Persistent organochlorine contaminants in hair samples of Northern Poland population, 1968-2009

The European regulation on chemicals, REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), came into force on 1 June 2007. With pre-registration complete in 2008, data for these substances may provide an overview of the expected chemical space and its characteristics. In this paper, using various in silico computation tools, we evaluate 48 782 neutral organic compounds from the list to identify hazardous and safe compounds. Two different classification schemes (modified Verhaar and ECOSAR) identified between 17% and 25% of the compounds as expressing only baseline toxicity (narcosis). A smaller portion could be identified as reactive (19%) or specifically acting (2.7%), while the majority were non-assigned (61%). Overall environmental persistence, bioaccumulation and long-range transport potential were evaluated using structure-activity relationships and a multimedia fugacity-based model. A surprisingly high proportion of compounds (20%), mainly aromatic and halogenated, had a very high estimated persistence (>195 d). The proportion of compounds with a very high estimated bioconcentration or bioaccumulation factor (>5000) was substantially less (6.9%). Finally, a list was compiled of those compounds within the applicability domain of the models used, meeting both persistence and bioaccumulation criteria, and with a long-range transport potential comparable to PCB. This list of 68 potential persistent organic pollutants contained many well-known compounds (all halogenated), but notably also five fluorinated compounds that were not included in the EINECS inventory. This study demonstrates the usability of in silico tools for identification of potentially environmentally hazardous chemicals.     

Heavy metal pollution status in surface sediments of Swan Lake lagoon and Rongcheng Bay in the northern Yellow Sea

The national ‘Shandong Peninsula Blue Economic Zone Development Plan’ compels the further understanding of the distribution and potential risk of metals pollution in the east coast of China, where the rapid economic and urban development have been taken off and metal pollution has become a noticeable problem. Surface sediments collected from the largest swan habitat in Asia, the Swan Lake lagoon and the surrounding coastal area in Rongcheng Bay in northern Yellow Sea, were analyzed for the total metal concentrations and chemical phase partitioning of five heavy metals (Cu, Zn, Pb, Cd, and Cr). Metal contents in the studied region have increased significantly in the past decade. The speciation analyzed by the sequential extraction showed that Zn and Cr were present dominantly in the residual fraction and thus of low bioavailability, while Cd, Pb and Cu were found mostly in the non-residual fraction thus of high potential availability, indicating significant anthropogenic sources. Among the five metals, Cd is the most outstanding pollutant and presents high risk, and half of the surface sediments in the studied region had a 21% probability of toxicity based on the mean Effect Range-Median Quotient. At some stations with comparable total metal contents, remarkably different non-residual fraction portions were determined, pointing out that site-specific risk assessment integrating speciation is crucial for better management practices of coastal sediments.     

广州市灰霾期PM10的化学组成对能见度的影响

采集广州市大气可吸入颗粒物(PM10)样品,并分别对冬、夏两季灰霾和非灰霾期PM10中有机碳(OC)、元素碳(EC)和水溶性离子进行分析。广州市灰霾期大气PM10中的主要化学成分按质量浓度大小排序为OC>NO3->SO24->NH4+>EC(非灰霾期则依次为OC>SO24->EC>NH4+>NO3-),其质量浓度分别为非灰霾期的4.7、12.5、3.7、3.2和2.3倍。相关性分析表明,灰霾期总碳[TC(OC+EC)]及NO3-的质量浓度对大气能见度的降低起主要作用,而非灰霾期则主要是TC和SO24-。     

淄博化工园区大气有机污染应急监测与管理对策

针对工业聚集区内多种恶臭混杂的情况,以淄博化工园区为例,研究了大气有机污染突发事件中有机物的应急监测方法,并提出了治理对策。利用便携式气相色谱-质谱联用仪,对重点企业事先监测,掌握各企业特征污染物,作为应急监测查找污染源头的依据;现场分析受污染空气中的化合物组成及浓度,通过查询、比对各企业特征污染物,确认责任排污企业。提出了末端监测处罚治理与对重点污染企业推行清洁生产相结合,应急监测与有机污染物在线监测相结合,建立企业污染源特征组分数据库,加强企业无组织排放监测与监管等治理大气有机污染的建议。     

南京市典型水域沉积物中重金属形态分布特征

采用顺序提取的方法对南京市典型河流和湖泊水域的沉积物进行重金属化学形态研究,分析了Cu、Zn、Pb、Cd、Ni、Cr 6种重金属元素在不同水体沉积物中各个形态赋存的含量分布特征。结果表明,6种元素生物有效性排序为:Cd PbZn Cu Ni Cr,其中Cd和Pb以弱酸提取态和可还原态为主要存在形态,其不仅会对上覆水体产生二次污染,对水生动植物也具有较强的危害性。另外,通过结果间接反映出受人类生产生活影响大的水体,受污染的程度更高,各种金属元素赋存的形态也更易迁移转化,在环境治理方面更应受到重视。     

Potential bioavailability of mercury in humus-coated clay minerals

It is well-known that both clay and organic matter in soils play a key role in mercury biogeochemistry, while their combined effect is less studied. In this study, kaolinite, vermiculite, and montmorillonite were coated or not with humus, and spiked with inorganic mercury (IHg) or methylmercury (MeHg). The potential bioavailability of mercury to plants or deposit-feeders was assessed by CaCl₂ or bovine serum albumin (BSA) extraction. For uncoated clay, IHg or MeHg extraction was generally lower in montmorillonite, due to its greater number of functional groups. Humus coating increased partitioning of IHg (0.5%–13.7%) and MeHg (0.8%–52.9%) in clay, because clay-sorbed humus provided more strong binding sites for mercury. Furthermore, humus coating led to a decrease in IHg (3.0%–59.8% for CaCl₂ and 2.1%–5.0% for BSA) and MeHg (8.9%–74.6% for CaCl₂ and 0.5%–8.2% for BSA) extraction, due to strong binding between mercury and clay-sorbed humus. Among various humus-coated clay particles, mercury extraction by CaCl₂ (mainly through cation exchange) was lowest in humus-coated vermiculite, explained by the strong binding between humus and vermiculite. The inhibitory effect of humus on mercury bioavailability was also evidenced by the negative relationship between mercury extraction by CaCl₂ and mercury in the organo-complexed fraction. In contrast, extraction of mercury by BSA (principally through complexation) was lowest in humus-coated montmorillonite. This was because BSA itself could be extensively sorbed onto montmorillonite. Results suggested that humus-coated clay could substantially decrease the potential bioavailability of mercury in soils, which should be considered when assessing risk in mercury-contaminated soils.     

加速溶剂萃取-气相色谱-负化学离子化质谱法测定土壤中有机磷农药

用加速溶剂萃取法(ASE)萃取土壤中的有机磷农药,用气相色谱-负化学离子化质谱法(GC-NCI-MS)进行测定,并与气相色谱-电子轰击电离质谱法(GC-EI-MS)进行了对比。结果表明,EI法和NCI法均能满足目前的有机磷农药的分析需要。GC-EI-MS的适用范围比较广,操作比较简单;GC-NCI-MS在选择性和灵敏度等方面均具有较强优势。     

环境监测及相关实验室二次污染水环境的有效控制

对环境监测及相关实验室在实验分析过程中造成水环境二次污染问题进行了论述和分析。在对实验室产生污染物以及含剧毒试剂污染物排放造成环境危害量化分析的同时,详细介绍了监测分析和在化学实验中,从源头上减少及有效控制二次污染的方法和途径。根据中国目前对化学实验室排污管理的现状和分析实验室工作中对污染控制的实际情况,通过与国际先进国家在化学分析实验室污染物排放管理上的对比,阐述了国内在实验室管理和污染物处理方面存在的问题和差距。从法律、法规建设和管理机制上,提出了从根本上减少和有效控制水环境二次污染的相关建议。     

锅炉省煤器H型鳍片管局部泄漏机理研究

本文以某电厂的#1机组锅炉炉省煤器H型鳍片管为研究对象,设计对比试验,从宏观分析和微观分析两方面,对鳍片管局部泄漏的原因进行了深入研究,最终推断发生泄漏是局部点蚀所致.在锅炉运行过程中,沟槽内灰分沉积致使S、Cl元素在沟槽底部富集而发生点蚀,减薄管壁,直至局部区域管壁不足以承压而发生泄漏.本文研究贴近工程实际,具有实际...     

连续紫外扫描光谱法快速测定废水的化学需氧量

探讨了紫外扫描光谱最佳吸收波段内的吸光度集合所组成的峰面积与被测定废水的COD含量的相关性,同时进行了精密度和标准方法的比对实验,取得较好效果.该方法适用于多成分有机混合物的快速测定.