Comparison of forest edge effects on throughfall deposition in different forest types

This study examined the influence of distance to the forest edge, forest type, and time on Cl⁻, SO₄²⁻, NO₃⁻, and NH₄⁺ throughfall deposition in forest edges. The forests were dominated by pedunculate oak, silver birch, or Corsican/Austrian pine, and were situated in two regions of Flanders (Belgium). Along transects, throughfall deposition was monitored at distances of 0-128 m from the forest edge. A repeated-measures analysis demonstrated that time, forest type, and distance to the forest edge significantly influenced throughfall deposition of the ions studied. The effect of distance to the forest edge depended significantly on forest type in the deposition of Cl⁻, SO₄²⁻, and NO₃⁻: the edge effect was significantly greater in pine stands than in deciduous birch and oak stands. This finding supports the possibility of converting pine plantations into oak or birch forests in order to mitigate the input of nitrogen and potentially acidifying deposition.     

Relationships between organic matter, black carbon and persistent organic pollutants in European background soils: Implications for sources and environmental fate

Black carbon (BC) and total organic carbon (TOC) contents of UK and Norwegian background soils were determined and their relationships with persistent organic pollutants (HCB, PAHs, PCBs, co-planar PCBs, PBDEs and PCDD/Fs) investigated by correlation and regression analyses, to assess their roles in influencing compound partitioning/retention in soils. The 52 soils used were high in TOC (range 54-460 mg/g (mean 256)), while BC only constituted 0.24-1.8% (0.88%) of the TOC. TOC was strongly correlated (p < 0.001) with HCB, PCBs, co-PCBs and PBDEs, but less so with PCDD/Fs (p < 0.05) and PAHs. TOC explained variability in soil content, as follows: HCB, 80%; PCBs, 44%; co-PCBs, 40%; PBDEs, 27%. BC also gave statistically significant correlations with PBDEs (p < 0.001), co-PCBs (p < 0.01) and PCBs, HCB, PCDD/F (p < 0.05); TOC and BC were correlated with each other (p < 0.01). Inferences are made about possible combustion-derived sources, atmospheric transport and air-surface exchange processes for these compounds.     

微塑料与有机污染物的相互作用研究进展

微塑料(粒径小于5 mm的塑料)作为海洋中一种新型的污染物正受到越来越多的关注。微塑料在全球多个海域均有检出,根据其来源分为原生微塑料和次生微塑料。原生微塑料由人工直接制造所得,常见于日常生活用品中;次生微塑料由大块塑料制品长期风化、磨损和光解形成。塑料自身含有多种有机添加剂,不断向环境中释放,污染海洋环境;微塑料表面还可吸附有机污染物,此吸附作用受两者的物理化学性质和环境条件影响,吸附污染物后的微塑料生物毒性增强。另外,聚合物复合光催化材料可加快有机污染物如染料的光降解反应速率,因而微塑料可能会促进有机污染物的光解。针对目前微塑料对有机物光降解的贡献、机理鲜见研究的问题,未来应加强以下3方面的研究:(1)微塑料对不同有机污染物光降解是否存在影响?(2)微塑料类型、尺寸以及反应条件对有机污染物光降解如何影响?(3)微塑料对有机污染物光降解影响的内在机制是什么?     

环境污染物计算毒理学分析及环境行为模拟研究进展

根据国内外研究报道,系统地总结了计算毒理学和化合物环境行为模拟在环境科学领域的研究进展,包括二者的概念、理论、研究方法以及在环境研究中的应用;分析了计算毒理学和化合物环境行为模拟在发展中所面临的挑战,并提出对策;展望了计算毒理学和化合物环境行为模拟在环境研究中的发展前景。     

西安市黑碳气溶胶浓度特征及与气象因素和常规污染物相关性

利用西安市环境监测站超级站2013年9月1日—2015年5月31日黑碳气溶胶(BC)的监测数据,研究空气中BC浓度特征及其与气象因素和常规污染物相关性。结果表明:BC小时平均浓度均值在春季、夏季和冬季的变化趋势呈"W"型,秋季呈"V"型,且冬季的第一个最低值和峰值比春季和夏季的分别延迟1 h和2~3 h,且20:00~次日6:00秋季BC小时平均浓度均值高于当年冬季。BC浓度在秋季和冬季较高,夏季较低。冬季BC/PM_(2.5)基本最低,秋季BC/PM_(2.5)相对最高。BC日平均浓度与气温、降水和风速的日平均值为极负显著相关,且风速小于1.0 m/s时,其与风速呈最显著的负相关。除O_3外,BC日平均浓度与其他常规空气污染物浓度呈显著相关,表明其同源性很强,且受机动车尾气排放的影响更大。     

复合人工湿地对有机污染物的去除效果初步研究

研究了由不同植物配置(驯化和未驯化)的两组下行和上行植物床组成的复合人工湿地对生活污水的净化效果。结果表明,CODCr和BOD5的去除率达67.3%,68.1%,总氮(TN)的去除率为26.9%,总磷(TP)的去除主要发生在上行床,去除率为81.6%。环芳烃(PAHs)中苊(Ace)、荧蒽(Flu)、芘(Py)、苯并[a]蒽(BaA)、屈(Chr)、苯并[b]荧蒽(BbF)、苯并[a]芘(BaP)、茚并[1,2,3-cd]芘(InP)和苯并[g,h,i](BPR)经下行床后,去除率超过80%,上行床去除较少。驯化床和未驯化床对PAHs的去除效果差异不显著。邻苯二甲酸酯(PAEs)中邻苯二甲酸二乙酯(DEP)和邻苯二甲酸二异丁酯(DiBP)经驯化床后,质量浓度显著升高,经未驯化床后邻苯二甲酸二(2-乙基)己酯(DEHP)含量显著降低。蚕豆根尖微核实验表明,不同植物配置对微核率影响差异并不显著,毒害物质经下行床后大部分被去除。     

小清河水体和沿岸地下水中有机污染物的监测及其毒性分析

本文对小清河水体和沿岸地下水中的有机污染物进行了色－质联用分析,共检出有机污染物１３类９３种。并对其毒性效应进行了分析和评价。     

洹河水中痕量有机污染物的研究

采用固相萃取技术 ,对洹河水中痕量有机物进行富集 ,大量的地表水被 C1 8键合相萃取后 ,洗脱液经干燥浓缩用于 GC和 GC/MS分析 ,鉴定出 64种有机物 ,并对苯系物、杂环类等 2 7种主要污染物作了定量测定 ,得出有机物的沿途变化规律。     

Deposition of reactive nitrogen during the Rocky Mountain Airborne Nitrogen and Sulfur (RoMANS) study

Increases in reactive nitrogen deposition are a growing concern in the U.S. Rocky Mountain west. The Rocky Mountain Airborne Nitrogen and Sulfur (RoMANS) study was designed to improve understanding of the species and pathways that contribute to nitrogen deposition in Rocky Mountain National Park (RMNP). During two 5-week field campaigns in spring and summer of 2006, the largest contributor to reactive nitrogen deposition in RMNP was found to be wet deposition of ammonium (34% spring and summer), followed by wet deposition of nitrate (24% spring, 28% summer). The third and fourth most important reactive nitrogen deposition pathways were found to be wet deposition of organic nitrogen (17%, 12%) and dry deposition of ammonia (14%, 16%), neither of which is routinely measured by air quality/deposition networks operating in the region. Total reactive nitrogen deposition during the spring campaign was determined to be 0.45 kg ha⁻¹ and more than doubled to 0.95 kg ha⁻¹ during the summer campaign.     

Soil type affects migration pattern of airborne Pb and Cd under a spruce-beech forest of the UN-ECE integrated monitoring site Zöbelboden, Austria

Anthropogenic trace element emissions have declined. However, top soils all over the world remain enriched in trace elements. We investigated Pb and Cd migration in forest soils of a remote monitoring site in the Austrian limestone Alps between 1992 and 2004. Large spatial variability masked temporal changes in the mineral soil of Lithic Leptosols (Skeltic), whereas a significant reduction of Pb concentrations in their forest floors occurred. Reductions of concentrations in the less heterogeneous Cambisols (Chromic) were significant. In contrast, virtually no migration of Pb and Cd were found in Stagnosols due to their impeded drainage. Very low element concentrations (<1 μg l⁻¹) in field-collected soil solutions using tension lysimeters (0.2 μm nylon filters) imply that migration largely occurred by preferential flow as particulate-bound species during intensive rainfall events. Our results indicate that the extent of Pb and Cd migration in soils is largely influenced by soil type.