杭州西湖水体富营养化的控制

本文综述了杭州西湖水体富营养化的状况,并为西湖水体富营养化的控制提出了建议和对策。     

膜生物法降解TNT弹药销毁废水的重要影响因素

采用水解酸化一好氧膜生物工艺对弹药销毁废水中TNT进行降解试验研究。结果表明,共代谢外加碳源对TNT的生物降解影响显著。无共代谢外加碳源的情况下,HRT=40h,TNT的去除率仅为53．4％。有共代谢外加碳源的情况下,外加碳源COD与TNT提供COD比值宜大于4．8,系统对TNT的去除率可高达99％。温度对水解酸化影响重大,当温度低于15℃时,水解酸化对TNT去除率低于33．3％,而当温度高于20℃时,水解酸化对TNT的去除率不小于83％。     

垃圾渗滤液生物处理出水臭氧氧化的研究

对垃圾渗滤液生物处理出水进行了臭氧氧化的研究。研究表明,随着氧化时间的延长,CODCr去除率增大;在碱性条件下进行臭氧氧化。pH越高,CODCr去除效率越高。采用BOD5／CODCr来表征垃圾渗滤液的生物降解性,研究了臭氧氧化前后垃圾渗滤液生物处理出水的生物降解性变化规律,表明臭氧氧化可以提高垃圾渗滤液生物处理出水的生物降解性,但提高的幅度不大。通过色谱-质谱法（GC—MC）对臭氧氧化前后垃圾渗滤液的成分进行分析,结果表明,臭氧氧化前后废水中的主要成分没有发生变化,仍然为难降解物质;臭氧氧化使废水中的部分物质发生了结构上的变化,减少、消失和生成的物质多为可降解物质。     

大学生问题行为现状调查研究

大学生行为问题问卷调查结果发现,目前大学生问题行为具体表现为:大学生整体状况良好;恋爱与性烦恼成为问题行为的主要表现;男生的问题行为高于女生。主要影响因素包括社会环境因素、学校教育因素、家庭因素和自身因素。高校教育工作者应充分了解大学生问题行为的现状与特点,重点分析成因,有目的性、针对性地开展大学生思想政治教育工作。     

NO oxidation performance and kinetics analysis of BaMO3 (M=Mn,Co) perovskite catalysts

Environmental Science and Pollution Research - Perovskite is an efficient and emerging catalyst for NO oxidation. In this study, BaMnO3 and BaCoO3 perovskite catalysts were synthesized by the...     

Adsorption of volatile benzene series compounds by surface-modified glass fibers: kinetics,thermodynamic adsorption efficiencies,and mechanisms

Environmental Science and Pollution Research - The presence of volatile benzene series compounds (VBSCs) in the environment is continually increasing, with the potential for negative effects on...     

Identifying the crash characteristics on freeway segments based on different ramp influence areas

Objective: This study aimed to explore the relationship between crash types and different freeway segments and identify the factors contributing to crashes on different freeway segments. Unlike most of the previous studies on freeway segments, this study separately investigates basic freeway segments, single ramp influence segments, and multiple ramp influence segments.

Methods: Nonlinear canonical correlation analysis (NLCCA) and proportionality test were used to identify the relationship between crash types and different freeway segments. The data sets for the different freeway segments accumulated for this study consist of 9,867 crash samples with complete information on all 22 chosen variables. A multinomial logit model (MNL) was used to estimate the influence of crash factors on different freeway segments.

Results: The results show that weaving and diverge overlap influence segments (WD) are more likely to have injury or fatal crashes; diverge and diverge overlap influence segments (DD) are more likely to have property damage–only (PDO) crashes; merge and merge overlap influence segments (MM) are more likely to have sideswipe crashes; and WD have non-sideswipe crashes; WD and weaving overlap influence segments (MW) are more likely to have rear end crashes; and MM segments are less likely to have hit object crashes. The contributing factors are identified by MNL and the results show that different traffic variables, environmental variables, vehicle variables, driver variables, and geometric variables significantly affected the likelihood of crashes on different freeway segments.

Conclusions: Investigation of crash types and factors contributing to crashes on different freeway segments is based on multiple ramp influence segments, which can promote a better understanding of the safety performance of various freeway segments.