固相萃取—气相色谱—质谱测定再生水中邻苯二甲酸酯类物质

探讨了一种再生水中邻苯二甲酸酯类物质的测定方法——固相萃取—气相色谱—质谱,检测了相关再生水标准中涉及的邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二(2-乙基己基)酯(DEHP)两类物质。在质量浓度为20～1 000μg/L时,两类物质的回归方程的相关系数均大于0.999,检出限分别是0.060、0.002μg/L,DBP、DEHP的相对标准偏差分别为4.1%～7.4%、5.1%～6.1%。利用固相萃取技术进行预处理,平均加标回收率为96.6%、89.6%。检测了北京市4座再生水厂出水中DBP和DEHP含量,其中,DBP在1.74～5.59μg/L,低于《城市污水再生利用景观环境用水水质》(GB/T 18921—2002)规定的限值(不超过0.1mg/L),但高于《城市污水再生利用地下水回灌水质》(GB/T 19772—2005)规定的限值(不超过3μg/L);DEHP在0.42～4.93μg/L,满足GB/T 19772—2005要求(不超过8μg/L)。     

原位热处理技术修复重质非水相液体污染场地研究进展

重质非水相液体(DNAPLs)是土壤及地下水中广泛存在的有机污染物,原位热处理技术是目前修复受DNAPLs污染土壤及地下水的最具潜力的技术之一。综述了国内外常用原位热处理技术的基本原理及其影响因素,介绍了相关现场应用实例,并展望了该技术未来的应用前景和发展趋势,以期为中国污染土壤及地下水的原位修复提供有益借鉴。     

Facilitating substance phase‐out through material information systems and improving environmental impacts in the recycling stage of a product

The amount of electrical and electronic products is increasing rapidly, and this inevitably leads to the generation of large quantities of waste from these goods. Some of the generated e‐waste ends up in regions with sub‐standard recycling systems and may be processed under poor conditions. During uncontrolled incineration, halogenated dioxins and furans can be generated from brominated and chlorinated compounds in the products. In order to reduce the health and environmental risks involved in the recycling stage of the life cycle of electronics, an effective design‐for‐environment process must be established during the product development phase. Knowledge of the chemical substances in the product is crucial to being able to make informed decisions. Through full knowledge of the material content of procured components, phase‐outs of unwanted substances, such as halogenated substances, can be performed in an effective manner. Therefore, information is the key to success in phasing‐out substances; facilitating compliance of legal provisions for manufacturers of electrical and electronic devices; and improving the environmental footprint of products as they reach the end of the life cycle. After an introduction to the challenges of electronics waste management, this paper describes supply chain information systems and how they are used to facilitate substance phase‐outs in the electronics industry. Sony Ericsson has been working with phase‐outs of unwanted substances since it was founded in 2001. Through the introduction of a material declaration system that keeps track of all substances in the components used in the company's products, Sony Ericsson has been able to replace unwanted substances to improve environmental impacts at the recycling stage of a product.     

Evaluation of C18 solid‐phase extraction cartridges for the isolation of select pesticides and metabolites

Abstract

Nine different C₁₈ solid‐phase extraction (SPE) cartridges were evaluated for their efficiency at extracting nine pesticides and two s‐triazine metabolites from spiked deionized water samples. The SPE cartridges were found to contain nitrogen (N) and/or phosphorus (P) contaminants and varied in their extraction efficiency for certain pesticides and metabolites. Four of the nine SPE cartridges gave acceptable (70 to 120%) pesticide and metabolite recovery percentages, while five cartridges had marginal (50 to 70%) to poor (< 50%) recoveries. Statistical analyses showed that the poor to marginal recoveries found for three compounds could not be explained by considering several indigenous chemical and physical traits of the cartridge. It is suggested that proper SPE cartridge selection for pesticide recovery should be evaluated using several different cartridges.     

Environmental monitoring of complex hydrocarbon mixtures in water and soil samples after solid phase microextraction using PVC/MWCNTs nanocomposite fiber

A novel nanocomposite based on incorporation of multiwalled carbon nanotubes (MWCNTs) in polyvinyl chloride (PVC) was prepared. Proposed nanocomposite was coated on stainless steel wire by deep coating. Composition of nanocomposite was optimized based on results of morphological studies using scanning electron microscopy. The best composition (83% MWCNTs:17% PVC) was applied as a solid phase microextraction fiber. Complex mixture of aromatic (BTEX) and aliphatic hydrocarbons (C₅–C₃₄) were selected as model analytes, and performance of proposed fiber in extraction of the studied compounds from water and soil samples was evaluated. Analytical merits of the method for water samples (LODs = 0.10–1.10 ng L⁻¹, r² = 0.9940–0.9994) and for soil samples (LODs = 0.10–0.77 ng kg⁻¹, r² = 0.9946–0.9994) showed excellent characteristics of it in ultra trace determination of petroleum type environmental pollutants. Finally, the method was used for determination of target analytes in river water, industrial effluent and soil samples.     

零价铁类Fenton试剂氧化降解废水中有机污染物的研究进展

综述了近年来国内外Fe0类Fenton试剂氧化反应降解废水中有机污染物的研究现状,介绍了Fe0-H2O2体系、紫外光-Fe0-H2O2体系和可见光-Fe0-H2O2体系处理有机污染物的机理、特点和效果,并对未来Fe0类Fenton试剂氧化反应体系处理有机污染物的发展前景进行了展望。     

曝气强度对同时硝化反硝化（SND）脱氮过程中N2O排放的影响

为了控制污水脱氮中N2O排放,在不同曝气强度下研究了好氧硝化段同时硝化反硝化（SND）系统的N2O排放特性,并采用PCR—DGGE技术分析微生物群落特征。结果发现,随着曝气强度的增强,系统总氮去除率下降,但脱氮中N2O—N所占比例则上升,实验中从低到高3个曝气强度下,总氮去除率分别为80．01％、65．28％和58．62％,脱氮中N2O—N所占的比例为1．89％、7．84％和9．20％。PCR—DGGE分析显示,和低曝气强度下相比中、高曝气强度下系统微生物群落发生明显变化,但中曝气强度和高曝气强度下系统微生物群落表现出较高相似性。这表明,不同曝气强度下系统N2O排放受到氮素转化和微生物群落变化的影响。适宜曝气强度不仅提高总氮去除率,还可有效控制N2O排放。     

β-环糊精接枝羧甲基壳聚糖吸附剂的制备及其性能

采用γ-氨丙基三乙氧基硅烷化学修饰活化后的硅胶,以戊二醛为交联剂,接上羧甲基壳聚糖,继而接枝上β-环糊精作为功能单体,制备了一种用于分离富集水样中Cu(Ⅱ)的固相萃取新材料。利用红外光谱(FT-IR)、比表面分析(BET)、X射线衍射光谱(XRD)以及热重分析(TG)等方法对吸附剂进行结构表征。采用火焰原子吸收(FAAS)作为检测手段,考察了溶液p H、振荡时间、吸附剂用量、样品流速、洗脱液浓度和体积等对吸附剂吸附Cu(Ⅱ)的影响。吸附剂饱和吸附容量为9.37 mg/g,最大富集倍数高达350。吸附过程能用准二级动力学模型和Langmuir等温吸附方程进行很好的拟合。应用于环境水样中Cu(Ⅱ)的分离富集与测定,回收率在96.8%~105.2%之间,效果较好。     

高效液相色谱-串联质谱法同时检测地表水中13种药物及个人护理品

采用高效液相色谱-串联质谱(HPLC-MS/MS)检测,建立了地表水中13种药物及个人护理品的测定方法。水样用盐酸与氢氧化钠溶液调p H值至7.0左右,过固相萃取小柱进行富集,用14 m L甲醇洗脱。以C18柱为分离柱,0.01%甲酸的甲醇-0.01%甲酸水溶液为流动相,目标物在10 min内分离,在0.50~250μg/L范围内,13种化合物峰面积与内标物质峰面积之比与质量浓度的线性关系良好(0.99),检出限在0.05~0.5 ng/L范围内。基质加标实验结果表明,13种化合物在水中的回收率分别在56.2%~123.2%之间(加标水平5 ng/m L)和58.0%~107.8%(加标水平50 ng/m L),相对标准偏差在1.60%~19.9%(n=6)之间。应用该方法测定了从2条纳污河流采集的10份水样,结果表明,除美托诺尔和普洛萘尔未被检出外,其余11药物的检出频率在30%~100%之间。在13种目标物质中,咖啡因的检测浓度最高达287.5ng/L,舒必利次之,为277.5 ng/L。本方法快速、准确,适用于地表水中PPCPs类的快速测定。     

纳米TiO2/CNTs复合材料的制备及其光学性质

TiO2在碳纳米管上的复合材料可以增加材料的光催化性能,已成为新的研究热点.本文采用低温液相法成功地合成了TiO2/CNTs复合材料,并用TEM、XRD和UV-vis对材料进行了表征,结果表明,TiO2很好地分散在CNTs上,具有显著的催化效果,有很好的应用前景.