Fine-scale distribution of juvenile Atlantic and Mediterranean loggerhead turtles (Caretta caretta) in the Mediterranean Sea

Loggerhead turtles nesting in the Mediterranean Sea exhibit remarkable genetic structuring. This paper tests the hypothesis that young loggerhead turtles from different rookeries do not distribute homogeneously among the major Mediterranean foraging grounds, due to a complex pattern of surface currents. We extracted long fragments of mitochondrial DNA from 275 stranded or bycaught juvenile turtles from six foraging grounds (Catalano-Balearic Sea, Algerian basin, Tyrrhenian Sea, Adriatic Sea, northern Ionian Sea and southern Levantine Sea). We used a Bayesian mixed-stock analysis to estimate the contributions from rookeries in the Mediterranean, the North-west Atlantic and Cape Verde to the studied foraging grounds. Differences were found in the relative contribution of juvenile turtles of Atlantic and Mediterranean origin to each foraging ground. A decreasing proportion of Atlantic juveniles was detected along the main surface current entering the Mediterranean, with a high prevalence of turtles from eastern Florida in the Algerian basin and lower numbers elsewhere. In regard to the turtles of Mediterranean origin, juveniles from Libya prevailed in central and western Mediterranean foraging grounds other than the Algerian basin. Conversely, the Adriatic Sea was characterised by a large presence of individuals from western Greece, while the southern Levantine Sea was inhabited by a heterogeneous mix of turtles from the eastern Mediterranean rookeries (Turkey, Lebanon and Israel). Overall, the distribution of juveniles may be related to surface circulation patterns in the Mediterranean and suggests that fisheries might have differential effects on each population depending on the overlap degree between foraging and fishing grounds.     

热活化过硫酸盐降解水中的2-氯苯酚

利用加入活化K2S2O8产生的硫酸根自由基(SO-4·)降解水中2-氯苯酚(o-chlorophenol),探讨了温度、pH、腐殖酸(HA)、无机离子对2-氯苯酚降解的影响.结果表明,增加溶液中过硫酸盐的浓度或提高溶液反应温度,可促进2-氯苯酚的降解,而且2-氯苯酚的降解符合准一级反应动力学规律,其反应表观活化能为4.32 kJ·mol-1.酸性条件下2-氯苯酚的降解效果明显好于碱性条件.2-氯苯酚的降解受到Cl-、CO2-3和腐殖酸的影响.其中,腐殖酸和CO2-3都对反应有明显的抑制作用.Cl-在酸性和中性条件下也会抑制2-氯苯酚降解,但在碱性条件对反应影响不大.2-氯苯酚在SO-4·的作用下会最终降解为乙酸等小分子有机物并最终矿化,有时会伴随有中间产物二聚物的生成.     

Analysis of the phenolic compounds in root exudates produced by a subalpine coniferous species as responses to experimental warming and nitrogen fertilisation

In terrestrial ecosystems, plant root exudates clearly play a crucial role in the belowground ecosystem. However, there have been few reports on root exudates from field-grown plants or mature trees in situ, especially when exposed to experimental warming. In this study, we adopted and modified a culture-based cuvette system developed especially for root exudation collection in the field to collect soluble root exudates of a subalpine coniferous species, Abies faxoniana, under experimental warming and nitrogen fertilisation treatments. We then analysed the chemical composition and relative abundance of root exudates using gas chromatography-mass spectrometry (GC-MS). The major chemical constituents of root exudates were phenols and their derivatives of all the different treatments, such as 2,6-di-tert-butyl-4-methylphenol. Experimental warming had significant effects on the relative contents of major compounds and an increase effect on the total phenolic acid compounds. By contrast, there were small significant effects of N fertilisation on root exudation and no significant effects of the warming×N fertilisation interaction. Meanwhile, warming also markedly increased soil polyphenol oxidase activity and it may be soil ecological adjustment response to changes of root exudation under global climate warming.     

大型环境监测实验室分析仪器绩效评估指标体系探索

大型环境监测实验室分析仪器是环境监测单位综合实力的集中体现,在环境监测工作中发挥着巨大作用。简述了仪器设备绩效评估研究现状,尝试构建大型环境监测实验室分析仪器绩效评估指标体系,并通过德尔菲法确定各项评价指标的权重值,最终计算绩效评估综合指数。在此基础上,对某省级环境监测机构的部分大型实验室分析仪器进行分析,提出,需合理配置仪器、加强日常维护管理以及开放共享等建议,为提高大型环境监测实验室分析仪器的精细化管理提供了科学依据。     

影响不同农作物镉富集系数的土壤因素

农作物的Cd富集系数（BCF）受多种因素影响.为明确田间条件下不同农作物的Cd富集系数特征差异及土壤性质对其影响,分别在我国水稻、小麦和玉米主产区不同污染程度的地块上作物收获期采集土壤和作物籽粒点对点样品,研究水稻、小麦、夏玉米和春玉米的Cd富集系数特征及土壤性质对不同农作物的Cd富集系数的影响,并通过多元回归方程建立以上农作物Cd富集系数与土壤性质的定量关系.结果表明,在田间土壤中Cd含量范围为0.15~2.66 mg·kg^-1条件下,水稻、小麦、夏玉米和春玉米Cd富集系数的均值分别为0.915、0.155、0.113和0.102,水稻明显高于小麦和玉米,春玉米的Cd富集系数最低.土壤中的Cd含量与小麦、夏玉米和春玉米的BCF呈极显著负相关;土壤有机质（SOM）与小麦、夏玉米BCF之间的关系呈极显著负相关;土壤pH和阳离子交换量（CEC）对作物BCF也有影响.引入土壤Cd含量、pH、SOM、CEC等因素,建立水稻、小麦、夏玉米和春玉米的Cd富集系数预测方程.水稻、小麦、夏玉米和春玉米的BCF预测方程相关系数分别为0.423^*、0.796^**、0.826^**和0.551^**,均达到显著或极显著水平,可以较好地预测不同土壤条件下不同农作物的BCF值.     

利用热风吹扫建立高效电除尘绝缘系统

介绍热风吹扫系统的组成,阐述热风吹扫系统应用于高露点烟气、高含湿量烟气电除尘方面的优势。     

PM10浓度及微观特征季节分布分析--以乌鲁木齐天山区2004年为例

利用2004年乌鲁木齐城区(以天山区为例)PM10日平均浓度和气象要素观测资料,对不同季节PM10浓度变化特征、不同级别污染日数进行统计分析.同时,结合环境扫描电镜/X射线能谱(ESEM-EDX)对不同季节的颗粒物的形貌及来源进行了初步探讨。结果表明2004年PM10浓度变化为:冬季>秋季>春季>夏季;冬季出现4级以上污染日数最多,占39.5%;夏季最为洁净,好于2级的日数占到76.1%.PM10和气象因子的相关分析表明浓度与风速成正比,与降水成反比,与温度,相对湿度和逆温层厚度相关比较复杂,有时成正相关,有时呈负相关。颗粒物的形貌在不同季节特征明显,冬季颗粒物多呈圆球形,春季形貌不规则,夏季既有圆球形又有不规则形貌的颗粒,而秋季颗粒物多呈链状.     

Effects of different types of biochar on the properties and reactivity of nano zero-valent iron in soil remediation

• Biochar enhanced the mobility and stability of zero-valent iron nanoparticles. • Particle performance was best when the BC:nZVI mass ratio was 1:1. • Bagasse-BC@nZVI removed 66.8% of BDE209. The addition of nano zero-valent iron (nZVI) is a promising technology for the in situ remediation of soil. Unfortunately, the mobility and, consequently, the reactivity of nZVI particles in contaminated areas decrease due to their rapid aggregation. In this study, we determined how nZVI particles can be stabilized using different types of biochar (BC) as a support (BC@nZVI). In addition, we investigated the transport behavior of the synthesized BC@nZVI particles in a column filled with porous media and their effectiveness in the removal of BDE209 (decabromodiphenyl ether) from soil. The characterization results of N₂ Brunauer–Emmett–Teller (BET) surface area analyses, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) indicated that nZVI was successfully loaded into the BC. The sedimentation test results and the experimental breakthrough curves indicated that all of the BC@nZVI composites manifested better stability and mobility than did the bare-nZVI particles, and the transport capacity of the particles increased with increasing flow velocity and porous medium size. Furthermore, the maximum concentrations of the column effluent for bagasse–BC@nZVI (B–BC@nZVI) were 19%, 37% and 48% higher than those for rice straw–BC@nZVI (R–BC@nZVI), wood chips–BC@nZVI (W–BC@nZVI) and corn stalks–BC@nZVI (C–BC@nZVI), respectively. A similar order was found for the removal and debromination efficiency of decabromodiphenyl ether (BDE209) by the aforementioned particles. Overall, the attachment of nZVI particles to BC significantly increased the reactivity, stability and mobility of B–BC@nZVI yielded, and nZVI the best performance.     

Effects of three biochars on copper immobilization and soil microbial communities in a metal-contaminated soil using a metallophyte and two agricultural plants

Environmental Geochemistry and Health - Biochar (BC) is a porous, carbonaceous material produced by slow pyrolysis of biomass under oxygen-limited conditions. BC production has been attracting...     

轮虫在生态毒理学中的研究进展

轮虫是浮游动物中的重要类群,因具有生活周期短、对毒物的敏感性高、有两性生殖方式、易培养和实用性强等优势特征,已被用作生态毒理学实验中重要的模式生物,颇有研究前景。本文简介了轮虫作为受试生物的特点及其生活史,并从实验方法、污染物种类、测试指标等角度对近几十年来轮虫在生态毒理学中的应用现状、主要成果和最新进展作了概述,主要包括轮虫在常规毒性评价中的应用:急性毒性、慢性毒性以及对其行为的影响效应;综述了几类典型环境污染物,例如重金属、UV辐射、持久性有机污染物以及农药化合物的胁迫对轮虫的毒性效应,特别对目前存在的问题、研究热点及今后需要加强研究的方向进行了讨论和展望,以期为应用轮虫生态毒理学进行环境污染及风险评估提供参考。