Bewertung von Abfallbehandlungsverfahren: Entscheidungsunterstützung durch die neue VDI‐Richtline 3925

The new VDI guideline 3925 presents assessment tools for the comparison of economic, ecological and also social aspects of different waste treatment processes. Objective of the guideline is to describe the application of suitable scientific and technical assessment methods to waste management strategies. The methods, their applicability, complexity, opportunities and limits are illustrated using practical examples.     

Assessing anodic microbial populations and membrane ageing in a pilot microbial electrolysis cell

First large-scale experiences of bioelectrochemical systems (BES) are underway. However, there is still little knowledge on how the different elements that integrate a BES behave in near real-life conditions. This paper aims at assessing the impact of long-term operation on the cation exchange membrane and on the anodic biofilm of two 16 L Microbial Electrolysis Cells (MEC) designed for hydrogen production and ammonia recovery from pig slurry. Membrane deterioration was examined by physical, chemical and microscopy techniques at different locations, revealing a strong attachment of microorganisms and a significant decay in membrane properties such as ion exchange capacity and thermal stability. Anode microbial communities did not show a dramatic shift in the eubacteria composition at different sampling areas, although the relative abundance of some bacterial groups showed a clear vertical stratification. After 100 days of continuous operation, MEC performance did not declined significantly maintaining ammonium transport rates and H₂ production rates of 15.3 gN d⁻¹ m⁻² and 0.2 LH₂·L⁻¹_reactor·d⁻¹ respectively.     

Hanford罐贮高放废物回取及废物最小化经验

介绍了美国Hanford场址罐贮高放废物的回取,包括废物回取标准,回取技术——改进型冲洗法、盐饼溶解法、真空回取法和移动回取法等,以及在实施罐贮废物的回取中的废物最小化方面的经验等。     

Stringency of regulation and innovation in waste management: an empirical analysis on EU countries

The transformation of waste into a valuable resource is a key process towards sustainable development and green growth and therefore represents a major concern for policy-makers. Technological innovation plays a crucial role in waste management and therefore understanding the way in which regulation may spur innovation in this domain constitute is crucial. This article aims at testing the weak version of the Porter hypothesis in waste management, by analysing the dynamic relationship between the stringency of environmental regulation and innovation in a European cross-country setting. Results confirm that the stringency of regulation positively affects innovation, but the effect is non-linear, suggesting the existence of an optimal cap to the stringency of regulation. Furthermore, the overall environmental conditions of the country, as well as the presence of highly polluting sectors hinder the development of environmental innovations.     

利用矿山固体废物料固结矿区路面的试验研究

白云鄂博西矿铁矿尾矿泥和甩尾碎石是矿山选矿厂排放的主要固体废弃物。利用尾矿泥代替砂、甩尾碎石代替级配碎石，采用碾压混凝土工艺进行矿区路面修筑，是改善矿区运输道路路况，延长汽车使用寿命的根本性措施。试验取得了其最佳含水量和最大比重的指标，28 d抗压强度达到18 MPa以上。工业试验路面选择在矿区主运输坡道上，一共做了4块,路面总长66.5 m，宽9.0 m，面积约600 m2，用料量共计165 t。根据路面混凝土芯样强度试验结果,尾矿泥碾压混凝土平均强度在18 MPa以上。     

核电厂离堆放射性废物处理中心辊道控制

辊道作为核电厂放射性固体废物流转的核心设备, 承担着装有各种固体废物的废物桶的转运工作, 其可靠性、稳定性和安全性关系着固废处理生产线的正常运作。本文介绍了某核电厂离堆放射性废物处理中心辊道控制系统的功能、组成、流程及其改进方案, 以实现废物桶全自动化转运, 避免操作人员过多的受到辐射照射, 保证作业过程的安全和高效。     

Theoretical Study on Free Fatty Acid Elimination Mechanism for Waste Cooking Oils to Biodiesel over Acid Catalyst

A theoretical investigation on the esterification mechanism of free fatty acid (FFA) in waste cooking oils (WCOs) has been carried out using DMol³ module based on the density functional theory (DFT). Three potential pathways of FFA esterification reaction are designed to achieve the formation of fatty acid methyl ester (FAME), and calculated results show that the energy barrier can be efficiently reduced from 88.597 kcal/mol to 15.318 kcal/mol by acid catalyst. The molar enthalpy changes (Δ_rH_m°) of designed pathways are negative, indicating that FFA esterification reaction is an exothermic process. The obtained favorable energy pathway is: H⁺ firstly activates FFA, then the intermediate combines with methanol to form a tetrahedral structure, and finally, producing FAME after removing a water molecule. The rate-determining step is the combination of the activated FFA with methanol, and the activation energy is about 11.513 kcal/mol at 298.15 K. Our results should provide basic and reliable theoretical data for further understanding the elimination mechanism of FFA over acid catalyst in the conversion of WCOs to biodiesel products.     

Life-cycle assessment of hydrogen technologies with the focus on EU critical raw materials and end-of-life strategies

We present the results of a life-cycle assessment (LCA) for the manufacturing and end-of-life (EoL) phases of the following fuel-cell and hydrogen (FCH) technologies: alkaline water electrolyser (AWE), polymer-electrolyte-membrane water electrolyser (PEMWE), high-temperature (HT) and low-temperature (LT) polymer-electrolyte-membrane fuel cells (PEMFCs), together with the balance-of-plant components. New life-cycle inventories (LCIs), i.e., material inputs for the AWE, PEMWE and HT PEMFC are developed, whereas the existing LCI for the LT PEMFC is adopted from a previous EU-funded project. The LCA models for all four FCH technologies are created by modelling the manufacturing phase, followed by defining the EoL strategies and processes used and finally by assessing the effects of the EoL approach using environmental indicators. The effects are analysed with a stepwise approach, where the CML2001 assessment method is used to evaluate the environmental impacts. The results show that the environmental impacts of the manufacturing phase can be substantially reduced by using the proposed EoL strategies (i.e., recycled materials being used in the manufacturing phase and replacing some of the virgin materials). To point out the importance of critical materials (in this case, the platinum-group metals or PGMs) and their recycling strategies, further analyses were made. By comparing the EoL phase with and without the recycling of PGMs, an increase in the environmental impacts is observed, which is much greater in the case of both fuel-cell systems, because they contain a larger quantity of PGMs.     

Waste electronics and electrical equipment disassembly and recycling using Petri net analysis: Considering the economic value and environmental impacts

The Industry Council for Electronic Equipment Recycling (ICER) has published estimates of waste generation based on both assumptions and analysis regarding the relationship between the market sales of Electrical and Electronic Equipment (EEE) in a given year and the expected lifetime of products as well as by employing market saturation factors. Waste EEE (WEEE) has an adverse impact on the environment. Therefore, it is important to reduce the quantity of WEEE through recycling. While attempting to improve the recycling rate of WEEE by enhancing the disassembly processes, two issues must be considered simultaneously—economy and safety. In this paper, a Petri Net (PN) based analysis approach is proposed to deal with the disassembly and recycling problems in End-Of-Life (EOL) WEEE. By using the PN analysis, the optimal tradeoff between the cost and environmental effectiveness of the disassembly processes is determined. A case study is used to illustrate the proposed analysis method.     

U.S. regulatory perspectives on the back end of the fuel cycle: EUROSAFE 2013 proceeding

For the United States Nuclear Regulatory Commission and the reactor licensees it regulates, there are a number of contemporary issues associated with the back end of the fuel cycle including, the agency's revision to its “Waste Confidence” decision and the path-forward for high-level waste disposal. Additionally, the 2012 Blue Ribbon Commission on America's Nuclear Future recommendations, the future of reprocessing, consolidated interim spent fuel storage, and maintaining technical competence within the NRC in challenging budgetary conditions are addressed. I conclude that there is confidence in the feasibility of safe storage of spent nuclear fuel following the licensed operational life of a reactor and any change in high-level waste policy will require Congressional action to amend the Nuclear Waste Policy Act.