环境一号卫星CCD相机应用于陆地气溶胶的监测

环境一号卫星CCD相机应用在陆地气溶胶的监测中,因缺少短波红外通道,使地表反射的去除变得异常困难.应用改进的暗目标法,利用辐射传输方程(6S)构建查找表,对CCD相机数据进行图像重采样和辐射定标处理,进而对查找表进行插值,获得气溶胶光学厚度(AOD)分布.通过AERONET地基数据的验证及与MODIS气溶胶产品的对比表明,环境一号卫星CCD相机对陆地气溶胶的监测结果在AOD较大(>0.2)时,精度与MODIS相近;在AOD较小(<0.2)时,结果欠理想.     

重金属污染土壤电动力学修复技术

电动力学修复技术是把电极插入受污染的土壤并通入直流电 ,发生土壤孔隙水和带电离子的迁移。土壤中的污染物质在外加电扬作用下发生定向移动并在电极附近累积 ,抽出处理从而被除去。新兴的电动力学原位修复技术去除土壤重金属污染正越来越多地被各国研究人员接受。一系列实验规模的研究和技术已日渐成熟 ,其中Lasagna技术和Electro klean技术已在美国肯塔基州和路易斯安那州等地进行了原位修复     

洮滆水系湖库富营养化生态风险的特点与比较

茅东水库、长荡湖、涌湖、太湖竺山湾是洮滆水系从上游到下游排列的4大典型湖库,2008年的监测分析表明,氮、磷是该水系湖库富营养化的主要污染因子,并沿流域呈加剧趋势,上下游TP质量浓度为0.081～0.296 mg/L,差异小,而TN质量浓度为0.314～5.67 mg/L,差异大,长荡湖到涌湖是洮滆水系首要污染物TN快...     

太湖湖滨带浮游植物群落特征及指示种筛选

针对太湖湖滨带,均匀布设49个点位,分别于2009年12月、2010年4、8月开展浮游植物及水质监测。结果显示,湖滨带浮游植物群落多样性整体较低,优势种从枯水期到丰水期呈"鱼腥藻-鱼腥藻-微囊藻"的演变趋势;西北部湖区(竺山湖、梅梁湾、西部沿岸)浮游植物密度明显高于东南部湖区(东部沿岸、东太湖、南部沿岸);湖滨带浮游植物群落结构与湖体相似,密度比湖体高1个数量级;RDA排序筛选出在显著水平上解释浮游植物分布的最小变量组合为TN、CODMn、SS、p H、SD,且方差分解指出TN是相对最重要的变量;当物种适合度为50%~100%时,与TN具有较好梯度响应关系的是四尾栅藻及弓型藻,并且这2个种与TN、TP及综合营养状态指数的组合变量也有较好的梯度响应关系,具备指示太湖湖滨带富营养化的可能,但定量指示意义尚待进一步研究。     

Comparison of polycyclic aromatic hydrocarbon uptake pathways and risk assessment of vegetables from waste-water irrigated areas in northern China

Atmospheric deposition is the dominant pathway for PAH uptake by vegetables grown in peri-urban areas. Different polycyclic aromatic hydrocarbon (PAH) uptake pathways and the associated health risk were investigated in vegetable samples collected from the Beijing-Tianjin city cluster, China, where irrigation with waste or reclaimed water has been practised for many decades. Sampling comprised 23 diverse sites and the roots and shoots of six types of vegetables. Among the different edible vegetable parts, the highest PAH concentrations were found in radish roots and the lowest in cauliflower heads. Bioconcentration factors (BCFs) for individual PAHs showed a weakly decreasing trend with increasing log K(OW). To investigate whether the air-leaf or soil-root-shoot uptake dominates, the measured values were compared with estimations from a generic one-compartment model. The results and related observations are more consistent with an atmospheric uptake pathway than a soil-uptake pathway. The PAH isomeric ratios are consistent with pyrogenic sources (from combustion of fossil fuel and biomass). A health risk assessment on the consumption of the edible parts of vegetables revealed that all studied vegetables, except for 16% of Chinese cabbage samples, are safe for consumption. The results of this study indicate the potential health risk of consuming vegetables from waste-water irrigated areas of this city cluster and provide new insights regarding the transfer of PAHs in vegetables grown in this region.     

仲丁醇对苯乙烯臭氧化反应生成二次有机气溶胶的影响:实验和模型研究

通过烟雾箱实验,研究了仲丁醇对苯乙烯臭氧化反应生成二次有机气溶胶(SOA)的影响.结果发现,在烟雾箱实验中,过量仲丁醇的加入导致生成SOA的产率明显下降.同时,结合MCM气相机理和气-粒分配理论,将Criegee中间体与醛类的双分子反应添加到箱式模型中模拟烟雾箱中SOA的生成过程.模拟结果表明,在没有仲丁醇存在的情况下,次级臭氧化物在SOA组分中占1/2左右的比例.仲丁醇的加入消耗了大量的·OH,同时使得[HO_2]/[RO_2]比值升高,影响自由基相关的反应机制,使得SOA产率下降.另外,研究发现,Criegee中间体与醛类反应的速率常数也是影响SOA生成模拟的一个重要参数,需要进一步开展相关的动力学实验和理论研究.     

紫外辐照引入含氧官能团对生物炭吸附气体和水中苯的影响

以椰壳为原料制备生物炭,采用365 nm紫外光辐照增加吸附剂表面含氧官能团,探究其对生物炭吸附气体和水中苯的影响.理化表征和吸附实验结果表明,生物炭表面含氧官能团增加后,对气体中苯的吸附量提高9.25倍,而对水中苯的吸附量却降低14.64%.生物炭对气体中苯的吸附过程符合Elovich动力学模型,而对水中苯的吸附过程符合准二级动力学模型.含氧官能团的引入使生物炭对气体和水中苯的等温吸附过程从符合Freundlich模型变为符合Langmuir模型.Weber-Morris模型分析认为,增加含氧官能团,可增强生物炭对气体中苯的表面吸附速率,却阻碍了苯从水中向吸附剂颗粒内扩散的过程,水分子与苯竞争吸附是导致生物炭对水中苯吸附量降低的主要原因.     

固定化微生物技术处理废水

归纳综述了固定化微生物技术在废水处理领域的应用,着重介绍了常用固定化方法、载体的选择、影响因素等3方面的内容。固定化微生物技术处理废水具有效率高、稳定性好、能纯化和保持高效菌种等优点,有广阔的应用前景。实际应用中,能否开发出成本低、寿命长,且能使固定微生物保持较长时间的强度和活度的载体及固定化方法,则是推广该技术的关键。     

以江苏省河流湖泊为例探讨基于物种与面积关系确定大型底栖动物最适及高效采样量

以江苏省河流湖泊为研究对象,选取不同水体代表性点位,运用多生境采样法和形态学鉴定获取淡水大型底栖无脊椎动物的物种数及对应的采样面积,拟合实际结果的物种数与面积关系对数函数曲线。所研究采样量包括采样面积值、样方及样带数。研究发现,不同水体点位最适采样量面积为1.45~12.75 m²,样方及样带总数为6~16个,其要求十分耗时耗力。为解决这一问题,以物种数与面积关系对数函数的一阶导数曲线y≈1值为临界点,提出"高效采样量"概念,并提出3条采样原则供讨论。同时得到江苏地区高效采样量:涉水可过河流采样面积为1.36 m²,涉水不可过河流采样面积为1.5 m²,不可涉水河流和浅水湖泊采样面积为1.75 m²,均需采集4个样方,1个样带。     

Complex effects of habitat amount and fragmentation on functional connectivity and inbreeding in a giant panda population

The relationships between habitat amount and fragmentation level and functional connectivity and inbreeding remain unclear. Thus, we used genetic algorithms to optimize the transformation of habitat area and fragmentation variables into resistance surfaces to predict genetic structure and examined habitat area and fragmentation effects on inbreeding through a moving window and spatial autoregressive modeling approach. We applied these approaches to a wild giant panda population. The amount of habitat and its level of fragmentation had nonlinear effects on functional connectivity (gene flow) and inbreeding. Functional connectivity was highest when approximately 80% of the surrounding landscape was habitat. Although the relationship between habitat amount and inbreeding was also nonlinear, inbreeding increased as habitat increased until about 20% of the local landscape contained habitat, after which inbreeding decreased as habitat increased. Because habitat fragmentation also had nonlinear relationships with functional connectivity and inbreeding, we suggest these important responses cannot be effectively managed by minimizing or maximizing habitat or fragmentation. Our work offers insights for prioritization of protected areas.