Thermodynamic analysis on heavy metals partitioning impacted by moisture during the MSW incineration

A thermodynamic calculation was carried out to predict the behavior and speciation of heavy metals (HMs), Pb, Zn, Cu, and Cd, during municipal solid waste (MSW) incineration with the different moisture levels. The calculation was based on the minimization of the total Gibbs free energy of the multi-components and multi-phases closed system reaching chemical equilibrium. The calculation also indicated the reaction directions and tendencies of HMs components. The impacts of chlorine additives (No PVC, 1%PVC, and 5%PVC) and moisture on the behavior of HMs were investigated at different temperature levels in the system (750 °C, 950 °C, and 1150 °C). Furthermore, because the incineration temperature falls down with the increase in moisture in waste, the co-influence of moisture and temperature in combusting MSW on the HMs was also studied with the given chlorine (as 1%PVC + 0.5%NaCl). The results showed that in the non-chlorine system, the impact of the moisture on Pb, Zn, and Cu was not significant, and the ratio of compound transformation was less than 10%, except the Cd compounds at 950 °C and 1150 °C. In the system with low chlorine (as 1%PVC) at constant temperature, the chlorides of HMs (Cd, Pb, Zn, and Cu) transferred to oxides, and when the content of chlorine rose up (as 5%PVC), the ratio of the chlorides of HMs (Cd, Pb, Zn, and Cu) transferring to oxides fell down noticeably. When the moisture varied together with the temperature, the Zn and Cu compounds transferred from chlorides to oxides with increase in moisture as well as decrease in temperature. At the temperature of 700–1000 °C, the impact of temperature on Pb and Cd was little and the moisture was the main factor; while at the temperature of 1000–1200 °C, the impact of increase in moisture and decrease in temperature on Pb and Cd was almost equal and reversed.     

中国风机制造技术转移模式与技术进步效果评价

根据技术转移过程中技术受方的性质,将中国风机制造技术转移分为"外商独资企业"、"中外合资企业"和"中资企业"三种模式.通过技术转移的层次、技术先进程度、技术转移的规模、技术转移的速度,对三种模式下技术转移的效果进行了评价.研究发现,通过技术转移,中国风机制造技术有了迅速的发展,但落后于国际先进水平的情况仍没有改变.中资企业的技术转移模式在转移技术的层次、技术转移规模和技术转移速度上,都要优于外商独资企业和中外合资企业模式,对中国风机制造技术进步的作用更大.在此基础上,本文提出,在中资企业模式下,在引进技术的同时,积极消化吸收,并重视与外国企业开展联合研发,才能最终获得创新能力.这也应当成为中国政府激励政策作用的重点.     

Canopy leaching of nutrients and metals in a mountain spruce forest

Precipitation and throughfall fluxes of major ions, nutrients (C, N, P), and metals (Al, Fe, Mn), and the chemical composition of litter fall and living plant tissue in Norway spruce stands (the Bohemian Forest; Czech Republic), were used to evaluate how microbial processes and decay of plant tissue in canopies influence canopy leaching (CL) of elements. Proton exchange for Mg²⁺, Ca²⁺, and K⁺ in decaying biomass and co-transport of Ca²⁺ and K⁺ out of plant cells with organic acid anions were the most likely processes contributing to CL of base cations. The CL of total P and N (and also NO₃^?) was minor. Important proportions of the N and P mineral forms were transformed to organic forms by microbial processes (primary and bacterial production), with the respective CL of ?13.9 and 16.4 mmol m^?2 yr^?1 for NH₄⁺ and organic N, and ?0.33 and 0.22 mmol m^?2 yr^?1 for dissolved reactive P (DRP) and organic P. Most of particulate P and N in throughfall (～90%) originated from microbial DRP and NH₄⁺ transformations, but particulate C mostly came from the fragmentation of plant tissue (58%). Among metals, CL was not observed for Al, was small for Fe (0.3 mmol m^?2 yr^?1), and greatest for Mn (0.9 mmol m^?2 yr^?1) due to leaching from decaying tissue by acidic precipitation.     

预应力锚索-地梁结构在岩体中传力规律研究

在建立受非均布线形荷载作用的地基力学模型的基础上,应用叠加原理推导出地基表面在非均布的线形荷载作用下,预应力锚索-地梁结构中垂直于梁轴线平面内的地基中深处的应力和位移计算公式,为研究预应力锚索-地梁结构在岩体中的传力规律提供了理论基础.以湖南省常张高速公路K123+160～K123+369边坡为试验区域,通过理论分析得出,在对锚索施加预应力后,锚索预应力通过地梁传递给被加固的岩土体,其传递方式在垂直于地梁轴线的平面内是以梁轴线与该平面的交点为端点的近似椭圆的等值面形式由内向外呈逐渐衰减趋势分布的.现场试验得出,两地梁周边岩体中的压应变随深度增加由小到大增至峰值,然后逐渐衰减为0,这种分布形式与理论结论一致.     

西南地区水库生态环境特征与研究展望

西南是我国水资源富集区,随着清洁能源"西电东送"、城镇化建设和水利水电发展战略的持续实施,西南地区水库的数量将不断被刷新,水库数量快速增长与日益凸显的生态环境问题存在突出矛盾。西南地区水库具有独特的地质地理背景和生态环境特征,主要表现在:1)具人工建造属性,水环境与生态系统演化起点不同于天然湖泊;2)水位逆周期人为调控,消落带生态功能退化;3)亚深水型,水体季节性分层控制了湖泊的关键物理、化学和生物过程;4)沉积物有机质和营养盐蓄积量大,潜在二次污染风险大;5)物质循环的累积效应对水库及下游水环境与水生态安全具重要影响;6)水体富营养化与重金属污染叠加、复合;7)物质循环和生物过程受多界面作用控制。当前对西南地区亚深水型水库生态环境的研究远落后于东部浅水湖泊,亟待对其生态环境演变过程与规律开展深入研究,研究建立与之适宜的水环境演变理论和治理技术体系,为该类型水库生态环境保护与治理提供有效科技支撑。     

RAMS contribution to efficient waste minimisation and management

The significance of waste management systems in recent years increased due to the growing problems of waste management chains affecting the daily lives of millions of people and the impact on the environment. Several promising approaches have been developed in the past few years. One of them is the waste management system modelling using reliability, availability, maintainability and safety software. This paper analyses and evaluates this approach. The main goal is to provide quantitative forecasts for various performance measures of waste management systems. They include availability, downtimes, number of failures, and cost. Evaluation of these measures is important for optimal decision making. The system design should both maximise the system performance leading to cleaner processing and minimise the overall cost within the allowable constraints. The effectiveness of this methodology is demonstrated through a case study.     

The Environmental Performance Strategy Map: an integrated LCA approach to support the strategic decision-making process

Life Cycle Assessment (LCA) is a well-known tool for analyzing environmental impacts on a wide perspective with reference to a product system and the related environmental and economic impacts. The need for a novel approach that complements environmental and financial considerations is addressed in this study with the introduction of a new graphical representation: the Environmental Performance Strategy Map. This graphical map allows one to combine the main environmental indicators (footprints) with the additional dimension of cost. The paper defines the Sustainable Environmental Performance Indicator as a single measure for sustainability of a given option. Comparison of different options for strategic decision-making purposes can be enhanced and facilitated by the use of this indicator.     

Bioconcentration potential and contamination with mercury of pantropical mushroom Macrocybe gigantea

The mushroom Macrocybe gigantea collected from the native stands in the Yunnan Province of China can be considered a species that efficiently bioconcentrates mercury (Hg) because the values of the bioconcentration factor (BCF) calculated for this element were well above unity, i.e., for caps, the BCF ranged from 4.8 to 24 and, for stipes, from 3.6 to 18. The Hg content of the composite samples of caps of the fruit bodies collected in the wild ranged from 0.48 to 1.78 mg kg^?1 dry matter and of stipes from 0.36 to 1.70 mg kg^?1 dry matter, whereas 0.37 and 0.25 mg kg^?1 dry matter were observed for farmed specimens. M. gigantea, because of a large biomass of the fruit bodies that emerge in a cluster, is an important food item in Yunnan, but knowledge on mineral composition and content of this species is largely absent. This study estimated the lifetime average daily dose intake of Hg through mushroom as well as the incremental lifetime cancer risk and non-cancer health hazard to consumers of this mushroom.     

便携式ＧＣ-ＭＳ测定空气中有毒物质的应用

文章介绍了便携式气相色谱-质谱联用仪(Gas Chromatograph-Mass Spectrometer,GC-MS)的结构原理,结合应急监测的需要,说明了仪器性能参数与分析操作模式,探讨了标准曲线的建立与验证。通过仪器的实际应用,指出该仪器能够解决应急监测中目前存在的对有机污染物难以快速定性、定量的问题。利用捕集浓缩器富集待测定空气中挥发性有机化合物(VOCs),可迅速判断出气体样品中的挥发性有机化合物组分,给出定量测定结果。并根据日常使用情况,总结了便携式GC-MS性能特点。