用现行设备进行烟气脱汞技术研究

基于布袋除尘器或静电除尘器吸附剂喷入技术是最有前景的脱汞技术,利用炭基吸附剂可以去除95%的汞,但是活性炭价格昂贵.常用飞灰或者钙基吸收剂代替,效果却不理想.WFGD可以去除80%-95%的Hg2+,但是Hg0的去除率为0.通过加入一些氧化剂可以有效控制汞的排放,抑止Hg2+向Hg0转化.SCR催化剂可以促进Hg0氧化从而增加WFGD对汞的去除率,该工艺除汞具有很大的潜在空间.     

我国氯碱行业汞污染现状与防治对策

介绍了汞污染的来源、危害及治理现状,分析了氯碱行业的高汞触媒污染严重、汞流失环节多、含汞废触媒回收处理中存在污染隐患等汞污染问题,提出了减少氯碱行业汞消耗与汞污染的对策和措施.     

热解吸对污染土壤中不同形态汞的去除作用

选取贵州省万山矿区的汞污染土壤样品进行不同形态汞的热解吸去除行为研究。研究了热解吸过程中∑Hg的去除效果及动力学,以及温度和时间对污染土壤中不同形态汞的去除作用。结果表明,热解吸修复技术可有效去除土壤中的汞,土壤中∑Hg的热解吸过程符合二级动力学方程。固定热解吸时间在10 min时,随着热解吸温度的升高,土壤中水溶态汞、盐酸溶态汞和碱溶态汞含量呈现先下降后上升再下降的趋势,王水溶汞和盐酸溶态汞始终呈现下降趋势,说明不同形态的汞之间发生了转化。热解吸温度为250℃时,随着热解吸时间的增加,环境风险大的水溶态汞、盐酸溶态汞、碱溶态汞和硝酸溶态汞的去除率大幅增加,土壤的有机质损失较少,说明在低温下,延长热解吸时间,对生物毒性强的形态汞有良好的修复效果,且此温度下处理后的土壤更容易恢复农田耕作。     

活性焦烟气脱汞的试验研究与数值模拟

采用固定床吸附系统,对自制褐煤活性焦的脱汞性能进行了试验研究,研究发现自制活性焦对烟气中Hg0有一定的吸附能力,随着Hg0的入口浓度的增加,活性焦质量的增加,活性焦的吸附量也在增加。40mg时3号活性焦由10ng/min汞入1：2浓度时26．68％的最大吸附效率提高到40ng／min汞入口浓度时的53．12％。10ng/min汞入口浓度时3号活性焦在40mg时的最大吸附效率为26．68％,而在80mg时吸附效率提高到43．2％。烟气中的SO2、NO气体对活性焦吸附汞有一定的促进作用。在试验的基础上建立了固定床吸附系统的数学模型,基于Lan—mguir吸附系数,考虑吸附过程中颗粒内、外的传质控制过程,建立质量平衡方程。通过Matlab模型计算,计算结果与试验结果基本吻合,计算的活性焦脱汞效率要优于试验数值,计算的是理想情况下活性焦对汞的吸附效率,实际情况会有所降低。     

一株假单胞菌降解石油污染物的降解动力学与降解机制

从某石油污染场地土壤中分离出一株石油降解菌B-1(Pseudomonas),研究了该菌株降解石油污染物的动力学,通过气相色谱(GC)/质谱(MS)分析了石油组分降解前后的变化规律,并对其降解机制进行了初探。结果表明:(1)苯、二甲苯、萘的降解动力学拟合方程大部分与一级降解动力学方程拟合效果良好,苯、二甲苯、萘的降解半衰期分别为0.47~1.67、1.54~3.60、4.41~7.00d;(2)可以通过全扫描图谱及检索出的代谢产物明确微生物降解苯、二甲苯、萘的降解途径。     

工业污染场地土壤中汞的化学形态及其环境限值探讨

汞是中国工业污染场地土壤中常见的重金属污染物,汞的常见形态包括单质汞、无机汞和甲基汞。比较了不同形态的汞及其化合物在物化性质、环境行为、毒性效应及致毒机制上的差异,还以美国、英国为例,探讨了针对不同形态的汞分别制定土壤环境限值的方法。最后指出,中国现有的土壤环境质量相关标准以及污染场地风险评估导则中均尚未区分汞的形态,仅给出总汞含量的限值。因此,在未来的相关标准制定中,应考虑按汞的各种形态制定不同的标准,这将更有利于客观准确评价工业污染场地土壤中汞的污染程度和环境风险。     

A GIS-based evaluation of the effect of decontamination on effective doses due to long-term external exposures in Fukushima

Despite the enormous cost of radiation decontamination, there has been almost no quantitative discussion on how much it would reduce the long-term external radiation exposure in the Evacuation Zone and Planned Evacuation Zone (restricted zone) in Fukushima. The aim of this study is to assess the effectiveness of decontamination and return options and to identify important parameters for estimating the long-term cumulated effective dose (CED) during 15, 30 and 70 year period using data on land-use, population and decontamination in the restricted zone (about 1100 km²) in Fukushima.     

The sea–air exchange of mercury (Hg) in the marine boundary layer of the Augusta basin (southern Italy): Concentrations and evasion flux

The first attempt to systematically investigate the atmospheric mercury (Hg) in the MBL of the Augusta basin (SE Sicily, Italy) has been undertaken. In the past the basin was the receptor for Hg from an intense industrial activity which contaminated the bottom sediments of the Bay, making this area a potential source of pollution for the surrounding Mediterranean. Three oceanographic cruises have been thus performed in the basin during the winter and summer 2011/2012, where we estimated averaged Hg_atm concentrations of about 1.5 ± 0.4 (range 0.9–3.1) and 2.1 ± 0.98 (range 1.1–3.1) ng m⁻³ for the two seasons, respectively. These data are somewhat higher than the background Hg_atm value measured over the land (range 1.1 ± 0.3 ng m⁻³) at downtown Augusta, while are similar to those detected in other polluted regions elsewhere. Hg evasion fluxes estimated at the sea/air interface over the Bay range from 3.6 ± 0.3 (unpolluted site) to 72 ± 0.1 (polluted site of the basin) ng m⁻² h⁻¹. By extending these measurements to the entire area of the Augusta basin (∼23.5 km²), we calculated a total sea–air Hg evasion flux of about 9.7 ± 0.1 g d⁻¹ (∼0.004 t yr⁻¹), accounting for ∼0.0002% of the global Hg oceanic evasion (2000 t yr⁻¹). The new proposed data set offers a unique and original study on the potential outflow of Hg from the sea–air interface at the basin, and it represents an important step for a better comprehension of the processes occurring in the marine biogeochemical cycle of this element.     

汞蒸汽被动式检气管的初步研制

初步研制的汞蒸汽被动式检气管是建立在气体分子扩散和化学吸收原理基础上的,新制备的碘化亚铜沉淀和乙醇、甘油、硝酸混合、研碎,伴入经活化的层析硅胶,填充到检气管中,当汞蒸气进入管内时,发生显色反应,检气管显色长度的平方与汞蒸汽浓度及采样时间的乘积成线性关系,检测下限为0.001ug/mL(1h)。该法集采样与分析于一体,结构简单,不需动力,便于携带,操作方便,实验室模拟运用,其灵敏度和标准偏差令人满意。