An environmental impact assessment of quantum dot photovoltaics (QDPV) from raw material acquisition through use

Some emerging technologies are expected to be pivotal for solving many of the environmental challenges faced today, especially those related to energy. However, many of these technologies may incur significant environmental impacts over their life cycle, while having environmental benefits during their use. This paper presents results of a Life Cycle Assessment (LCA) of a proposed type of nanophotovoltaic, quantum dot photovoltaic (QDPV) module. The LCA is confined to the stages of raw materials acquisition, manufacturing, and use. The impacts of QDPV are compared with other types of PV modules and energy sources - both renewable and nonrenewable. To provide a comprehensive comparative assessment, QDPV modules were compared with mature as well as emerging PV types for which data are available. Comparative assessment with other types of energy sources includes coal, oil, lignite, natural gas, diesel, nuclear, wind, and hydropower.QDPV modules may have the potential to overcome two current barriers of solar technology: low efficiencies and high manufacturing costs. If higher efficiencies are realized, QDPV modules could pave the way to large scale implementation of solar energy, helping nations move toward greater energy independence. On the other hand, candidate materials as quantum dots for solar cell applications are mostly compound semiconductors such as cadmium selenide, cadmium telluride, and lead sulfide which may be toxic and for which renewable options are limited. Toxic effects of these materials may be exacerbated by their nanoscale features.The LCA was carried out using the software SimaPro, and the Ecoinvent Life Cycle Inventory (LCI) database supplemented with available literature and patent information. Our results indicate that while QDPV modules have shorter Energy PayBack Time (EPBT), lower Global Warming Potential (GWP), SO_x and NO_x emissions than other types of PV modules, they have higher heavy metal emissions, underscoring the need for investigation of emerging technologies, especially nano-based ones, from a life cycle perspective. QDPV modules are better in all impact categories assessed than carbon-based energy sources but they have longer EPBT than wind and hydropower and higher GWP.     

Assessment of eco-labelling criteria development from a strategic sustainability perspective

To turn current patterns of consumption and production in a sustainable direction, solid and understandable market information on the socio-ecological performance of products is needed. Eco-labelling programmes have an important role in this communication. The aim of this study is to investigate what gaps there may be in the current criteria development processes in relation to a strategic sustainability perspective and develop recommendations on how such presumptive gaps could be bridged. First a previously published generic framework for strategic sustainable development is described and applied for the assessment of two eco-labelling programmes. Data for the assessment is collected from literature and in semi-structured interviews and discussions with eco-labelling experts.The assessment revealed that the programmes lack both an operational definition of sustainability, and a statement of objectives to direct and drive the criteria development processes. Consequently they also lack guidelines for how product category criteria might gradually develop in any direction. The selected criteria mainly reflect the current reality based on a selection of negative impacts in ecosystems, but how this selection, or prioritization, is made is not clearly presented. Finally, there are no guidelines to ensure that the criteria developers represent a broad enough competence to embrace all essential sustainability aspects.In conclusion the results point at deficiencies in theory, process and practice of eco-labelling, which hampers cohesiveness, transparency and comprehension. And it hampers predictability, as producers get no support in foreseeing how coming revisions of criteria will develop. This represents a lost opportunity for strategic sustainable development. It is suggested that these problems could be avoided by informing the criteria development process by a framework for strategic sustainable development, based on backcasting from basic sustainability principles.     

自然保护区生态补偿定量方案研究——基于“虚拟地”计算方法

自然保护区生态补偿的“补给谁”和“补多少”在理论和实践上都是生态补偿中的重点和难点所在。传统的通过计量保护区正外部性以确定生态补偿数量的方法存在两个主要问题：一是违背经济学原理,二是与管理体制不符且法理不足。据此,并考虑到中国相当数量的保护区“没有保护好”的主要因素是保护区社区居民生产生活的干扰,论文认为应通过控制保护区社区的负外部性来达成对保护区的生态补偿。通过生产函数理论分析,发现通常情况下保护区社区的经济产出与土地面积单调正相关,因此在没有生态补偿的情况下,保护区的划建会使周边社区居民经济收入减少,解决周边社区对保护区干扰的根本途径是利用生态补偿资金发展替代产业以提高单位面积土地的经济产出。以此认识为基础,文章提出了“虚拟地”概念并发展了定量方法来确定保护区的生态补偿最低标准,采用武夷山保护区的数据进行了这一方法的案例分析。     

云贵高原湖区湖泊营养物生态分区技术方法研究

提出一种基于主成分分析、聚类分析、判别分析和空间自相关的分区模型,用于对云贵高原湖区湖泊营养物生态分区的研究.首先运用主成分分析方法对众多指标进行了降维综合处理,产生彼此互补相关又能综合反映湖区情况的4个新指标,累计贡献率达到93.69%,具有充分的代表性,构建了云贵高原湖区湖泊营养物生态分区指标体系.在此基础上,根据各区域新指标值,结合聚类模型初步将湖泊流域分为5类,再利用判别分析完成非湖泊流域的类别判别,最后运用空间自相关分析方法,按聚类结果进行全局自相关分析,Moran’sI为0.320,且检验值Z值为68.2,远大于临界值(显著水平1%所对应的临界值2.58),表明聚类结果与空间位置具有显著相关性,之后运用局部自相关对区域各因素的主成分综合得分的空间分布格局进行了量化分析,揭示了零散分类区块在空间地域分布上的关联和差异,根据关联结果完成最终的分区.结果表明,利用此分区模型可以尽量避免人为因素,得到更为客观的分区结果,具有良好的适应性和可行性,可为探索适合我国湖泊营养物生态分区的指标体系和分区技术方法,完成全国湖泊营养物生态分区和科学地制定我国湖泊营养物基准和富营养化控制标准提供技术支持.     

淀山湖入湖水质净化的生态工程实践研究

作为上海境内最大的天然淡水湖泊以及黄浦江上游重要的水源保护地,淀山湖的水质状况对上海市饮用水水源安全起着举足轻重的作用。文章运用生物治理与工程措施相结合的手段,在淀山湖大朱厍港实施了净化人湖水质的生态工程试验。研究表明工程示范区域存在风浪大、水位较深、水流较急等特点,是水生植被尤其是沉水植物恢复的重要限制因素。通过选择...     

中药工业废水处理研究进展

概述了目前中药工业废水处理应用的各种物化、生物处理技术;对主要处理工艺的应用特点进行了论述;指出了中药工业废水处理技术今后的研究开发方向和思路。     

环境科学领域中欧科技教育合作的探讨

欧盟高等教育有着悠久的历史,在环境科学领域处于世界领先水平。随着欧盟一体化进程的深入推进,中国工业化和城市化步伐的加快,环境科学领域面临着新的机遇和挑战,必将给中欧之间的科技教育合作创造更多的机会。面对新形势,有必要认真分析中欧在环境科学领域科技教育合作的现状与机遇,总结经验,找出问题,提出对策,进而促进中欧合作的健康发展。     

环评监测现场采样中应注意的问题

根据环境影响评价监测的要求,提出了环评监测中方案的细化、点位布设方面存在的问题,阐述了如何合理设置监测点位、准确把握采样方法、科学选择分析方法等问题。     

使用量和单位常见错误浅析

以《量和单位》（GB3100—3102-1993）为依据,列举了各种常见的错误使用量和单位的名称和符号、量和单位非标准化的例子,对其进行了分析和探讨,提出标准化对策。     

辽河源头区坡耕地面源污染阻控技术研究

辽河源头区多为低山丘陵区域.由于人类对土地资源的不合理开发利用,致使森林覆盖率降低,坡耕地面积增多.为提高单位面积的农作物产量,主要措施之一就是增加化肥投入量.随着农田生态系统化肥投入量的增加,不被作物吸收的营养物质通过淋溶渗透地表径流等进入水环境中.坡耕地面源污染阻控研究是基于其产生的原因及迁移过程,采取农业耕作措施、水土保持工程措施和生物措施等相结合方式,构建坡耕地面源污染控制技术体系.