The toxicity of composted sediments from Mediterranean ports evaluated by several bioassays

This work investigates the ecotoxicological evaluation of contaminated dredged sediments from French Mediterranean navy harbour (A), commercial port (B) and two composite specimens (C) and (D) coming from the mixture of A and B with other port sediments. The toxicity of elutriates from these sediments is estimated using embryo-toxicity test, Microtox® solid phase test, LuminoTox, phytotoxicity tests and genotoxicity test. Bioassay responses are not clearly correlated with chemical contamination in the whole sediment and vary as a function of tested organisms. The highest contaminated samples (A and C) are almost always more toxic than the less contaminated samples (B and D). Among composite sediments, the mixture effect with other sediments is not efficient to decrease toxicity in sample C, suggesting that other parameters influence toxicity level such as particle size or organic matter content. These parameters should be taken into consideration in order to improve the efficiency of the mixture process and produce composite sediments with low toxicity.     

Removal of carotene-like colored compounds by liquid-liquid extraction during polycyclic aromatic hydrocarbons analysis of plant tissue

Plants contain a wide variety of chemicals, some of which may have similar chromatographic behavior to polycyclic aromatic hydrocarbons (PAHs). During solid phase extraction (SPE) with Si-gel for instance, the co-elution of carotene-like colored compounds with PAHs has been observed. In this paper, liquid–liquid extraction was applied for the separation and subsequent analysis of PAHs from plant extracts. PAHs containing 2–6 rings, which include naphthalene, phenanthrene, pyrene, benzo[a]pyrene and benzo[ghi]perylene, were used as representative target chemicals. Carotene-like compounds extracted from Komatsuna (Brassica campestris) shoot by acetone followed by Si-gel treatment were incorporated as undesired components in the model matrix. Results showed the feasibility of employing either acetonitrile or 2% (w/v) KOH–methanol as solvents for high PAHs recovery and low extraction of colored fraction. For acetonitrile, 86.9–93.5% of each PAH could be recovered after three extraction cycles (relative standard deviation, RSD < 1.6%) with only about 10% co-extraction of colored fraction. For 2% KOH–methanol, PAHs recoveries ranging from 79.3% to 83.1% after five cycles (RSD < 1.5%) were achieved while the percent extraction of colored fraction was also low at 10%. The relatively higher selectivity of the solvents for PAHs over the colored fraction as well as the solubility of the matrix solution in the solvent may have contributed to these results. On this basis, liquid–liquid extraction is very useful for the pre-treatment of plant extracts for PAHs analysis.     

Biodegradation of mono-alkyl phthalate esters in natural sediments

Mono-alkyl phthalate esters (MPEs) are primary metabolites of di-alkyl phthalate esters (DPEs), a family of industrial chemicals widely used in the production of soft polyvinyl chloride and a large range of other products. To better understand the long term fate of DPEs in the environment, we measured the biodegradation kinetics of eight MPEs (-ethyl, -n-butyl, -benzyl, -i-hexyl, -2-ethyl-hexyl, -n-octyl, -i-nonyl, and -i-decyl monoesters) in marine and freshwater sediments collected from three locations in the Greater Vancouver area. After a lag period in which no apparent biodegradation occurred, all MPEs tested showed degradation rates in both marine and freshwater sediments at 22 °C with half-lives ranging between 16 and 39 h. Half-lives increased approximately 8-fold in incubations performed at 5 °C. Biodegradation rates did not differ between marine and freshwater sediments. Half-lives did not show a relationship with increasing alkyl chain length. We conclude that MPEs can be quickly degraded in natural sediments and that the similarity in MPE degradation kinetics among sediment types suggests a wide occurrence of nonspecific esterases in microorganisms from various locations, as has been reported previously.     

Determination of phenolic and steroid endocrine disrupting compounds in environmental matrices

BACKGROUND, AIM AND SCOPE: Many pollutants have received significant attention due to their potential estrogenic effect and are classified as endocrine disrupting compounds (EDCs). EDCs comprise many classes of organic compounds. The development or optimization of analytical protocols for the simultaneous determination of EDCs in environmental samples is an analytical challenge because these compounds exhibit different physicochemical characteristics, they occur in the aquatic environment in relatively low concentrations and, furthermore, environmental samples are considered as complex matrices. The aim of this study is the development of analytical methods for the simultaneous determination of phenolic and steroid EDCs in aqueous and solid samples. The target compounds are 4-nonylphenol, 4-octylphenol, their ethoxylate oligomers (mono- and di-ethoxylates of nonylphenol and octylphenol), bisphenol A, the estrogens (estriol, estrone, 17beta-estradiol, 17alpha-estradiol) and the synthetic steroids (mestranol and 17alpha-ethynylestradiol). MATERIALS AND METHODS: Solid phase extraction employing Oasis HLB cartridges and different elution solvents was used for the recovery studies of the target compounds from various types of water samples (ultrapure water, artificial seawater, river water and seawater). Ultrasonic assisted extraction was applied for the recovery of the target EDCs from the solid samples. The recoveries were assessed using various solvents for the extraction and the elution of EDCs from different SPE cartridges used for clean up. Gas chromatography-mass spectrometry after derivatization with N,O-bis(trimethylsilyl)-trifluoroacetamide was employed for the determination of these compounds. RESULTS AND DISCUSSION: The recovery rates of three elution solvents (methanol, acetone and ethylacetate) for the extraction of target EDCs from artificial seawater were assessed after preconcentration on SPE cartridges. Acetone showed better recoveries and was further tested for its extraction efficiency in different water types (river water, seawater). Ultrasonic assisted extraction was used for the recovery of target EDCs from solid matrices. Acetone, methanol, mixture of acetone-methanol (1:1) and ethylacetate were used as extraction solvents. Ethylacetate and the mixture of acetone-methanol (1:1) exhibited better extraction efficiencies. An additional clean up step was necessary for sediment samples. Different SPE cartridges were employed for clean up of the extracts (Oasis HLB, C18, Florisil, silica, combination of silica and alumina). Florisil cartridges were finally used. The proposed methods were further validated on the determination of target EDCs in field collected samples (river water, seawater, wastewater, total suspended solids and sediments) from the major area of Thessaloniki, Greece. CONCLUSIONS: Efficient and accurate integrated methods for the simultaneous determination of alkylphenols (nonylphenol, octylphenol), their ethoxylate oligomers (mono- and di-ethoxylate of nonylphenol and octylphenol), bisphenol A and steroids (estriol, estrone, 17beta-estradiol, 17alpha-estradiol, mestranol and 17alpha-ethynylestradiol) in aqueous and solid samples were developed. The proposed methods were applied for the determination of the target compounds in representative environmental samples in the area of Thessaloniki, Northern Greece. RECOMMENDATIONS AND PERSPECTIVES: This study confirms the occurrence of selected EDCs in inland and marine waters in the area of Thessaloniki, Northern Greece. Since there is no previous data on the occurrence of the target EDCs in the major area, an extended survey is in progress to evaluate the occurrence and fate of these compounds.     

Analysis of a gas-phase partitioning tracer test conducted in an unsaturated fractured-clay formation

The gas-phase partitioning tracer method was used to estimate non-aqueous phase liquid (NAPL), water, and air saturations in the vadose zone at a chlorinated-solvent contaminated field site in Tucson, AZ. The tracer test was conducted in a fractured-clay system that is the confining layer for the underlying regional aquifer. Three suites of three tracers were injected into wells located 14, 24, and 24 m from a single, central extraction well. The tracers comprised noble gases (traditionally thought to be nonsorbing), alkanes (primarily water partitioning), perfluorides (primarily NAPL partitioning), and halons (both NAPL and water partitioning). Observations of vacuum response were consistent with flow in a fractured system. The halon tracers exhibited the greatest amount of retardation, and helium and the perfluoride tracers the least. The alkane tracers were unexpectedly more retarded than the perfluoride tracers, indicating low NAPL saturations and high water saturations. An NAPL saturation of 0.01, water saturation of 0.215, and gas saturation of 0.775 was estimated based on analysis of the suite of tracers comprising helium, perfluoromethylcyclohexane and dibromodifluoromethane, which was considered to be the most robust set. The estimated saturations compare reasonably well to independently determined values.     

HPLC法测定水和废水中的醛酮类化合物

将水样用1mol／L柠檬酸缓冲液调节至酸性(pH=3),其中醛酮类化合物与2,4-二硝基苯肼(DNPH)发生衍生化反应,生成稳定的化合物——腙,经C18固相萃取小柱富集、乙腈淋洗后,用带有二极管阵列检测器的高效液相色谱仪(HPLC)经32 min完成15种醛酮类化合物定性、定量分析。当测定样品为100mL时,检测限均为μg／L级,其中丙酮最高为16μg／L,丁醛最低为1.1μg／L,一般在2μg／L～6μg／L之间。     

崇明岛种子植物区系及植被资源

崇明岛共有区系植物55科157属198种，区系组成复杂，地理成分多样，涵盖全部15个分布区类型，具有明显的热带-温带过渡性质，落叶树种占木本植物种类的90．5％，属于北亚热带常绿落叶阔叶混交林地带。群落外貌及属的相似性系数分析表明，崇明岛植物区系更接近江苏宜兴，而与临近的大金山岛和佘山差别略大。此外，岛上还有栽培植物和外来植物共235种，其中蔷薇科、菊科、禾本科、豆科、木犀科等科的种类较丰富，以加拿大一枝黄花、臭荠、刺果毛莨、一年蓬、空心莲子草、大米草、互花米草等对当地植被资源和生态系统的影响最大。崇明岛植物群落结构单一，缺乏灌木层，草本层多为广布杂草，其植被资源可以根据功能划分为江防海防林、湿地植被、道路绿化带、庭院景观林、游憩林、大田作物及经济林、水源涵养林等7大类，其中江防海防林及湿地植被是崇明岛植被生态系统的关键成分。提供了崇明岛新纪录野生及外来种子植物名录。     

东北地区玉米低温冷害综合指标研究

在以往对低温冷害指标研究的基础上，将低温冷害成分不同的发育阶段进行分析，结合发育期日数和初霜日研究等，讨论分析了东北地区玉米的低温冷害问题，提出一个玉米低温冷害综合指标。该指标生物学和农学意义明确，计算较为方便，便于在预报上的应用。     

两相消化系统产酸相酸化特性模型

通过物料衡算建立产酸相的酸化特性分段模型 ,并求得本研究两相消化系统处理淀粉配制废水情况下产酸相动力学参数为 :产酸菌产率系数 Y=0 .2 8mg·mg^-1,产酸菌衰减系数 kd=0.054h^-1,产酸菌最大比增长率μm=3.1 h^-1,饱和系数 Ks=1866mg·L^-1.讨论了产酸相酸化率对整个系统运行状况的影响 ,表明高酸化率有利于提高系统的处理效率和沼气回收 .     

北京工业废水和城市污水环境激素污染状况调查

利用固相萃取前处理技术和高效液相色谱、气相色谱方法,分析研究北京地区重点污染源排水(包括工业废水和城市污水)中主要环境激素(邻苯二甲酸酯、有机氯农药、有机氮农药、有机磷农药、菊酯类农药、烷基酚和双酚A)的残留状况. 调查分析了分布在北京市10个区县的污水处理厂、化工行业、冶金焦化行业、医院及其洗涤中心、印钞行业、食品加工行业和制药行业等7类22个单位排水中的8种邻苯二甲酸酯,17种有机氯农药,7种有机氮和有机磷农药,4种菊酯类农药,4种烷基酚及双酚A共40种环境激素类物质的质量浓度. 并着重分析了污水处理厂进、出水中的环境激素的浓度水平. 结果表明,北京地区工业废水和城市污水中广泛存在着环境激素污染,但其质量浓度并未超过现行排放标准.