废旧塑料分选及其化学回收循环再利用技术研究进展

塑料污染已是全球防治环境污染的重大问题,我国每年有大量的废旧塑料产生,仅废旧塑料的分选这一工艺就要耗费大量的人力物力财力,回收后的循环再利用,又要增加昂贵的处理成本。综述了废旧塑料几种主要的分选技术,包括色彩分选技术、光谱分选技术、密度分选技术、风力分选技术、静电分选技术、溶剂萃取分选技术。对废旧塑料化学回收循环利用相关技术进行介绍,包括热裂解法、催化裂解法、氢化裂解法、光催化裂解法等。总结了对废旧塑料分选及化学回收循环再利用的重要性,并对此提出了规模化、产业化的发展愿景。     

城市生活垃圾分选技术探究

随着人们生活水平的提高,城市的生活环境也在逐渐变化,城市生活垃圾的种类及物化特性也逐渐变得复杂.首先概括了传统的生活垃圾处理方法,重点总结了传统垃圾分选技术的进展,介绍了一些新的垃圾处理技术,如红外吸收光谱分析技术、图像识别技术、变重分选、温度传感技术等,在此基础上对传统技术及新技术的研究提出建议,认为一些在其他领域兴起的技术也 行变革进入该领域,以提高垃圾的无害化和资源化程度,有利于环境保护和社会的可持续发展的建设.     

废旧塑料的分离与回收利用

简要地论述了回收废旧塑料的意义，介绍了几种主要的分离与回收混合废塑料的方法以及重新利用的加工技术。     

废旧塑料综合利用技术的应用

废旧塑料的回收利用是环境污染控制所面临的一个重要课题,近年来,人们在这方面进行了大量的研究工作,取得了很多成果.详细叙述了国内外废旧塑料回收处理的方法,分析了我国在废旧塑料回收利用方面的现状及存在的问题,并对如何进一步开展废旧塑料回收利用工作提出了一系列切实可行的建议.     

废旧塑料的回收与利用

塑料制品给人类带来便利,但因其难以降解,所造成的环境污染问题已成为各国广泛关注的环境问题。当前,由于石油和煤炭等化石资源的紧缺,废旧塑料的回收利用成为缓解能源与环境危机的途径之一。总结了塑料回收与再利用的现状,研究塑料垃圾回收利用的各种关键技术,并介绍了近年来中国塑料回收和处理技术的研究进展。     

综合分选处理村镇垃圾的技术方案研究

通过回收垃圾中的资源,提高垃圾的处理率,利用先进的分选技术,将垃圾减量化、资源化和无害化处理,使垃圾中的资源得到有效的利用。特别是城乡结合部垃圾的治理,提出了处理工艺和方案。     

废旧塑料的处理工艺

介绍了当前国内外几种处理和利用废旧塑料的方法,特别对废旧塑料掩埋、再生、回收、焚烧、热裂解制造燃料油和化学品的技术和存在的问题作了重点探讨.     

浅析城市生活垃圾分类回收

城市生活垃圾分类回收有别于混合收集,是垃圾收集的一种新趋势.结合我国垃圾的特点,阐明了当前垃圾分类收集的现状,并指出了我国垃圾分类回收的意义;根据当前垃圾收集存在的问题,提出了一些具体化的对策.通过垃圾的分类回收,减少了垃圾的最终处置量,提高垃圾资源化率.     

废旧塑料回收利用现状及问题

塑料制品在给人类带来便利的同时,也带来了极大的负效应,随着塑料使用量的大幅增加,废旧塑料由于难以自然降解,所造成的环境污染日趋严重。回收利用为处理废旧塑料垃圾开辟了减量化、无害化、资源化的道路。目前各国对废旧塑料回收利用都非常重视,投入大量人力、物力,乃至通过立法,开发各种废旧塑料回收利用的关键技术。综述了废旧塑料的回收和利用现状,以及国内近些年来废旧塑料处理和回收利用技术的研究进展及其发展趋势。     

提高废旧塑料再生产品品质的预处理技术

废旧塑料是一种很有价值的可回收利用资源,经过再生可制取高品质塑材制品。但目前因塑料种类、颜色等原因,难有统一、合适的预处理技术,从而导致废旧塑料回收率低和塑材产品品质低等问题。针对废旧塑料的分选、破碎、清洗预处理技术影响塑材产品品质因素进行研究,重点考察破碎料粒度与氯乙烯(VCM)含量对再生塑料物化性质的多因素影响,实验结果表明,PVC型材产品杂质粒子数≤12个/900cm2,优于国标GB5761-1993相应的SG3型号优等品要求的16个/900cm2,且水循环利用率大于90%,环保效益好,具有极大的推广价值。     

Cryo-comminution of plastic waste

Recycling of plastics is a big issue in terms of environmental sustainability and of waste management. The development of proper technologies for plastic recycling is recognised as a priority. To achieve this aim, the technologies applied in mineral processing can be adapted to recycling systems. In particular, the improvement of comminution technologies is one of the main actions to improve the quality of recycled plastics. The aim of this work is to point out suitable comminution processes for different types of plastic waste. Laboratory comminution tests have been carried out under different conditions of temperature and sample pre-conditioning adopting as refrigerant agents CO2 and liquid nitrogen. The temperature has been monitored by thermocouples placed in the milling chamber. Also different internal mill screens have been adopted. A proper procedure has been set up in order to obtain a selective comminution and a size reduction suitable for further separation treatment. Tests have been performed on plastics coming from medical plastic waste and from a plant for spent lead batteries recycling. Results coming from different mill devices have been compared taking into consideration different indexes for representative size distributions. The results of the performed tests show as cryo-comminution improves the effectiveness of size reduction of plastics, promotes liberation of constituents and increases specific surface size of comminuted particles in comparison to a comminution process carried out at room temperature.     

国外城市垃圾回收利用与管理的新动向

介绍发达国家美、日、德、瑞士、澳大利亚、新加坡等城市生活垃圾回收利用、管理与政策方面的最新发展动向。     

大连实施垃圾分类回收积极推进垃圾资源再生利用产业化

大连在全国率先创建新型垃圾分类回收体系,实现废旧物资回收与垃圾分类回收在同一个垃圾分类回收站内完成,有利于各类废物资源集中收集、分类回收、资源化利用或处理,彻底改革了我国传统落后的废旧物资回收与垃圾收集处理方式,为废旧物资与垃圾资源再生与循环利用提供了保障条件,也为垃圾处理产业化奠定了坚实的基础。     

Pyrolysis of plastic packaging waste: A comparison of plastic residuals from material recovery facilities with simulated plastic waste

Pyrolysis may be an alternative for the reclamation of rejected streams of waste from sorting plants where packing and packaging plastic waste is separated and classified. These rejected streams consist of many different materials (e.g., polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), aluminum, tetra-brik, and film) for which an attempt at complete separation is not technically possible or economically viable, and they are typically sent to landfills or incinerators. For this study, a simulated plastic mixture and a real waste sample from a sorting plant were pyrolyzed using a non-stirred semi-batch reactor. Red mud, a byproduct of the aluminum industry, was used as a catalyst. Despite the fact that the samples had a similar volume of material, there were noteworthy differences in the pyrolysis yields. The real waste sample resulted, after pyrolysis, in higher gas and solid yields and consequently produced less liquid. There were also significant differences noted in the compositions of the compared pyrolysis products.     

Biodegradability of degradable plastic waste.

Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.     

城市垃圾处理方法综述

综述了目前我国城市垃圾的处理方法，并分析比较了各处理方法的化缺点以及对我国的适宜性，重点介绍了垃圾焚烧发电在我国的发展前景以及存在的有关问题。     

塑料废弃物的回收与再生

论述了国内外塑料废弃物回收再生技术的发展现状及各种回收再生方法的原理和特点,并分析了回收再生技术的主要发展方向和前景.