负载多壁碳纳米管的多孔Ti/SnO2-Sb-Ni电极电催化氧化双酚A

为发展废水中双酚A（BPA）的处理技术和保护水环境安全,采用“电沉积-热分解”法制备负载多壁碳纳米管（MWCNTs）的多孔Ti/SnO₂-Sb-Ni电极,研究了电极对BPA的去除能力、动力学特征和矿化效率,初步分析了BPA的降解途径.结果表明,当浸渍液中n（Sn）∶n（Sb）∶n（Ni）为100∶10∶1、ρ（MWCNTs）为0.8g·L^-1时,制备的电极对BPA的去除效果最好;负载MWCNTs使得电极表面的晶体尺寸更小,可增大电极的比表面积,为电催化反应提供更多的活性位点,进而提高电极的电催化效率.当c（Na₂SO₄）为10mmol·L^-1、反应液初始pH为5和电流密度为50 mA·cm^-2时,对50 mg·L^-1的BPA降解60 min时去除效率达到99.76%;去除过程符合一级反应动力学方程,速率常数为0.096 min^-1;电解120 min时,TOC去除率达到67.01%.采用液相色谱-串联质谱分析法（...     

施加牛粪熟肥对黄土吸附双酚A的影响

为研究施加腐熟牛粪对黄土吸附BPA（双酚A）的影响,采用批量平衡试验法,分析不同因素[如黄土粒径、体系温度、初始ρ （BPA）、离子强度、pH等]对BPA在黄土及施加牛粪熟肥黄土上吸附量的影响.结果表明:BPA在黄土中的吸附均符合先快后慢并最终达到平衡的吸附规律,准二级动力学模型能较好地描述其吸附动力学过程.BPA在黄土与施加腐熟牛粪黄土上的解吸量远小于其吸附量,说明吸附-解吸过程中存在解吸滞后性.黄土与施加腐熟牛粪黄土对BPA的热力学吸附过程符合Freundlich等温吸附模型,并且吸附等温线符合L-型吸附等温模式,BPA的吸附吉布斯自由能（ΔGθ） < 0,焓变（ΔHθ） < 0,熵变（ΔSθ） < 0,表明该吸附属于混乱程度减小、可自发放热的吸附过程.影响因素分析结果显示,黄土对BPA的吸附量随其粒径的减小而增大,而不论是否施加腐熟牛粪,其对BPA的吸附量均随体系温度升高而减少,且随初始ρ （BPA）的增加而升高.此外,加入的阳离子（Ca2+、Mg2+）会与BPA形成竞争吸附,不论是黄土还是施加腐熟牛粪黄土,其对BPA的吸附量均随加入阳离子浓度的升高而降低.当pH为3~7时,黄土与施加腐熟牛粪黄土对BPA的吸附量随着pH的升高而增加,而pH为7~10时对BPA的吸附量变化较小,表明该范围内pH变化对黄土与施加腐熟牛粪黄土吸附BPA的影响不明显.研究显示,施加牛粪等腐熟肥可能导致BPA的吸附行为发生改变.      

双酚A在城市污水和污泥中的赋存与分析方法的研究进展

双酚A(BPA)作为典型的环境内分泌干扰物,由于其在环境中痕量浓度即可对生物产生内分泌干扰效应,因此受到了越来越广泛的关注。城市污水为BPA重要污染源,污水处理过程中部分BPA转移到污泥中,成为潜在的环境隐患。本文综述了双酚A在环境中的赋存情况以及相应的萃取技术、分析检测方法。此外,通过对比不同的回收率与检测下限,对几种常用的分析方法进行了比较,并展望了这一领域未来的研究发展趋势。     

高价铬及双酚A在铁-乳酸体系中的同时光处理

研究了Fe(Ⅲ)-乳酸配合物体系同时对Cr(Ⅵ)的光还原及双酚A(BPA)的光氧化处理,考察了光源、初始pH值、Fe(Ⅲ)、乳酸盐、Cr(Ⅵ)及BPA初始浓度等因素对Cr(Ⅵ)及BPA光处理效率的影响。结果表明:光照条件下,铁-乳酸配合物能有效实现对六价铬及BPA的同时光处理。同一体系中,Cr(Ⅵ)的光还原快于BPA的光氧化,Fe(Ⅲ)初始浓度的增加可同时提高Cr(Ⅵ)的光还原效率和BPA的光氧化效率;Fe(Ⅲ)-乳酸盐配合物光解产生的Fe(Ⅱ)是Cr(Ⅵ)的主要还原剂,其次级光反应中产生的.OH是BPA的氧化剂。     

气相沿面放电—活性炭纤维吸附联合降解双酚A废水研究

利用气相沿面放电—活性炭纤维(ACF)吸附(简称放电—吸附)联合处理含双酚A(BPA)废水,探讨了联合处理对BPA的降解效果,并通过处理过程中O3利用率变化以及处理前后ACF的表观状态变化分析了反应的作用机制。结果表明,放电—吸附联合处理相比单独放电和单独ACF吸附能显著提高BPA的降解率;在一定范围内,加大放电电压能提高放电—吸附联合处理的BPA降解效果,但放电电压超过一定值后,放电产生的O3量进一步增多,对ACF表面的结构破坏作用增加,反而导致BPA的降解效果降低,本研究较佳的放电电压为8.5kV;扫描电镜分析结果表明,经放电—吸附联合处理后,ACF表面出现大量的孔道,提高了表面的BPA富集浓度,同时也增加反应的活性位点;傅里叶变换红外光谱分析结果表明,联合处理后ACF表面的C—O、C=C、O—H等官能团都有所减少,可能是联合处理过程中O3等活性物质与ACF表面的这些还原性官能团发生了反应,诱导O3分解出了更多的自由基,从而促进了BPA的降解。     

Ubiquity of bisphenol A in the atmosphere

Bisphenol A (BPA) is a suspected endocrine disruptor in the environment. However, little is known about its distribution and transport in the atmosphere. Here, the concentrations of BPA in the atmospheric aerosols from urban, rural, marine, and the polar regions were measured using solvent extraction/derivatization and gas chromatography/mass spectrometry technique. The concentrations of BPA (1-17,400 pg m⁻³) ranged over 4 orders of magnitude in the world with a declining trend from the continent (except for the Antarctica) to remote sites. A positive correlation was found between BPA and 1,3,5-triphenylbenzene, a tracer for plastic burning, in urban regions, indicating that the open burning of plastics in domestic waste should be a significant emission source of atmospheric BPA. Our results suggest that the ubiquity of BPA in the atmosphere may raise a requirement for the evaluation of health effects of BPA in order to control its emission sources, for example, from plastic burning.     

Distribution of pesticides and bisphenol A in sediments collected from rivers adjacent to coral reefs

To investigate the deteriorating health of coral reefs in Okinawa, Japan, natural sediment samples were analyzed for diuron, Irgarol 1051, chlorpyrifos, and bisphenol A (BPA) which are hazardous to corals. Samples were analyzed by solid-phase extraction (SPE) followed by high-performance liquid chromatography with tandem mass spectrometry (LC–MS–MS). Although diuron and chlorpyrifos usage is only well recorded for farms and not for cities, these chemicals were detected in both rural and urban areas. Additionally, diuron concentration in urban areas was in some cases higher than in rural areas, which might be caused by greater consumption of these chemicals in home gardens in city areas. Irgarol 1051 was detected in downstream river areas, which are situated far from the source sites such as pier or fishery harbor (0.6–3.2 km). This result suggested that Irgarol 1051 could be transported from the river mouths to the sampling sites during flood tides. High BPA concentrations were associated with urban areas (<1.2–22.0 μg kg⁻¹), while low concentrations were associated with rural areas (nd–6.8 μg kg⁻¹). The river sediments under study are delivered to coral reefs in large quantity through runoff caused by typhoons and other heavy rains. The highly hazardous chemicals are carried into coral reefs on these sediments. Therefore, these hazardous chemical substances may already be influencing the coral reefs.     

Fabrication of electrochemically-modified BiVO4-MoS2-Co3O4composite film for bisphenol A degradation

A new electrochemically-modified BiVO₄-MoS₂-Co₃O₄ (represented as E-BiVO₄-MoS₂-Co₃O₄) thin film electrode was successfully synthesized for environmental application. MoS₂ and Co₃O₄ were grown on the surface of BiVO₄ to obtain BiVO₄-MoS₂-Co₃O₄. E-BiVO₄-MoS₂-Co₃O₄ film was achieved by further electrochemical treatment of BiVO₄-MoS₂-Co₃O₄. The as-prepared E-BiVO₄-MoS₂-Co₃O₄ exhibited significantly enhanced photoelectrocatalytic activity. The photocurrent density of E-BiVO₄-MoS₂-Co₃O₄ thin film is 6.6 times that of BiVO₄ under visible light irradiation. The degradation efficiency of E-BiVO₄-MoS₂-Co₃O₄ for bisphenol A pollutant was 81.56% in photoelectrochemical process. The pseudo-first order reaction rate constant of E-BiVO₄-MoS₂-Co₃O₄ film is 3.22 times higher than that of BiVO₄. And its reaction rate constant in photoelectrocatalytic process is 14.5 times or 2 times that in photocatalytic or electrocatalytic process, respectively. The improved performance of E-BiVO₄-MoS₂-Co₃O₄ was attributed to the synergetic effects of the reduction of interfacial charge transfer resistance, the formation of oxygen vacancies and sub-stoichiometric metal oxides and higher separation efficiency of photogenerated electron-hole pairs. E-BiVO₄-MoS₂-Co₃O₄ is a promising composite material for pollutants removal.     

Construction of dual Z-scheme Bi2WO6/g-C3N4/black phosphorus quantum dots composites for effective bisphenol A degradation

In this work, a novel dual Z-scheme Bi₂WO₆/g-C₃N₄/black phosphorus quantum dots (Bi₂WO₆/g-C₃N₄/BPQDs) composites were fabricated and utilized towards photocatalytic degradation of bisphenol A (BPA) under visible-light irradiation. Optimizing the content of g-C₃N₄ and BPQDs in Bi₂WO₆/g-C₃N₄/BPQDs composites to a suitable mass ratio can enhance the visible-light harvesting capacity and increase the charge separation efficiency and the transfer rate of excited-state electrons and holes, resulting in much higher photocatalytic activity for BPA degradation (95.6%, at 20 mg/L in 120 min) than that of Bi₂WO₆ (63.7%), g-C₃N₄ (25.0%), BPQDs (8.5%), and Bi₂WO₆/g-C₃N₄ (79.6%), respectively. Radical trapping experiments indicated that photogenerated holes (h⁺) and superoxide radicals (•O₂⁻) played crucial roles in photocatalytic BPA degradation. Further, the possible degradation pathway and photocatalytic mechanism was proposed by analyzing the BPA intermediates. This work also demonstrated that the Bi₂WO₆/g-C₃N₄/BPQDs as effective photocatalysts was stable and have promising potential to remove environmental contaminants from real water samples.     

处理BPA模拟废水的SBR工况参数对污泥有机毒性的影响研究

在处理双酚A(BPA)模拟废水的序批式活性污泥系统(SBR)反应器中,保持进水COD含量均为300 mg·L-1左右,通过改变水力停留时间HRT从12~8 h,污泥龄SRT从20~10 d,考察污泥有机毒性和其他水质指标的变化.试验分析了空白组和40 mg·L-1初始浓度BPA对照组在不同工况条件下周期末出水COD值、污泥有机毒性分布规律以及稳定期单周期内COD值和污泥有机毒性的变化趋势.结果表明,缩短水力停留时间和污泥龄有利于活性污泥降解BPA,并消减稳定期污泥的有机毒性;出水COD稳定在50 mg·L-1左右,且水相和泥相均无BPA残留.在应用PCR-DGGE技术分析SBR系统内微生物菌群多样性和不同样品间的相似性过程中,得出污泥总毒性抑制率与微生物多样性呈负相关性关系,进水成分的不同和运行参数改变是导致污泥总毒性差异的主要原因.