多环芳烃类化合物在土壤上的吸附

研究了几种多环芳烃化合物在土壤上的吸附行为．通过一个连续投药－取样试验装置,在没有任何其它有机试剂干扰的情况下,测定了荧蒽与菲在土壤上的吸附量．研究表明,这两种多环芳烃化合物在土壤上的吸附量与土壤有机质含量之间呈显著相关．对多环芳烃化合物的分子结构及理化特性,如辛醇－水分配系数、溶解度等参数与ＬｏｇＫｏｃ关系的研究发现多环芳烃化合物的ＬｏｇＫｏｃ与化合物的水溶性、辛酸－水分配系数以及分子结构中的苯环数线性相关．     

土壤中多环芳烃源解析技术研究进展

多环芳烃是一类广泛存在于各种环境介质中的持久性有机污染物。针对土壤中多环芳烃的污染现状, 为了更加全面明确地识别污染源, 进而能从源头上对多环芳烃的产生与排放加以控制, 综合论述了国内外土壤中多环芳烃定性和定量源解析技术的研究进展; 在介绍各种多环芳烃污染源解析模型的原理和特点的同时, 通过对比国内外相关研究的实例说明各解析方法的使用前提和适用范围, 讨论了源解析技术进步对污染物控制、治理的意义和重要性; 并对土壤中多环芳烃源解析技术研究未来的发展趋势作出展望, 为区域环境治理和能源利用结构调整等相关决策地制定提供参考依据。     

南亚热带森林土壤动物群落多样性研究

以鼎湖山为代表,研究南亚热带常绿阔叶林土壤动物群落的多样性。首先比较了几种多样性测度的效果,由于Ｇｏｗｅｒ系数和作者１９９０年提出的ＤＧ指数都是基于各物种在群落中都有同等独立性,宜在不同群落间进行种类比较的假设,因而对于复杂的土壤动物群落多样性测度可以获得比较贴切的结果,但ＤＧ指数可以为多个群落同时比较,计算也简单,其次比较了中亚热带的资料,表明南亚热带土壤动物具有的多样性和更多的热带成分,两地区     

多环芳烃在土壤中的行为

多环芳烃（PAHs)在土壤中达到吸附平衡时存在“快”和“慢”两个吸附过程,植物能够从土壤中吸收低分子量的PAHs并向植物的地上部分迁移转化,但PAHs在植物体内主要的累积方式是植物地上部分的空气污染,微生物对PAHs的降解依然是去除PAHs的主要方式,主要通过微生物产生的酶的作用,本文详细分析了影响PAHs生物去除的各种因素。     

我国农业土壤及农作物中多环芳烃污染特征与来源

为准确评估我国农田区域环境状况,以多环芳烃(PAHs)为研究对象,收集并整理近十年的农业土壤及农作物PAHs污染调查结果,基于此,系统分析我国农业土壤及农作物中PAHs的含量、组成、分布特征及来源.结果表明:我国大部分农业土壤PAHs污染为中低污染水平,残留值为0～40300.0μg/kg,中位值为499.2μg/kg...     

污染土壤中多环芳烃的共代谢降解过程

1　前　言多环芳烃是一类普遍存在于环境中的重要有机污染物 ,因其致癌性、致畸性、致突变性而被认为是危险物质。由于其水溶性低 ,辛醇 水分配系数高 ,因此 ,该类化合物易于从水中分配到生物体内、沉积层中。土壤成为多环芳烃的重要载体 ,多环芳烃污染土壤的生物修复也因此倍受关注。多环芳烃在土壤中有较高的稳定性 ,其苯环数与其生物可降解性明显呈负相关关系。很少有能直接降解高环数多环芳烃的微生物。研究表明 ,高分子量的多环芳烃的生物降解一般均以共代谢方式开始[1 3] 。共代谢作用可以提高微生物降解多环芳烃的效率 ,改变微生物碳…     

土壤,植物样品中多环芳烃（PAHs）分析方法研究

土壤、植物和籽实样品分别用四氢呋喃、甲醇、乙酸乙酯以超声技术提取。提取液经旋转浓缩蒸发仪浓缩,经硅胶柱净化后,由高效液相色谱（ＨＰＬＣ）分离,萤光检测分析。对于土壤、植物和籽实样品,其方法回收率根据各个ＰＡＨ化合物的理化性质不同分别为４５．６８－９３．４２、７７．５９－１０８．１３和７９．１１－９８．９６％,结果表明,二氯甲烷、四氢呋喃适合作为土壤样品的提取剂;甲醇、乙酸乙酯分别适合于植物和籽实样     

南亚热带退化植被重建中土壤动物群落变化

在广东省中部的鹤山市鹤山丘陵综合试验场,分别在草坡、松林、荷木混交林(荷混林)、马占相思林(马占林)和豆科混交林(豆混林)选取5块样地,分别代表5种处理方式(重建植被类型)。在2003~2004年的4个不同季度内分3层取土样,利用Tullgren干漏斗法采集土壤动物,并分析土壤动物群落个体数量、类群丰度和DG指数的变化。研究结果表明,季节、植被类型和土层深度对土壤动物群落的各项指标都有极显著影响(P<0·01,three-way-ANOVA):土壤动物群落指标,在秋季显著为高(P<0·05,DMRT),而夏季显著为低(P<0·05,DMRT);随土层加深而逐级显著降低;不同植被类型比较,豆混林>马占林>荷混林、松林和草坡。此外,植被类型还与季节和土层间存在显著的交互作用:土壤动物群落各项指标秋季最高,不同植被类型间的差异也最大;而土壤动物群落各项指标较高的植被类型内不同土层间的差异也较大。由此推测,对退化生态系统进行人工改造是有积极意义的,而不同植被类型间土壤动物的差异可能与凋落物的数量与质量密切相关。     

表面活性剂对土壤中多环芳烃生物有效性影响的研究进展

表面活性剂能够改变多环节烃(Polycyclic aromatic hydrocarbons,PAHs）在土壤中的溶解度、吸附/解吸平衡和与土壤微生物的相互作用,从而改变PAHs的生物有效性,表面活性剂主要通过降低土壤-水之间的界面张力,增加PAHs的溶解度、促进PAHs的运输等方式来加强PAHs的生物有效性,但由于表面活性剂本身对微生物的毒害作用或无毒的表面活性剂优先作为微生物的生长基质,可能会对PAHs的生物有效性起到抑制作用,另外,表面活性剂对土壤中不同形态的PAHs生物有效性的影响不同,表面活性剂、PAHs和土壤微生物的类型浓度以及土壤的物理化学条件等都对PAHs的生物有效性有影响。     

Occurrence,distribution and possible sources of organochlorine pesticides in peri-urban vegetable soils of Changchun,Northeast China

The characterizations of residue levels and sources of organochlorine pesticides (OCPs) in soils are necessary to evaluate the potential pollution and risks of OCPs to the ecosystems and human health. A total of 51 surface soil samples were collected from peri-urban vegetable fields of Changchun and 13 OCPs were analyzed to learn the composition, spatial distribution and sources. The concentrations were in the ranges of 0.94–107.8 ng g^?1 for DDTs, 0.89–98.3 ng g^?1 for HCHs, 0.22–18.20 ng g^?1 for Chlordanes, nd–4.49 ng g^?1 for aldrin and nd–9.66 ng g^?1 for dieldrin, respectively. The total OCPs concentrations ranged from 2.44 to 177.1 ng g^?1 and the higher residues were mainly distributed in northeast and southwest sites, as well as sites along the Yitong River. According to the concentrations and detection frequencies, DDTs and HCHs were the most dominant compounds. Compositional analysis and principal component analysis suggested that DDT, HCH and chlordane in most soil samples derived from historical application except the slight fresh introduction at some locations. There exist a variety of OCPs residues in peri-urban vegetable soils of Changchun, but it is still safe and suitable for agricultural production for the most part, and some specific locations with high OCPs residues ought to be a cause for concern.     

Pollution assessment of organochlorine pesticides in urban agricultural soils of Jilin City,China

The content, source, and pollution level of organochlorine pesticides (OCPs) in soils are necessary to assess potential risks to eco-environment and human health, and to target environment-friendly policies. A total of 50 surface soil samples were collected from urban vegetable fields of Jilin City and thirteen OCPs were analyzed. The concentrations were in the ranges of 3.16–48.35 ng·g^?1 for Dichloro-Diphenyl-Tricgloroethanes (DDTs, sum of o, p′-DDT, p, p′-DDT, p, p′-DDD, and p, p′-DDE), 4.37–44.77 ng·g^?1 for Hexachlorocyclohexanes (HCHs, sum of α-HCH, β-HCH, γ-HCH, and δ-HCH), 1.19–13.17 ng·g^?1 for Chlordanes (sum of heptachlor, t-chlordane, and c-chlordane), 0.24–2.60 ng·g^?1 for aldrin, and nd–3.43 ng·g^?1 for dieldrin, respectively. The different compositions indicated that the residues of DDTs and HCHs originated mainly from the historical application, while chlordanes were mostly from recent input. On the basis of soil quality standards of China and the Netherlands, DDTs and chlordanes in this study were categorized as light pollution, and HCHs were classified as no pollution for the majority of soil samples. There are a variety of OCPs residues in urban vegetable soils of Jilin City, but it is still safe and suitable for agricultural production.     

多环芳烃微生物降解基因的研究进展

多环芳烃(PAHs)是环境中普遍存在的一类有机污染物,微生物的降解是PAHs去除的主要途径。近年来,有关PAHs微生物降解途径和代谢产物的研究已有很多报道。小分子PAHs一般可以直接被微生物降解,而大分子PAHs则需要微生物以共代谢的方式降解。在过去20年中,微生物降解PAHs的基因相继被发现,各种基因在调控PAHs降解过程中的功能也越来越清晰。本文概述了PAHs微生物降解基因方面的研究进展,详细介绍了微生物对萘、菲的降解基因,最后对PAHs微生物降解基因的应用前景进行了展望。     

Contamination,source identification,and risk assessment of polycyclic aromatic hydrocarbons in agricultural soils around a typical coking plant in Shandong,China

Coking is one of the most important emission sources of polycyclic aromatic hydrocarbons (PAHs) in China. Investigation of the contamination, distribution, and sources of PAHs in agricultural soils around Rong Xin coking plant, China, was conducted, and the potential human health risks were addressed. The total concentration of the 16 PAHs (∑₁₆PAHs) on the United States Environmental Protection Agency priority list had a range from 1774 to 4621 µg/kg (mean 3016 µg/kg). Meanwhile, seven carcinogenic PAHs (∑PAH_7c) owned the total concentrations of 684–2105 µg/kg, and they had the benzo[a]pyrene equivalent (BaP_eq) concentrations at 139.616–1672.850 µg/kg. All soil samples were dominated by PAHs with two to four rings. Data analyses for the potential sources of PAHs showed that the PAHs in soils were principally from pyrogenic sources. Ecological risk assessment of soil PAHs showed that the BaP_eq concentrations of ∑PAH_7c accounted for 99% of the total ∑₁₆PAHs, being a major carcinogenic contributors of ∑₁₆PAHs. Higher levels of PAHs and higher total BaP_eq concentrations in this study indicate a potential carcinogenic risk for humans. Therefore, long-term exposure to coking plants may increase the PAH concentrations in the environment and further raise a potential risk to human health.     

微生物降解多环芳烃(PAHs)的研究进展

从多环芳烃(PAHs)的降解菌株的筛选、降解机制以及PAHs污染的生物修复等方面介绍了微生物降解PAHs的最新研究进展。     

大辽河水系表层水中多环芳烃的污染特征

采用GC/MS对大辽河水系的浑河、太子河和大辽河表层水和悬浮物中的多环芳烃 (PAHs) 进行了定量分析,探讨了大辽河水系表层水和悬浮物中多环芳烃分布特征与来源.结果表明,水样和悬浮颗粒物中PAHs总量浓度分布范围分别为：水样946.1～13 448.5 ng·L^-1;悬浮颗粒物317.5～238 518.7 ng·g^-1.多环芳烃的浓度分布表现为太子河>大辽河>浑河,靠近工业区的PAHs浓度明显高于城市和非工业区.水样中PAHs以3～5环为主,悬浮颗粒物样中PAHs以2环为主.PAHs特定分子比率分析表明,大辽河水系受到石油输入和热解的复合PAH污染,采样站位附近石油化工和钢铁工业是PAHs的主要来源.与世界其他河流和海洋地区相比,水和悬浮颗粒物中污染浓度较高,具有一定的生态风险.     

Distribution, sources and potential toxicological significance of polycyclic aromatic hydrocarbons (PAHs) in Taihu Lake sediments, China

Taihu Lake is one of the largest freshwater lakes in China. The lake is very shallow with a mean depth of 1.9 m and an area of 2428 km². This is the first time that polycyclic aromatic hydrocarbon concentrations in the surface sediments of Taihu Lake have been analyzed. A distinctive spatial distribution of PAHs was observed. Sediments from Lake Wulihu and Meiliang Bay (sites 1–5) had significantly higher PAH concentrations (858–5260 g kg^–1 dw) than any other area of Taihu Lake. These high PAH levels were associated with the input of untreated and partially treated domestic and industrial sewage from Wuxi, Changzhou, Wujin and other cities. Special PAH ratios, such as phenanthrene/anthracene and fluoranthene/pyrene, were calculated to evaluate the relative importance of different origins. The data confirmed a relatively high level of petrogenic contamination in sites 1–5 (mainly sewage discharge and the river runoff). The other samples were further from the sources of pollution and have relatively low PAH concentrations (410–768 g kg^–1 dw). The sources of PAHs in these sites (6–13) were characterized by combustion-derived PAH contamination associated with atmospheric deposition. In addition, effects range low (ERL) and effects range median (ERM) guidelines (Long et al., 1995) were used to estimate the potential of adverse effects resulting from PAH contamination in Taihu Lake sediments. The results indicated that some sites in the northern part of the lake had levels of PAH that exceeded the ERL value. This was interpreted to mean that acute biological effects may occasionally be expected to occur.     

黄河三角洲石油化工区农田土壤-玉米体系PAHs的分布特征及风险评价

为明确黄河三角洲石油开采区表层土壤和玉米中多环芳烃（PAHs）的含量及其污染水平,采集农田土壤和玉米各71个样品,检测农田土壤和玉米各部位中16种PAHs含量,并采用内梅罗指数法和健康风险评价模型评估了农田土壤中多环芳烃的生态健康风险。结果表明,农田土壤、玉米根、茎和叶中多环芳烃的含量分别为256.6-1936、291.4-680.9、324.9-527.9、289.5-2400 μg/kg。农田土壤中多环芳烃以4-6环为主。多环芳烃在玉米根茎叶富集系数大小排序为：叶 > 茎 > 根。玉米不同组织中PAHs浓度与相应农田土壤中PAHs浓度的进行相关分析结果表明,农田土壤中PAHs含量与玉米根、茎中PAHs含量均存在极显著正相关关系,相关系数分别为0.98（P<0.01）、0.98（P<0.01）,表明玉米根和茎的多环芳烃主要来源于农田土壤中,农田土壤中PAHs的含量影响着PAHs在玉米根茎中的积累和分布。玉米叶中PAHs含量与农田土壤中PAHs含量与玉米根、茎中PAHs含量不存在相关关系,表明玉米叶中多环芳烃并非来自土壤中PAHs的迁移,可能来源于大气。内梅罗指数结果表明,农田土壤PAHs达到了中度污染,其中BaA、Pyr和BbF达到了偏重污染;健康风险评价结果表明,农田土壤PAHs对儿童和成人的平均非致癌风险分别为0.44和0.12（均小于1）,表明农田土壤多环芳烃对成人和儿童的非致癌风险是可接受;农田土壤PAHs对儿童和成人的平均致癌风险分别为3.6×10^-5、9.0×10^-6,没有超过致癌风险水平上限（10^-4）,致癌风险尚在可接受范围内。3种暴露途径中,皮肤接触是土壤PAHs的最主要暴露方式,其次是经口摄食,吸入暴露途径甚微,可忽略不计。PAHs对儿童健康的威胁风险要大于成人,所以应尽可能避免儿童直接接触或误食土壤等其他介质的污染物。     

微生物降解多环芳烃的研究进展

多环芳烃(PAHs)是具有严重危害的环境污染物质。介绍PAHs的降解菌,降解机理和PAHs的生物修复方面的研究进展。土壤中PAHs的生物修复被认为是解决污染的有效方法,目前,菲的生物降解途径已经比较清楚,但对结构更为复杂的多环芳烃研究较少。文章还对消除环境中多环芳烃的相关生物技术提出展望。     

Measurement of biodegradability parameters for single unsubstituted and methylated polycyclic aromatic hydrocarbons in liquid bacterial suspensions

Substrate depletion experiments were conducted to characterize aerobic biodegradation of 20 single polycyclic aromatic hydrocarbons (PAHs) by induced Sphingomonas paucimobilis strain EPA505 in liquid suspensions. PAHs consisted of low molecular weight, unsubstituted, and methyl-substituted homologs. A material balance equation containing the Andrews kinetic model, an extension of the Monod model accounting for substrate inhibition, was numerically fitted to batch depletion data to estimate extant kinetic parameters including the maximal specific uptake rates, q(max), the affinity coefficients, K(S), and the substrate inhibition coefficients, K(I). Strain EPA505 degraded all PAHs tested. Applied kinetic models adequately simulated experimental data. A cell proliferation assay involving reduction of the tetrazolium dye WST-1 was used to evaluate the ability of strain EPA505 to utilize individual PAHs as sole energy and carbon sources. Of the 22 PAHs tested, 9 supported bacterial growth. Evaluation of the biokinetic data showed that q(max) correlated highly with transmembrane flux as theoretically estimated by a diffusion model, pointing to transmembrane transport as a potential rate-determining process. The biodegradability data generated in this study is essential for the development of quantitative structure-activity relationships (QSARs) for biodegradability and for modeling biodegradation of simple PAH mixtures.