Climate change, urban air problems and transport policy in the European Union

This paper surveys some recent studies on conventional air pollution and climate change in the transport sector in Europe. Fuel efficiency standards, car emission standards and transport pricing instruments are analysed from an economic perspective taking into account environmental and economic efficiency objectives. This revised version was published online in July 2006 with corrections to the Cover Date.     

Saving power to conserve your reputation? The effectiveness of private versus public information

Environmental damage is often an unseen byproduct of other activities. Disclosing environmental impact privately to consumers can reduce the costs and/or increase the moral benefits of conservation behaviors, while publicly disclosing such information can provide an additional motivation for conservation - cultivating a green reputation. In a unique field experiment in the residence halls at the University of California – Los Angeles, we test the efficacy of detailed private and public information on electricity conservation. Private information was given through real-time appliance level feedback and social norms over usage, and public information was given through a publicly visible conservation rating. Our analysis is based on 7,120 daily observations about energy use from heating and cooling, lights and plug load for 66 rooms collected over an academic year. Our results suggest that while private information alone was ineffective, public information combined with private information motivated a 20 percent reduction in electricity consumption achieved through lower use of heating and cooling. Public information was particularly effective for above median energy users.     

Evaluation of Saccharomyces cerevisiae strains as probiotic agent with aflatoxin B1 adsorption ability for use in poultry feedstuffs

In this study the aflatoxin B₁ (AFB₁) removal capacity, the tolerance to salivary and gastrointestinal conditions, autoaggregation and coaggregation with pathogenic bacteria of Saccharomyces cerevisiae strains isolated from broiler feces, were evaluated. Only four of twelve isolated strains were identified as Saccharomyces cerevisiae using molecular techniques. The results obtained in AFB₁ binding studies indicated that the amount of AFB₁ removed was both strain and mycotoxin-concentration dependent. Therefore, a theoretical model was applied in order to select the most efficient strain to remove AFB₁ in a wide range of mycotoxin concentration. The results indicated that S. cerevisiae 08 and S. cerevisiae 01 strains were the most efficient microorganisms in the mycotoxin removal. Viability on simulated salivary and gastrointestinal conditions was investigated and S. cerevisiae 08 strain showed the best results, achieving 98% of total survival whereas S. cerevisiae 01 reached only 75%. Autoaggregation and coaggregation assays showed S. cerevisiae 08 as the most appropriate strain, mainly because it was the unique strain able to coaggregate with the four bacterial pathogens assayed. Consequently, S. cerevisiae 08 is the best candidate for future in vivo studies useful to prevent aflatoxicosis. Further quantitative in vitro and in vivo studies are required to evaluate the real impact of yeast-binding activity on the bioavailability of AFB₁ in poultry. However, this study could be useful in selecting efficient strains in terms of AFB₁ binding and provide an important contribution to research into microorganisms with potential probiotic effects on the host.     

应用自动识别和定量系统评价两种污水再生工艺对微量有机污染物的去除效果

采用气质联用分析,并结合自动识别与定量系统(AIQS-DB)考察2种再生水厂采用的深度处理工艺对微量有机污染物的去除效果。结果表明,以污水为原水的膜生物反应器(MBR)+臭氧氧化+生物活性炭滤池(BAC)工艺用于再生水生产,MBR工艺对有机污染物的去除起主要作用;城市污水厂二级出水为原水的混凝沉降+浸没式超滤(SMF)/连续微滤(CMF)+部分反渗透(RO)+臭氧氧化工艺用于再生水生产,其SMF和CMF工艺段的膜截留作用均可有效消减有机污染物含量,SMF的效果优于CMF;2种工艺中采用的臭氧技术都能进一步加强部分物质的去除效果。气质联用结合AIQS-DB可用于再生水中污染物的筛查和不同污水再生工艺对微污染物消减效果的评价。     

土壤跳虫(Folsomia candida)对食物中铜污染物的吸收和排泄

重金属污染物在生物体内的累积、迁移和传递已成为当今的研究热点。土壤弹尾目昆虫作为土壤生态系统的重要组成部分,针对其对重金属的吸收、积累和排泄的动态过程以及相应解毒机制的研究意义重大。本研究通过弹尾目跳虫(Folsomia candida)对Cu的吸收-排泄效率实验发现,跳虫体内Cu含量随暴露时间的延长而显著增加(r~2=0.8878,F_(1,5)=29.59,P<0.01);跳虫体内Cu含量随排泄时间的延长而明显逐渐降低(r~2=0.7836,F_(1,3)=7.13,P<0.01)。跳虫对Cu的吸收-排泄Budget实验表明,只有少量的Cu被跳虫摄取到体内,其中小部分被体内组织消化吸收,大部分则可能通过中肠细胞的褪皮作用和产卵等方式排出体外。可见,褪皮和排卵是跳虫排泄重金属Cu的重要途径,跳虫对Cu具有较低的吸收率(8.13%)和较高的排泄率(57.3%),表明跳虫对Cu可能有较高的耐受性。     

Is energy efficiency capitalized into home prices? Evidence from three U.S. cities

We test for evidence that energy efficiency features are capitalized into home prices in three U.S. metropolitan areas. Using hedonic regressions and multiple matching procedures, we find that Energy Star certification is associated with higher sales prices in two of the markets: the Research Triangle region of North Carolina and Portland, Oregon. We find that local “green” certifications in Portland and in Austin, Texas, are also associated with higher prices and that the estimated price impacts are larger than those from Energy Star. Matching on observables proves to be important in some cases, reducing the estimated impacts compared with models without matching. We calculate the implied energy savings from the estimated premiums and find that, in the Research Triangle market, the Energy Star premiums approximately equal the savings that program is designed to achieve, but in Portland, the premiums are slightly greater than the program's savings due to low energy costs in the region.     

相对湿度对钙基脱硫剂干法烟气脱硫效率的影响

为得到干法烟气脱硫较优的相对湿度,并验证钙基脱硫剂在干法烟气脱硫中的可行性,在模拟干法烟气脱硫实验台上,研究了钙基脱硫剂在不同相对湿度(0~45%)条件下,脱硫剂的出口浓度、脱硫效率和固硫量。结果表明,在相对湿度从0变化至45%时,可以稳定运行的穿透时间由160 min增加到720 min,可达100%脱硫效率的运行时间由0增至580 min,脱硫剂的固硫量从43.37 mg增加到332.09 mg;增加相对湿度能显著提高烟气脱硫效率,在保证烟气不穿透物料且不出现黏壁现象的条件下,较优的相对湿度为45%。研究明确了在低相对湿度条件下此种脱硫剂的可行性并确定了较优化的干法脱硫湿度,为干法脱硫条件的选择提供了参考。     

1994—2008年河南省植被净第一性生产力及其时空变化

基于地理信息系统和卫星遥感技术,利用地面气象数据、遥感数据和土地分类等数据,根据河南省实际植被覆盖和自然地理情况,应用改进的CASA模型估算了1994—2008年间河南省植被净第一性生产力及其时空变化。结果表明：河南省植被净第一性生产力与年均温度的相关性好于植被年净第一性生产力与年降水量和年均太阳辐射之间的相关性,温度是限制河南省植被净第一性生产力的主要因子;15年来河南省植被净第一性生产力呈增加趋势,但不明显;河南省主要植被类型的净第一性生产力从大到小依次为林地、灌丛、耕地、草地、其它植被,它们随时间的变化趋势极为一致。     

不同水生植物配置对河涌污水的净化效果

研究不同配置的挺水植物组合对河涌污水污染物的净化效果,为在河涌污水治理上构建有效的人工湿地植物处理系统提供依据。选择10种净化能力较强的挺水植物,组成6种不同配置的挺水植物组合,采用无土栽培的方式模拟人工湿地的环境进行静态培养试验,测定出不同水生植物组合及在不同污水的停留时间（HRT）下对河涌污水污染物的去除率。6种不同配置的水生植物组合在HRT为5 d时对NH4＋-N、TN、TP、CODCr、BOD5的去除率（平均去除率分别为98.2%、81.2%、91.3%、71.8%、79.4%）均较高;以组合1：香根草Vetiveria zizanioides＋风车草Cyperus alternifolius＋美人蕉Canna indica＋菖蒲Acorus calamus＋再力花Thalia dealbata的处理效果为最佳。不同水生植物系统对污水的净化效率取决于HRT,当HRT从1～5 d时,NH4＋-N、TN、TP去除率每天的增幅均逐渐增加,当HRT从5～7 d时,NH4＋-N、TN、TP去除率每天的增幅却均迅速下降;说明3种不同配置的水生植物系统对河涌污水NH4＋-N、TN、TP的净化效率均以HRT为5 d时最高。