氢氟酸的污染与防治

综述氢氟酸烷基化装置，运行过程中氢氟酸的危害，污染源的分析，防治措施及取得效果．     

Treatability studies of naphthalene in soil,water and air with persulfate activated by iron(Ⅱ)

Chemical oxidation was applied to an artificially contaminated soil with naphthalene (NAP). Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. The importance of the air phase analysis was emphasized by demonstrating how NAP behaves in a sealed system over a 4 hr reaction period. Design of Experiments method was applied to the following variables: sodium persulfate concentration [SP], ferrous sulfate concentration [FeSO₄], and pH. The system operated with a prefixed solid to liquid ratio of 1:2. The following conditions resulted in optimum NAP removal [SP] = 18.37 g/L, [FeSO₄] = 4.25 g/L and pH = 3.00. At the end of the 4 hr reaction, 62% of NAP was degraded. In the soil phase, the chemical oxidation reduced the NAP concentration thus achieving levels which comply with Brazilian and USA environmental legislations. Besides the NAP partitioning view, the monitoring of each phase allowed the variabilities assessment over the process, refining the knowledge of mass reduction. Based on NAP distribution in the system, this study demonstrates the importance of evaluating the presence of semi-volatile and volatile organic compounds in the air phase during remediation, so that there is greater control of the system as to the distribution and presence of the contaminant in the environment. The results highlight the importance of treating the contaminant in all its phases at the contaminated site.     

Recent advances in catalytic decomposition of ozone

Ozone (O₃), as a harmful air pollutant, has been of wide concern. Safe, efficient, and economical O₃ removal methods urgently need to be developed. Catalytic decomposition is the most promising method for O₃ removal, especially at room temperature or even subzero temperatures. Great efforts have been made to develop high-efficiency catalysts for O₃ decomposition that can operate at low temperatures, high space velocity and high humidity. First, this review describes the general reaction mechanism of O₃ decomposition on noble metal and transition metal oxide catalysts. Then, progress on the O₃ decomposition performance of various catalysts in the past 30 years is summarized in detail. The main focus is the O₃ decomposition performance of manganese oxides, which are divided into supported manganese oxides and non-supported manganese oxides. Methods to improve the activity, stability, and humidity resistance of manganese oxide catalysts for O₃ decomposition are also summarized. The deactivation mechanisms of manganese oxides under dry and humid conditions are discussed. The O₃ decomposition performance of monolithic catalysts is also summarized from the perspective of industrial applications. Finally, the future development directions and prospects of O₃ catalytic decomposition technology are put forward.     

Chemical characteristics of road dust PM2.5 fraction in oasis cities at the margin of Tarim Basin

In order to understand the compositions characteristics of particulate matter with aerodynamic diameter less than 2.5 μm (PM_2.5) fraction in road dust (RD_2.5) of oasis cities on the edge of Tarim Basin, 30 road dust (RD) samples were collected in Kashi, Cele, and Yutian in the spring, 2018, and RD_2.5 was collected using the resuspension approach. Eight water-soluble ions, 39 trace elements and 8 fractions of carbon-containing species in PM_2.5 were analyzed. Ca²⁺ and Ca were the most abundant ions and elements in RD_2.5 (7.1% and 9.5%). Cl^- in RD_2.5 was affected not only by attributed to saline-alkali soils in oasis cities of the Tarim Basin and dust from Taklimakan Desert but also by human activities. Moreover, the organic carbon/elemental carbon (OC/EC) ratio indicated that carbon components in RD_2.5 in Cele town mainly come from fossil fuel combustion, while those in Yutian and Kashi mainly come from biomass combustion. It is noteworthy that high Ca in RD_2.5 was seriously affected by anthropogenic emissions, and high Na and K contents in RD_2.5 could be derived from soil and desert dust. It was estimated that Cd, Tl, Sn and Cr were emitted from anthropogenic emissions using the enrichment factor. The coefficients of divergence (COD) result indicated that the influence of local emission on road dust emission is greater than that of long-distance transmission. This study is the first time to comprehensively analyze the chemical characteristics of road dust in oasis cities, and the results provides the sources of road dust at the margin of Tarim Basin.     

Concentrations and chemical compositions of PM10 during hazy and non-hazy days in Beijing

In order to study the concentrations of major components,characteristics and comparison in hazy and non-hazy days of PM_(10) in Beijing,aerosol samples were collected at urban site in Beijing from December 29,2014 to January 22,2015.Heavy metals like Zn,Pb,Mn,Cu,As,V,Cr and Cd were deeply studied considering their toxic effects on human being;nine water-soluble inorganic ions(SO_4~(2-),NO_3~-,NH_4~+,Na~+,K~+,Cl~-,Ca~(2+) and Mg~(2+)) and carbon fractions(OC and EC) were also analyzed.The concentrations of heavy metals were 1.03–1.98 times higher in hazy days than those in non-hazy days,mainly due to biomass burning and coal burning.The trends in total heavy metals concentrations were basically consistent with the trends in PM concentrations except for two obvious periods(12.29–12.30;1.14–1.15);but when air masses accumulated locally or around Beijing,trends in PM concentrations and heavy metals were opposite.The proportion for NO_3~-/SO_4~(2-) indicated that mobile sources such as automobiles were important reasons for haze in Beijing.Correlation between OC and EC during non-hazy days was strong(R~2= 0.95) but it was low(R~2= 0.67) during hazy days,and large variations for OC/EC values occurred in hazy days.The calculated mass concentration of SOC is 2.58 μg/m~3,which only accounted for 10.1% of the OC concentration.When air masses from the far north-west,they decreased PM concentration in Beijing and they were relatively clean;however,those from the near east,south-east and south of the mainland increased PM concentration and they were dirty.     

红壤丘陵区典型流域地表水水环境特征研究——以浏阳河流域为例

选取浏阳河流域为例,根据近十年河流断面监测数据,采用改进的综合污染指数法来评价水质污染程度,研究了该红壤丘陵区典型河流水质的时空变化特征,并结合土地利用和土壤特征等分析地表水质变化原因。结果表明,改进的综合污染指数法有较好的适用性;从时间特征上看,由于面源污染加剧,使得浏阳河近十年的水质污染呈增长趋势;从空间特征上看,浏阳河从上游到下游,河流污染呈增长趋势,上游水质较好,中游表现为重金属铅和汞的污染较大,而下游则是氨氮污染加剧。     

近年来宁夏对沙尘天气的监测及对沙漠化防治对策

宁夏在全区范围内建立沙尘暴监测网络,开展对沙尘天气的应急监测。宁夏作为沙源区和沙尘过往的主要通道,2002年全区共监测沙尘天气12次,沙尘粒径多分布在大于2 1μm。为防治沙漠化,宁夏积极寻求国际间合作,采取退耕还林还草、划管封育、禁牧、把握人工降雨时机等一系列措施,加大对沙漠化的防治力度。     

Pollution prevention at ports: clearing the air

Seaports are major hubs of economic activity and of environmental pollution in coastal urban areas. Due to increasing global trade, transport of goods through ports has been steadily increasing and will likely continue to increase in the future. Evaluating air pollution impacts of ports requires consideration of numerous sources, including marine vessels, trucks, locomotives, and off-road equipment used for moving cargo. The air quality impacts of ports are significant, with particularly large emissions of diesel exhaust, particulate matter, and nitrogen oxides. The health effects of these air pollutants to residents of local communities include asthma, other respiratory diseases, cardiovascular disease, lung cancer, and premature mortality. In children, there are links with asthma, bronchitis, missed school days, and emergency room visits. The significance of these environmental health impacts requires aggressive efforts to mitigate the problem. Approaches to mitigation encompass a range of possibilities from currently available, low-cost approaches, to more significant investments for cleaner air. Examples of the former include restrictions on truck idling and the use of low-sulfur diesel fuel; the latter includes shore-side power for docked ships, and alternative fuels. A precautionary approach to port-related air pollution would encourage local production of goods in order to reduce marine traffic, greener design for new terminals, and state-of-the art approaches to emissions-control that have been successfully demonstrated at ports throughout the world.     

南京市建筑施工环境噪声的管理与对策

针对建筑施工环境噪声扰民问题投诉居高不下，提出环境监理部门要积极宣传环保法律法规，规范举报工作，认真受理投诉，以取得市民的理解与支持；严格审批夜间建筑施工，加大监管力度，做好对夜间施工现场的核查；加强行风建设，通过内强素质，提高自身的业务水平，监督与服务并重；拓展工作思路，加强与建工、公安、市容、市政供电等部门的合作，共同解决噪声扰民问题。     

ADMS模型解析城区总悬浮颗粒物来源

以污染源排放数据为基础,应用ADMS-城市扩散模型模拟分析了鞍山市尘各污染源对空气环境质量的贡献。结果表明,来自污染源的浓度贡献值占总量的52%;二次尘及外来尘浓度贡献占48%;矿山开采二次尘的浓度贡献占16%;鞍钢炼铁厂的浓度贡献占19.6%;鞍钢化工总厂浓度贡献占5.6%;供暖锅炉浓度贡献占9.3%。低、中、高架源浓度贡献百分比分别为68.1%、29.0%、2.9%。低架源吨排放量浓度贡献为高架源的2.4倍。