白塔堡河不同粒级有机物的三维荧光特征解析

利用三维荧光扫描(3DEEM)和体积积分法(FRI),分析了辽河流域白塔堡河在春汛期水中溶解性有机物(DOM)、小粒径有机物(0.22~0.7μm)和大粒径有机物(>0.7μm)的分布。结果显示:白塔堡河中有机物以芳香类蛋白质和溶解性微生物代谢产物为主,腐植酸类物质含量极少;5类组分在不同粒径有机物中分布相似,在0.22μm以下的DOM中分布最多;溯源分析显示,DOM来源较单一,表现出较强的内源生物降解特性,而颗粒状有机物则表现出内源和陆源的双重特性;多元统计分析显示,白塔堡河点位有机物分布基本上呈现区域性分布特征。     

厦门PM_(2.5)污染类型及其成因分析

PM_(2.5)污染已成为目前我国空气污染领域关注的焦点问题。为研究厦门地区PM_(2.5)污染的不同类型,于2013年1月、4月、7月和10月选择厦门市五个代表性环境监测站进行了同步的PM_(2.5)离线滤膜和在线数据采集,并收集了同期的AQI、SO_2、NO_2、CO、O_3及气象数据。对滤膜中的水溶性无机离子、元素和碳组分进行了实验分析。基于实验分析数据,利用IMPROVE方程定量计算了厦门空气污染期间PM_(2.5)中不同组分的颗粒物消光系数。根据不同组分消光系数的大小,将厦门市的PM_(2.5)污染分为三种类型:硫酸盐主导污染类型、有机物主导污染类型以及各区域不同污染物主导污染类型。对不同污染类型的成因进行了深入分析,发现其主要与本地污染物排放、外来污染物输送以及气象要素有关。     

江门市燃生物质成型颗粒锅炉的排污现状与对策研究

生物质成型颗粒是《江门市能源发展"十三五"规划》中着力发展的能源之一.根据江门市燃生物质成型颗粒锅炉当前的使用状况和排污情况,分析总结了造成颗粒物和氮氧化物超标的原因主要为锅炉内部结构、燃烧操作以及燃生物质成型颗粒质量等.在此基础上,探讨改善江门市燃生物质成型颗粒锅炉污染的对策,提出了科学定位生物质成型颗粒,促进行业健康发展,加快各相关企业升级改造,藉此也为其他地区的燃生物质成型颗粒锅炉提供参考.     

单次降水对高寒草地温室气体通量昼夜变化的影响研究

在全球变化背景下,青藏高原降水格局发生改变,并影响高寒草地温室气体排放.为了更好地认识降水变化与高寒草地温室气体排放的关系,在2015年7月24日,通过人工降水6.7 mm,研究了单次降水对高寒草地温室气体昼夜变化的影响.表明:(1)单次降水没有改变土壤温度,但显著增加了土壤湿度;(2)单次降水后24小时内,高寒草地CH4吸收量降低了2.46倍,CO2和N2 O排放量分别提高15.3%和98.9%;(3)单次降水弱化了高寒草地CH4和N2 O排放量与土壤温度的关系.     

土壤中总石油烃预处理方法研究

采用了索氏提取法、超声波萃取法和加速溶剂萃取对土壤中的总石油烃预处理进行了研究分析,方法在0 mg/L~500 mg/L范围内均有良好的线性.采用索氏提取法时,总石油烃的方法检出限均在0.001 mg/kg~0.016 mg/kg范围内,回收率在65%~80%之间,相对标准偏差均在6.8%~12%之间;采用超声波萃取法时,总石油烃的方法检出限均在0.002 mg/kg~0.023 mg/kg范围内,回收率在60%~88%之间,相对标准偏差均在8.6%~15%之间;采用加速溶剂萃取时,总石油烃的方法检出限均在0.001 mg/kg~0.009 mg/kg范围内,回收率在70%~95%之间,相对标准偏差均在2.5%~8.8%之间.实验表明三种方法均可以作为土壤中总石油烃的预处理分析方法,但加速溶剂萃取更加快捷方便,更适合实际样品的分析.     

废旧锂电池中有价金属的回收技术研究

锂电池以其优异的性能得到了广泛的应用,其废弃量也在逐步增加.如果不对其进行有效的处理回收,不仅给环境保护带来巨大的压力,而且也会造成钴、锂、镍和锰等有价金属的极大浪费.综述了国内外对废旧锂电池回收技术的研究现状,比较了不同回收途径的优缺点,讨论了回收技术的发展方向,着重介绍了共沉淀法在废旧锂电池有价金属回收中的应用.此外,随着锂离子电池生产技术的发展,新的电极材料将会出现并取代过渡金属氧化物,同时也需要相应的电解液与之匹配,这将向废旧锂电池回收技术提出了新的要求.     

PAHs pass through the cell wall and partition into organelles of arbuscular mycorrhizal roots of ryegrass

The subcellular process and distribution of polycyclic aromatic hydrocarbons (PAHs) in arbuscular mycorrhizal plants remains to be elucidated. This work used a greenhouse experiment to show that, accompanied by the apoplastic and symplastic water movement through the root, acenaphthene (ACE) as a representative PAH passed through the cell-wall boundary, dissolved in the cell solution, and partition organelles in arbuscular mycorrhizal roots of ryegrass (Lolium multiflorum Lam.). The observed concentrations of ACE in organelles were 0.6 to 4.4 times higher than in the cell walls. The cell wall and organelles were the dominant storage domains for ACE in the root, and the distribution of ACE in cells of mycorrhizal ryegrass roots was, in descending order, cell organelles (40.8-70.8%) > cell wall (19.7-3.8%) cell solution (9.6-20.5%).     

Chloropicrin emissions after shank injection: two-dimensional analytical and numerical model simulations of different source methods and field measurements

Understanding the control mechanisms of fumigant movement in soil is a fundamental step for developing management strategies to reduce atmospheric emissions. Most soil fumigants including chloropicrin (CP) are applied by shank injection, and the application process often leaves vertical soil fractures that would potentially cause preferential fumigant movement and increased emissions. This potential transport pathway was evaluated by comparing cumulative emissions and soil air concentrations of CP from direct field measurements with those predicted using analytical and numerical models after assuming either point or rectangle sources for the injected CP. Results clearly showed that shank-injected CP, when treated as vertical rectangle sources, produced cumulative emission losses similar to the field measurements. Treating the shanked CP as point sources caused approximately 50% underprediction than the field measurements. The study also demonstrated that fumigant cumulative emissions can be predicted, with reasonable accuracy, using either analytical or numerical simulations.     

Metal contamination in sediments of the western Bohai Bay and adjacent estuaries, China

Twelve sediment cores were collected in July 2007 in open waters of western Bohai Bay, the Port of Tianjin, and the adjacent estuaries of the Haihe and Yongding Rivers. While overall concentrations of trace metals at incremental depths in these cores met the Marine Sediment Quality (GB18668-2002) criteria of China, the magnitude of both metal enrichment factors (EF) and geoaccumulation indices (I(geo)) suggested that pollution with Ag, Cd, Cr, Cu and Zn was occurring in the estuaries and Port. Risk analysis also suggested that Ag and Ni concentrations were sufficiently elevated as to cause adverse biological effects in the study area. Although metal concentrations in western Bohai Bay were of less concern, a positive relationship between EF values and excess (210)Pb activity for several metals suggested that their concentrations were increasing over time.