Plastic Degradation and its Environmental Implications
Plastic Degradation and its Environmental Implications
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塑料降解及其环境影响
DOI：
10.21741/9781644901335-12
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
M. Rani
中科院分区：
文献类型：
--
作者：
U. Shanker;M. Rani
人类活动对不可生物降解塑料的广泛使用正在对全球环境构成严重威胁，其形式是大规模的废物处理和封闭的垃圾填埋场问题以及水和土地污染的增加。一旦生物体以食物的形式消耗塑料，它们的生命就会面临挑战。此外，塑料碎片可能含有可能浸出的添加剂化学品。因此，适当降解塑料以减少对环境的负面影响是必要的。早些时候人们对这个问题一无所知，然而，现在，人们对它的负面影响是认真的。因此，生物降解塑料正在成为市场的趋势。塑料（吸附特性）与环境的相互作用在动态情况下在其表面上产生新的官能团。在这些情况下，对塑料的氧化、热、生物基和光催化降解的需求很高。通常，在不同的聚合物如聚乙烯、聚丙烯和聚对苯二甲酸乙二醇酯中，已经发现不同的速率沿着不同的路径。聚乙烯光降解导致尖锐的红外峰的酮，酯，和酸由于氧化反应。过氧化氢是通过对聚对苯二甲酸乙二醇酯主链中的亚甲基的氧化作用产生的。本章将提供有关塑料中使用的各种聚合物以及塑料环境问题的汇编信息，最后本章将全面详细介绍各种塑料的降解情况。还包括可降解塑料市场的最新发展，重点是可再生原料的可回收塑料和生物降解塑料的原理设计。本章还讨论了影响塑料降解和代谢途径的因素，包括过去和现在的情景。
Extensive use of non-biodegradable plastic by anthropogenic activities is posing a severe threat to the global environment in the form of massive waste disposal and problems of closed-landfill sites and rising water and land pollution. Organisms are facing challenge to their lives once they consume plastic in the form of food. In addition, the plastic debris may have additive chemicals having possibility to leach out. Therefore, proper degradation of plastic to lessen negative environmental implications is necessary. Earlier the people were ignorant about this problem however, now-a-days, people are serious about its negative impact. Hence, biodegradable plastics are coming into the trend in the market. Interaction of plastic (adsorbing characteristics) with the environment results in new functional groups on its surface in a dynamic situation. In these circumstances, oxygenated, thermal, bio-based, and photocatalytic degradation of plastics is in high demand. Usually, different-rates along with diverse-pathways have been found in variable polymers like polyethylene, polypropylene, and polyethylene terephthalate. Polyethylene photo-degradation resulted in sharp infrared-peaks of ketones, esters, and acids due to oxidation reaction. Hydrogen peroxide is generated by oxidative action on methylene groups in the backbone of polyethylene terephthalate. The present chapter will provide compiled information about various polymers used in plastic as well as environmental concerns of plastic, finally the chapter concludes with comprehensive details about the degradation of various types of plastics. State-of-the-art on degradable plastics market with an emphasis on principle design for recyclable plastics and biodegradable plastics from renewable raw materials are also included. Factors affecting plastic degradation and metabolic pathways including past and present scenarios have also been discussed in this chapter.