The morality behind sustainability

The concepts of sustainable agriculture, organic agriculture, regenerative agriculture, and alternative agriculture are receiving increasing attention in the academic and popular literature on present trends and future directions of agriculture. Whatever the reasons for this interest, there nevertheless remain differences of opinion concerning what counts as a sustainable agriculture. One of the reasons for these differences is that the moral underpinnings of a policy of sustainability are not clear. By understanding the moral obligatoriness of sustainability, we can come to understand precisely what must be sustained, and by implication, how. This article discusses the arguments that can be advanced for sustaining anything and initially concludes that our obligations to future generations entail sustaining more than just sufficient food production or an adequate resource base. Indeed, a tradition of care and community must underlie whatever agricultural and resource strategies we are to develop under the rubric of sustainability. A consideration of the larger social and environmental system in which agriculture operates and the constraints this system places on agriculture forces us to recognize that sustainability has to do with larger institutional issues, including our ability to incorporate our common morality democratically into our institutions, practices, and technologies.     

世界替代农业及其发展趋势

本文对世界替代农业的主要类型和特点、中国的生态农业与发达国家的替代衣业的区别以及世界替代农业存在的主要问题进行了较详细的阐述，最后对世界替代农业的发展趋势作了展望。     

广西发展燃料乙醇产业总体方案替代方案优选

规划环评的目的不是减小规划对环境的影响,而是通过比较,选出规划对环境影响最小的替代方案。本文运用AHP-模糊数学法,结合广西发展燃料乙醇产业总体方案,从大气环境、水环境、废弃物、资源承载力、资源能源消耗和生态环境保护等六个方面,合理选取指标,建立了方案布局合理性指标体系,并用AHP-模糊数学法对四种替代方案进行了计算,得出方案一的结果为77．44,方案二的结果为78．62,方案三的结果为78．23,方案四的结果为82．13。方案四为“零作为”方案,计算结果为环境本底参照值。论文以方案四为参照,同时结合各方案的隶属度,选出了最佳替代方案。     

重污染天气下电力行业排放对京津冀地区PM2.5的贡献

利用CAMx(区域空气质量模型)中的PSAT(颗粒物源示踪技术),分析了重污染天气下分区域、分行业的污染物排放对京津冀地区PM_2.5的贡献,设计了分行业排放的环境影响效率系数(EESCR)计算方法,并对“电能替代”(以电力行业产能替代民用能源消耗)情景方案下的排放进行模拟分析. 结果表明:在重污染天气背景下,电力行业排放对京津冀地区ρ(PM_2.5)的贡献率较低,各地均低于10%,并且区域排放的贡献次序为京津冀以外地区>京津冀其他城市>当地,这与电力行业高架源排放的特征有关,而工业和民用行业对区域排放的贡献次序相反. PM_2.5主要组分和前体物的分行业EESCR计算结果表明,电力行业ESSCR值均在y=1/2x趋势线之下,远低于其他行业,因此优先控制其他行业排放才是改善京津冀地区空气质量的关键.电能替代的情景模拟结果表明,电能替代是有效降低京津冀地区ρ(PM_2.5)的可行方式. 研究显示,充分利用电力行业高架源排放的特点和便于集中处理的行业优势,尽力降低因产能增长带来的排放增量,实施电能替代可成为改善区域空气质量的有效途径之一.      

Disinfection byproducts in drinking water and regulatory compliance: A critical review

Disinfection by-products (DBPs) are regulated in drinking water in a number of countries. This critical review focuses on the issues associated with DBP regulatory compliance, including methods for DBP analysis, occurrence levels, the regulation comparison among various countries, DBP compliance strategies, and emerging DBPs. The regulation comparison between China and the United States (US) indicated that the DBP regulations in China are more stringent based on the number of regulated compounds and maximum levels. The comparison assessment using the Information Collection Rule (ICR) database indicated that the compliance rate of 500 large US water plants under the China regulations is much lower than that under the US regulations (e.g. 62.2% versus 89.6% for total trihalomethanes). Precursor removal and alternative disinfectants are common practices for DBP regulatory compliance. DBP removal after formation, including air stripping for trihalomethane removal and biodegradation for haloacetic acid removal, have gained more acceptance in DBP control. Formation of emerging DBPs, including iodinated DBPs and nitrogenous DBPs, is one of unintended consequences of precursor removal and alternative disinfection. At much lower levels than carbonaceous DBPs, however, emerging DBPs have posed higher health risks.     

全氟辛烷磺酸盐(PFOS)替代品对中国白羽鹌鹑的生态毒性

为研究全氟辛烷磺酸盐(perfluorooctane sulfonate,PFOS)替代品对环境生物的毒害效应,选用中国白羽鹌鹑作为受试生物,建立其环境危害评价毒性测试方法,并对PFOS替代化学品进行了急性经口、急性饲喂及繁殖毒性的风险评价。结果表明,全氟丁基有机铵盐阳离子表面活性剂急性经口毒性实验的LD50为500.44mg·kg-1,其余3种替代化学品在上限浓度2000mg·kg-1,白羽鹌鹑均未出现明显死亡,4种PFOS替代品对中国白羽鹌鹑的急性经口毒性均为低毒。全氟丁基有机铵盐阳离子表面活性剂急性饲喂毒性实验的LC50为970.50mg.kg-1,对白羽鹌鹑的饲喂毒性为中毒,而其余3种替代化学品在上限浓度5000mg·kg-1,白羽鹌鹑均未出现明显死亡,对中国白羽鹌鹑的急性饲喂毒性为低毒。在长期饲喂过程中,织物三防整理剂和C6织物三防整理剂会表现出一定的生殖毒性,造成中国白羽鹌鹑的孵化率降低,胚胎死亡率及未受精率升高;全氟丁基有机铵盐阳离子表面活性剂会影响到中国白羽鹌鹑的未受精率,C4织物三防整理剂未表现出明显的生殖毒性。     

全氟辛烷磺酸盐(PFOS)替代品对中华蜜蜂的毒性

选用中国蜂种中华蜜蜂工蜂作为受试生物,建立其环境危害评价毒性测试方法,用所建立的方法对全氟辛烷磺酸盐(PFOS)替代品进行了接触急性毒性及经口急性毒性风险评价,并比较了"小烧杯法"和"饲喂管法"两种经口毒性方法的优缺点及对毒性结果的影响。研究结果表明,"小烧杯法"实验中C4织物三防整理剂对中华蜜蜂的24h-LC50为1435mg·L~(-1),48h-LC_(50)为284.67mg·L~(-1);其余替代品在限度实验均未出现蜜蜂死亡,4种PFOS替代品对中华蜜蜂的接触毒性及经口毒性均为低毒,但"小烧杯法"测得的经口毒性结果比"饲喂管法"高。     

全氟辛烷磺酸盐(PFOS)替代品对家蚕大造的生态毒性

以中国本地家蚕品种大造作为受试生物,实现实验室规模化饲料饲养和初步实验动物化;建立家蚕大造环境危害评价急性毒性测试方法;对4种PFOS替代品包括:50%的全氟丁基有机铵盐阳离子表面活性剂、用调聚法合成的织物三防整理剂(含固率23.7%)、用电解氟化法合成的C4和C6织物三防整理剂,进行了急性接触毒性、急性饲喂毒性及慢性饲喂毒性的安全风险评价。实验使用的4种PFOS替代品试验急性饲喂浓度均达到或超过2000mg·L-1,家蚕未出现明显死亡;在接触实验浓度达到10g·L-1时,家蚕未出现明显死亡,以上结果证明,4种PFOS替代品对大造蚕种的急性饲喂毒性和接触毒性均为低毒。较低浓度的表面活性剂会严重影响到大造蚕种的结茧率,当表面活性剂浓度为0.4g·kg-1时,蚕种不能结茧,其余3种化学品在浓度大于0.004g·kg-1,对大造蚕种的结茧率产生一定的影响作用,但抑制作用相对较为平缓。替代品均会降低家蚕茧层率,表面活性剂在浓度为0.04g·kg-1时,茧层率剧烈下降,其他3种替代品抑制作用相对平缓。织物三防整理剂、C4和C6织物三防整理剂几乎不会影响蚕卵孵化,但表面活性剂会造成家蚕孵化率降低,在0.04g·kg-1后孵化率为0。     

个人乘用车用可替代燃料与我国未来的选择

个人乘用车排放量占道路交通运输二氧化碳(CO2)排放量的三分之一。因此,逐步实现其燃料由传统石化燃料汽柴油向新能源转变是交通运输行业低碳减排和绿色发展的重要抓手之一。本文对当前可供个人乘用车使用的4大类新能源即生物燃油、燃料乙醇、氢和电的属性,特别是其CO2减排效果和使用成本进行了分析和对比,并对新能源加注(充电)设施在欧盟和美国的布局战略和实施成果进行了介绍。结合欧美的实践和中国的实际,本文提出了未来个人乘用车用可替代燃油布局的建设,建议我国直接从传统石化汽油跨越至氢和/或电,并将其作为未来个人乘用车的燃料。