生物炭固定化微生物技术在去除水中污染物的应用研究进展

许多研究致力于固定化微生物技术在去除水环境中污染物方面的应用。生物炭具有高的比表面积、大的孔隙率、低成本和来源广等优势,生物炭与固定化微生物技术结合在处理水中污染物方面具有很大的应用潜力。因此,了解生物炭固定化微生物对水中污染物去除的作用机制对于其在环境修复和废水利用中的应用至关重要。文章综述了微生物固定化方法、载体的选择、生物炭作为载体材料在固定化微生物技术中的优势及应用以及生物炭固定化微生物在去除水中不同种污染物的应用及其作用机制。同时,还探讨了初始污染物浓度、pH、温度、接触时间和颗粒投加量等对生物炭固定化微生物对去除水中污染物的影响,并分析这些环境因素对微生物生长、生物炭特性以及污染物去除效果的影响。当前研究表明:生物炭相比于其他固定化载体而言更加适宜微生物的生长,生物炭固定化微生物去除污染物的主要作用机制是吸附和生物降解的协同作用,以及生物炭对微生物具有保护及快速定殖作用。另外,过高的初始浓度、过高或过低的pH和温度都会影响微生物的活性而不利于污染物的去除。生物炭固定化微生物颗粒对污染物的去除能力随着时间和颗粒投加量的增加而提高。此外,文章分析了生物炭固定化微生物技术在水环境应用中存在的问题,可为未来相关领域的研究提供参考。     

纳米颗粒对淡水藻类生长的影响:毒性机制与复合毒性

近年来,纳米颗粒在生活、工业生产中的应用日益广泛,而这些纳米颗粒的应用引起的一系列环境问题越来越被密切关注.纳米材料在使用过后不可避免地会释放到水环境中,不仅会影响水生生物的生长代谢,也会污染水体,影响水源水质.而藻类作为水生食物链的初级生产者,对于纳米颗粒在水环境中的积累和迁移起着至关重要的作用.本文首先总结了不同种类的纳米颗粒对水环境中不同藻类生长代谢的影响和相关的毒性机制,包括破坏细胞完整性、氧化应激胁迫、破坏光合系统、基因水平异常和有毒物质的释放等.其次,系统总结了纳米颗粒表面特性(如粒径、晶型、表面电荷、亲疏水性、光敏性、表面涂覆、老化和纳米颗粒的均相与非均相等)、水环境影响因素(如自然有机物质、环境胶体、离子强度、pH、硬度、光照和温度等)和藻类胞外聚合物对纳米材料毒性的影响.最后,还综述了水环境中关键污染物和纳米颗粒对藻类的复合毒性.对于纳米颗粒对水环境中藻类生长的毒性作用、影响机制以及复合毒性的系统总结,有利于全面了解纳米颗粒的环境行为和生物毒性.     

水环境中新烟碱类农药去除技术研究进展

新烟碱类农药的大量使用导致其在水环境中普遍存在,对生态系统和人体健康构成巨大威胁.传统的生物处理技术对新烟碱类农药几乎没有去除效果,高效的去除技术成为目前水环境领域的研究热点.本文系统分析了水环境中新烟碱类农药的来源、危害及污染现状,综述了物理、化学和生物去除技术的研究进展,重点讨论了高级氧化技术,详细阐述了不同技术对新烟碱类农药的去除效果、机理及影响因素等,并指出了各技术的应用优势和限制,最后对新烟碱类农药去除技术的研究提出了展望.     

不同高度大气颗粒物中多环芳烃的粒径分布

在天津地区20m,40m和60m三个不同高度同步采集冬季大气颗粒物中PM10样品,测定了16种多环芳烃(PAHs)含量．不同高度PM10中PAHs的含量均表现出大气颗粒物中随高度先增后降的趋势,颗粒物质量中值直径(MMD)也呈现类似规律,但PAHs总浓度的MMD则呈向上递增的趋势．不同高度PAHs的粒径分布差别不大,高分子量的PAHs主要集中在空气动力学直径Dp＜2um的细颗粒上,而Dp＞2um的粗颗粒上低分子量的PAHs相对较多．     

北京市地面街尘与径流中重金属的污染特征（Characteristics of Heavy Metals in Street Dusts and Urban Runoff in Beijing）

街尘作为城市各种污染物的载体和地表径流污染物的主要来源对水环境的影响日益受到关注.论文分析了北京市城区街尘与地表径流中重金属浓度和颗粒的粒径分布.结果表明:不同城市土地利用类型对街尘和径流中的重金属含量、颗粒粒径分布具有重要影响.在商业区、主要道路、住宅区、城中村4种土地利用类型中,街尘重金属浓度和地面单位面积重金属质量均以主要道路最高;径流重金属浓度由高到低顺序依次为:主要道路>城中村>居民区;主要道路和商业区街尘颗粒中细粒径占的比例较高,在全部土地利用类型的径流水样中颗粒物粒径分布差别不大;随着街尘中颗粒物粒径的减小,重金属浓度增加;街尘中小于149μm的颗粒物质量百分比和重金属浓度均较高,且在径流中这个粒径段的颗粒物含量也高,体积比达80%以上.建议在今后的城市街尘面源污染控制中应特别关注土地利用类型和街尘粒径的影响.     

复合塘-湿地系统水生植物时空分布对氮磷去除的影响

利用复合生态塘-湿地处理系统水生植物时空格局异质性,研究了水生植物分布对氮、磷去除影响.结果表明,水生植物种类和数量的分布差异导致各单元氮、磷去除呈现不同的周期变化;水生植物主要通过改变硝化/反硝化进程、自身代谢和化学沉降速率影响NH3、NOx-、有机氮和总磷的去除.系统不同单元中氮、磷去除机制差异决定了NH3和总磷主要在曝气养鱼塘(去除率分别为29.5%、30.1%)、鱼塘(16.9%、17.8%)和水生植物塘(24.5%、19.4%)去除;NOx-主要在芦苇湿地(出水<0.4 mg/L)去除;而有机氮则主要在复合兼性塘(32.3%)和鱼塘(28.1%)去除.此外,生态塘出水中水生植物绝大部分被芦苇湿地所截滤,它们的腐败/释放导致湿地中NH3和总磷的表观去除率偏低(分别小于8.5%和11.5%).     

水体中金属(氧化物)纳米颗粒的环境行为与污染控制研究进展

金属(氧化物)纳米材料在生产和使用过程中,可以通过各种途径进入到水环境中,对水生生物、生态环境和人体健康产生威胁.理解纳米颗粒在水体中的环境行为,对于评估纳米材料的归趋及其对环境和人体的健康风险至关重要.本文概述了金属(氧化物)纳米颗粒的性质、来源和毒性危害,汇总了表征纳米颗粒浓度、粒径及形貌的分析方法与技术,分析了它们在水环境中的环境行为以及影响其稳定性的主要环境因素,并总结了水体中金属(氧化物)纳米颗粒的去除方法和效果的最新研究进展.随着金属(氧化物)纳米材料的广泛应用,未来有必要加强对自然水体中纳米颗粒环境行为的研究,并系统开展纳米颗粒健康风险评估工作,为预测纳米材料进入水环境后的归趋和风险提供科学依据.     

柳州市大气颗粒物中多环芳烃的分布特征及来源

采用气相色谱/质谱联用技术(GC/MS)检测了柳州市大气颗粒物样品中的PAHs,比较了柳州市各区大气颗粒物中多环芳烃含量的差异以及不同季节对多环芳烃含量的影响,讨论了其分布规律及污染源。     

长江水体分散颗粒物对对乙酰氨基酚光降解的影响

研究了药物对乙酰氨基酚在长江水体颗粒物表面的吸附及颗粒分散体系中的光降解规律,探讨了体系pH、颗粒物浓度及加入柠檬酸、草酸、腐殖酸对对乙酰氨基酚光降解的影响.结果表明,对乙酰氨基酚在颗粒物表面的吸附符合Langmuir型吸附等温式,分散颗粒物可以促进对乙酰氨基酚的光降解,光降解符合一级反应动力学规律;pH=9时光降解速率最快;加入草酸、柠檬酸可以加快对乙酰氨基酚的光降解,而腐殖酸则抑制其光降解.     

珠江下游不同水体中金属元素在颗粒相和胶体相中的分布和分配

为了研究不同水体中重金属在颗粒相和胶体相中的分布特征,运用连续流离心机、切面流超滤分离技术(UF)和反渗透技术(RO),从流花湖公园的湖泊和珠江下游的水库、河流、河口共4种水体中分离了大量的颗粒物、胶体,然后用电感耦合等离子体/质谱(ICP-MS)对其中的重金属进行了定量分析。对比不同水体中颗粒态重金属的浓度(ng·L~(-1))的季节变化,发现春季受降水影响,重金属的浓度最高。通过比较颗粒物、UF-胶体和RO-胶体中重金属的浓度,可以得到重金属在颗粒物、不同粒径的胶体中的分布情况。结果显示富营养化程度高的湖泊水体(LHH)中,大多数重金属主要分布在颗粒相中。河口中Cr、Mn、Zn、Pb、Co、Ag、Cd这些主要由人类活动产生的重金属,受河口絮凝沉降作用的影响,主要存在于大分子颗粒相中。不同水体中重金属在两相中和在胶体中的分配情况各不相同,说明重金属在两相中的分配与颗粒物、胶体及重金属的性质有关。     

Estimating the removal of atmospheric particulate pollution by the urban tree canopy in Beijing北大核心CSCD

Urban green space, particularly the tree canopy, plays an important role in potential mitigation against atmospheric particulate pollution and protecting human health. In this study, current and future air particulate matter [including total suspended particulate (TSP), particulate matter 10 (PM10), and particulate matter 2.5 (PM2.5)] removal by the urban tree canopy of Beijing was estimated. A modeling approach was used based on the distributed measurement evaluation and a modified version. The urban tree canopy of Beijing, including mostly Platycladus sp., Pinus sp., Quercus sp., Robinia pseudoacacia, and economic forests, currently removes about 8.33 million kg/a air particulates, in which TSP accounted for 4.51 million kg/a, PM10 accounted for 2.74 million kg/a, and PM2.5 accounted for 1.08 million kg/a. The study on the removal of air particulates by different aged tree canopies showed that in coniferous trees, the ability to capture air particulates changed in the order of mature and over-mature > near-mature forest > young forest; in broadleaf forest, the ability changed in the order of near-mature forest > mature and over-mature > young forest. For total particulate matter, the biggest contribution was coarse particulates (60.74%); the contribution rate of fine particulates was different owing to different tree species groups. The results suggested that the ability of different trees to capture particles and age of forests varied widely and that suitable trees should be chosen to enhance pollution mitigation for city greening. © 2018 Science Press. All rights reserved.     

Partikelentfernung in der Trinkwasseraufbereitung: Problematiken und Lösungsansätze

The drinking water treatment plant (WTP) in Irsch-Treves is one of the WTPs operated by the Public Utility Company of Treves (SWT) responsible for supplying the city of Treves with drinking water. This treatment plant has been responsible for the treatment of raw, soft water from the oligotrophic reservoir Riveris since 1958. The main functions of the WTP are the removal of particulate matter, manganese, iron, aluminium and organic material, especially humic substances. The removal of particulate matter such as bacteria, other microorganisms and plankton is very important to ensure a microbiologically and hygienically stable drinking water. Insufficient removal of particulate manganese may lead to manganese scaling in the supply system and, in extreme conditions, may lead to a brown-coloured drinking water. The so called Multi-Barrier-System is being used in the entire water treatment process. Under this system, great importance is given to the monitoring of the catchment area, the inflows, and the reservoirs. After a preliminary and subsequent sedimentation and biological treatment in the preliminary and in the main reservoirs respectively, the raw water is finally treated through flocculation filtration over the rapid multi-layer sand filters in the WTP Irsch. With this approach, only a rigid application of the above mentioned steps and the application of the latest recognized technology to maintain the supply system can best guarantee a constant supply of clean drinking water. Online particle count in raw water and in drinking water is one of the main quality control measures applied in the WTP Irsch. The conventional flocculation filtration is not always able to fulfil the increasing quality demands for drinking water, especially during adverse raw water quality conditions. This is the reason why more and more membrane filtration units are currently being installed in completely new plants, as substitutes in conventional plants, or for upgrade purposes. The SWT is currently planning an enlargement and upgrade of the WTP Irsch, integrating ultrafiltration, which was successfully tested in a pilot study. The upgrade of the elimination of particulate matter is one of the most important targets, after the enlargement and upgrade of the plant.     

济南市不同来源大气颗粒物的特征分析

本文对济南市几个典型来源的大气颗粒物用Ｘ光光电子能谱和电子自共振波谱仪（ＥＳＲ）进行表征,并模型酸雨对这些颗粒物进行了淋洗,分析淋洗液中的金属含量,结果表明：电厂颗粒物中的硫主要以ＳＯ３,ＳＯ＾２－４,ＳＯ２,ＳＯ＾２－３和Ｓ等多种形式存在,钢厂颗粒物中的表面硫主要以ＳＯ＾２－４和Ｓ＾２－的形式存在,炼油厂颗粒表面硫以ＳＯ＾２－４和ＳＯ２的形式存在,但颗粒物内层的硫主要以ＳＯ＾２－４形式存在,而且     

气溶胶中正构烷烃的碳优先指数研究

本文研究了北京、广州两地不同季节气溶胶颗粒物上正构烷烃的碳优先指数值(CPI)随季节和颗粒物粒径的变化规律。结果表明,北京地区气溶胶中正构烷烃的CPI值:春>夏>秋>冬;广州地区为冬>春>夏,显示了不同的地区特征,而且随着气溶胶颗粒物粒径的减小,正构烷烃的CPI值亦减小。     

兰州市大气颗粒物中水溶性离子研究

本文对兰州市不同季节大气颗粒物中水溶性离子的主要理化特性及其与降水的关系进行了研究，认为大气颗粒物中水溶性离子是当地降水中ＳＯ４＾２－，Ｃａ＾２＋，Ｃｌ＾－等主要离子的来源。在１３种被测的水溶物中，ＳＯ４＾２－和Ｃａ＾２＋离子所占比例较高，分别占总离子的３１．４％和２７．８％，年均浓度值为１０．７２μｇ／ｍ＾３和３．９６μｇ／ｍ＾３。同时大气颗粒物中水溶物浓度与ＳＯ２，ＴＳＰ等大气污染物浓度之间也     

单甲脒盐酸盐农药在水体悬浮颗粒物上的吸附行为

用批量平衡法研究了单甲脒农药在三种水体悬浮颗粒物上的吸附规律，所得数据进行回分析后，发现吸附规律符合Ｆｒｅｕｎｄｉｌｉｃｈ方程，并且在悬浮颗粒物上的吸附能力随着颗粒物中有机碳含量的增加而稍有减少。     

铅在模拟预处理稳定塘中的归宿

本文较全面地研究了城市污水中的铅在模拟预处理稳定塘中的归宿。不论在哪种预处理稳定塘中,悬浮颗粒态锅的沉降作用是去除污水中铅的主要作用。进入城市污水中的铅,大部分和污水中的悬浮物结合转变成悬浮颗粒态铅,它们输入到模拟预处理预处理稳定塘,这些悬浮颗粒态铅即可在很短的时间内（１ｄ）通过沉降作用得以有效地去除。停留时间分别为１,２,３,５和１０ｄ的实验表明,模拟预处理稳定塘对城市污水中铅的去除率可达５２－     

Magneto-biomonitoring of intra-urban spatial variations of particulate matter using tree leaves

Preliminary mineral magnetic results from a pilot project investigating the suitability of roadside tree leaves as depositories of vehicular pollution are presented. Tree leaf surfaces (Lime: Tilia europaea; Sycamore: Acer pseudoplatanus) at four roadside and one woodland location in Wolverhampton, UK, have been monitored (July 2003 to November 2003). Mineral magnetic technologies have revealed spatial variations of particulate pollution concentration throughout the conurbation and data analysis indicates that magnetic concentration parameters are suitable proxies for fine particulate pollution, which are particularly hazardous to health. Site-specific traffic management and associated vehicle behaviour appear to be chiefly responsible for the magnetic concentration differences between sites. Magneto-biomonitoring in this way allows the high-resolution spatial mapping of particulate matter (PM) pollution, which may also benefit epidemiology in better assessing exposure to vehicular-derived particulates. Given the speed, measurement sensitivity and non-destructive nature of the technique, it is proposed that this low-cost approach offers some advantages over centralised monitoring stations to monitor urban roadside particulate pollution.     

Gas-phase and aerosol chemistry interactions in South Europe and the Mediterranean region

The atmospheric chemical composition is affected by the interaction mechanisms among gases and particulate matter through a wide range of chemical reactions that can occur with the aid of particulate matter (e.g. particles act as reacting or absorbing surfaces) or be influenced by the presence of particulate matter in the atmosphere (photochemical reactions). Physical and chemical processes are also bonded in an interactive way that often leads to the influence of the radiation budget, cloud physics and the warming or cooling of the lower atmospheric levels. The Euro-Mediterranean region is a key-sensitive area due to the unique climatic and air quality characteristics associated with the regional climatic patterns, geomorphology (land and water contrast) and coexistence of pollutants from different origin. Focusing on this region, the gas-aerosol interactions are studied using state-of-the-art atmospheric and chemical transport modeling tools following the necessary development in the chemical transport model CAMx. Sensitivity and large-scale simulations have shown significant responses of the modeling system to the inclusion of natural species emissions, the direct shading effect of dust particles on photochemical processes and the formation of new types of aerosols through heterogeneous uptake of gases on dust particles. Including such interactions in the chemical transport model often led to the improvement of the model performance compared with available measurements in the region.