Uranium and other trace elements’ distribution in Korean granite: implications for the influence of iron oxides on uranium migration

To understand trace radionuclide (uranium) migration occurring in rocks, a granitic batholith located at the Korea Atomic Energy Research Institute (KAERI) site was selected and investigated. The rock samples obtained from this site were examined using mineralogical methods, including scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The changes in the distribution pattern of uranium (U) and small amounts of trace elements, and the mineralogical textures affected by weathering, were examined. Based on the element distribution analyses, it was found that Fe²⁺ released from fresh biotite is oxidized in short geological time, forming amorphous iron oxides, such as ferrihydrite, around silicate minerals. In that case, the amorphous ferrihydrite does not show distinct adsorption for U. However, as it gradually crystallizes to goethite or hematite, the most U-rich phases were found to be associated with the secondary iron oxides having granular forms. This evidence suggests that the geological subsurface environment is favorable for the crystallized iron oxides to keep their structures more stable for a long time as compared with the amorphous phases. There is a possibility that the long residence of U which is in contact with the stable crystalline phases of iron may finally lead to the partial sequestration of U in their structure. Consequently, it seems that Fe-oxide crystallization can be a dominating mechanism for U uptake and controls long-term U transport in granites with low U contents.     

Specific Features of the Dynamics of Murine Rodent Communities under the Effects of Urbanization: 1. Dynamics of Species Composition and Abundance

The long-term population dynamics of rodent communities in park forests of Yekaterinburg was studied. The results showed that deep population depressions occurring in natural communities are not characteristic of the urban communities. In the urban environment, the density of rodents is always maintained at a relatively high level due to the appearance of species that are atypical for the natural communities. This fact deserves attention in view of the increasing risk of tick-borne encephalitis (TBE) in the region, as a high rodent abundance may provide for the maintenance of a stable TBE focus in the city.     

气溶胶和餐厅烟尘中有机氯农药特征与来源

使用GCIECD（气相色谱／电子捕获检测器）及毛细色谱柱定量分析粤港地区气溶胶和餐厅烟尘中有机氯农药的组成和分布特征,并分析其主要来源研究表明,从研究区大气环境中的气溶胶样品及餐厅烟尘颗粒物中,检出12种有机氯农药．其中6种DDT（滴滴涕）及其代谢物,3种BHC（六六六）和其它3种含氯农药,浓度范围在0.20～60.78pg/m³．靠近农田和果园的气溶胶及餐厅烟尘颗粒物中4,4'－DDT和2,4'－DDT浓度较高,说明大气环境中的DDT不仅来源于农药施撒过程和农田表层土壤,而且还来源于动物脂肪高温裂解的释放。     

乳化液膜法提取活性艳蓝KN-R工艺研究

利用表面活性剂TH-1、民用煤油、载体N235和内水相NaOH溶液组成的液膜体系,采用正交试验法,对提取活性艳蓝KN-R工艺进行了研究。结果表明:以5%TH-1,5%N235,10%NaOH,油内比Roi为1∶1.5的乳状液膜体系,处理初始浓度为6000mg/L活性艳蓝KN-R废水,在pH值为1,传质温度为25℃,乳水比Rew为1∶5的传质条件下,提取率可达94.8%。     

铁屑吸附-微波辐照-内电解协同处理结晶紫染料废水

以结晶紫为模型化合物,提出了一种新的“铁屑吸附—微波辐照—内电解”协同处理染料废水的方法。试验结果表明,吸附在铁屑表面的染料通过微波催化裂解和内电解协同作用迅速降解,染料溶液的脱色率和COD去除率分别达到99％和95％以上。废铁屑经8次使用后仍有良好的处理效果。研究了各种相关因素对染料废水脱色的影响。     

南响堂石窟表面粉尘特征及对石雕影响的研究

从对石窟石雕表面所覆盖的粉尘进行的物、化性能测试分析入手,对粉尘的特征、来源进行了系统地研究,指出粉尘主要由水泥尘、粘土尘、烟及煤炭尘组成,其来源为石窟周边的工业污染源.同时对粉尘与碳酸盐岩石雕表面所发生的各种反应进行了讨论,提出该工业粉尘是导致石窟石雕表面破损的一个不可忽视的重要因素.      

重庆市主城区大气细颗粒物污染特征与来源解析

重庆市主城区大气细颗粒物(PM_(2.5))浓度从1990s的100μg·m~(-3)下降至当前的约70μg·m~(-3),但仍高于环境标准限值.为探讨重庆市主城区PM_(2.5)化学组成与来源特征,于2012—2013年在渝北区大气超级站利用四通道采样仪连续采集了颗粒物样品,分析了其中水溶性离子、碳质组分和无机元素含量.采样期间,重庆市主城区大气PM_(10)和PM_(2.5)的年日均浓度分别为103.9和75.3μg·m~(-3),扩散条件不利的冬季,细颗粒物污染较为严重.受静稳天气影响的1月和2月,受沙尘影响的3月,及二次转化显著的6月是重庆市细颗粒物污染较重的月份.重庆市PM_(2.5)组成以有机物(OM,30.8%)为主,其次为硫酸盐(SO_4~(2-),23.0%)、硝酸盐(NO_3~-,11.7%)、铵盐(NH_4~+,10.9%)、地壳物质(Soil,8.2%)、元素碳(EC,5.2%)、K~+(1.1%)、Cl~-(1.0%)和微量元素(Trace,0.6%).较高的SO_4~(2-)浓度和逐步上升的[NO_3~-]/[SO_4~(2-)]比值反映了重庆市燃煤污染较重,同时机动车污染比例逐步增加.采用主因子分析/绝对主因子得分法解析了重庆城区细颗粒物5类主要来源是:二次粒子(41.7%)、燃煤(15.6%)、建筑/道路尘(12.4%)、土壤尘(11.0%)和工业尘(10.4%),通过各污染源季节变化及与其他结果对比,该源解析结果能够较可靠反映重庆市细颗粒物的来源信息.     

北京市典型排放源PM_(2.5)成分谱研究

为了建立和完善北京市PM_(2.5)本地化源谱,对北京市11类排放源PM_(2.5)进行采集,并测定其26种组分,分析了不同排放源源谱的组分特征.结果表明,在有组织排放源中,燃煤电厂PM_(2.5)中OC和Si含量很高,占PM_(2.5)的质量分数分别为8.56%和6.19%(平均值),而供热/工业锅炉排放PM_(2.5)中则是SO_4~(2-)(占48.38%)和OC(11.0%)比例最高,水泥窑炉PM_(2.5)中OC(7.12%)、Ca(4.81)和Si(4.41%)占有较大比例;垃圾焚烧排放的PM_(2.5)中Si、Ca、K和SO_4~(2-)均较高,分别占8.15%、9.36%、7.17%和6.79%,且Cl~-含量(2.5%)高于其他所有源,生物质燃烧源PM_(2.5)中OC(21.7%)、Si(6.75%)、Ca(6.15%)较为丰富,餐饮源PM_(2.5)中OC(19.44%)、SO_4~(2-)(5.76%)和K(3.11%)含量均较高;无组织开放源中,道路扬尘和土壤风沙PM_(2.5)化学组分含量变化较为一致,均是Si(分别为16.8%和9.3%)和OC(分别为8.89%和6.61%)最高,建筑水泥尘PM_(2.5)中Ca(17.46%)含量高于其他源;流动排放源PM_(2.5)中OC、EC比例最高,其中,重型柴油车的OC(29.79%)与EC(26.5%)排放比例相当,而轻型汽油车OC排放占有绝对优势(占75%).本文通过对比国内外部分排放源PM_(2.5)成分谱的差异,指出不同区域相同源类排放的PM_(2.5)化学组分差异较大,在应用受体模型中的化学质量平衡模型(CMB)判断受体颗粒物来源时,应基于本地的排放源成分谱,以避免较大的误差.     

活性氧化铁/石英砂吸附剂去除水体中的重金属

介绍了活性氧化铁／石英砂吸附剂的特点和制备方法。该吸附能有效去除水体中的重金属，包括阳离子、阴离子、重金属颗粒物及一些络离子，且容易再生，被吸附的金属可以回收。     

渗透胁迫下两种生物质能源植物的抗渗透胁迫能力及稳定碳同位素组成

本研究以麻疯树(Jatropha curcas L.)和油桐(Vernicia fordii H.)幼苗为材料,考察了麻疯树和油桐幼苗的生理指标和稳定碳同位素组成对渗透胁迫的响应情况。结果表明,麻疯树比油桐更具有抗渗透胁迫能力,主要体现在:随着渗透胁迫程度的加剧,麻疯树叶片相对含水量与叶绿素含量的下降幅度均小于油桐,脯氨酸含量和可溶性糖含量的增加幅度高于油桐,相对电导率的上升幅度小于油桐;随着渗透胁迫程度的加剧,两种植物幼苗叶片的δ13 C值也都显著升高,但是在同一渗透胁迫水平下,麻疯树幼苗叶片的δ13 C值较油桐高,表明其拥有较高的水分利用效率,能够在干旱胁迫下更好地生长,暗示着植物叶片的δ13 C值在一定情况下可以表征植物的抗旱性。