶相为CoS2、夹杂少量NiO相、具有三维多孔风叶结构的CoS2/NF电极材料。当溶液中钴硫物质的量之比为1∶5时,在140℃下保温18 h,获得了由10 nm厚度的纳米片构成的三维风叶结构的晶态CoS2/NF电催化剂。CoS2/NF在肼氧化及析氢反应中均表现出优异的催化性能,在水合肼碱性介质中,获得-10 mA·cm-2的析氢电流密度时,需要的过电势仅为83 mV,获得50 mA·cm-2的氧化电流密度时,需要的肼氧化电位仅为51 mV(vs RHE);在水合肼辅助电解水双功能电解槽中,获得100 mA·cm-2的电流密度时,需要的分解槽压仅为0.550 V,远低于其在同条件下全水分解的2.075 V,大幅减小了电能消耗,极大地提高了电解水产氢效率。无论在三电极体系还是双电极体系,CoS2/NF均表现出优异的长效稳定性及耐用性。分析认为,电极表面多孔风叶结构的形成,...  相似文献   

3.
以泡沫镍(NF)为基底,采用一步水热法制备了主晶相为CoS2、夹杂少量NiO相、具有三维多孔风叶结构的CoS2/NF电极材料。当溶液中钴硫物质的量之比为 1∶5 时,在 140 ℃下保温 18 h,获得了由 10 nm 厚度的纳米片构成的三维风叶结构的晶态CoS2/NF电催化剂。CoS2/NF在肼氧化及析氢反应中均表现出优异的催化性能,在水合肼碱性介质中,获得-10 mA·cm-2的析氢电流密度时,需要的过电势仅为83 mV,获得50 mA·cm-2的氧化电流密度时,需要的肼氧化电位仅为51 mV(vs RHE);在水合肼辅助电解水双功能电解槽中,获得100 mA·cm-2的电流密度时,需要的分解槽压仅为0.550 V,远低于其在同条件下全水分解的2.075 V,大幅减小了电能消耗,极大地提高了电解水产氢效率。无论在三电极体系还是双电极体系,CoS2/NF均表现出优异的长效稳定性及耐用性。分析认为,电极表面多孔风叶结构的形成,使其电化学活性面积增加了24倍,为催化反应的发生提供了海量的活性位点及物质传递通道。CoS2及NiO相的形成,在一定程度上协同改善了本征析氢活性。CoS2/NF的组成、结构特性共用造就了其优异催化性能,其中结构优势起主导作用。通过机理研究,提出了CoS2/NF在析氢及肼氧化过程中的反应路径。  相似文献   

4.
通过水浴-逆共沉淀法制备磁性催化剂MnFe2O4@AC (MFA),并对其结构和磁性进行了系统表征。结果显示,MnFe2O4纳米颗粒包覆在活性炭(AC)表面,构成了多级孔结构。MFA较AC基体材料的比表面积有所下降,但仍高达176 m2·g-1,平均孔径为8.49 nm。MFA的比磁化强度高达38.92 emu·g-1,可利用外磁场实现高效固液分离。以MFA为催化剂,在紫外光辅助下活化过硫酸氢钾(PMS)降解盐酸四环素(TC)。研究表明,在紫外光辐照下MFA/PMS体系对TC降解率能够达到97.70%,是无紫外光照射体系的1.2倍;共存阴离子、药剂制度、TC初始质量浓度等因素对系统的催化性能具有显著影响。循环5次之后,降解率仍可达到82.76%。自由基猝灭实验表明,超氧自由基(·O2-)和单线态氧(1O2)是紫外光辅助MFA/PMS高级氧化体系中的主要活性氧。机理分析表明,MFA的高吸附性为催化降解提供了良好的基础,紫外光辐照和MFA/PMS高级氧化体系的协同效应可显著提升活性基团的生成效率,从而促进了有机分子的降解。  相似文献   

5.
过硫酸盐活化高级氧化新技术   总被引:35,自引:0,他引:35  
过硫酸盐在热、光、过渡金属催化等条件激活下产生强氧化性的硫酸根自由基·SO4-。基于·SO4-的过硫酸盐活化“高级氧化技术”在环境污染治理领域的应用,是刚刚发展起来的崭新的研究方向,具有广阔的应用前景。本文在分析其基本原理的基础上,综述了过硫酸盐活化技术在国内外土壤地下水有机污染原位修复、难降解有机废水处理等环境污染治理方面的研究进展,并就存在问题进行了研究展望。  相似文献   

6.
    
Benzophenone-3, fipronil and propylparaben are micropollutants that are potential threats to ecosystems and have been detected in aquatic environments. However, studies involving the investigation of new technologies aiming at their elimination from these matrices, such as advanced oxidation processes, remain scarce. In this study, different iron complexes (FeCit, FeEDTA, FeEDDS and FeNTA) were evaluated for the degradation of a mixture of these micropollutants (100 µg L−1 each) spiked in municipal wastewater treatment plant (MWWTP) effluent at pH 6.9 by solar photo-Fenton. Operational parameters (iron and H2O2 concentration and Fe/L molar ratio) were optimized for each complex. Degradation efficiencies improved significantly by increasing the concentration of iron complexes (1:1 Fe/L) from 12.5 to 100 µmol L−1 for FeEDDS, FeEDTA and FeNTA. The maximum degradation reached with FeCit for all iron concentrations was limited to 30%. Different Fe/L molar ratios were required to maximize the degradation efficiency for each ligand: 1:1 for FeNTA and FeEDTA, 1:3 for FeEDDS and 1:5 for FeCit. Considering the best Fe/L molar ratios, higher degradation rates were reached using 5.9 mmol L−1 H2O2 for FeNTA and FeEDTA compared to 1.5 and 2.9 mmol L−1 H2O2 for FeEDDS and FeCit, respectively. Acute toxicity to Canton S. strain D. melanogaster flies reduced significantly after treatment for all iron complexes, indicating the formation of low-toxicity by-products. FeNTA was considered the best iron complex source in terms of the kinetic constant (0.10 > 0.063 > 0.051 > 0.036 min−1 for FeCit, FeNTA, FeEDTA and FeEDDS, respectively), organic carbon input and cost-benefit (USD 327 m−3 > USD 20 m−3 > USD 16 m−3 > USD 13 m−3 for FeEDDS, FeCit, FeEDTA and FeNTA, respectively) when compared to the other tested complexes.  相似文献   

7.
The electro-Fenton process, in which ferrous ions are produced on the anode and used as catalyst, was applied for treating the bioeffluent of petrochemical manufacturing wastewater.  相似文献   

8.
通过水浴-逆共沉淀法制备磁性催化剂MnFe2O4@AC (MFA),并对其结构和磁性进行了系统表征。结果显示,MnFe2O4纳米颗粒包覆在活性炭(AC)表面,构成了多级孔结构。MFA较AC基体材料的比表面积有所下降,但仍高达176 m2·g-1,平均孔径为8.49 nm。MFA的比磁化强度高达38.92 emu·g-1,可利用外磁场实现高效固液分离。以MFA为催化剂,在紫外光辅助下活化过硫酸氢钾(PMS)降解盐酸四环素(TC)。研究表明,在紫外光辐照下MFA/PMS体系对TC降解率能够达到97.70%,是无紫外光照射体系的1.2倍;共存阴离子、药剂制度、TC初始质量浓度等因素对系统的催化性能具有显著影响。循环5次之后,降解率仍可达到82.76%。自由基猝灭实验表明,超氧自由基(·O2-)和单线态氧(1O2)是紫外光辅助MFA/PMS高级氧化体系中的主要活性氧。机理分析表明,MFA的高吸附性为催化降解提供了良好的基础,紫外光辐照和MFA/PMS高级氧化体系的协同效应可显著提升活性基团的生成效率,从而促进了有机分子的降解。  相似文献   

9.
    
Zero-valent iron (ZVI)- and zero-valent aluminium (ZVA)-activated persulfate (PS) oxidation procedure was applied to remove the industrial pollutants 3,5-dichlorophenol (3,5-DCP; 12.27 µM) and 2,4-dichloroaniline (2,4-DCA; 12.34 µM) from aqueous solutions. The effects of PS concentration and pH were investigated to optimize heterogeneous treatment systems. Negligible removals were obtained for both pollutants by individual applications of nanoparticles (1 g/L) and PS (1.00 mM). PS activation with ZVI resulted in 59% (1.00 mM PS; 1 g/L ZVI; pH 5.0; 120 min) and 100% (0.75 mM PS; 1 g/L ZVI; pH 5.0; 80 min) 3,5-DCP and 2,4-DCA removals, respectively. The ZVA/PS treatment system gave rise to only 31% 3,5-DCP (1.00 mM PS; 1 g/L ZVA; pH 3.0; 120 min) and 47% 2,4-DCA (0.25 mM PS; 1 g/L ZVA; pH 3.0; 120 min) removals. The pH decreases from 5.0 to 3.0 and from 3.0 to 1.5 enhanced contaminant removals for ZVI/PS and ZVA/PS treatments, respectively. Pollutant removal rates were in correlation with the consumption rates of the oxidants. Metal ion (Al, Fe) release increased in the presence of PS and with decreasing pH.  相似文献   

10.
    
Arsenite removal from aqueous medium is quite challenging as most of the conventional methods fail to exhibit arsenite removal completely. The present article examines the possibility of electrochemical advanced oxidation processes to remove arsenite from water medium. Anodic oxidation and electro-Fenton processes failed to remove generated arsenate in the system but found effective to oxidize arsenite completely from its initial concentrations of 1 mg/L and 10 mg/L. Arsenite oxidation is mainly due to in-situ generated hydrogen peroxide and hydroxyl radicals for anodic oxidation and electro-Fenton processes. However, peroxicoagulation process was found effective for the oxidation of arsenite as well as removal of arsenic in water. Complete removal of arsenic was observed within 30 min of electrolysis time for pH range in between 3 to 11. Overall, peroxicoagulation is an effective way to remove arsenic from aqueous solution.  相似文献   

11.
    
3D-MoS2 can adsorb organic molecules and provide multidimensional electron transport pathways, implying a potential application for environment remediation. Here, we study the degradation of aromatic organics in advanced oxidation processes (AOPs) by a 3D-MoS2 sponge loaded with MoS2 nanospheres and graphene oxide (GO). Exposed Mo4+ active sites on 3D-MoS2 can significantly improve the concentration and stability of Fe2+ in AOPs and keep the Fe3+/Fe2+ in a stable dynamic cycle, thus effectively promoting the activation of H2O2/peroxymonosulfate (PMS). The degradation rate of organic pollutants in the 3D-MoS2 system is about 50 times higher than without cocatalyst. After a 140 L pilot-scale experiment, it still maintains high efficiency and stable AOPs activity. After 16 days of continuous reaction, the 3D-MoS2 achieves a degradation rate of 120 mg L−1 antibiotic wastewater up to 97.87 %. The operating cost of treating a ton of wastewater is only US$ 0.33, suggesting huge industrial applications.  相似文献   

12.
    
3D‐MoS2 can adsorb organic molecules and provide multidimensional electron transport pathways, implying a potential application for environment remediation. Here, we study the degradation of aromatic organics in advanced oxidation processes (AOPs) by a 3D‐MoS2 sponge loaded with MoS2 nanospheres and graphene oxide (GO). Exposed Mo4+ active sites on 3D‐MoS2 can significantly improve the concentration and stability of Fe2+ in AOPs and keep the Fe3+/Fe2+ in a stable dynamic cycle, thus effectively promoting the activation of H2O2/peroxymonosulfate (PMS). The degradation rate of organic pollutants in the 3D‐MoS2 system is about 50 times higher than without cocatalyst. After a 140 L pilot‐scale experiment, it still maintains high efficiency and stable AOPs activity. After 16 days of continuous reaction, the 3D‐MoS2 achieves a degradation rate of 120 mg L?1 antibiotic wastewater up to 97.87 %. The operating cost of treating a ton of wastewater is only US$ 0.33, suggesting huge industrial applications.  相似文献   

13.
    
Methane (CH4) is a potent greenhouse gas and the second highest contributor to global warming. CH4 emissions are still growing at an alarmingly high pace. To limit global warming to 1.5 °C, one of the most effective strategies is to reduce rapidly the CH4 emissions by developing large-scale methane removal methods. The purpose of this perspective paper is threefold. (1) To highlight the technology gap dealing with low concentration CH4 (at many emission sources and in the atmosphere). (2) To analyze the challenges and prospects of solar-driven gas phase advanced oxidation processes for CH4 removal. And (3) to propose some ideas, which may help to develop solar-driven gas phase advanced oxidation processes and make them deployable at a climate significant scale.  相似文献   

14.
    
Benzotriazole UV stabilizers (BUVs) have gained popularity, due to their absorption properties in the near UV range (200–400 nm). They are used in the technology for manufacturing plastics, protective coatings, and cosmetics, to protect against the destructive influence of UV radiation. These compounds are highly resistant to biological and chemical degradation. As a result of insufficient treatment by sewage treatment plants, they accumulate in the environment and in the tissues of living organisms. BUVs have adverse effects on living organisms. This work presents the use of peracetic acid in combination with d-electron metal ions (Fe2+, Co2+), for the chemical oxidation of five UV filters from the benzotriazole group: 2-(2-hydroxy-5-methylphenyl)benzotriazole (UV-P), 2-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)-4-methylphenol (UV-326), 2,4-di-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)phenol (UV-327), 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV-328), and 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (UV-329). The oxidation procedure has been optimized based on the design of experiments (DoE) methodology. The oxidation of benzotriazoles follows first order kinetics. The oxidation products of each benzotriazole were investigated, and the oxidation mechanisms of the tested compounds were proposed.  相似文献   

15.
多肽合成中几种形成二硫键方法的介绍   总被引:6,自引:0,他引:6  
综述了多肽合成中几种形成二硫键的方法。介绍了经典的空气氧化法、铁氰化钾氧化法和碘氧化法及近年来发展起来的二甲亚砜氧化法、三氟乙酸铊氧化法和氯硅烷-亚砜氧化法等方法的特点,同时还介绍了形成两对或多对二硫键的策略。  相似文献   

16.
Catalytic activities of Pt/Co2SnO4, Pt/(Co3O4+SnO2), Pt/SnO2, and Pt/Co3O4 catalysts for CO oxidation were investigated by varying CO concentration at room temperature. Reaction rates over Pt/Co2SnO4 and Pt/Co3O4 catalysts were not affected from increase in CO concentration. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

17.
It was reported in literature, that CoS1+y oxidizes to CoO only, although it appears from Co-S-O predominance phase diagrams, that CoSO4 is stable phase at partial pressures of SO2 typical for sulfides oxidation. The experiments with CoS1.023 oxidation with the air and the air/SO2 gas mixture described in this paper, reveal that CoSO4 phase is a product of such oxidation. However, the quantity of CoSO4 is only of 1.4% of total cobalt content in the sample oxidized with the air and of 5.6-10.8% for oxidation with the air/SO2 gas mixture. It is probably due to CoO layer, formed on CoS1.023 grain's core, which results in hindering of oxidation after several minutes during the process. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

18.
段成茜  高作宁 《分析测试学报》2011,30(10):1113-1117
运用循环伏安法(CV)、计时电流法(CA)、计时库仑法(CC)、方波伏安法(SWV)研究了卡马西平(CBZ)在纳米二氧化钛(nano-TiO2)与离子液体1-苄基-3-甲基咪唑六氟磷酸盐([BnMIM]PF6)复合修饰碳糊电极(nano-TiO2-[BnMIM] PF6/CPE )上的电化学行为、电化学动力学性质及电分...  相似文献   

19.
20.
楚弘宇  王天予  王崇臣 《化学进展》2022,34(12):2700-2714
环境中的病原微生物对人类的健康造成了较大的威胁,传统抗菌剂不足以满足当今人类的需求,因此开发新型高效抗菌剂是目前重要的研究领域。由于具有较大的孔隙度、丰富的表面电荷、周期性分散的金属团簇和活性位点,金属有机框架(MOFs)基材料不仅能够通过可控地缓释金属离子实现除菌,还能通过光催化、活化过硫酸盐、类Fenton反应、电催化等高级氧化过程对细菌产生高效杀灭效果。本文系统总结了具有高级氧化除菌性能的MOFs材料及其复合物、衍生物和宏观器件的研究进展,对MOFs基材料的设计理念、抗菌性能和机理进行了讨论。最后提出了MOFs基材料在除菌领域所面对的挑战,并对其应用前景进行了展望。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号