危险废物分级管理方法研究

危险废物因具有毒性、易燃性、腐蚀性和反应性等多种危害特性,如果暴露于环境中将会对人类健康和生态环境造成很大威胁.深入分析了欧美等一些国家对危险废物进行分级管理的方法,针对中国目前危险废物的产生现状和管理现状,提出了综合考虑危险废物的产生量和活性大小等各个方面,借助风险评价对危险废物进行分级管理的方法和原则,以及相应的分级管理程序的建议,为完善中国的危险废物管理体系提供参考.     

Preparation and characterisation of green clay-polymer nanocomposite for heavy metals removal

ABSTRACT

Natural polymer Moringa oleifera seed as coagulant and bentonite clay as adsorbent were used for preparing novel composite coagulant. Results obtained from FTIR, SEM, TEM and P-XRD show that the bentonite clay and M. oleifera seed biopolymers physico-chemically interact with each other during the preparation of clay-polymer composite. The FTIR results show that the major functional groups present in bentonite clay and M. oleifera seed are integrated at nano levels in the novel composite to remove heavy metals from aqueous systems. The coagulo-adsorption using clay-polymer composite may be used for the adsorption of heavy metals ions from the aqueous systems. It becomes possible due to the structural characteristics of the clay crystallites together with the functional attraction of the biopolymer and it results in the formation of clay-polymer metal complexes. The clay-polymer nano-composite of M. oleifera seed and bentonite clay showed considerable cadmium, chromium and lead removal property.     

Developing a CFD heat transfer model for applying high expansion foam in an LNG spill

Liquefied natural gas (LNG) is widely used to cost-effectively store and transport natural gas. However, a spill of LNG can create a vapor cloud, which can potentially cause fire and explosion. High expansion (HEX) foam is recommended by the NFPA 11 to mitigate the vapor hazard and control LNG pool fire. In this study, the parameters that affect HEX foam performance were examined using lab-scale testing of foam temperature profile and computational fluid dynamics (CFD) modeling of heat transfer in vapor channels. A heat transfer model using ANSYS Fluent® was developed to estimate the minimum HEX foam height that allows the vapors from LNG spillage to disperse rapidly. We also performed a sensitivity analysis on the effect of the vaporization rate, the diameter of the vapor channel, and the heat transfer coefficient on the required minimum height of the HEX foam. It can be observed that at least 1.2 m of HEX foam in height are needed to achieve risk mitigation in a typical situation. The simulation results can be used not only for understanding the heat transfer mechanisms when applying HEX foam but also for suggesting to the LNG facility operator how much HEX foam they need for effective risk mitigation under different conditions.     

典型因素对含锌废盐酸制备磷酸锌的影响机制研究

以含锌废盐酸为原料制备磷酸锌［Zn3(PO4)2］,探讨含锌废盐酸中Zn、Fe、Cr、Ni等重金属质量分数、TOC质量浓度、磷酸体积分数和反应时间等典型因素对Zn3(PO4)2纯度及化学组成结构的影响,并用XRD及SEM表征Zn3(PO4)2的物相结构。结果表明,含锌废盐酸可制备纯度较高、结构较为稳定的Zn3(PO4)2产品,制备过程中废盐酸中的Fe对Zn3(PO4)2产出纯度的影响较大;Zn3(PO4)2的产出纯度随TOC质量浓度的升高而下降;当磷酸体积分数低于85%时,对Zn3(PO4)2产出纯度总体呈正相关趋势,而高于85%后,产出纯度则有所降低;反应时间为5 h时制备Zn3(PO4)2的效率最高。     

危险废物焚烧处置与管理

结合美国的危险废物焚烧处置与管理实际，介绍了危险废物焚烧处置的主要技术环节及对环境的影响，在展望焚烧处置技术发展前景的同时，希望其在我国的危险废物的处置工作中发挥作用．     

建立有效回收网络,防治危险废物污染环境

工业废弃物中，废酸碱、重金属、废矿物油等都属于危险废物，我们日常生活中的废电池、灯管、显像管、空调、冰箱等都含有大量成分的危险废物。开展危险废物的有效回收，建立有效回收网络，才能从根本上防治危险废物进入环境，防治危险废物给人类与环境造成严重灾难。     

危险废物处理处置技术

危险废物具有腐蚀性、急性毒性、易燃性、反应性和感染性等特点。处理处置危险废物的方法有多种,本文通过对危险废物的特点分析,比较常用的几种处理处置技术方法,最后提出危险废物处理处置的相关建议。     

大中型城市医疗废物集中处置中心工程建设探索

结合具体工程实践 ,对建设我国地区级城市医疗废物集中处置中心的总体规划、处置工艺以及经济运作等方面进行系统的研究 ,提出了一些具有可操作性的实施依据。     

Making or breaking waste facility siting successes with a siting framework

Waste facility siting successes depend on many linked factors of facility design and impacts, site characteristics, and community beliefs and values. A facility siting framework is constructed to combine important elements and cause–effect linkages that affect the siting outcome. The framework consists of three main components: (1) core elements of facility design, effects, and community beliefs, attitude and response; (2) contributing factors of site and community characteristics, community beliefs and values that affect the interpretation of the facility and its effects; and (3) siting management interventions to manage the process and facility impacts. The framework is applied in an unsuccessful and a successful siting case to determine the key elements that contribute to siting outcome: (1) thorough need justification for the facility from the proponent's and the community's perspective; (2) careful facility design and prediction of the impacts and to select impact management compensation measures; (3) screening and selection of communities where the beliefs and values are compatible with the type of facility and its effects, (4) cooperatively selected impact reduction (i.e., prevention, control, and mitigation) measures followed by compensation and incentives; and (5) intensive process management to balance the community characteristics and values with the proponent's efforts to plan, design, assess and manage impacts, and ultimately, gain approval of the facility. The siting framework provides a comprehensive and robust structure of key factors that contribute to siting outcome and, therefore, provides the tool to identify, evaluate, and design siting interventions to enhance the chances of successful siting outcome.     

Further study of the intrinsic safety of internally shorted lithium and lithium-ion cells within methane-air

National Institute for Occupational Safety and Health (NIOSH) researchers continue to study the potential for lithium and lithium-ion battery thermal runaway from an internal short circuit in equipment for use in underground coal mines. Researchers conducted cell crush tests using a plastic wedge within a 20-L explosion-containment chamber filled with 6.5% CH₄-air to simulate the mining hazard. The present work extends earlier findings to include a study of LiFePO₄ cells crushed while under charge, prismatic form factor LiCoO₂ cells, primary spiral-wound constructed LiMnO₂ cells, and crush speed influence on thermal runaway susceptibility. The plastic wedge crush was a more severe test than the flat plate crush with a prismatic format cell. Test results indicate that prismatic Saft MP 174565 LiCoO₂ and primary spiral-wound Saft FRIWO M52EX LiMnO₂ cells pose a CH₄-air ignition hazard from internal short circuit. Under specified test conditions, A123 systems ANR26650M1A LiFePO₄ cylindrical cells produced no chamber ignitions while under a charge of up to 5 A. Common spiral-wound cell separators are too thin to meet intrinsic safety standards provisions for distance through solid insulation, suggesting that a hard internal short circuit within these cells should be considered for intrinsic safety evaluation purposes, even as a non-countable fault. Observed flames from a LiMnO₂ spiral-wound cell after a chamber ignition within an inert atmosphere indicate a sustained exothermic reaction within the cell. The influence of crush speed on ignitions under specified test conditions was not statistically significant.