Green supplier selection generic framework: a multi-attribute utility theory approach

This paper presents a generic framework integrating environmental and social criteria leading to a comprehensive selection process of green suppliers. Traditionally, price, quality, lead time and flexibility are considered for the supplier selection. With the increase in awareness of environmental and social responsibility issues, many companies are tending towards adopting green concepts and sourcing green suppliers. This study proposes a framework consisting of environmental (E), green (G) and organisational (O) factors that are required for the green supplier selection process. These factors are further classified as criteria for which attributes are presented. A hierarchy is constructed to facilitate in evaluating the importance of the selected criteria and alternatives of green suppliers. To cater to the multi-criteria decision-making approach with both quantitative and qualitative attributes, we applied the multiple attribute utility theory, which is a decision support that helps managers formulating viable sourcing strategies. A hypothetical example is presented to illustrate the applicability of the approach.     

Pyrolysis of waste tyres: A review

Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H₂, C₁–C₄ hydrocarbons, CO₂, CO and H₂S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale.     

The review programme in the European Union for existing biocidal active substances—outcome of the notification process

The European Commission Biocidal Products Directive 98/8/EC lays down rules and procedures concerning the placing of biocidal products on the EU market. Based on the Directive, a First Review Regulation was adopted for the review of existing biocidal active substances. These substances had to be either identified or notified (two different processes) to the European Chemicals Bureau (ECB) by 28 March 2002. More than 1000 companies took part in the review programme. In total 953 different existing active substances were identified and 372 different substances were notified. This article presents an analysis of the notified substances regarding the number of notifications per substance, notifiers per substance and per Member State and number of notified substances per product type. The results are compared with data from former statistics.     

水质基准方法学中若干关键技术探讨

我国正在开展系统的水质基准研究,对发达国家的水质基准理论和技术处于学习和研究阶段. 物种敏感度分布分析、“最少毒性数据需求”以及基准的修正是水质基准推算中的若干关键技术. 以氨氮水生生物基准为例,对这些关键技术进行了研究与探讨,提出在我国本土生物毒性数据缺乏的情况下可在种的水平上对水质基准进行推算. 另外,可先利用全部生物的毒性数据进行物种敏感度分析,确定需重点获取的敏感生物类群的毒性数据,再用于基准推算,有望降低推算过程中对毒性数据量的需求. 最后,基于中美生物物种分布的差异,借鉴美国修订国家水质基准的水效应比法,提出利用生物效应比法对美国国家水质基准进行修订以获取我国水质基准.      

Protection performance of bicycle helmets

IntroductionThe evaluation of head protection systems needs proper knowledge of the head impact conditions in terms of impact speed and angle, as well as a realistic estimation of brain tolerance limits. In current bicycle helmet test procedures, both of these aspects should be improved. Method: The present paper suggests a bicycle helmet evaluation methodology based on realistic impact conditions and consideration of tissue level brain injury risk, in addition to well known headform kinematic parameters. The method is then applied to a set of 32 existing helmets, leading to a total of 576 experimental impact tests followed by 576 numerical simulations of the brain response. Results: It is shown that the most critical impacts are the linear-lateral ones as well as the oblique impact leading to rotation around the vertical axis (ZRot), leading both to around 50% risks of moderate neurological injuries. Based on this test method, the study enables us to compare the protection capability of a given helmet and eventually to compare helmets via a dedicated rating system.     

辽河流域河流底栖动物完整性评价指标与标准

根据2005年4月期间辽河流域25个样点的底栖动物数据(参照点12个,受损点13个),通过指数值分布范围、相关关系和判别能力分析,从20个候选指数中筛选出了辽河流域的B-IBI构成指标体系,包括总分类单元数、EPT分类单元数、摇蚊分类单元数、前3位优势分类单元个体相对丰度、敏感类群个体相对丰度和粘附者个体相对丰度6个生物指数.其中总分类单元数、EPT分类单元数、摇蚊分类单元数反映群落丰度,前3位优势分类单元个体相对丰度反映个体数量比例,敏感类群个体相对丰度反映生物耐污能力,粘附者个体相对丰度反映小生境质量.采用比值法计算每种生物的指数值,并将各个生物指数值加和得到B-IBI指数值.根据参照点B-IBI值的25%分位数值确定健康等级标准,并对小于25%分位数值的分布范围进行4等分,提出了底栖动物完整性评价标准:B-IBI＞3.66为健康,B-IBI=2.75～3.66为亚健康,B-IBI=1.83～2.75为一般,B-IBI=0.92～1.83为差,B-IBI＜0.92为极差.评价结果表明,辽河流域25个样点中9个为健康,8个为亚健康,2个为一般,3个为较差,3个极差.B-IBI与水质状况、栖息地环境质量显著相关,其中与DO、栖息地指数呈显著正相关,与CODCr、CODMn、BOD5、悬浮物、氨氮、总磷、总氮、电导率呈显著负相关.     

一种确定湖泊水质基准参照状态浓度的新方法

在确立湖泊营养物基准的过程中,湖泊水体参照状态的确定是十分重要的一个步骤.本文基于广义极值分布理论,发展提出了一种确定湖泊参照状态浓度的新方法.该方法克服了频率分析法等描述性统计方法存在的数据分组可能造成人为误差和不便于统计推断,难以进行可信度评价的缺陷,能有效地推断给出参数和物质浓度置信区间.将该方法应用到太湖的水质基准参照状态中,通过对太湖湖心两个站点1995～2006年总氮(total nitrogen,TN),总磷(total phosphorus,TP)和叶绿素a(chlorophyll a,Chl-a)的数据进行分析,其年最小值的相反数符合广义极值分布,验证了方法的可行性.推荐采用25%分位点的值作为太湖总氮,总磷和叶绿素a的参照状态,即太湖的参照状态是:总氮0.71 mg·L-1,总磷0.025 mg·L-1,叶绿素a为1.81μg·L-1,并分别得出了它们各自的95%置信区间.     

太湖和辽河沉积物重金属质量基准及生态风险评估

以太湖、辽河的表层沉积物为研究对象,运用相平衡分配法（EqP）初步探讨了两流域沉积物中4种重金属（Cd,Cu,Pb,Zn）的沉积物质量基准（C_SQC）推荐值,并对两流域沉积物中的重金属进行了生态风险评估. 根据美国国家环境保护局（US EPA）基于水生生物对重金属的最终慢性毒理水平的淡水水质基准,制定了太湖及辽河4种重金属（Cd,Cu,Pb和Zn）的沉积物质量基准推荐值分别为6.42,55.3,20.6和201.5 mg/kg及5.42,52.8,18.9和177.7 mg/kg. 通过与不同国家及地区制定的C_SQC值进行比较,推算出4种重金属的C_SQC值大都接近所有数据的中间值. 从沉积物固相和间隙水相2个不同的角度对沉积物中重金属进行的生态风险评估表明,两流域的大部分区域同步可提取重金属（SEM）与酸可挥发性硫化物（AVS）含量的差值大于0,而_i［C_Ti］/［C_SQC,i］值与_i［C_IW,i］/［CCC_i］值均大于1,说明在整体上两流域沉积物中的重金属存一定的生态风险. 由于未考虑各金属元素之间的拮抗或协同等作用以及底栖生物敏感性的问题,所使用的生态风险方法在评价生态风险方面可能会相对有所偏差.      

Distribution and contamination of metals and biogenic elements in sediments from Zhifu Bay of the Yellow Sea, China

Metals and biogenic elements were analyzed from surface sediments of sixteen stations and a 32 cm core collected from Zhifu Bay in July 2009. High concentrations of biogenic silica (BSi) reflected the high diatom productivity in the Bay. Meanwhile, total organic carbon (TOC) in Zhifu Bay was mainly from terrestrial sources. All metals were lower than the marine sediment quality guidelines. Based on the vertical profiles of biogenic elements, there was a clear increase of TOC, total nitrogen (TN), and total phosphate (TP) between 1985 and 2000. TN concentrations decreased after the start of the operation of the sewage treatment plant in 1998; however TOC and BSi remained at high levels. Metal concentrations showed a general increase from the bottom to the top of the core. Most anthropogenic metals reached a maximum during 1996 and 2000, and decreased after the startup of the sewage plant; however, they have increased again recently. The results from correlation analysis and principal component analysis show that industrial pollution is the main source of Cd, Cr, Cu, Ni, Pb and Zn contamination in Zhifu Bay, and Yantai Port and ship transportation also contribute a lot to Cd, Cu, Hg, and Pb pollution.