徐州土壤多环芳烃的环境地球化学迁移特征

选择江苏徐州黄棕壤进行不同深度层位多环芳烃含量的定量分析,研究并探讨了多环芳烃在土壤深度剖面中的地球化学迁移特征。研究结果显示,多环芳烃在徐州土壤剖面中主要集中在地表0~20 cm内。其中低环多环芳烃化合物的迁移能力较强,4~6环等高环化合物相对较难迁移,主要残留于地表生态系统环境中。     

粤东柘林湾表层沉积物中的多环芳烃

近岸海域是绝大数污染物的最终归宿,其中多环芳烃(PAHs)的污染目前已成为国内外环境问题的焦点之一[1~3].20世纪80年代以来,国内外对河口湾、港湾、近岸海域等海洋环境中PAHs的含量、组成、分布、归趋及来源等做了大量的调查[4~15].比如,中国科学院广州地化所对珠三角水域和厦门大学对厦门港一带均做了大量的工作,结果发现表层沉积物中16种优控PAHs总量在珠江口达到156~9220 ng/g,闽江口为175~817ng/g,厦门西港则在196~675 ng/g之间,证明我国东南沿海主要河口及港湾沉积物中的PAHs污染已经达到中等水平[13~15].     

The impact of salt water inflows on the distribution of polycyclic aromatic hydrocarbons in the deep water of the Baltic Sea

Salt-water inflows into the Baltic Sea are important events for renewing the deep and bottom waters of the deep basins of the Baltic Sea. These events occur only at irregular intervals. The last strong event was in January 1993 followed by minor inflows in winter 1993/1994. As a result of these inflows, the deep water of the central Baltic basins was completely renewed.Based on extensive observations of polycyclic aromatic hydrocarbons (PAHs) in water, fluffy layer material and surface sediments between 1992 and 1998, the transformation of PAHs and the modification of their distribution in the Baltic deep water is discussed in connection with the spreading of the inflowing highly saline and oxygen-rich water along its pathway from the sills into the central basins. In the course of the inflows in 1993/1994, the PAH concentration in the deep water of the different basins increased significantly. The concentrations were elevated, at least by a factor of 2 and as much as seven to eight times (for the four-ring PAHs) compared to the previous and the following years. Two hypotheses for the causes were discussed: the inflowing salt water may have entrained more highly polluted surface water in the western Baltic Sea, or it may have entrained contaminated fluffy layer material or sediment particles along the route of transport.     

Comparative tolerance of two estuarine annelids to fluoranthene under normoxic and moderately hypoxic conditions

The tolerance of the oligochaete Monopylephorus rubroniveus and the polychaete Streblospio benedicti to sediment-associated fluoranthene was characterized under normoxic (>80% dissolved oxygen saturation) and moderately hypoxic ( approximately 50% dissolved oxygen saturation) conditions. Under both conditions, M. rubroniveus was highly tolerant of fluoranthene. Streblospio benedicti was considerably less tolerant of fluoranthene compared with M. rubroniveus. In addition, S. benedicti was less tolerant to fluoranthene under moderately hypoxic conditions, although no differences in sensitivity between the two oxygen conditions were observed based upon median lethal tissue residues. Bioaccumulation factors were higher for S. benedicti exposed to moderate hypoxia, suggesting that behavioral adaptations to compensate for the lower dissolved oxygen increased its bioaccumulation of fluoranthene. The results of the present laboratory study demonstrate that (1). changes in annelid tolerance to fluoranthene under varying oxygen conditions is a species-dependent phenomenon and (2). the differential tolerance of these two annelids to these combined stressors is consistent with their relative abundances in the field.     

Polycyclic aromatic hydrocarbons in water, seston and copepods in a harbour area in the Western Mediterranean (Ligurian Sea)

Polycyclic aromatic hydrocarbons (PAHs) are widespread carcinogenic, mutagenic and teratogenic pollutants that can significantly affect ecosystems and exert an influence on marine planktonic and benthic communities as well as on higher organisms such as fish and mammals, including humans. In this paper the concentrations of six PAHs in water, seston and copepods were examined in a harbour zone of the Genova Gulf (Ligurian Sea) from November 1997 to June 1998. The importance of freshwater inputs coming from a polluted stream and the influence of seasonal and atmospheric factors were also considered. Highest PAH values were recorded during spring. Fluoranthene, Benzo[b]fluoranthene and Benzo[k]fluoranthene were the most abundant PAHs either in water, seston or copepods. The concentration of total PAHs in seawater was often lower than the detection limit: recorded values ranged between 0.001 and 0.06 ppb. In seston, total PAHs ranged between 0.033 and 6.26 ng·g^?1 and in copepods between 0.01 and 2.34 ng·g^?1. With this study, PAH contamination in the harbour zone of Genova Sestri‐Ponente and the importance of inputs of organic pollutants coming from land and freshwaters have been emphasized.     

太原市区土壤中多环芳烃污染特征研究

采用1个样/km2的密度,1个分析组合样/25km2的方法,对太原市区土壤中多环芳烃进行了调查。结果表明,太原市区土壤中多环芳烃的平均含量为8.65μg/g;空间分布上北高南低,高值点主要位于工业区及交通要道地段;组成上以四环及四环以上的多环芳烃为主。通过与国内外城市土壤的对比可知,太原市土壤PAHs污染已相当严重,其来源主要是煤炭的燃烧。太原市工业布局、能耗类型和地理位置是造成土壤PAHs污染的主要原因。     

Effect of particles on the photodegradation of PAHs in natural waters-A case study for the Yellow River

Photodegradation of chrysene, benzo （a） pyrene and benzo （g, h, i） perylene in natural water of the Yellow River was studied using simulation sunlight. The effects of particulates on the photodegradation were explored. Several results arose from this study. （1） The photodegradation of PAHs can be fitted with first-order kinetics when no particulate exists in water system, and the first-order constant increases with decreasing of initial concentration of PAHs. The photodegradation rates of the three PAHs are related to their molecule absorption spectrum. （2） The existence of loess exerts two kinds of effects on the photodegradation of PAHs, including the inner filter effects and the photosensitizing effects of humic substance in loess. These two contrary effects lead to the difference of net effects among different contents of loess. When the loess contents are 0.1 and 5.0 g/L, the existence of loess stimulates the photodegradation of chrysene, benzo （a） pyrene. When the loess content is 5.0 g/L, the existence of loess stimulates the photodegradation of benzo （g, h, i） perylene. In addition, the photodegradation of PAHs can be fitted with the second-order kinetics when there is loess in the water system. （3） The soluble humic substances in loess can accelerate the photodegradation of PAHs while the in soluble part cannot. （4） Since the soluble humic substances in the suspended solids of the river have been dissolved in water,     

MODELING THE FATE AND TRANSPORT OF HYDROPHOBIC ORGANIC COMPOUNDS IN AN UNSTEADY RIVER-ESTUARINE SYSTEM

1 INTRODUCTION Extensive literature (Brown et al., 1985; Sawhney et al., 1981; Bierman and Swain, 1982; Connolly, 1980; Lopez-Avila and Hites, 1980; O扖onnor, 1988) described lots of sorbed pollutants or toxic substances in bed sediments of rivers, even after the effluent was halted for a long time. This is particularly true for hydrophobic organic compounds that can be sorbed on the particles and accumulated in the river bed sediments (Karickhoff et al., 1979). Pollution events of…     

污染土壤中多环芳烃的微生物降解及其机理研究进展

多环芳烃(PAHs)是一类普遍存在于环境中的难降解危险性“三致”有机污染物。微生物对多环芳烃的降解是去除土壤中多环芳烃的主要途径。研究表明，对于土壤中低分子量多环芳烃类化合物，微生物一般以唯一碳源方式代谢；而大多数细菌和真菌对四环或四环以上的多环芳烃的降解作用一般以共代谢方式开始。本文重点论述了高分子量多环芳烃：芘和苯并(a)芘的微生物降解及其机理。并介绍了多环芳烃污染的微生物—植物联合修复机制，最后展望了污染土壤中多环芳烃的研究趋势。