TOXIC EFFECTS OF PETROLEUM AND SHALE JP-4 AND JP-8 AVIATION FUELS ON FATHEAD MINNOWS1

ABSTRACT: Static 96-hour median lethal concentrations were determined for the water-soluble fraction (WSF) of both petroleum-derived and shale-derived avaiation fuels (JP-4 and JP-8) using fathead minnows. JP-8 was more toxic than JP-4 except for one shale JP-4 sample that was as toxic as the JP-8. Petroleum and shale JP-8 were similar in toxicity. The toxicity of shale JP-4 was less clear. Shale JP-4 from three vendor sources revealed differing toxicity values. One shale JP-4 sample was more toxic and one less toxic than its petroleum analogue, with the third being equally toxic. Toxicity of the fuels may be enhanced by compounds in the WSF that correspond to chemicals containing 10 or more carbon atoms.     

氧化剂对土壤中石油污染物去除率的影响

以FeSO_4-柠檬酸为催化剂,探讨了不同氧化剂的类型、浓度、与催化剂的比例等因素对土壤中石油污染物去除率的影响。实验结果表明:各氧化剂体系的石油去除率大小顺序为KMnO_4CaO_2≥H_2O_2K_2S_2O_8;随着反应时间的延长,各体系的石油去除率均呈现出先快速增涨、再缓慢增加后略有降低的趋势;在氧化剂浓度相同条件下,H_2O_2体系和Na_2S_2O_8体系的石油去除率分别比对照增加了145.5%~238.7%和112.6%~167.5%;在催化剂用量相同条件下,H_2O_2体系和Na_2S_2O_8体系达到最高石油去除率时的n(氧化剂)∶n(催化剂)分别为50∶1和100∶1;H_2O_2体系对残油族组分的去除率大小顺序为非烃芳烃饱和烃沥青质。     

Water quality assessment at Ömerli Dam using remote sensing techniques

Water quality at Omerli Dam, which is a vital potable water resource of Istanbul City, Turkey was assessed using the first four bands of Landsat 7-ETM satellite data, acquired in May 2001 and water quality parameters, such as chlorophyll-a, suspended solid matter, secchi disk and total phosphate measured at several measurement stations at Omerli Dam during satellite image acquisition time and archived at the Marine Pollution and Ecotoxicology laboratory of the Marmara Research Center, where this study was carried out. Establishing a relationship between this data, and the pixel reflectance values in the satellite image, chlorophyll-a, suspended solid matter, secchi disk and total phosphate maps were produced for the Omerli Dam.     

Oxidative DNA damage levels and catalase activity in the clam Ruditapes decussatus as pollution biomarkers of Tunisian marine environment

Levels of the oxidative DNA damage 7, 8-dihydro-8-oxo-2′-deoxyguanosine (8-oxodG) and catalase (CAT) activity were measured in the digestive gland and gills of clams Ruditapes decussatus, related to the presence of pollutants along Tunisian marine environment. Increased levels of CAT were observed in tissues of clams from all the sites studied, compared to control values, and elevated 8-oxodG levels were observed at specific sites. Results obtained in this work indicate that the measurement of 8-oxodG levels and CAT activity in tissues of R. decussatus is promising in pollution monitoring studies of the Tunisian marine environment.     

基于Landsat-8数据和劈窗算法的地表温度反演及城市热岛效应研究

陆地表面温度(Land Surface Temperature,LST)是地表能量平衡组分中的一个重要参数。随着卫星遥感技术的快速发展,遥感反演成为获取区域LST的一个重要手段。目前已有学者提出多种基于遥感数据反演LST的算法,其中劈窗算法被证明是一种精度较高的算法。基于Landsat-8卫星30 m空间分辨率的陆地成像仪(OLI)数据和100 m分辨率的热红外传感器(TIRS)数据,采用劈窗算法计算了无锡地区的LST,并采用地面实测水温数据和同步的MODIS温度产品对Landsat-8的计算结果进行了验证和对比分析。结果表明:基于Landsat-8数据和劈窗算法获取的LST精度较高,误差1K。在计算的LST结果基础上,进一步提取了热场变异指数来分析城市热岛空间分布特征,给出了城市热岛效应的定量化描述,并就不同地表覆盖类型对热岛效应的影响进行了分析。     

Assessment of oxidative stress due to exposure to pesticides in plasma and urine of traditional limited-resource farm workers: Formation of the DNA-adduct 8-hydroxy-2-deoxy-guanosine (8-OHdG)

The objective of this study was to assess the risk of genotoxicity caused due to oxidative stress using plasma and urinary levels of 8-hydroxy-2-deoxyguanosine (8-OHdG) in farm workers for six months during a growing season. Blood and urine samples were collected once a month for six months (June to November 2003) from farm workers (n = 15) and urban unexposed controls (n = 10). Plasma and urinary levels of 8-OHdG were evaluated by Enzyme Linked Immunosorbent Assay (ELISA) technique. There was no significant difference in the urinary levels of 8-OHdG between the farm workers and the control group, but there was an approximately four-fold increase in mean values of plasma 8-OHdG levels in the farm worker group (P ≤ 0.05).     

八羟基喹啉改性膨润土预处理养殖废水

以八羟基喹啉为改性剂,天然膨润土为原料,制备一种新型吸附剂,并将其应用于养殖废水的预处理中。确定了改性膨润土的最佳制备条件:土液比为4 g/L,改性剂浓度为0.3 g/L,改性时间为50 min,改性温度为50℃。并以扫描电镜方法对改性膨润土行进表征:八羟基喹啉已经有效进入层间,改变了膨润土的性状,提高了吸附效果。优化了改性膨润土处理养殖废水的工艺条件:投土量为1 g/L,pH为4,搅拌时间为30 min,搅拌速度为350 r/min,沉淀时间为40 min。在此优化条件下,改性膨润土对养殖废水的COD去除率最高可达79.18%,且吸附动力学结果满足二级动力学模型。     

Photocatalytic removal of organic pollutants in aqueous solution by Bi(4)Nb(x)Ta((1-x))O(8)I

In this work, Bi₄Nb_xTa_(1−x)O₈I photocatalysts have been synthesized by solid state reaction method and characterized by powder X-ray diffraction, scanning electron microscope and UV-Vis near infrared diffuse reflectance spectroscopy. The photocatalytic activity of these photocatalysts was evaluated by the degradation of methyl orange (MO) in aqueous solutions under visible light, UV light and solar irradiation. The effects of catalyst dosage, initial pH and MO concentration on the removal efficiency were studied, and the photocatalytic reaction kinetics of MO degradation as well. The results indicated that Bi₄Nb_xTa_(1−x)O₈I exhibited high photocatalytic activity for the removal of MO in aqueous solutions. For example, the removal efficiency of MO by Bi₄Nb_0.1Ta_0.9O₈I was as high as 92% within 12 h visible light irradiation under the optimal conditions: initial MO concentration of 5-10 mg L⁻¹, catalyst dosage of 6 g L⁻¹ and natural pH (6-8), the MO molecules could be completely degradated by Bi₄Nb_0.1Ta_0.9O₈I within 40 min under UV light irradiation, and the photodegradation efficiency reaches to 60% after 7 h solar irradiation. Furthermore, the photocatalytic degradation of Bisphenol A (BPA) was also investigated under visible light irradiation. It is found that 99% BPA could be mineralized by Bi₄Nb_0.1Ta_0.9O₈I after 16 h visible light irradiation. Through HPLC/MS, BOD, TOC, UV-Vis measurements, we determined possible degradation products of MO and BPA. The results indicated that MO was degradated into products which are easier to be biodegradable and innocuous treated, and BPA could be mineralized completely. Furthermore, the possibility for the photosensitization effect in the degradation process of MO under visible light irradiation has been excluded.     

Is BDE-175 an important enough component of commercial octabromodiphenyl ether mixtures to be listed in Annex A of the Stockholm Convention?

Commercial octabromodiphenyl ether mixtures, containing hexabromodiphenyl ethers and heptabromodiphenyl ethers were listed in Annex A of the Stockholm Convention on May 2009 (Fourth Conference of the Parties) (UNEP, 2009a). Four compounds are specifically mentioned: 2,2′,4,4′,5,5′-hexabromodiphenyl ether (BDE-153), 2,2′,4,4′,5,6′-hexabromodiphenyl ether (BDE-154), 2,2′,3,3′,4,5′,6-heptabromodiphenyl ether (BDE-175), and 2,2′,3,4,4′,5′,6-heptabromodiphenyl ether (BDE-183). Presumably they were identified as key components of commercial mixtures and found to be present in environmental samples. However, since BDE-175 and BDE-183 co-elute on common HRGC columns, the presence of BDE-175 as an important component in technical octa-BDE mixtures has not been illustrated. The successful HRGC/LRMS separation of a 1:1 mixture of BDE-175 and BDE-183, as well as ¹H NMR analysis of technical material, has allowed us to confirm that this congener is not present in technical products (e.g. Great Lakes DE-79™) in quantifiable amounts.     

Detecting deforestation with a spectral change detection approach using multitemporal Landsat data: a case study of Kinabalu Park, Sabah, Malaysia

Tropical deforestation is occurring at an alarming rate, threatening the ecological integrity of protected areas. This makes it vital to regularly assess protected areas to confirm the efficacy of measures that protect that area from clearing. Satellite remote sensing offers a systematic and objective means for detecting and monitoring deforestation. This paper examines a spectral change approach to detect deforestation using pattern decomposition (PD) coefficients from multitemporal Landsat data. Our results show that the PD coefficients for soil and vegetation can be used to detect deforestation using change vector analysis (CVA). CVA analysis demonstrates that deforestation in the Kinabalu area, Sabah, Malaysia has significantly slowed from 1.2% in period 1 (1973 and 1991) to 0.1% in period 2 (1991 and 1996). A comparison of deforestation both inside and outside Kinabalu Park has highlighted the effectiveness of the park in protecting the tropical forest against clearing. However, the park is still facing pressure from the area immediately surrounding the park (the 1km buffer zone) where the deforestation rate has remained unchanged.