废塑料的回收利用及降解塑料的生产现状

介绍了废塑料的再生利用，热分解回收低分子化合物和焚烧回收热能的技术，并对国内降解塑料的生产现状进行了评述。     

废塑料在炼铁工艺中的应用

介绍了废塑料的处理和利用方法 ,叙述了高炉喷吹废塑料的工艺、优点和国外的实际应用。通过比较 ,认为在高炉中应用废塑料作还原剂能带来较好的社会效益和经济效益 ,指出随着喷吹技术的不断完善 ,高炉喷吹废塑料在我国具有广阔的应用前景     

废弃热固塑料回收利用对策研究

随着电子产品、汽车报废高峰期的到来，作为其基本材料的热固性塑料的废弃量增长迅速。通过对国内外废弃热固塑料资源化技术进行分析，可以发现目前废弃热固塑料资源化存在的主要问题是收集困难，分类辨识技术低。由于废弃热固塑料的来源存在明显差异，在其回收体系中分别采用P-R模式、D-R模式和P-C-R模式，对不同来源的废弃热固塑料进行回收；并通过制定经济激励措施，细化并强制执行塑料分类标识标准，规范再生行业，加快废弃塑料分类辨识技术研发等对策来促进废弃热固塑料的资源化。     

交联壳聚糖富集分离火焰原子吸收法测定环境样品中微量锰

提出了交联壳聚糖 (CCTS)分离富集火焰原子吸收法测定环境样品中微量锰的新方法。研究了富集的最佳条件及洗脱方法 ;考察了共存元素的影响。方法的检出限为 2 .6μg/L ,RSD为 2 .9% ,用于牡蛎和人发标样中微量锰的测定 ,结果满意。     

废塑料催化裂解生成汽柴油中试工艺的研究

研究开发了一套废塑料催化裂解一次转化成汽、柴油的中试装置 ,可日产汽、柴油 2 t,能够实现进料、出油和排渣的连续化操作。裂解反应器具有传热效果好、生产能力大的特点。试验结果表明 :在催化剂加入量为 1%～ 3%、反应温度为 35 0～ 380℃条件下 ,汽油和柴油的总收率可达 70 %以上 ;由废聚乙烯、废聚丙烯和废聚苯乙烯炼制的汽油辛烷值分别为 72、77和 86 ,柴油的凝固点分别为 3℃、-11℃和 -2 2℃。该工艺操作安全 ,无“三废”排放。     

我国一次性塑料污染管理对策研究

一次性塑料垃圾对生态环境和人体健康的危害已经引起国际社会的广泛关注,加强一次性塑料的管理正逐步成为人类的共识,也是我国塑料生产和使用过程中面临的重要现实问题.通过对世界各国和地区一次性塑料管理措施进行系统梳理,归纳出目前出台的相关政策措施主要有征税、自愿协议、全部或部分禁止、禁令和征税并行4类.对我国一次性塑料管理现状进行总结发现,我国当前针对一次性塑料的管理政策存在分散性以及滞后性等问题,尚未达到系统化.借鉴国际经验,在我国现存制度的基础上,针对一次性塑料制品的生产、使用和回收处理的全生命周期过程,提出完善我国一次性塑料污染的管理对策:①源头管理措施包括分阶段、分领域限制和禁止使用一次性塑料,使用税收等经济工具将一次性塑料垃圾外部成本内部化,探索替代品实现一次性塑料使用减量化;②使用过程的管理主要是通过提高一次性塑料的使用次数从而达到减量化使用的目的;③末端管理措施包括完善一次性塑料垃圾产生者责任制,提高垃圾回收中一次性塑料分拣效率和加快技术创新、促进再生利用等;④加强公众参与,提高公众减少使用一次性塑料制品的环境意识,这也是一次性塑料全生命周期管理体系的重要组成部分.      

Monitoring the levels of brominated and organophosphate flame retardants in passenger cars: Utilisation of car air filters as active samplers

Filters in residential and office air conditioning(A/C) systems have been used as sampling devices for monitoring different pollutants.However,cabin air filters(CAFs) in the A/C system of passenger cars have not been utilised for this purpose.In this study,we collected22 used CAFs from passenger cars in Hanoi,Vietnam to analyse for 8 polybrominated diphenyl ethers(PBDEs) and 10 organophosphate esters(OPEs).All the analytes were detected in more than 50% of samples with the exception of BDE153 and BDE154.The average concentrations of ∑_(10)OPEs and ∑_8 BDEs in the captured dust were 2600 and 40 ng/g,respectively with Tris(1-chloro-2-propyl) phosphate(TCIPP) and BDE209 as the dominant congener in OPE and BDE groups,respectively.CAFs are a potential tool to qualitatively assess the levels of semi-volatile chemicals in suspended dust in cars as a screening step for exposure assessment of those chemicals.     

多因素下小尺度油罐火火焰倾角的研究

以柴油为研究对象,搭建了小尺度油罐火实验台,采用理论分析与实验研究相结合的方法,开展了有风条件下不同液位深度和罐顶开口宽度的小尺度油罐火火焰倾角的实验研究。结果表明,火焰倾角随风速的增加先迅速增加,然后趋于平稳。在相同的罐顶开口宽度和风速条件下,火焰倾角随着液位深度的增加呈现出减小的趋势。这是因为火焰微元在油罐开口处的速度随着液位深度的增加而增加,风速对火焰倾角的影响显著减小。当风速和液位深度一定时,质量损失速率随罐顶开口宽度的增大而增大,火焰倾角随着罐顶开口宽度的增大逐渐减小。     

Effect of ignition position on vented hydrogen–air deflagration in a 1 m3 vessel

This study investigates the effect of the ignition position on vented hydrogen-air deflagration in a 1 m³ vessel and evaluates the performance of the commercial computational fluid dynamics (CFD) code FLACS in simulating the vented explosion of hydrogen-air mixtures. First, the differences in the measured pressure-time histories for various ignition locations are presented, and the mechanisms responsible for the generation of different pressure peaks are explained, along with the flame behavior. Secondly, the CFD software FLACS is assessed against the experimental data. The characteristic phenomena of vented explosion are observed for hydrogen-air mixtures ignited at different ignition positions, such as Helmholtz oscillation for front ignition, the interaction between external explosion and combustion inside the vessel for central ignition, and the wall effect for back-wall ignition. Flame-acoustic interaction are observed in all cases, particularly in those of front ignition and very lean hydrogen-air mixtures. The predicted flame behavior agree well with the experimental data in general while the simulated maximum overpressures are larger than the experimental values by a factor of 1.5–2, which is conservative then would lead to a safe design of explosion panels for instance. Not only the flame development during the deflagration was well-simulated for the different ignition locations, but also the correspondence between the pressure transients and flame behavior was also accurately calculated. The comparison of the predicted results with the experimental data shows the performance of FLACS to model vented mixtures of hydrogen with air ignited in a lab scale vessel. However, the experimental scale is often smaller than that used in practical scenarios, such as hydrogen refueling installations. Thus, future large-scale experiments are necessary to assess the performance of FLACS in practical use.     

The effect of vent size and concentration in vented gasoline-air explosions

Experimental data from vented explosion tests using gasoline-air mixtures with concentrations from 0.88 to 2.41% vol. are presented. A 2L vessel was used for the tests with vent sizes of 25 cm², 50 cm² and 100 cm². The tests were focused on the effect of gasoline vapor concentration and vent size on the pressure development and the flame behavior inside and outside the vessel. It was found that the inner flame propagation speed was mainly dependent on the initial concentration, while the maximum flame spreading distance was mainly influenced by the vent size. The external flame speed and duration could be influenced by the combination of the two properties. The internal pressure increases gradually with the flame propagated inside the vessel and decreased sharply when the vent failed. High-pressure durations containing pressure peaks were recorded by transducers in front of the vent and oscillations could be observed besides the vent. At any measure point, the maximum external pressures for A = 25 cm² or 50 cm² were significantly larger than those for A = 100 cm².