Compared catalytic properties of OMS-2-based nanocomposites for the degradation of organic pollutants

In this study,Mn catalysts have been designed based on manganese oxide octahedral molecular sieve(OMS-2) supports to optimize the catalytic activity in the degradation of organic pollutants.Herein,two different synthetic strategies:Pre-incorporation vs.wet-impregnation have been employed to synthesize[PW]-OMS-2 and [PW]/OMS-2.For [PW]-OMS-2,energy dispersive X-ray spectroscopy(EDX) confirmed that dispersed granular phosphotungstic acid attached and located at the surface of OMS-2,meanwhile some W atoms have been doped into frameworks of OMS-2.However,for [PW]/OMS-2,the W atoms cannot enter the OMS-2 frameworks.A correlation has been established between the different synthetic strategies and catalytic activities.The [PW]-OMS-2 is the most highly effective and stable over than[PW]/OMS-2 and OMS-2 itself for the organic pollutants removal.This may be caused not only by the synergetic effect of [PW] and OMS-2,but also by doping W into frameworks of OMS-2.Therefore,this work provides a new environmentally-friendly and heterogeneous PMS activator and it may be put into practice to degrade organic pollutants.     

基于6LoWPAN技术的气体环境监控系统

针对日趋严重的大气污染问题,提出了一种基于6LoWPAN技术的大气环境监测方案。通过IPv6通信协议组建的6LoWPAN星型网络,能够实现大规模传感控制网络,解决了IPv4 地址枯竭、各厂商协议不统一等问题。各个PAN采集到的数据通过路由器发送给监控终端,使用Labview为开发平台进行数据汇总后实现对环境中有害气体的实时监控,并通过以太网进行数据共享。实验结果表明,该系统数据采集准确无误,并对环境污染起到了预防作用,可保证社会的可持续发展。     

Efficient Biocatalytic Degradation of Pollutants by Enzyme‐Releasing Self‐Propelled Motors

The first example of a self‐propelled tubular motor that releases an enzyme for the efficient biocatalytic degradation of chemical pollutants is demonstrated. How the motors are self‐propelled by the Marangoni effect, involving simultaneous release of SDS surfactant and the enzyme remediation agent (laccase) in the polluted sample, is illustrated. The movement induces fluid convection and leads to the rapid dispersion of laccase into the contaminated solution and to a dramatically accelerated biocatalytic decontamination process. The greatly improved degradation efficiency, compared to quiescent solutions containing excess levels of the free enzyme, is illustrated for the efficient biocatalytic degradation of phenolic and azo‐type pollutants. The high efficiency of the motor‐based decontamination approach makes it extremely attractive for a wide‐range of remediation processes in the environmental, defense and public health fields.     

保留时间两点校正反相高效液相色谱法测定持久性有机污染物的正辛醇-水分配系数

采用改进的反相高效液相色谱法(RP-HPLC)测定了持久性有机污染物(POPs)包括多环芳烃(PAHs)、多氯二苯并二恶英(PCDDs)、多氯二苯并呋喃(PCDFs)和十溴二苯乙烷(DBDPE)等的正辛醇-水分配系数(logKow)。采用保留时间双点校正法(DP-RTC)校正因色谱柱老化等引起的保留时间漂移。以37种有可靠logKow实验值的苯系物、PAHs、PCDD/Fs类似物为模型化合物,建立了logKow和外推至纯水相的保留因子logkw的定量结构-色谱保留关系(QSRR)模型,回归方程为logKow=(1.18±0.02)logkw+(0.36±0.11),其相关系数(R2)为0.985,交叉验证相关系数(R2cv)为0.983,标准偏差(SD)为0.16。进而,用4个已有可靠logKow实验值的验证化合物(联苯、芴、PCDD 1和PCDF 114)对模型进行了外部验证,表明RP-HPLC测得的logKow值与摇瓶法/慢搅法结果有很好的一致性,尤其是对疏水性强的化合物。采用该模型测定了29种特别受关注的POPs的logKow值,这些化合物的logKow实验值均未见报道。所建立的DP-RTC-HPLC是测定强疏水性POPs的logKow值的一种值得推荐的方法。     

分散液-液微萃取技术在污染物分析中的应用

分散液-液微萃取技术是一种新型的、具有巨大潜力的样品前处理技术,已经越来越多地被应用到多种污染物的富集过程中。此方法具有简单、快速、价格低廉、环境友好、回收率和富集倍数高等优点。近年来,作为一种可行的分析技术,分散液-液微萃取技术获得了持续的关注和广泛应用。该文综述了分散液-液微萃取技术的研究进展及其在不同介质污染物分析中的应用。     

Efficient removal for multiple pollutants via Ag2O/BiOBr heterojunction: A promoted photocatalytic process by valid electron transfer pathway

Multiple pollutants including pathogenic microorganism contaminations and emerging organic contaminations (EOCs) have shown a growing threat to the environment, especially the natural waters. However, the control and removal of pathogenic microorganism contaminations and EOCs have been greatly limited since limited knowledge of their environmental behaviors. Thus, a novel and efficient photocatalyst Ag₂O/BiOBr heterojunction was synthesized and used for removal of multiple pollutants including Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), tetracycline and acetaminophen under visible light. The results showed that there were valid electron transfer pathways between BiOBr and Ag₂O, the main electron transfer direction was the BiOBr to Ag₂O. Photo-generated electrons were stored in Ag₂O and thus separation efficiency between holes and photo-generated electrons was obviously enhanced. Active oxygen species were highly produced and eventually end up with the high efficiency of removal of multiple pollutants. For Ag₂O/BiOBr with Ag₂O content at 3% (the best performance) under visible light, log decrease of E. coli was 7.16 (removal efficiency was 100%) in 120 min, log decrease of S. aureus was 7.23 (removal efficiency was 100%) in 160 min, C/C₀ of tetracycline was 0.06 in 180 min, C/C₀ of acetaminophen was 0.17 in 180 min. This work could provide a promising candidate in the actual contaminated natural waters for cleaning multiple pollutants.     

环境化学开放性实验设计:重金属污染土壤的化学淋洗*

介绍了一个开放性环境化学实验。该实验以被重金属污染的土壤为研究对象,分别使用稀盐酸、乙二胺四乙酸、氯化钙为淋洗剂,对其进行化学淋洗修复。通过电感耦合等离子体光谱仪分析比较修复前后土壤中铅、镉的含量,用以帮助学生加深理解配合/螯合作用、酸-碱反应、离子交换反应、胶体的性质、土壤重金属形态、土壤性质与组成等相关环境化学知识。实验所用的土壤样品由学生自选,不同类型土壤的理化性质影响淋洗效果,从而增加了实验结果的不确定性。本实验贴近学科前沿且联系工程实际,可激发学生独立思考和探索精神,提高学生的科研能力与解决复杂问题的能力。     

基于钨(钼)酸铋半导体复合材料的合成及其在光催化降解中的应用

由于全球的工农业的迅速发展,水污染已成为人类所面临的最大危机。基于半导体光催化法是治理水污染的绿色技术之一,能够有效地降解和去除水中的污染物。在众多光催化材料中,金属氧化物半导体由于其具有低毒性、高稳定性和对水溶液中化学腐蚀的较高的抵抗力等优点,而被科学家们广泛地研究和应用。其中,三元组分的金属氧化物因其具有较窄的禁带宽度和可见光响应性质,在光催化降解领域上的能力已经超过其他的金属化合物。本文系统地介绍了两种典型的三元金属氧化物——钨酸铋和钼酸铋,围绕着基于钨酸铋和钼酸铋的复合型催化剂的制备和在光催化降解废水处理领域中的应用以及发展进行了综述,提出了目前关于钨酸铋和钼酸铋的复合材料的设计、机理研究和改性修饰方法中的所存在的主要问题,并对未来的发展趋势进行了展望。     

An overview of emerging pollutants in air: Method of analysis and potential public health concern from human environmental exposure

Air pollutants are perhaps the largest cause of diseases and death in the world today. Increasing urbanization and industrialization have caused an increase in number of diverse forms and types of new pollutants, which are difficult to detect and characterize due to their stench behaviour and complex sources of production. Such pollutants have been called emerging pollutants (EPs) and their list is ever increasing. Therefore, the understanding of the method of analysis and health implication of (EPs) in air is critical to providing a more robust understanding of exposure routes, regulations and mitigation. EPs in air discussed in this study are not in any way exhaustive but limited to emerging VOCs (including acrylonitrile, 1−3-butadiene, chloroform, dichloromethane, ethylene oxides, formaldehyde, toluene, trichloroethylene, 1,4-Dioxane) and metals (arsenic, manganese, and vanadium), ultrafine particles, micro- and nano- plastics, engineered nanoparticles, diesel/black carbon and bioaerosols. Occurrence, detection and health implications of these EPs in air are still unfolding due to limited monitoring studies, lack of standard methodology and regulations. To address this knowledge gap, authors conducted an in-depth review of available information. Their spatial distribution, analytical methods and health implications are discussed including the novel coronavirus (COVID-19) as a potential EP in air. The study concluded with highlights of gaps in knowledge and suggestions to key areas for future research. This information is of general interest to environmental scientists and of specific interest to both health and sanitation workers and policymakers at private, government and international organizations.