重庆冬季水芹浮床对富营养化水体的修复

结合重庆地区冬季水体富营养化现状和水芹生长特性,通过水芹构建了生态浮床,实验观察了不同密度、不同基质水芹浮床在冬季低温条件下对富营养化水体的净化效果。研究表明,在9.5~10.5℃下,水芹浮床对富营养化水体有较好的净化效果,总氮(TN)、总磷(TP)和叶绿素a的平均去除率分别为78.8%、86.0%和67.8%。水芹浮床对TP去除效果与密度有关,密度越大效果越好。不同基质水芹浮床对TN的去除有较好的促进作用,陶粒基质的去除效果优于黄砂基质对TN的去除效果。水芹浮床的溶解氧(DO)呈现先下降后上升的趋势,范围在5.5~10.1 mg/L。     

催化铁内电解法处理硝基苯废水的机理与动力学研究

对催化铁内电解法处理硝基苯废水降解动力学特性进行了研究。结果表明，降解过程符合准一级动力学规律。进水浓度、pH值和反应温度强烈影响硝基苯的降解速率。在实验pH值范围内，反应速率常数依次为：强酸性〉弱碱性〉弱酸性〉中性；循环伏安扫描图显示了硝基苯可以在铜电极上直接得电子还原，该反应在强酸和弱碱性条件下效果较好。反应速率常数随进水浓度的增大而减小。提高反应温度可改善处理效果，在30-45℃范围内，提高温度对处理效果的改善并不显著；当温度升高到45℃以上时，升温可以显著改善处理效果。     

高寒草甸土地退化及其恢复重建对土壤碳氮含量的影响

针对我国青藏高原草地大面积退化及由此引发的一系列生态环境问题,从土壤生态功能恢复和区域可持续发展的角度出发,将原生高寒嵩草草甸封育系统作为对照,研究了土地退化对土壤碳氮含量的影响,检验了不同人工重建措施(3个人工种植处理:混播、松耙单播、翻耕单播和1个自然恢复处理)对土壤碳含量的相对影响程度。研究结果如下:原生植被封育处理每平方米土壤平均碳、氮含量分别为7.47kg和0.647kg,而重度退化地碳、氮含量分别为3.67和0.448kg·m-2,可以推算,由于土地退化而造成的土壤(0~20cm层)碳氮丢失量分别为3.80kg·m-2和0.199kg·m-2,即高寒草甸土地退化导致0~20cm土壤层中50.87%的有机碳和30.75%的氮流失,可以看出高寒草甸土壤退化后流失的碳比氮多;混播处理、松耙单播处理、翻耕单播处理和自然恢复处理土壤单位面积有机碳含量分别是原生植被土壤有机碳的70.5%,69.0%,49.0%和80%,单位面积氮含量分别是原生植被土壤全氮的86.9%,88.7%,71.1%和91.7%。但是,与重度退化地相比,除翻耕单播处理外,其它恢复重建措施均能部分恢复系统的碳氮含量,因此,将重度退化地进行自然恢复或松耙混播重建多年生植被可以作为系统固定碳(碳汇)的一个途径。     

环境专家系统

本文介绍了国内外环境专家系统的发展状况。环境专家系统成功的应用表明环境专家系统是解决环境问题的一个有力工具，环境专家系统将越来越广泛地应用于环境科学中，环境专家系统与决策支持系统相结合以及将神经网络技术应用于环境专家系统中，是环境专家系统的发展方向，文中还介绍了我们正在研究的大气污染总量控制规划专家系统。     

水环境中卤素离子和HCO_3~-对氯贝酸光降解的影响研究

在模拟太阳光照射下,研究无机离子对氯贝酸(CA)光降解的影响。结果表明,卤素离子和HCO_3~-存在时,CA的光降解均符合拟一级动力学。Cl~-和Br~-在浓度较低时可促进CA的光降解,浓度较高时可抑制CA的光降解;I~-和HCO_3~-则可抑制CA的光降解。     

水体中几种无机离子对硝酸根敏化甲芬那酸光降解影响研究

以中压汞灯为光源,研究环境浓度范围内硝酸根对甲芬那酸(MEF)光降解的影响机制.结果表明,甲芬那酸在不同浓度硝酸根溶液中的光解反应符合准一级动力学规律,其降解速率常数随硝酸根离子浓度增大而增大,当硝酸根离子浓度由0增至1 mmol·L-1时其速率常数由0.00627 min-1增至0.0232 min-1;以异丙醇为分子探针检测到羟基自由基存在于MEF光解过程中;光解过程中产生亚硝酸根,其浓度随着反应的进行而不断增大;碱性水环境对硝酸根敏化甲芬那酸的光解反应有利;碳酸盐、氯离子、三价铁对硝酸根敏化甲芬那酸光解产生抑制作用.采用UPLC/MS/MS对硝酸根敏化MEF光降解产物进行鉴定,并提出3条可能的光解路径.毒性研究表明,在硝酸根敏化甲芬那酸光降解过程中,生成了具有较甲芬那酸而言更高风险的中间产物.     

吉林省糠醛工业发展现状与地方环境标准的比对分析

糠醛工业属重污染行业。本文结合吉林省糠醛工业实际生产状况和污染防治的发展趋势,针对糠醛工业粉尘、甲醇、丙酮、气态糠醛及臭气浓度排放量的实测数据进行了系统的比对分析,并为吉林省《糠醛工业污染物控制要求》中"大气污染物排放要求"的进一步完善、升级提出了合理化建议。     

Effect of culturing temperatures on cadmium phytotoxicity alleviation by biochar

Biochar produced from rice straw at 400 °C (RS400) was prepared to determine its alleviating effect on Cd phytotoxicity to wheat seedlings under different cultivation temperatures and pH. A hydroponic system (pH 4.3) and a loam soil slurry system were designed to respectively simulate acidic and neutral soil condition, and cultivation at increasing temperatures (20, 25, and 30 °C) were performed to evaluate the greenhouse effect. The root and shoot elongation and the Cd concentration in root and solution were measured; furthermore, batch experiments for Cd adsorption were undertaken. An increasing inhibition of the root by Cd addition was observed at increasing temperatures. The inhibition rate was 50.50 and 20.80% in hydroponic system and slurry system at 25 °C, respectively; however, the corresponding inhibition rates of root were significantly decreased to 25.5 and 3.5% with addition of RS400. This is mainly attributed to the reduction of Cd migration into the roots by RS400, which decreased Cd bioavailability. The mechanism behind the reduced Cd bioavailability is attributed to the Cd adsorption and the strong buffering capacity of acidity by RS400. Therefore, biochar could be a potential amendment for the remediation of Cd-contaminated soil even at increasing culturing temperatures.

     

液膜法处理硫普罗宁废水的研究

采用W／O型乳状液膜法提取水溶液中的硫普罗宁,考察了载体、温度、硫普罗宁浓度以及油内比、试剂比、乳水比对提取率的影响,并得出了液膜法提取硫普罗宁的最佳乳液配方：油内比＝1：1,乳水比＝1：2,试剂比＝6－8,载体浓度＝5％,温度20℃,转速＝240－250r.min^-1,其提取率高达90％。     

Dynamic equity carbon permit allocation scheme to limit global warming to two degrees

Significant international collaboration is required to limit global temperature increase to below 2 °C above pre-industrial levels. Equity is the foundation of cooperation, and therefore, this study proposed a new dynamic carbon permit allocation scheme based on four principles: equality, historical responsibility, capability, and future development opportunities. Decision makers could have different preferences for allocating carbon permits, therefore, four equity rules or indicators (equality, responsibility, capacity, and sovereignty) were assigned different weights. Based on the global carbon budget of the 2 °C target, emission permits were calculated and relevant economic implications analyzed using the Global Change Assessment Model. Results indicated that developed countries should reduce emissions immediately, while allowances for developing regions could permit an initial increase in emissions until peaking. Applying different weights to the indicators resulted in multifarious regional allowances. Developed regions would benefit from the “preferring sovereignty” scenario and most developing countries would benefit under the “preferring responsibility” and “preferring capacity” scenarios. Compared with the Intended Nationally Determined Contributions submitted to the United Nations Framework Convention on Climate Change, this study found that in the short term, developed countries might insist on sovereignty as the preferred indicator. However, preferring sovereignty would place substantial mitigation pressures on developing countries in the long term. Therefore, in addressing global climate change, a dynamic choice in the weighting distribution for different indicators might be conducive to international agreement. Furthermore, a market-based trading instrument could help all participants both mitigate global climate change by reducing regional and global costs and facilitate mitigation capital flow from developed to less developed regions.