UiO-66/UiO-66-PYDC的制备及其对UO22+吸附性研究

通过水热法合成了两种锆基有机骨架材料,采用XRD、SEM、IR、TG、EDS、BET等技术对材料的结构和形貌进行了表征,并通过静态吸附实验在不同条件下测试所制材料对UO2+2的吸附性能,考察了时间、温度、初始铀浓度、pH、CO2-3对吸附的影响.结果表明:Ui O-66体系对铀酰离子的吸附以化学吸附为主,通过表面的羧基官能团与铀酰离子结合从而达到吸附的目的.此外,本实验中材料的比表面积对吸附的影响不明显.在初始最佳pH为10.5的条件下,通过热力学模型拟合发现,低浓度下Ui O-66拥有更大的吸附量.随着溶液中初始铀酰离子浓度的升高,Ui O-66-PYDC展现出更好的吸附效果.     

Chemical characteristics and source apportionment of PM2.5 between heavily polluted days and other days in Zhengzhou, China

PM_(2.5) samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM_(2.5) concentrations and annual average values exceeded the Chinese National Ambient Air Quality Daily and Annual Standards, indicating serious PM_(2.5) pollution. The average concentration of water-soluble inorganic ions was 2.4 times higher in heavily polluted days(daily PM32.5 concentrations 250 μg/mand visibility 3 km) than that in other days, with sulfate, nitrate, and ammonium as major ions. According to the ratio of NO-3/SO2-4,stationary sources are still the dominant source of PM_(2.5) and vehicle emission could not be ignored. The ratio of secondary organic carbon to organic carbon indicated that photochemical reactivity in heavily polluted days was more intense than in other days.Crustal elements were the most abundant elements, accounting for more than 60% of 23 elements. Chemical Mass Balance results indicated that the contributions of major sources(i.e., nitrate, sulfate, biomass, carbon and refractory material, coal combustion, soil dust,vehicle, and industry) of PM_(2.5) were 13%, 16%, 12%, 2%, 14%, 8%, 7%, and 8% in heavily polluted days and 20%, 18%, 9%, 2%, 27%, 14%, 15%, and 9% in other days, respectively.Extensive combustion activities were the main sources of polycyclic aromatic hydrocarbons during the episode(Jan 1-9, 2015) and the total benzo[a]pyrene equivalency concentrations in heavily polluted days present significant health threat. Because of the effect of regional transport, the pollution level of PM_(2.5) in the study area was aggravated.     

Chemical characteristics of haze particles in Xi'an during Chinese Spring Festival: Impact of fireworks burning

Fireworks burning releases massive fine particles and gaseous pollutants, significantly deteriorating air quality during Chinese Lunar New Year(LNY) period. To investigate the impact of the fireworks burning on the atmospheric aerosol chemistry, 1-hr time resolution of PM_(2.5) samples in Xi'an during the winter of 2016 including the LNY were collected and detected for inorganic ions, acidity and liquid water content(LWC) of the fine aerosols. PM_(2.5) during the LNY was 167 ± 87 μg/m~3, two times higher than the China National Ambient Air Quality Standard(75 μg/m~3). K~+(28 wt.% of the total ion mass) was the most abundant ion in the LNY period, followed by SO_4~(2-)(25 wt.%) and Cl-(18 wt.%). In contrast, NO_3~-(34 wt.%) was the most abundant species in the haze periods(hourly PM32-2.5 75 μg/m), followed by SO_4(29.2 wt.%) and NH_4~+(16.3 wt.%), while SO_4~(2-)(35 wt.%) was the most abundant species in the clean periods(hourly PM_(2.5) 75 μg/m~3), followed by NO_3~-(23.1 wt.%) and NH_4~+(11 wt.%). Being different from the acidic nature in the non-LNY periods, aerosol in the LNY period presented an alkaline nature with a pH value of 7.8 ± 1.3. LWC during the LNY period showed a robust linear correlation with K_2SO_4 and KCl, suggesting that aerosol hygroscopicity was dominated by inorganic salts derived from fireworks burning. Analysis of correlations between the ratios of NO--3/SO_4~(2-) and NH_4~+/SO_4~(2-) indicated that heterogeneous reaction of HNO_3 with NH_3 was an important formation pathway of particulate nitrate and ammonium during the LNY period.     

Impact of Post-Methanation Distillery Effluent Irrigation on Groundwater Quality

Molasses-based distilleries generate large quantities of effluent, which is used for irrigation in many countries including India. The effluent is rich in organic and inorganic ions, which may leach down and pollute the groundwater. An on-farm experiment was conducted to assess the impact of long-term irrigation with post-methanation distillery effluent (PMDE) on nitrate, sulphate, chloride, sodium, potassium, and magnesium contents in the groundwater of two sites in northwest India. Electrical conductivity (EC), pH, total dissolved solids (TDS), sodium adsorption ratio (SAR) and colour were also determined to assess the chemical load in the groundwater. Nitrate content in the groundwater samples ranged from 16.95 mg L⁻¹ in the unamended fields to 59.81 mg L⁻¹ in the PMDE-amended fields during the 2-year study (2001–2002). Concentrations of TDS in water samples from tubewell of the amended field was higher by 40.4% over the tubewell water of the unamended field. Colour of the water samples of the amended fields was also darker than that of the unamended fields. The study indicated that the organic and inorganic ions added through the effluent could pose a serious threat to the groundwater quality if applied without proper monitoring.     

痕量离子促进厌氧消化过程的试验研究

用正交试验方法研究了Ｍｇ，Ｍｎ，Ｍｏ，Ｎｉ，Ｃｏ痕量金属离子对厌氧消化过程的促进作用，试验发现，当Ｍｇ离子为０．６ｍｇ／Ｌ，Ｍｎ，Ｍｏ，Ｎｉ，Ｃｏ离子为１．０ｍｇ／Ｌ的组合浓度时，厌氧污泥活性提高最明显，同时还得到了这些痕量离子促进厌氧消化过程的主次顺序。     

华北城市地区潜水中主要离子含量变化的反应途径模拟

近三十年来，由于污染，华北城市地区潜水中主要离子如Ｃａ￣（２＋）、Ｍｇ￣（２＋）等含量逐年升高，影响工农业生产，本文采用反应途径模拟的方法对上述情况进行了研究，作者共设计了７种反应途径，分别模拟了含碳酸盐或硅酸盐、铝硅酸盐较丰富地区地下水中盐效应和ＣＯ＿２分压升高对其主要离子含量的影响．模拟过程中考虑了２２种化学反应，３３种存在形式（包括气体、固体）。结果表明，盐效应和ＣＯ＿２分压升高对地下水中Ｃａ￣（２＋）、Ｍｇ￣（２＋）浓度的升高有明显影响，上述两种因素对Ｃａ、Ｍｇ硅酸盐、铝硅酸盐溶解的影响更为明显。     

Diatomic remains in sediments of Le An River flowing into Po Yang Lake

ＤｉａｔｏｍｉｃｒｅｍａｉｎｓｉｎｓｅｄｉｍｅｎｔｓｏｆＬｅＡｎＲｉｖｅｒｆｌｏｗｉｎｇｉｎｔｏＰｏＹａｎｇＬａｋｅ￥ＣｈａｎｇＴｓａｎｇＰｉ（ＲｅｓｅｎＳｔｒ．２２．Ｄ－８５７１６Ｌｏｈｈｏｆ，Ｇｅｒｍａｎｙ）；ＷａｎｇＷｅｎｈｕａ（Ｒｅｓｅａｒｃ...     

金属离子修饰纳米TiO2薄膜光催化降解苯酚

通过溶胶-凝胶法制备纳米TiO2薄膜，在制备过程中分别掺杂一定量的Fe^3 、Zn^2 、Pd^2 等金属离子。以高压汞灯做光源，用制得的纳米TiO2薄膜对苯酚作光催化降解实验，结果表明：掺杂Fe^3 、Zn^2 、Pd^2 的纳米TiO2催化剂光催化性能明显提高。并探讨了金属离子掺杂浓度和氧化剂对光催化的影响。     

Cd2+、Cu2+ 和Zn2+ 对5种单细胞藻酯酶基因表达调控的影响

在Cu^2 ,Cd^2 和Zn^2 的作用下，三角褐指藻（Phaeodactylum tricornutum Bohlin)，湛江叉鞭藻（Dicrateria Zhanjiangensis Hu)，绿色巴夫藻（Pavlova viridis Tseng,Chen et Zhang sp.nov.)青岛大扁藻（Platymonas helgolandica var.Tsingtaoensis Tseng et T.J.Chang) ,小球藻（Chlorella sp.) 等单细胞藻酯酶安生明显的变化，受高浓度的Cu^2 胁迫时三角褐指藻的Est-3座位的a基因，受中等浓度Cd^2 胁迫时的湛江叉鞭藻的Est-3座位的b基因，受低等浓度Cd^2 胁迫时的绿色巴夫藻的Est-1座位的a,b,两个,高浓度Zn^2 胁迫时绿色巴夫藻Est-1座位的b基因，受高浓度Cd^2 胁迫时青岛大扁藻的Est-2座位的c基因，受Cu^2 胁迫时小球藻的Est-1座位的b基因，受中低浓度的Cd^2 ,Zn^2 和低浓度的Cu^2 胁迫时小球藻的Est-2座位的b基因等基因的表达明显增强，而绝大部分位点的基因表达受3种离子的抑制。图5表5参9     

南京市降水化学成分特征及变化趋势

通过对１９９２－１９９８年南京市降水化学成分特征及其变化趋势的分析，表明南京市降以化明显，但无恶化迹象，降水化学成分中ＳＯ＾２－４对酸化起主要作用，但其作用呈下降趋势，而ＮＯ＾－３，Ｃｌ＾－的作用呈上升趋势。Ｃａ＾２＋，ＮＨ＾４＋在中和降水的酸性方面起十分重要的作用，Ｃａ＾２＋的作用逐渐减弱，而ＮＨ＾＋４的作用则逐渐增大。