高分子量多环芳烃--苯并[a]芘的生物降解研究进展

多环芳烃(PAHs)是一类广泛分布于海洋环境中的含有两个以上苯环的有机化学污染物.苯并[a]芘(BaP)是一种由5个苯环组成的分布广泛、致癌性极强的多环芳烃化合物,人们将其作为多环芳烃的指示物,通过研究其在环境中的产生、迁移、转化、降解及毒理作用来判断多环芳烃的污染情况.BaP已成为国内外环境监测的重要指标之一.本文综述了不同环境中BaP的来源与分布,BaP在环境中的行为,微生物对BaP的代谢途径,以及微生物降解BaP的相关限制因子,并结合作者在这方面研究的部分工作与目前国际研究的热点,提出值得进一步探究的有关问题.图4表3参51     

中国西北干旱区水资源利用及其生态环境问题

近５０年来,西北干旱区随水土资源开发利用规模的不断扩展,使区域内工农业与经济得以稳定持续发展。但同时,引起一系列生态环境变化。①大多数河流下游水量锐减,甚至断流,河道缩短,终端湖泊萎缩或干涸,水质咸化和污染趋势加剧；②土壤沙漠化和盐碱化,沙漠化土地面积达６７４９３×１０^４ｈｍ^２,盐碱化耕地面积逾１３５５６×１０^４ｈｍ^２；③植被退化,生物多样性减少,与５０年代初相比,天然森林面积减少４９％～５８％,草地面积减少１６％～９２％；④沙尘暴灾害发生频数增加,灾害程度加剧。节约与高效化利用水资源以及生态环境效益与经济效益间统一协调是西北干旱区可持续发展的根本途径     

Microwave photocatalytic degradation of Rhodamine B using TiO2 supported on activated carbon： Mechanism implication

The photocatalytic degradation of Rhodamine B (RhB) was carried out using TiO2 supported on activated carbon (TiO2-AC) under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X-ray di raction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET). In the process of microwave-enhanced photocatalysis (MPC), RhB (30 mg/L) was almost completely decoloured in 10 min, and the mineralization e ciency was 96.0% in 20 min. The reaction rate constant of RhB in MPC using TiO2-AC by pseudo first-order reaction kinetics was 4.16 times of that using Degussa P25. Additionally, according to gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) identification, the major intermediates of RhB in MPC included two kinds of N-de-ethylation intermediates (N,N-diethyl-N’-ethyl-rhodamine (DER)), oxalic acid, malonic acid, succinic acid, and phthalic acid, maleic acid, 3-nitrobenzoic acid, and so on. The degradation of RhB in MPC was mainly attributed to the destruction of the conjugated structure, and then the intermediates transformed to acid molecules which were mineralized to water and carbon dioxide.     

活性炭吸附回收高含量油气的研究

利用3种活性炭吸附分离汽油蒸汽和空气的混合气,研究了其吸附回收油气的动力学、热力学性能.活性炭ACl、AC3在20℃时的吸附容量分别为0.295 g/g、0.189 g/g,30 ℃时为0.284 g/g、0.165 g/g.活性炭吸附高含量油气时,吸附热高,如吸附油气摩尔分数为0.3 mol/mol时,吸附床温升达50～60 ℃.活性炭导热系数为0.15～0.20 W/m·℃,吸附过程可视为绝热吸附.建立了活性炭吸附油气热效应估算式,可用来评价活性炭吸附容量、进料油气摩尔分数、油气回收率与活性炭温升的关系.活性炭解吸宜先采取真空解吸,在解吸后期适当加入微量微热空气吹扫而深度脱附.解吸操作压力应低于1 kPa,解吸时间可控制在60 min内,热空气温度宜控制在50℃以下.油气吸附分离方法将主要用作其他分离方法的深度处理,以确保油气回收设备尾气达标排放.     

Repercussions of COVID-19 pandemic on solid waste generation and management strategies

• Implication of COVID-19 on medical waste and MSW generation is studied. • Challenges and effective strategy of solid waste generation is reviewed. • 2.9 million tons of COVID-19 related medical waste has been generated until Sep. 22. • The pandemic has postponed policies related to the reduction of plastic use. • Blockade resulted in a significant drop in waste generation in some regions. It has been over ten months since the beginning of the 2019 coronavirus disease (COVID-2019), and its impact on solid waste management, especially medical waste, is becoming clearer. This study systematically reviews the potential influences of the COVID-19 pandemic on medical waste, personal protection equipment waste and municipal solid waste (MSW), and discusses the corresponding measures and policies of solid waste management in typical countries. The results show that the generation of medical waste from the pandemic increased significantly, with 18%‒425% growth. It is estimated that the daily output of COVID-19 medical waste increased from 200 t/d on Feb. 22 to over 29000 t/d at the end of September 2020 throughout the world. The use of personal protective equipment will continue to grow in the long-term, while the blockade and isolation measures greatly reduced the volume of commercial waste, especially for tourist cities, and part of this waste was transferred to household waste. Residents’ attitudes and behavior toward food waste have changed due to the COVID-19 pandemic. In response to the pandemic, international organizations and several countries have issued new policies and guidelines and adjusted their management strategies for medical waste and MSW treatment. The pandemic has brought specific challenges to the disposal capacity of medical waste worldwide. It has also brought about the stagnation of policies related to the reduction of plastic products and waste recycling. This study will provide some useful information for managers and governmental officials on effective solid waste management during and after the COVID-19 pandemic.     

软岩地基下AP1000核电屏蔽厂房结构地震响应研究

以AP1000核电屏蔽厂房结构为研究对象,进行考虑土-结构相互作用的地震响应分析,探讨不同厚度和不同地表倾斜角度软岩场地对屏蔽厂房结构地震响应的影响。利用ABAQUS有限元软件建立了软岩层厚度分别为25、30、35、40m以及地表倾斜角度分别为0°、3°和6°的土-结构相互作用模型,实现了地震动输入。对计算所得楼层响应谱进行对比分析可知,软岩层较硬岩层对地震传播有一定的放大效应,软岩层厚度的增加会使峰值频率往低频方向移动;倾斜场地对楼层响应谱高频部分有一定的放大效应。该研究结果对软岩场地下核电厂抗震安全评价具有一定参考意义。     

特征分析方法在江河水质评价中的应用

本文着重介绍了特征分析方法的理论模型,并把该模型具体地运用到了吉林省江河水质评价中,依据其分析结果,对我省的江河水质污染程度进行了分级划分,相信对江河治理会起到一定的指导作用。     

循环流化床锅炉脱硫对尾部电除尘器的影响

分析了循环流化床锅炉添加石灰石、生石灰和熟石灰脱硫对尾部除尘器的影响 ,主要从烟气含尘浓度和粉尘比电阻两个方面进行计算分析。     

长江,嘉陵江重庆段水环境容量研究

根据特定的水环境容量定义，推导出计算长江嘉陵江重庆干流段和城区段水任人唯贤容量的数学模型，并对计算条件进行了叙述，同时对计算出的水环境容量对空分布也作了较详细的分析。     

SBR工艺特点及改进类型

介绍了SBR污水处理的方法 ,包括它们的处理原理、相应的特点及应用范围