光化学反应的环境效应

光化学反应具有良好的环境效应，本文概述了有机合成和环境化学中光化学反应对环境的影响。     

欧拉观测的大气扩散参数计算方法探析及应用

根据湍流扩散统计理论，讨论了利用欧拉观测的风速资料求解正态扩散模式中大气扩散参数的计算方法及其实现，并以海南洋埔开关区各稳定度大气扩散参数的计算为实例作了分析。     

FOREST HARVESTING AND STREAMWATER INORGANIC CHEMISTRY IN WESTERN NORTH AMERICA: A REVIEW1

The solution chemistry of forested streams primarily in western North America is explained by considering the major factors that influence this chemistry — geological weathering; atmospheric precipitation and climate; precipitation acidity; terrestrial biological processes; physical/chemical reactions in the soil; and physical, chemical, and biological processes within streams. Due to the complexity of all these processes and their varying importance for different chemicals, stream water chemistry has exhibited considerable geographic and temporal variation and is difficult to model accurately. The impacts of forest harvesting on stream water chemistry were reviewed by considering the effects of harvesting on each of the important factors controlling this chemistry, as well as other factors influencing these impacts ‐ extent of the watershed harvested, presence of buffer strips between streams and harvested areas, nature of post‐harvesting site preparation, revegetation rate following harvesting, pre‐harvesting soil fertility, and soil buffering capacity. These effects have sometimes reinforced one another but have sometimes been counterbalancing or slight so that harvesting impacts on stream water chemistry have been highly variable. Eight major knowledge gaps were identified, two of which — a scarcity of detailed stream chemical budgets and knowledge of longitudinal variation in stream chemistry — relate to undisturbed streams, while the remainder relate to forest harvesting effects.     

Role of water chemistry on estrone removal by nanofiltration with the presence of hydrophobic acids

Hydrophobic acid organic matter (HpoA) extracted from treated effluent has been known to improve the rejection of steroid hormone estrone by reverse osmosis (RO) and nanofiltration (NF) membranes. In this study, the effects of solution chemistry (solution pH and ionic strength) on the estrone rejection by NF membrane with the presence of HpoA were systematically investigated. Crossflow nanofiltration experiments show that the presence of HpoA significantly improved estrone rejection at all pH and ionic strength levels investigated. It is consistently shown that the “enhancement effect” of HpoA on estrone rejection at neutral and alkaline pH is attributed to the binding of estrone by HpoA macromolecules via hydrogen bonding between phenolic functional groups in feed solutions, which leads to an increase in molecular weight and appearance of negative charge. The membrane exhibited the best performance in terms of estrone rejection at pH 10.4 (compared to pH 4 and pH 7) as a result of strengthening the electrostatic repulsion between estrone and membrane with the presence of HpoA. At neutral pH level, the ability of HpoA macromolecules to promote estrone rejection became stronger with increasing ionic strength due to their more extended conformation, which created more chances for the association between estrone and HpoA. The important conclusion of this study is that increasing solution pH and salinity can greatly intensify the “enhancement effect” of HpoA. These results can be important for NF application in direct/indirect potable water reuse.     

土壤重金属的植物污染化学研究进展

针对中国土壤重金属污染加剧的趋势,为改善土壤环境质量和保障农产品安全,提出了土壤重金属的植物污染化学研究领域.结合多年的研究工作,从土壤重金属的植物根际化学行为、土壤重金属的植物吸收与解毒机制和重金属污染土壤的植物-微生物交互作用等方面简要阐述了土壤-植物系统中重金属的分布、存在形态、迁移转化、累积及生物学效应和控制规律的研究进展,并对将来的植物污染化学理论研究提出了展望.     

Long term changes in atmospheric N and S throughfall deposition and effects on soil solution chemistry in a Scots pine forest in the Netherlands

In a Scots pine forest the throughfall deposition and the chemical composition of the soil solution was monitored since 1984. (Inter)national legislation measures led to a reduction of the deposition of nitrogen and sulphur. The deposition of sulphur has decreased by approximately 65%. The total mineral-nitrogen deposition has decreased by ca. 25%, which is mainly due to a reduction in ammonium-N deposition (−40%), since nitrate-N deposition has increased (+50%). The nitrogen concentration in the upper mineral soil solution at 10 cm depth has decreased, leading to an improved nutritional balance, which may result in improved tree vitality. In the drainage water at 90 cm depth the fluxes of NO₃⁻ and SO₄²⁻ have decreased, resulting in a reduced leeching of accompanying base cations, thus preserving nutrients in the ecosystem. It may take still several years, however, before this will meet the prerequisite of a sustainable ecosystem.     

石油化工行业特征挥发性有机物主要成分研究

2014年青奥会期间,南京市采用苏玛罐采样和GC-MS分析的方法对2家石油化工企业部分典型工艺的特征挥发性有机物进行监测分析.结果表明:石油化工行业挥发性有机物主要组分为烷烃、苯系物、含氧有机物、卤代烃和烯烃;主要特征污染物包括异丁烷、正戊烷、正丁烷、正己烷、正庚烷、正辛烷、苯、甲苯、二甲苯、甲醇、乙醛、丙酮、二氯乙烷、三氯苯等.对石油化工行业挥发性有机物主要成分分析,为“十三五”开展的石油化工行业自行监测和环境管理提供了基础资料.     

大气气溶胶中碘形态研究进展

大气中的碘直接影响对流层中多种光化学反应并间接影响全球气候变化,因而碘的大气化学机制研究受到越来越多关注.气溶胶中的碘是其大气化学反应的最终产物,通过其赋存形态可以推测和了解碘的大气化学过程.大气碘化学理论一直认为IO3-是大气碘沉降中最主要的碘形态,但近年来的各地实测数据发现大气气溶胶中的碘形态大多以可溶性有机碘或I-为主.这种分歧说明目前的大气碘化学理论尚有待完善.本文详细介绍了近年来碘的大气化学以及气溶胶颗粒物中碘形态的研究进展.     

湖北丹江口水库主要离子化学季节变化及离子来源分析

2004～2006年对丹江口水库中的5个点位水质的 t 、pH、EC、TDS、ORP、SO^2-₄、Cl^-、NO^-₃、HCO^-₃、Ca²⁺、Mg²⁺、Na⁺、K⁺和Si进行了测定.综合运用方差分析及主成分分析对它们的季节变化及其来源进行了研究.结果表明,丹江口库区水体呈弱碱性,属于弱矿化度水,水质类型为HCO^-₃-Ca型水.主要阴、阳离子浓度范围为：Cl^-,（4.0±0.5～6.9±1.8）mg·L^-1;NO^-₃,（4.6±0.9～6.8±1.7）mg·L^-1;SO^2-₄,（24.3±2.7～35.4±6.9） mg·L^-1;HCO^-₃,（133.0±11.7～153.5±29.6）mg·L^-1;Na⁺,（2.0±0.3～5.3±1.0）mg·L^-1;K⁺,（0.7±0.09～1.6±0.7） mg·L^-1;Ca²⁺,（33.0±2.1～46.6±0.8）mg·L^-1;Mg²⁺,（8.0±2.5～10.5±3.2）mg·L^-1.方差分析显示除HCO^-₃和Si外,t、pH、EC、TDS、ORP、SO^2-₄、Cl^-、NO^-₃、Na⁺、K⁺、Ca²⁺、Mg²⁺都表现出了显著的季节性差异,主要离子化学汛期浓度均小于对应的非汛期浓度.Na⁺和Mg²⁺的浓度只表现出秋汛<秋季,NO^-₃和SO^2-₄浓度却呈现出秋汛>秋季,这主要归因于降雨的大气沉降对水化学的贡献不同.HCO^-₃占主要阴离子的75%～88%,Ca²⁺和碱土金属分别占主要阳离子的60%～80%和87%～96%,表明碳酸盐岩风化是水体质子的主要来源及主要化学风化类型.参照我国及世界卫生组织饮用水标准,主要离子的浓度并未对人体产生危害.     

“三江”河源地区主要河流的水资源特征

该文在长江、黄河、澜沧江河源地区水资源特征分析研究的基础上,重点对河源地区主要河流的水化学特征进行了较为全面的研究。分析了各干、支流河水的主要离子成分、水化学类型、河水的矿化度、总硬度、总碱度以及河水的主要微量元素组成。并根据中国生活饮用水水质标准和工农业生产用水标准的要求,对“三江”河源地区主要河流的水质状况进行了评价。