废旧塑料的再生利用技术与展望

废旧塑料是一种可以回收利用的资源。介绍并评述了废旧塑料的几种典型处理技术和再生利用方法，以及可降解塑料研究开发的情况。这些方法和技术对于治理白色污染具有重要作用。     

超临界流体技术在废旧塑料解聚中的应用

介绍了超临界流体及其特性，并综述了不同废旧塑料在超临界流体中解聚的应用现状，指出超临界解聚技术是一项处理废旧塑料的“绿色技术”，为废旧塑料的回收利用开辟了新的途径，最后展望了该技术的应用前景及需要研究解决的问题。     

超临界流体技术在废旧塑料解聚中的应用

介绍了超临界流体及其特性,并综述了不同废旧塑料在超临界流体中解聚的应用现状,指出超临界解聚技术是一项处理废旧塑料的"绿色技术",为废旧塑料的回收利用开辟了新的途径,最后展望了该技术的应用前景及需要研究解决的问题.     

废塑料资源化新技术及其进展

随着社会的发展 ,人们对物质的要求日益增大 ,而自然资源和能源却日趋匮乏 ;另一方面 ,可再生利用的高分子材料的消耗所产生的废弃物也造成了严重的污染 ,威胁到人类的生存。有人提出废旧塑料的资源化是 2 1世纪全人类的重要课题。本文综述了国内外废旧塑料资源化新技术及其进展。     

废塑料资源化新技术及其进展

随着社会的发展，人们对物质的要求日益增大，而自然资源和能源却日趋匮乏；另一方面，可再生利用的高分子材料的消耗所产生的废弃物也造成了严重的污染，威胁到人类的生存。有人提出废旧塑料的资源化是21世纪全人类的重要课题。本文综述了国内外废旧塑料资源化新技术及其进展。     

废旧塑料无水清洁装置的设计及其清洗实验

为提高回收塑料识别、分离准确度和再生塑料产品的质量,需对废旧塑料进行清洗。传统的水洗清洁方法会产生大量污染废水,后续的污水处理系统和干燥装置增加了清洗成本。为了克服湿法清洁带来的污染和高成本,设计和运行了一种轻质废旧塑料无水清洁装置,以廉价砂石和空气作为清洗介质,在不产生二次污染的前提下对废旧塑料膜进行无水清洗。结果表明:无水清洁40 min和50 min的样品清洗率分别达到92.72%和94.90%,接近于水洗样品的94.56%;无水清洁40 min和50 min的样品平均遮光率分别达到43.56%和40.10%,接近于水洗样品的41.84%。     

重金属废水的生物处理技术

介绍了重金属废水生物处理技术的一般原理 ,主要分析了微生物絮凝法、生物吸附法和植物修复技术的研究现状及应用前景。指出了利用生物化学方法处理重金属废水是一种长期、高效、经济、可靠的方法。     

重金属废水的生物处理技术

介绍了重金属废水生物处理技术的一般原理，主要分析了微生物絮凝法、生物吸附法和植物修复技术的研究现状及应用前景。指出了利用生物化学方法处理重金属废水是一种长期、高效、经济、可靠的方法。     

激光散射技术及其对絮凝剂分子特性检测和性能研究

本文提出一种将激光散射技术应用于对絮凝剂性能研究的方法。综述了利用该技术可实现对絮凝剂胶体分子粒径、形态结构、粒径分布和重均分子量的精确测量 ,论述了激光散射技术在絮凝剂沉降性能的研究及絮凝剂改进提高方面的重要作用     

电解法用于消毒的原理、技术特点与主要应用方式:电产次氯酸钠及电化学消毒

电解法是利用电能实现氧化还原反应的方法,其应用于消毒通常有电产次氯酸钠消毒剂和电化学消毒2种方式。为深入了解电产次氯酸钠及电化学消毒技术机理,进一步探讨电解法在水处理和公共环境卫生消毒领域的应用,从消毒原理、技术特点、使用方法和消毒应用方面,对电解法制备次氯酸钠与电化学消毒水处理技术进行了介绍与分析,并提出了目前存在的问题和技术发展前景,为该技术的实际应用提供参考。     

选矿技术在城市固体废弃物资源化中的应用

选矿技术作为一种成熟的矿物分离技术已广泛应用于城市固体废弃物资源化领域 ,促进了环境的保护和资源的综合回收 ;同时也开辟了选矿技术新的应用领域。结合实例介绍国内外常用的各种城市固体废弃物的分选工艺 ,指出选矿技术的运用对固体废弃物的资源化有着重要的实际意义     

Comparison of Analytical Techniques for Measuring Hydrocarbon Emissions from the Manufacture of Fiberglass-Reinforced Plastics

ABSTRACT

Research Triangle Institute and the U.S. Environmental Protection Agency conducted several projects to measure hydrocarbon emissions associated with the manufacture of fiberglass-reinforced plastics. The purpose of these projects was to evaluate pollution prevention techniques to reduce emissions by altering raw materials, application equipment, and operator technique. Analytical techniques were developed to reduce the cost of these emission measurements. Emissions from a small test mold in a temporary total enclosure (TTE) correlated with emissions from full-size production molds in a separate TTE. Gravimetric mass balance measurements inside the TTE generally agreed to within ± 30 % with total hydrocarbon (THC) measurements in the TTE exhaust duct. Pure styrene evaporation tests served as quality control checks for THC measurements and generally agreed to within ± 5 %.     

Biodegradable microplastics (BMPs): a new cause for concern?

Environmental Science and Pollution Research - With the increasingly serious pollution of plastics, biodegradable plastics (BDPs) have attracted attention as a new material that can replace...     

Characterization of semi-volatile organic compounds emitted during heating of nitrogen-containing plastics at low temperature

Because of recent volume increases, appropriate management of plastic recycling, which generates various organic compounds, is required to ensure the chemical safety of the processes. The processing temperature and resin type are the important factors determining both the efficiency of the processes and the emission of chemicals. Therefore, we studied the thermal degradation of various plastics at various temperatures from 70 to 300 °C under oxygen-present conditions to identify the semi-volatile organic compounds (SVOCs) emitted and to understand their thermal behaviors. The plastics examined were nitrogen-containing resins, such as polyamide 6, polyurethane, melamine formaldehyde, urea formaldehyde and acrylonitrile-butadiene-styrene. Major commodity plastics were also investigated for comparison. In total, more than 500 SVOCs were detected as emissions from plastics. While various nitrogen-containing SVOCs were detected from nitrogen-containing resins, the major commodity plastics released only these, which possibly were included as additives. These results indicate that the nitrogen atoms in the SVOCs emitted originated from the resins and additives, and not from ambient air at low temperature. As a result of the detection of raw materials, degradation chemicals and by-products of the polymers in the emissions, we found that the variation in chemical species is dependent on the resins. Additives were also emitted from all the resins, meaning that these chemicals were also released to the environment at the temperature examined. In most cases, the numbers and concentrations of SVOCs increased with increasing heating temperature. The variation of thermal behaviors of SVOCs was related to the origins and chemical species of SVOCs.     

An intelligent way for discerning plastics at the shorelines and the seas

Irrespective of how plastics litter the coastline or enter the sea, they pose a major threat to birds and marine life alike. In this study, an artificial intelligence tool was used to create an image classifier based on a convolutional neural network architecture that utilises the bottleneck method. The trained bottleneck method classifier was able to categorise plastics encountered either at the shoreline or floating at the sea surface into eight distinct classes, namely, plastic bags, bottles, buckets, food wrappings, straws, derelict nets, fish, and other objects. Discerning objects with a success rate of 90%, the proposed deep learning approach constitutes a leap towards the smart identification of plastics at the coastline and the sea. Training and testing loss and accuracy results for a range of epochs and batch sizes have lent credibility to the proposed method. Results originating from a resolution sensitivity analysis demonstrated that the prediction technique retains its ability to correctly identify plastics even when image resolution was downsized by 75%. Intelligent tools, such as the one suggested here, can replace manual sorting of macroplastics from human operators revealing, for the first time, the true scale of the amount of plastic polluting our beaches and the seas.

     

堆肥生物过滤器净化苯、甲苯混合废气的实验研究

选取木块和多孔塑料为填料,选择苯为VOCs代表,研究堆肥生物过滤器对高低浓度的苯生物降解性能。实验结果表明,（1) 以木块和多孔塑料为填料的堆肥生物过滤器对高、低浓度苯净化效率呈现降低后升高,最后再降低的过程,对高低浓度甲苯均呈现缓慢升高后降低的过程,高浓度苯的最大净化效率为90.5%和97.7%,甲苯的最大净化效率为71.34%和66.45%;（2) 以多孔塑料为填料的堆肥生物过滤器对高浓度苯具有较好的抗冲击性和抗负荷性,以木块为填料的堆肥生物过滤器对高浓度甲苯有更好的净化效果;（3) 堆肥生物过滤器对高低浓度苯、甲苯的平均净化率为68%和56%以上,低浓度苯和甲苯的平均去除能力分别为0.122和0.012 g/（m³·h）,最大去除能力为0.148和0.015 g/（m³·h）,而高浓度苯和甲苯的平均去除能力为0.94和0.11 g/（m³·h）,最大去除能力为1.32和0.135 g/（m³·h）。     

An experimental study on usage of plastic oil and B20 algae biodiesel blend as substitute fuel to diesel engine

Usage of plastics has been ever increasing and now poses a tremendous threat to the environment. Millions of tons of plastics are produced annually worldwide, and the waste products have become a common feature at overflowing bins and landfills. The process of converting waste plastic into value-added fuels finds a feasible solution for recycling of plastics. Thus, two universal problems such as problems of waste plastic management and problems of fuel shortage are being tackled simultaneously. Converting waste plastics into fuel holds great promise for both the environmental and economic scenarios. In order to carry out the study on plastic wastes, the pyrolysis process was used. Pyrolysis runs without oxygen and in high temperature of about 250–300 °C. The fuel obtained from plastics is blended with B20 algae oil, which is a biodiesel obtained from microalgae. For conducting the various experiments, a 10-HP single-cylinder four-stroke direct-injection water-cooled diesel engine is employed. The engine is made to run at 1500 rpm and the load is varied gradually from 0 to 100 %. The performance, emission and combustion characteristics are observed. The BTE was observed to be higher with respect to diesel for plastic-biodiesel blend and biodiesel blend by 15.7 and 12.9 %, respectively, at full load. For plastic-biodiesel blend, the emission of UBHC and CO decreases with a slight increase in NO _x as compared to diesel. It reveals that fuel properties are comparable with petroleum products. Also, the process of converting plastic waste to fuel has now turned the problems into an opportunity to make wealth from waste.     

Qualitative determination of 10,10'-oxybisphenoxarsine and decabromodiphenyl ether in plastics

Plastics destined for facilities holding aquatic fauna, such as aquaculture and aquatic toxicology laboratories, were studied. The plastics were extracted with dichloromethane. The fungicide 10,10'-oxybisphenoxarsine (OBPA) was detected by silver nitrate after cleanup on a silica cartridge and TLC in petroleum ether-diethyl ether-acetic acid 80:20:1. The flame retardant decabromodiphenyl ether (DBDPO) was crystallized from dichloromethane and confirmed by IR spectrum. A UV-spectrophotometric method is suggested for the estimation of the leaching potential of additives from plastics.