污染场地土壤气被动采样技术研究进展

在VOCs（挥发性有机物）污染场地调查中,土壤气采样的重要性日益受到重视.常规的土壤气采样主要依赖吸附管和采样罐等主动采样方法,但主动采样有很多缺点.作为一种新兴的采样技术,被动采样具有成本低、操作简单、更能代表长时间人体暴露、可用于低渗透性地层等优点,已经成为污染场地调查领域的研究热点.对被动采样的理论基础、采样器类型、吸附剂类型、采样误差的来源进行了介绍,对土壤气被动采样中存在的技术难题以及前沿研究方向进行了讨论,并对该技术在我国场地调查领域的应用前景进行了展望和建议.结果表明:在被动采样中准确控制采样器的采样速率（uptake rate）是保证其定量能力的关键,当控制采样速率低于土壤气中VOCs的补给速率时,可以实现良好的定量效果.影响采样速率的主要因素包括待测VOCs的性质、吸附剂种类、采样器结构以及各类环境因素,挥发性强的VOCs较难被捕集且容易发生逃逸.不同被动采样器用于不同种类VOCs采样时的采样速率可以相差6个数量级,从最低的0.005 5 mL/min到最高的125 mL/min.因此,建议在实际采样中应选用结构合理的采样器,控制采样速率不宜过大,以降低饥饿效应的产生;应选用与待测物匹配的吸附剂,对待测物兼具良好的保留能力和脱附能力;应加强环境因素（温度、湿度、土壤性质）对采样速率影响机制及场地校准方法的研究;应该结合研究和实践经验制定符合我国国情的土壤气被动采样技术指南.      

Assessment of Urban Air Quality in South Estonia by Simple Measures

In countries having limited resources, it is difficult to assess urban air quality on contemporaneously, due to the absence of on-line information about air pollution levels and emission rates. An alternative approach is recommended for smaller cities with lower demands of resources. The applied scheme consists of a database of air pollution sources (NO _x and CO from industry, traffic, and domestic heating), the simple Gaussian-plume model AEROPOL and a series of measurements by passive monitors. This method was used in Tartu, a small city situated in the valley of the river Emajõgi, within a landscape with noteworthy topographical variations. Simulations of annual average and maximal concentrations were performed, and a fair agreement obtained with NO₂ monitoring results from passive Palmes monitors. Inventories of pollution sources in 1998 revealed that official statistics of stationary sources covered 64% of SO₂,36% of CO, 37% of NO _x and 32% of total particulate matter emissions. Recommendations for measures for reducing air pollution levels and for further investigations towards improving air quality assessment and management, are given.     

被动式个体采样器在环境监测中的应用

本文报道了用被动式个体采样器监测空气小常见污染物ＮＯ２，ＳＯ２．提出了样品测定之前对每种污染物的具体实验要求。对济南市有关场所空气进行了监测。总结了个体采样器的优点。     

新型吸附搅拌棒被动采样器研制及应用——基于多壁碳纳米管的改性

结合传统被动采样器原理和新发展的吸附搅拌棒技术,研制了以多壁碳纳米管-聚二甲基硅氧烷(MWCTNs/PDMS)作为涂层的新型吸附搅拌棒被动采样器,并以苯酚(PhOH)、己烯雌酚(DES)和铅(Pb)作为目标污染物,考察被动采样器其吸附性能,优化其吸附条件.结果表明,与商业化PDMS涂层吸附搅拌棒被动采样器相比,含MWCTNs/PDMS涂层吸附搅拌棒被动采样器能更快达到吸附平衡时间、具有更大的饱和吸附容量.甲醇是PhOH和DES优良解吸剂,0.6mol/L HNO₃为Pb最优解吸剂.该新型被动采样器重复使用50次以上其解吸效率仍能达到70%以上,具有良好的稳定性和重复利用效果.     

上海市环境空气臭氧浓度时空分布特征的调查

上海市机动车保有量逐渐增加,为监测机动车尾气造成的氧化型光化学烟雾的污染,采用被动扩散管的监测方法在上海市大面积布设点位,经连续１４个月的监测,得出上海市环境空气中臭氧（Ｏ３）浓度的时分布特征。     

Attenuation of metal species in acidic solutions using bentonite clay: implications for acid mine drainage remediation

A laboratory batch experimental study has been carried out to evaluate the adsorption capacity of selected metal species in acid mine drainage (AMD) by bentonite clay. Bentonite clay was mixed with simulated AMD at specific solid–liquid (S/L) ratios and agitated in a reciprocating shaker and adsorption of selected toxic metals assessed over time. Cation exchange capacity varied from 1140 to 1290 meq kg^?1. Contact of AMD with bentonite leads to increase in pH and a possible reduction in electrical conductivity and total dissolved solids. At constant agitation time of 60 min, the pH increased with dosage of bentonite. Removal of Mn²⁺, Al ³⁺, and Fe³⁺ was observed to be greatest at 60 min of agitation. Bentonite clay exhibits high adsorption for Al³⁺ and Fe³⁺ at concentration less than 300 mg L^?1, while the capacity for Mn²⁺ was observed to be lower. Adsorption capacity for SO₄^2? was low with a great percentage of the SO₄^2? remaining in solution. Adsorption capacity of bentonite with more complex formulated AMD and gold tailing leachates was low for Fe³⁺, Al³⁺, and Mn²⁺. This indicates that optimum adsorption of bentonite clay is dependent on the chemistry of the AMD and its application might be site specific.     

Air monitoring of solvent exposed workers with passive samplers in comparison to “biological monitoring (BM)"†

A study was performed comparing ambient air monitoring (AM) and biological monitoring (BM) in order to evaluate the reliability of passive sampling (PS) in occupational medicine.

Five groups of persons (total number = 188) exposed to tetrachloroethene, isopropanol, toluene, xylene and styrene at the workplace were examined.

AM was performed over several hours using one or two brands of passive samplers (Monitor 3500 and/or ORSA 5). BM includes the determination of the solvent and specific metabolites resp. in blood or urine samples taken at the end of workshift. On the basis of our results we recommend that PS can supply relevant data for the estimation of external exposure to several solvents like chlorinated‐ and aromatic‐hydrocarbons.     

污染场地土壤气中VOCs定量被动采样技术研究及应用

污染场地中土壤气样品的采集是蒸气入侵风险评估的关键,目前最常用的主动土壤气采集技术包括真空苏玛罐和泵吸附管,其操作繁琐、成本高、易受多种因素影响、只能采集短时间的浓度.土壤气定量被动采样技术是一种新兴的采样技术,很好地克服了主动式采样存在的不足,是目前污染场地中土壤气调查的研究热点.通过总结现有研究,就定量被动采样技术的理论、被动采样器吸附剂和外壳材料的选择、被动采样器吸附速率的研究及定量被动采样在污染场地中的应用进行论述.综合研究发现,只要严格控制吸附速率,被动采样能够提供准确的定量土壤气浓度测量;采样器结构的设计、外壳材料的选择能够有效控制吸附速率;吸附速率受环境因素和土壤性质的影响,场地校正是获得准确结果的有效途径.我国在土壤气采样领域的研究刚刚起步,建议:加大高效、广谱型或混合型吸附材料及相应测试方法和设备的研发;加强吸附速率的影响因子及场地校准方法的研究;加强土壤钻孔内土壤气的补给速率的模型和场地实测研究;增加不同种采样器的现场应用比较研究;进行适合我国国情的技术标准的研究与制订.      

贵州煤矿酸性废水“被动处理”技术的新方法探讨

论文在综述国内外有关酸性矿山废水治理的现行技术和方法的基础上,围绕贵州煤矿废水排放的现状及特点,把贵州煤矿废水归纳为两种主要类型,并针对性地提出两种预防和治理矿山酸性排水的方法:对正在开采矿山实行碳酸盐岩充填采空区技术,避免酸性矿山水外排;对废弃矿山排水采取坑口"(有氧/缺氧)垂向折流式反应池"技术,对酸性废水进行有效治理。     

应用被动采样监测技术研究区域空气污染特征

应用被动式吸收采样监测技术,在辽宁省中部城市群区域首次开展了包括城市、市郊、农村地区空气SO2,NO2环境质量调查,将被动监测数据绘制成污染物浓度图,对区域环境空气污染的特点、浓度分布及城市间污染的相互影响进行了分析研究。