Double Green Process: a low environmental impact method for recycling of CdTe,a-Si and CIS/CIGS thin-film photovoltaic modules

On the basis of the method for managing the end of life of CdTe photovoltaic panels previously proposed by the authors, a new method for the recycling of all types of thin-film panels (CdTe, a-Si and CIS/CIGS) has been developed and optimised under a research project founded by Enel Foundation and CRUI Foundation. The DGP process has been developed through a feasibility study carried out from three points of view: technical, environmental and economic. The process is composed by two sub-processes matched to each other, one suitable for CdTe panels (named DGPa) and the other one for a-Si and CIS/CIGS panels (DGPb). The Double Green Panel process is based mainly on mechanical treatments with a minimum use of chemicals and it is characterised by a greater level of automation and a high flexibility in production capacity. The potential environmental impacts of various configurations of the DGP process have been extensively analysed with LCA tool in order to develop an environmentally friendly process. The economic feasibility has been assessed through the Discounted Cash Flow Analysis (DCFA) method. The revenues associated to the recovery of valuable and common materials and the recycling costs have been taken into account.     

小分子有机酸对紫色土及其溶液中Pb的赋存影响

以紫色土中铅(Pb)为研究对象,采用以0.01 mol·L~(-1)硝酸钠(NaNO_3)为背景电解质的一步提取法,研究了不同浓度下乙酸,酒石酸和柠檬酸对土壤中Pb的释放作用,并通过土壤重金属形态的分步提取法和地球化学平衡软件Visual MINTEQ v3.0,进一步分析和预测了小分子有机酸作用下土壤中Pb以及土壤溶液中Pb的形态变化.在此基础上,分析了小分子有机酸对Pb作用的环境意义与环境风险.结果表明,3种小分子有机酸均显著增加了紫色土中Pb的释放量,活化效果表现为柠檬酸酒石酸乙酸.在有机酸作用下,土壤中交换态Pb总量增加,碳酸盐结合态Pb和铁锰氧化物结合态Pb总量降低;土壤溶液中Pb以有机结合态为主,占总Pb质量的45.16%~75.05%,游离态次之,占22.71%~50.25%,且随着浓度增加,柠檬酸和酒石酸作用下的土壤溶液中的游离态Pb和无机结合态Pb增加,而有机结合态Pb减少,乙酸则呈相反趋势.总体上看,小分子有机酸提高了紫色土中Pb的生物有效性,且存在地下水的淋溶风险,其中柠檬酸的淋溶风险远大于酒石酸和乙酸.     

环境工程与可靠性工程的关系初探

可靠性工程和环境工程是型号研制过程中的两套工程体系,在确保产品可靠使用上,可靠性工程和环境工程具有互补关系,但是两者在概念和方法上有较大区别。现代可靠性工程的发展使传统可靠性工程和环境适应性工程具备了互相融合的基础,环境工程与可靠性工程的融合是现代可靠性工程发展的趋势。     

陆地边界资源开发管理的经验与重点——以新疆北部陆地资源开发为例

新疆在长期边界资源开发的实践中形成了一套具有地方特色的陆地边界资源开发机制,成功地实现了对边界资源开发的有序管控。这些成功经验主要包括:对国家政策与地方政策进行相互配套,通过制度化建设将边界地区的资源开发服务于地方经济发展。在新形势下,边界资源开发出现了一些的新的动向与重点,其中包括在资源开发中注重环境保护问题,以及注重资源开发与边界地区经济发展相适应。总结以往经验,解决这些问题的关键是借助国家的一带一路建设,在实现边界地区安全稳定的基础上,以资源开发的可持续发展作为发展目标,通过经济发展促进边界地区的和谐、安全与稳定。     

球形棕囊藻(Phaeocystis globosa Scherffel)赤潮成因分析

对1997年冬季和1999年夏季发生于广东省饶平枯林湾海域的棕囊藻赤进行了现场调查和监测，结果表明，棕囊藻赤潮的爆发是海洋环境变化和棕囊藻自身特性共同决定的，长期集约化养殖引起枯林湾海域的N、P、Fe、Mn浓度较高，特别是Fe浓度明显高于广东沿海的其它海区，为赤潮的爆发提供了物质基础，棕囊藻增殖过程中对DIN（可溶性无机氮）的需求量较高，特别对NO3^－-N有明显的主动吸收，与DIP（可溶性无机氮）相比，海水DIN浓度恢复速率较慢。可能成为限制棕囊藻赤潮的规模和持续时间的关键因子，海水温度的异常增高及降雨量偏少，与棕囊藻赤潮的发生紧密相关。     

藻华聚集的环境效应:对漂浮植物水葫芦光合作用的影响

利用适应性强、生物量大的水生植物来净化污染水体,已成为目前水体生态修复的一种快捷有效的方法.然而,在夏季蓝藻水华严重聚集的水体,藻华聚集后对水生植物的生理生态影响及其环境效应,尚缺乏系统研究.本研究以水葫芦为代表,模拟在高温阶段(水温WT25℃)、水华严重聚集时,对水葫芦的光合作用的影响进行研究,以揭示蓝藻水华聚集后造成的浅水生态系统中水生植物消亡的深层机制,并为减轻藻华聚集对水生植物的不良影响、充分发挥水生植物的水体净化功能提供理论依据.结果表明,藻华聚集会很快消耗掉水生植物根区内的溶氧,呈现缺氧状态(DO0.2 mg·L-1);植物根区内ORP出现明显下降现象,实验进行1 d后低于-100 m V,实验结束时达-200 m V,水体呈现强还原环境.与对照相比,根区内p H值低0.7个单位.藻华细胞在死亡、分解后释放大量的无机营养盐于水体中,植物根区内的NH+4-N含量比对照实验中高102倍;较高的NH+4-N含量(平均为45.6 mg·L-1)加之缺氧的协迫作用,导致植物机体受到破坏,植物的光合作用能力严重下降.叶片的平均净光合速率仅为对照的0.6倍,实验结束时其光合速率Pn为3.96μmol·(m2·s)-1,而同期对照实验的叶片净光合速率Pn为22.0μmol·(m2·s)-1;叶片蒸腾速率仅为对照的0.55倍,至实验结束时其蒸腾速率为1.38 mmol·(m2·s)-1,同期对照实验的叶片蒸腾速率为7.61 mmol·(m2·s)-1,表明藻华长期的聚集对植物产生了不可逆的伤害作用.在实际生产中,要避免蓝藻的严重堆积和快速消亡,以减轻藻华暴发对植物的伤害,充分发挥植物的水体净化功能.     

宁夏总量减排与环境质量改善的相关性分析

利用SPSS统计软件分析宁夏“十一五”期间主要污染物总量控制指标与环境质量数据的关联程度,并建立回归模型.结果表明:宁夏总量减排与环境质量改善存在高度关联,拟合曲线均为一元线性回归曲线.随着SO2排放总量降低,重点城市空气质量稳步改善,两者呈现同向变化的趋势;随着COD排放总量降低,黄河宁夏段水环境质量稳步改善,两者亦呈现同向变化的趋势.宁夏总量减排在环境质量改善上成效已显现,污染防治政策较为成功,环保成绩显著.     

A mathematical model of crevice corrosion for buried pipeline with disbonded coatings under cathodic protection

Crevice corrosion occurs in a holiday and disbonded region between coating and pipeline steel. Cathodic protection (CP) is generally recognized as the most effective method for corrosion prevention of pipeline, but its effectiveness may be reduced at defects in a disbonded coating. It is difficult to measure and probe corrosion parameters accurately based on experimental work. Therefore, a mathematical model is necessary to identify the phenomena and mechanisms that contribute to the crevice corrosion process. In this work, a mathematical model was developed to determine the evolution of chemical and electrochemical transient processes of crevice corrosion in NaCl dilute solution, and the effect of cathodic protection and crevice width on corrosion of 20# steel pipeline with disbonded coatings. Results have demonstrated that the extent of crevice corrosion depends on the crevice geometry and could be influenced by the increase of crevice depth and decrease of its width. The oxygen concentrations drop significantly inside a crevice whether CP is applied or not and whether crevice width decreased or not. The pH values and conductivity of crevice solution increase with the time. The research provides a theoretical foundation for cathodic protection of pipelines and establishes an effective corrosion model which can identify the phenomena and mechanisms of the crevice corrosion process. This work could be used to help mitigate the corrosion failure of pipelines to prevent catastrophic accidents in oil, gas and chemical process industries.     

Predictive Model of Avian Electrocution Risk on Overhead Power Lines

Electrocution on overhead power structures negatively affects avian populations in diverse ecosystems worldwide, contributes to the endangerment of raptor populations in Europe and Africa, and is a major driver of legal action against electric utilities in North America. We investigated factors associated with avian electrocutions so poles that are likely to electrocute a bird can be identified and retrofitted prior to causing avian mortality. We used historical data from southern California to identify patterns of avian electrocution by voltage, month, and year to identify species most often killed by electrocution in our study area and to develop a predictive model that compared poles where an avian electrocution was known to have occurred (electrocution poles) with poles where no known electrocution occurred (comparison poles). We chose variables that could be quantified by personnel with little training in ornithology or electric systems. Electrocutions were more common at distribution voltages (≤33 kV) and during breeding seasons and were more commonly reported after a retrofitting program began. Red‐tailed Hawks (Buteo jamaicensis) (n = 265) and American Crows (Corvus brachyrhynchos) (n = 258) were the most commonly electrocuted species. In the predictive model, 4 of 14 candidate variables were required to distinguish electrocution poles from comparison poles: number of jumpers (short wires connecting energized equipment), number of primary conductors, presence of grounding, and presence of unforested unpaved areas as the dominant nearby land cover. When tested against a sample of poles not used to build the model, our model distributed poles relatively normally across electrocution‐risk values and identified the average risk as higher for electrocution poles relative to comparison poles. Our model can be used to reduce avian electrocutions through proactive identification and targeting of high‐risk poles for retrofitting. Modelo Predictivo del Riesgo de Electrocución de Aves en Líneas Eléctricas Elevadas     

Credibility and advocacy in conservation science

Conservation policy sits at the nexus of natural science and politics. On the one hand, conservation scientists strive to maintain scientific credibility by emphasizing that their research findings are the result of disinterested observations of reality. On the other hand, conservation scientists are committed to conservation even if they do not advocate a particular policy. The professional conservation literature offers guidance on negotiating the relationship between scientific objectivity and political advocacy without damaging conservation science's credibility. The value of this guidance, however, may be restricted by limited recognition of credibility's multidimensionality and emergent nature: it emerges through perceptions of expertise, goodwill, and trustworthiness. We used content analysis of the literature to determine how credibility is framed in conservation science as it relates to apparent contradictions between science and advocacy. Credibility typically was framed as a static entity lacking dimensionality. Authors identified expertise or trustworthiness as important, but rarely mentioned goodwill. They usually did not identify expertise, goodwill, or trustworthiness as dimensions of credibility or recognize interactions among these 3 dimensions of credibility. This oversimplification may limit the ability of conservation scientists to contribute to biodiversity conservation. Accounting for the emergent quality and multidimensionality of credibility should enable conservation scientists to advance biodiversity conservation more effectively.