有机污染物生物降解途径的理论预测

本文报道了一个可用于有的生物降解途径理论预测的软件包，应用ＣＮ－ＤＯ／２方法计算分子的结构参数，经过解析结构参数给出有机污染理论上可能遵循的生物降解途径。     

Effects of surface coatings on electrochemical properties and contaminant sorption of clay minerals

Surface charges play a major role in determining the interactions of contaminants with soils. The most important sources of soil charges are clay mineral colloids, whose electrochemical properties are usually modified by metal-oxides and organic matter in natural environments. In this study, effects of coatings of organic matter and Fe- and Al-oxides on a series of electrochemical properties and heavy metal sorption of three clay minerals (kaolinite, montmorillonite and illite) predominant in natural soils were investigated using batch techniques. The results indicate that the coatings increased the specific surface area of the clay minerals, except for the Al-oxide coated montmorillonite and organic matter coated 2:1 clay minerals. The sesquioxide coatings increased amount of positive charges but decreased negative charges. This causes great reduction of the negative potential on the clay surfaces, shift of the zero point of charge to a higher pH, and promotion of fluoride sorption due to presence of more OH- and OH2 on the oxide surfaces than on the clay surfaces. In contrast, the organic coating significantly increased the negativity of surface charges, and thus the zero point of charge and zeta-potential of the clays dropped down. The organic coating also induced a reduction of fluoride sorption on the clays. With respect to the sorption of lead and cadmium, the sesquioxide coatings produced insignificant effects. The experiments of lead/cadmium competitive sorption show that on both the oxide-coated surface and the original clay surface there exist different types of sites, each of which preferentially binds with a heavy metal.     

重庆地区酸化水体中的浮游生物

对我国重酸雨区重庆市郊六个不同酸度水体中的藻类和浮游动物进行调查和比较的结果表明，酸化水体（ＰＨ＜５．０）中的藻类和浮游动物的种类数分别较同一地区正常水体的少４１．８８％５０．０％；细胞或个体密度分别较正常水体的少７０．０％和３４－６７％。轻度酸化水体（６．０＞ＰＨ＞５．０）的上述指标亦较正常水体的低，但不如酸化水体的明显。     

烟气脱硫石膏催化还原为硫化钙的研究

采用Fe-Ni复合催化剂,在温度650℃条件下即可将烟气脱硫石膏催化还原为硫化钙,还原率达95%以上。研究了反应温度、催化剂加入量及还原气体含量因素对还原反应的影响。     

阳离子絮凝剂P(AM-DMC)的合成及其对活性染料废水的絮凝脱色

以K2S2O8-脲为引发剂,通过自由基聚合法合成了丙烯酰胺-2-甲基丙烯酰氧乙基三甲基氯化铵P（AM—DMC）絮凝剂,并研究了其对4种活性染料模拟废水的脱色效果,考察了P（AM—DMC）加入量、阳离子度、特性粘数、染料溶液pH等因素对脱色效果的影响。实验结果表明：最佳P（AM—DMC）加入量随染料分子中磺酸基数目的增加而增加,随絮凝剂阳离子度的增大而减少;阳离子度大于52％时,最高脱色率基本相同;特性粘数对脱色效果影响很小;在染料溶液为弱酸性及中性条件下,P（AM—DMC）的脱色效果较好。P（AM—DMC）对活性染料废水的脱色机理是,P（AM—DMC）中的-N^＋（CH3）3与染料分子中的-SO3^-结合,生成-N^＋（CH3）3SO3^-,同时也形成了分子间氢键,通过键合作用使染料分子聚集沉降。     

The proliferation rule of Microcystis aeruginosa under different initial pH conditions and its influence on the pH value of the environment

Environmental Science and Pollution Research - This study investigated the characteristics of the proliferation process of Microcystis aeruginosa and its changes to environmental pH values under...     

Exploring the impact of new particle formation events on PM2.5 pollution during winter in the Yangtze River Delta, China

New particle formation（NPF） events are an increasingly interesting topic in air quality and climate science. In this study, the particle number size distributions, and the frequency of NPF events over Hefei were investigated from November 2018 to February 2019. The proportions of the nucleation mode, Aitken mode, and accumulation mode were 24.59%,53.10%, and 22.30%, respectively, which indicates the presence of abundant ultrafine particles in Hefei. Forty-six NPF events occurred during the obser...     

通过南方冰冻灾害对应急对策的几点思考

本文从2008年中国南方冰雪灾害引发的社会现象中总结防灾减灾管理工作中的不足,采用灾害链的研究方法,对规划设计、长周期气象灾害、现代化发展过程中的传统手段备份、应急机制、灾害信息披露等方面,提出一些原则性的建议。