无铅焊料合金中重金属元素浸出行为的研究

选用Sn.3.5Ag-0.5Cu、Sn-3.5Ag、Sn-0.5Cu无铅焊料合金及它们与Cu的钎焊接头,研究了它们在典型的酸性、碱性和盐溶液中的重金属元素的浸出规律.结果表明,焊料合金中的主要浸出元素Sn在酸性或碱性溶液中的浸出量都不是太多,而在NaCl盐溶液中浸出量增大2个数量级.制备成钎焊接头后,在酸性环境中,Sn-3.5Ag和Sn.0.5Cu钎焊接头中Sn的浸出量增加1个数量级以上,而在NaOH碱性环境中.Sn-3.5Ag-0.5Cu钎焊接头中Sn的浸出量相对较高.该结果对电子垃圾填埋环境选择及相关决策提供了参考.     

Degradation of carbon tetrachloride in thermally activated persulfate system in the presence of formic acid

The thermally activated persulfate (PS) degradation of carbon tetrachloride (CT) in the presence of formic acid (FA) was investigated. The results indicated that CT degradation followed a zero order kinetic model, and CO ₂ ^– · was responsible for the degradation of CT confirmed by radical scavenger tests. CT degradation rate increased with increasing PS or FA dosage, and the initial CT had no effect on CT degradation rate. However, the initial solution pH had effect on the degradation of CT, and the best CT degradation occurred at initial pH 6. Cl^– had a negative effect on CT degradation, and high concentration of Cl^– displayed much strong inhibition. Ten mmol·L^–1HCO ₃ ^– promoted CT degradation, while 100 mmol·L^–1NO ₃ ^– inhibited the degradation of CT, but SO ₄ ^2– promoted CT degradation in the presence of FA. The measured Cl–concentration released into solution along with CT degradation was 75.8% of the total theoretical dechlorination yield, but no chlorinated intermediates were detected. The split of C-Cl was proposed as the possible reaction pathways in CT degradation. In conclusion, this study strongly demonstrated that the thermally activated PS system in the presence of FA is a promising technique in in situ chemical oxidation (ISCO) remediation for CT contaminated site.     

An interval joint-probabilistic programming method for solid waste management: a case study for the city of Tianjin, China

Currently, environmental protection and resources conservation continue to be challenges faced by solid-waste managers in China. These challenges are being further compounded by rapid socioeconomic devel- opment and population growth associated with increased waste generation rates and decreased waste disposal capacities. In response to these challenges, an interval joint-probabilistic mixed-integer programming （IJMP） method is developed for supporting long-term planning of waste management activities in the city of Tianjin, which is one of the largest municipalities in the northern part of China. In the IJMP, joint probabilistic constraints are introduced into an interval-parameter mixed-integer programming framework, such that uncertainties presented in terms of interval values and random variables can be reflected. Moreover, a number of violation levels for the waste-management-capacity constraints are examined, which can facilitate in-depth analyses of tradeoffs among economic objective and system-failure risk. The results indicate that reasonable solutions have been generated. They are valuable for supporting the adjustment of the city＇s existing waste-management practices and the long- term planning of the city＇s waste-management facilities.     

纳米材料诱导细胞自噬及其"双刃剑"作用

细胞自噬是细胞维持自身稳态的关键生物学过程。近年来,纳米材料诱发的细胞自噬效应及其生物学结局受到了研究人员的高度关注,成为纳米医学和纳米毒理学的重要研究方向。一方面,纳米材料诱发的自噬效应可作为纳米药物发挥治疗作用的重要过程,另一方面,其诱发的自噬效应也可成为纳米材料诱发细胞死亡和机体损伤的重要原因。本文重点阐述纳米材料诱导自噬发生的过程及相关机制,进一步探讨纳米材料诱导自噬的不同结局、机制和影响因素,以期为深入认识纳米材料自噬效应并对其进行毒理学评价提供科学依据。     

用CAF涡凹气浮设备处理含油污水

用CAF涡凹气浮设备进行含油污水处理的试验，结果表明：当进水油、CODCr平均浓度分别为40.7mg/L、883.8mg/L，平均去除率分别为86.05%,32.62%，出水可满足后续生化处理的进水要求。     

含模糊随机变量的水污染控制系统研究

在水流量为模糊随机变量且河流中工业污水含量标准给定的条件下,以极小化污水处理费用为目标,建立了水污染控制系统问题的模糊随机机会约束规划模型。采用将模糊随机模拟、神经元网络及遗传算法相结合的混合遗传算法来求解该模型,并用算例进行了验证,结果表明该算法是有效可行的。     

生态学原理在城市改造中的应用——以天津市为例

随着中国城市化进程的加快,城市改造的速度也在加快,但是由于缺少科学的理论指导,城市改造往往表现为盲目的重建。天津市在城市的改造中,以生态学原理指导城市改造,注重城市景观多样性的保护和发展,成功地对部分城区进行了改造。对城市改造应遵循的生态学理念进行了阐述,并指出,生态学原理的运用是解决目前中国城市改造中存在的问题的有效途径;并结合天津市“五大道”和海河改造的实例说明生态学原理在城市改造中的应用。     

Monitoring the genotoxicity of Lake Taihu, using two kinds of micronucleus tests

Mutagenicity of surface water in Lake Taihu was monitored by genotoxicological methods. The goal is to determine the situation concerning the contamination by mutagens, their distribution in the lake, and the potential effect on public health. In this study, the micronucleus test of Vicia faba root tip, a standard monitoring technique now in China, was carried out to make a preliminary screening of environmental mutagens in 39 representative sites of the lake. Highly significant differences in MCN permillage (average number of micronuclei per 1000 cells) and PI (pollution index) values were found among these sites. From the results, a rough distribution of the contamination could be obtained: mainly concentrated in the north-west area of the lake from several tributaries flowing into the lake. In order to provide further evidence, organic extracts from four entrances and one outlet of the five major tributaries were examined by the micronucleus test of human peripheral lymphocytes. The results were in accord with those of the micronucleus tests using Vicia faba. The tests also revealed that the intensity and mechanism of the pollutants were diverse in the different sources.     

发达国家和地区污染场地法律制度体系及启示

我国正在起草《土壤污染防治法》,这将为我国土壤、场地污染防治管理提供基本法律依据,并逐步建成完善的污染场地管理的法律制度体系。其中,监管体系、资金体系和责任体系是污染场地管理体系中的3大重要方面。美国、日本等发达国家和我国台湾地区在各自污染场地管理法律制度体系中,均规定了明确的监管主体,采用了多样化的监管手段,建立了可持续的污染场地专项基金,确定了明晰的责任判定和追究原则,为我国场地污染防治立法和制度设计中监管体系、资金体系和责任体系的建设提供了宝贵的借鉴。     

基于CAMx模型的珠江口东岸秋季臭氧来源解析

秋季是广东省臭氧(O_3)污染最严重的季节。以三维空气质量模型(CAMx)为工具,选取深圳西乡为研究对象,综合运用多种手段深入研究珠江口东岸秋季O_3污染过程及生成的敏感性,并定量研究了O_3的来源。结果表明:受偏北贴地气流的影响,珠江口东岸秋季容易发生O_3污染;珠江口东岸秋季午后O_3浓度有约60%是背景浓度,深圳本地排放对O_3的贡献较少,而周边地区东莞市和惠州市对O_3的贡献较大(午后O_3最高浓度约10μg/m3),梅州市、河源市和广州市也有一定的O_3贡献,但广东省其他地区对O_3的贡献较少,可以忽略,而江西省和福建省对O_3的贡献较大,在午后约有20%~30%的O_3浓度贡献;按排放类型分,除去背景浓度,秋季对珠江口东岸O_3贡献最大的排放源是火电、工业和飞机高架排放源,午后O_3浓度贡献可达15μg/m3,其次是天然源和交通源,午后O_3浓度分别各贡献10μg/m3左右;秋季,珠江口东岸的O_3在早上与傍晚大多在NOx敏感区内生成,中午前后更多的O_3在VOCS敏感区内生成。要控制珠江口东岸地区的O_3污染,应在秋季重点控制北面省市的火电、工业高架源排放等。