Compostability of polymers

In recent years, biobased polymers have gained attention from industries, consumers and governments as a way to reduce municipal solid waste. Much attention has been given to their production and implementation. However, these materials only reach their potential environmental benefits when they are recovered through recycling or composting and/or their energy is recovered by incineration. These end‐of‐life scenarios allow closing the carbon cycle loop. A lot of confusion and misunderstanding about these new materials and their end‐of‐life scenarios, particularly composting, have been generated. This paper addresses definitions and environmental performance of these materials and their compostability. Current methods for measuring biobased content and biodegradability of polymers and factors affecting it, such as exposure conditions and polymer characteristics, are discussed, and the use of life cycle assessment as a tool to evaluate the environmental performance of biopolymers is presented. Although there are some obstacles for the growth and implementation of biobased polymers, such as consumer adoption and available composting facilities accepting these materials, new opportunities are growing due to government regulation and business initiatives in the past five years. However, consumers' understanding of when the use of these materials provides environmental benefits and when not is still missing. Therefore, to adopt and to implement these new biopolymers cooperative work among industry, consumers and government is needed. Copyright © 2008 Society of Chemical Industry     

城市生活垃圾处理的可持续性发展

人类进入21世纪后，面临社会、经济、环境等诸多问题，可持续发展已成为人类的必然选择。文中对城市生活垃圾现状及卫生填埋、堆肥、焚烧等处理方法的优缺点进行了阐述，指出必须对垃圾进行减量化、无害化、资源化处理，为我国21世纪的可持续发展打下良好的基础。     

城市污水厂污泥堆肥技术研究

随着城市的发展,城市污水厂污泥也迅速增加。目前污泥堆肥化处理已经成为国内外学者研究的热点。将污泥进行堆肥化处理是污泥资源化利用的前提和有效手段。文章对污泥好氧堆肥的系统分类、影响因素、腐熟度评价指标等进行综述,并简要指出了今后的研究方向。     

不同类型的外加碳源对污泥堆肥过程氮素损失的影响

以城市污泥为研究对象,采用葡萄糖、蔗糖、秸秆粉及其混合物作为外加碳源,研究了不同类型的外加碳源对堆肥系统一次发酵周期内氨气挥发的影响。探讨了碳源的降解效率与堆肥系统氮素损失的作用关系。结果表明,与对照试验氨气挥发总量相比(3.05g/kg·ds),单独添加葡萄糖(2.46g/kg·ds)与蔗糖(2.17g/kg·ds)均能控制氨气的挥发,但单独使用秸秆粉没有显著效果(3.1g/kg·ds)。蔗糖与秸秆粉混合添加对高温期氨气挥发的控制效果最好(1.92g/kg·ds),堆肥系统中总氮损失由对照试验53.1%减少至27.7%;堆肥过程中氨气挥发与碳源的降解具有显著负相关性(R=-0.94,p0.005),秸秆粉与葡萄糖、蔗糖混合添加增强了微生物对有机碳的降解能力,促进无机氮的固定作用,减少了氮素的损失。     

太阳能在污泥高效堆肥中的应用研究

基于不同的蓄热性能,设计了普通堆肥、大棚堆肥和太阳能堆肥装置,对比研究了城市污泥在3种不同装置中的高温好氧堆肥效果.结果表明,太阳能可为污泥好氧堆肥过程提供稳定的热源,确保堆肥在高效温度段运行,经过40 d的堆肥处理,太阳能堆肥装置可使污泥的含水率从59.59％降低到47.20％、TOC含量由92％降至65％、GI值达到108.3％,堆肥效果最佳.     

Synthesis and physicochemical properties of new (bio)degradable poly(ester-urethane)s containing polylactide and poly[(1,4-butylene terephthalate)-co-(1,4-butylene adipate)] segments

(Bio)degradable poly(ester-urethane)s containing polylactide (PLA) and poly[(1,4-butylene terephthalate)-co-(1,4-butylene adipate)] (BTA) segments in the main chain were synthesized and their properties were examined. Novel poly(ester-urethane)s were obtained from isophorone diisocyanate (IPDI), synthetic PLA-diol and/or synthetic BTA-diol oligomers in a two-step process. PLA-diol and BTA-diol oligomers were received via glycolysis of their respective polymers: PLA and BTA. Butanediol (BD) was used as a polymer chain extender.The synthesized poly(ester-urethane)s were characterized by DSC, NMR, GPC, FTIR and X-ray methods. The poly(ester-urethane)s that were examined had a single glass transition temperature (T_g), which pointed to a one-phase system. The biodegradability of the received poly(ester-urethane)s was examined under industrial composting conditions. The results prove the possibility of synthesizing new perspective application materials, surrendering (bio)degradation in the environment.     

固体废物的污染状况分析及废物资源化的思路

现阶段中国生活垃圾总量正成逐年上升趋势,因为长期缺乏合理治理措施,导致了城市垃圾日益增多。固定废物垃圾严重影响着人们正常生活,给人们生活带来严重危害。针对固定废物垃圾的污染状况进行了分析并提出了合理的废物资源化方式。     

造纸污泥好氧堆肥处理技术研究

造纸污泥是一种生物固体废弃物，通过调节水分与C／N比，在强制通风与定期翻堆情况下，由于微生物作用，有机质发生降解，C／N比在不断下降，经过2个月左右高温堆肥，可以转化为高效的有机肥料。从堆肥过程的物理、化学及生物学指标变化可以看出，添加富含纤维素降解菌的发酵料，可以加速造纸污泥的腐熟，堆肥的阳离子交换量(CEC)与盆栽玉米增产率之间具有较好的相关性，CEC值可以作为造纸污泥堆肥腐熟程度的控制指标，CEC值≥80mmol／100g时，认为造纸污泥堆肥已经腐熟。     

城市污泥堆肥处理及其产业化发展中的几个关键问题

污泥堆肥处理后其有机质和N、P等营养元素可被农作物利用,促进作物增产,被认为是适合中国国情的污泥处理与处置方式.但受处理技术水平、人们的认知和可接受程度的限制以及国家政策法规、产品出路等问题的困扰,城市污泥堆肥处理及其产业化过程仍面临诸多不利因素.为从根本上解决城市污泥的处理与处置难题,城市污泥堆肥处理及其产业化过程中存在的问题必须予以解决,以加快其产业化进程.     

生物传感器在堆肥过程控制与动态监测中的研究进展

生物传感器作为一种新兴的分析工具,在堆肥过程控制与动态监测中具有广泛的应用价值.该文主要介绍了生物传感器的工作原理、分类、特点及其在堆肥过程中的应用.