Experimental study on the impact of temperature on the dissipation process of supersaturated total dissolved gas

Water temperature not only affects the solubility of gas in water but can also be an important factor in the dissipation process of supersaturated total dissolved gas （TDG）. The quantitative relationship between the dissipation process and temperature has not been previously described. This relationship affects the accurate evaluation of the dissipation process and the subsequent biological effects. This article experimentally investigates the impact of temperature on supersaturated TDG dissipation in static and turbulent conditions. The results show that the supersaturated TDG dissipation coefficient increases with the temperature and turbulence intensity. The quantitative relationship was verified by straight flume experiments. This study enhances our understanding of the dissipation of supersaturated TDG. Furthermore, it provides a scientific foundation for the accurate prediction of the dissipation process of supersaturated TDG in the downstream area and the negative imp）acts of high dam projects on aquatic ecosystems.     

Distribution and variation of mercury in frozen soils of a high-altitude permafrost region on the northeastern margin of the Tibetan Plateau

Environmental Science and Pollution Research - The Tibetan Plateau (TP) is home to the largest permafrost bodies at low- and mid-latitudes, yet little is known about the distribution and variation...     

粉末活性炭对水溶液中邻苯二甲酸二(2-乙基己基)酯的吸附

采用静态吸附法研究了邻苯二甲酸二(2-乙基己基)酯(DEHP)在粉末活性炭上的吸附性能,探讨了粉末活性炭对DEHP的吸附等温线、吸附动力学和吸附热力学特征。结果表明,粉末活性炭对DEHP吸附等温线符合Langmuir吸附等温式;分别采用拟一级反应、拟二级反应和颗粒内扩散反应模型对吸附动力学过程进行了拟合,实验数据遵循颗粒内扩散模型;在20、30、40和50℃下,对应的吉布斯自由能(ΔG0)分別为-2.014、-1.441、-0.868和-0.296 kJ/mol,表明该反应自发进行;焓变(ΔH0)<0,证实该反应为放热反应;熵变(ΔS0)<0,说明该吸附反应是熵值减小的过程;吸附活化能Ea=7.234 kJ/mol和粘附概率S*=0.036分别介于5～40 kJ/mol和0～1范围内,表明该吸附过程主要为物理吸附;活性炭吸附前后红外谱图分析,也验证物理吸附为PAC吸附DEHP之主要机制。     

武汉市狮子山地区土地利用结构变化与肥力评价

通过对武汉市狮子山地区８０年代与９０年代土地利用结构及土壤肥力５个养分因子的综合分析，初步了解该区土地利用结构及土壤肥力变化特点。以土壤肥力评价为重点，提出了４种肥力评价模型，用最优模型对该区土壤肥力进行了分级评价。为城郊土地资源的合理利用提供依据。     

曝气辅助上向流人工湿地的除污效能研究

人工湿地系统具有投资运行费用低、设备少、管理简单、处理效果稳定、便于就地回用等特点。在上向流人工湿地的基础上增加曝气装置,通过厌氧和好氧处理的结合,推动了系统对COD的去除作用以及氨氮的硝化作用。结果表明,在进水COD为326 mg/L、NH4＋-N为32 mg/L的条件下,其出水平均浓度分别为20 mg/L、4 mg/L,达到了GB18918-2002的一级A标准。沿人工湿地床层分布的氧化还原电位趋势线表明由附加曝气所产生的厌氧区和好氧区之间有明显的差异。     

Metal nanowires for transparent conductive electrodes in flexible chromatic devices: a review

Environmental Chemistry Letters - Smart electronics and optoelectronics such as smart windows, touch panels and solar cells have profoundly changed our lives over the last decade, as a result of...