大气非均相反应及其环境效应

大气颗粒物是地球大气的重要组成成分之一,以全球气候和区域环境质量具有重要影响.由于大气颗粒物具有区域牲强、寿命较短和组成多样且不均匀等特点,使得其气候和环境效应具有相当大的不确定性,而颗粒物表面发生的非均相反应,一方面可改变痕量气体的源汇平衡,另一方面会改变颗粒物本身的表面组成、形貌和与之相关的吸湿性和光学性质,从而进...     

Fast and reversible adsorption for dibenzothiophene in fuel oils with metallic nano-copper supported on mesoporous silica

Environmental Science and Pollution Research - Dibenzothiophene (DBT) in fuel oils causes the release of toxic sulfur oxide gases, and it is necessary to remove DBT in fuels. Herein, metallic...     

Review of heterogeneous photochemical reactions of NOy on aerosol－A possible daytime source of nitrous acid (HONO) in the atmosphere

As an important precursor of hydroxyl radical, nitrous acid (HONO) plays a key role in the chemistry of the lower atmosphere. Recent atmospheric measurements and model calculations show strong enhancement for HONO formation during daytime, while they are inconsistent with the known sources in the atmosphere, suggesting that current models are lacking important sources for HONO. In this article, heterogeneous photochemical reactions of nitric acid/nitrate anion and nitrogen oxide on various aerosols were reviewed and their potential contribution to HONO formation was also discussed. It is demonstrated that HONO can be formed by photochemical reaction on surfaces with deposited HNO3 , by photocatalytic reaction of NO2 on TiO2 or TiO2 -containing materials, and by photochemical reaction of NO2 on soot, humic acids or other photosensitized organic surfaces. Although significant uncertainties still exist in the exact mechanisms and the yield of HONO, these additional sources might explain daytime observations in the atmosphere.     

西河污灌区环境污染对居民健康影响的调查研究

本文对污灌区居民健康状况及水样致突性的调查,显示污灌区居民消化系统主要疾病(慢性胃炎,急、慢性肠炎)患病率,肝肿大率以及总标化死亡率均显著高于对照区(P<0.01)。污灌区消化系恶性肿瘤标化死亡率高于对照区(P<0.01)。污灌区消化系恶性肿瘤标化死亡率高于对照区(P<0.05);水样紫露草微核率亦高于对照区,并有显著性差异(P<0.01)。污灌区居民由于受饮用水和食物等污染,每年的健康经济损失总计为127.2050万元。     

淮南潘集采煤沉陷区地表水中氮、磷特征

根据2012年11月至2013年9月的9次监测数据,分析了淮南潘集开放型和封闭型采煤沉陷区地表水中氮、磷时空分布特征及污染源;通过相关性分析揭示了同类水体内氮、磷之间的响应关系和运移特征;通过各形态氮、磷比率分析了两类水体中氮、磷组成.结果表明,NH3-N(氨氮)年内时间差异性较小,整体呈KB(开放型地表水)>FB(封闭型地表水),最大值分别为0.621 mg·L-1(6月)和0.813 mg·L-1(6月);NO-2-N(亚硝酸氮)时空差异性均较小,NO-3-N(硝酸盐氮)和TN(总氮)年内时间差异性较大,空间差异性较小,整体上均呈FB>KB.KB与FB内NO-2-N最大值分别为0.0485 mg·L-1(6月)和0.0532 mg·L-1(6月),NO-3-N(硝酸盐氮)最大值分别为0.635 mg·L-1(11月)和0.623 mg·L-1(4月),TN最大值分别为2.295 mg·L-1(11月)和2.261 mg·L-1(1月).PO3-4和DTP(溶解性总磷)含量基本呈KB>FB,两形态磷在KB内的最大值分别为0.174 mg·L-1(11月)和0.055 mg·L-1(11月),FB内最大值分别为0.0298 mg·L-1(6月)和0.0391 mg·L-1(5月);TP(总磷)基本呈KB相似文献   

环境微界面过程的原位和在线研究方法

环境微界面过程是污染物在各环境要素中迁移转化的基本过程,也是研究污染控制方法的基础.发展原位和在线研究方法,对于揭示污染物在环境微界面的迁移转化规律和进行污染控制过程的研究具有重要意义.本文基于环境微界面过程的基本特征,在针对多相环境催化的原位研究方法基础上,分析了用于环境微界面过程的原位和在线研究方法所面临的挑战和相应对策,主要介绍了红外光谱、拉曼光谱和质谱等技术在气固环境微界面过程原位研究中的应用,提出了发展环境微界面过程原位和在线研究方法体系的构想.     

Differences of the oxidation process and secondary organic aerosol formation at low and high precursor concentrations

Current atmospheric quality models usually underestimate the level of ambient secondary organic aerosol(SOA), one of the possible reasons is that the precursors at different concentrations may undergo different oxidation processes and further affect SOA formation. Therefore, there is a need to perform more chamber studies to disclose the influence. In this work, SOA formation over a wide range of initial precursor concentrations(tens of ppb to hundreds of ppb levels) was investigated in a 30 m3 indoor smog chamber,and mainly through the analysis of multiple generations of VOCs detected from HR-To FPTRMS to expound the difference in the oxidation process between low and high precursor concentrations. Compared to high initial concentrations, gas-phase intermediates formed at low concentrations had a higher intensity by about one order of magnitude, and the lowvolatility compounds also had a higher formation potential due to the competition between semi-volatile intermediates and precursors with oxidants. In addition, the formed SOA was more oxidized with higher f44 value(0.14 ± 0.02) and more relevant to real atmosphere than that formed at high concentrations. This work should help to deeply understand SOA formation and improve the performance of air quality models for SOA simulation.     

Simplified creation of polyester fabric supported Fe-based MOFs by an industrialized dyeing process: Conditions optimization, photocatalytics activity and polyvinyl alcohol removal

MIL-53(Fe) was successfully prepared and deposited on the surface carboxylated polyester (PET) fiber by an optimized conventional solvothermal or industrialized high temperature pressure exhaustion (HTPE) process to develop a PET fiber supported MIL-53(Fe) photocatalyst ([email protected]) for the degradation of polyvinyl alcohol (PVA) in water under light emitting diode (LED) visible irradiation. On the basis of several characterizations, [email protected] was tested for the photocalytic ability and degradation mechanism. It was found that temperature elevation significantly enhanced the formation and deposition of MIL-53(Fe) with better photocatalytic activity. However, higher temperature than 130°C was not in favor of its photocatalytic activity. Increasing the number of surface carboxyl groups of the modified PET fiber could cause a liner improvement in MIL-53(Fe) loading content and photocatalytic ability. High visible irradiation intensity also dramatically increased photocatalytic ability and PVA degradation efficiency of [email protected] Na₂S₂O₈ was used to replace H₂O₂ as electron acceptor for further promoting PVA degradation in this system. [email protected] prepared by HTPE process showed higher MIL-53(Fe) loading content and slightly lower PVA degradation efficiency than that prepared by solvothermal process at the same conditions. These findings provided a practical strategy for the large-scale production of the supported MIL-53(Fe) as a photocatalyst in the future.