Centre for Natural Resources and the Environment (CERENA), Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
CERENA, Department of Biological Engineering, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal.
Sci Total Environ. 2023 Sep 20;892:164629. doi: 10.1016/j.scitotenv.2023.164629. Epub 2023 Jun 5.
For the past two decades, with the increase in plastic consumption came a rise in plastic waste, with the bulk of it ending up in landfills, incinerated, recycled or leaking into the environment, especially in aquatic ecosystems. Plastic waste poses a significant environmental threat and a wealth issue due to its non-biodegradability and recalcitrant nature. Polyethylene (PE) remains one of the major utilized polymers in different applications amid all the other types because of its low production costs, simplistic nature prone to be modified and historically predominant researched material. Since the common methods for plastic disposal are troubled by limitations, there is a growing need for more appropriate and environment friendly methods alternatives. This study highlights several ways that can be used to assist PE (bio)degradation and mitigate its waste impact. Biodegradation (microbiological activity driven) and photodegradation (radiation driven) are the most promising for PE waste control. The shape of the material (powder, film, particles, etc.), the composition of medium, additives and pH, temperature and incubation or exposure times contribute to plastic degradation efficiency. Moreover, radiation pretreatment can enhance the biodegradability of PE, providing a promising approach to fighting plastic pollution. This paper relates the most significant results regarding PE degradation studies followed by weight loss analysis, surface morphology changes, oxidation degree (for photodegradation) and mechanical properties assessment. All combined strategies are very promising to minimize the polyethylene impact. However, there is still a long way to go through. The degradation kinetics is still low for the currently available biotic or abiotic processes, and complete mineralization is thoroughly unseen.
在过去的二十年中，随着塑料消费的增加，塑料垃圾也随之增加，其中大部分最终被填埋、焚烧、回收或泄漏到环境中，尤其是在水生生态系统中。由于其不可生物降解性和顽固性，塑料废物对环境构成了重大威胁，也是一个财富问题。聚乙烯 (PE) 因其生产成本低、易于改性且历史上主要研究材料的简单性质，仍然是各种应用中主要使用的聚合物之一。由于常见的塑料处理方法受到限制，因此越来越需要更合适和环保的替代方法。本研究强调了几种可用于协助 PE（生物）降解和减轻其废物影响的方法。生物降解（微生物活性驱动）和光降解（辐射驱动）是控制 PE 废物的最有前途的方法。材料的形状（粉末、薄膜、颗粒等）、介质的组成、添加剂和 pH 值、温度和孵育或暴露时间都有助于塑料降解效率。此外，辐射预处理可以增强 PE 的生物降解性，为应对塑料污染提供了一种有前途的方法。本文介绍了与 PE 降解研究相关的最重要结果，随后进行了失重分析、表面形貌变化、氧化程度（光降解）和机械性能评估。所有综合策略都非常有希望最大限度地减少聚乙烯的影响。然而，还有很长的路要走。目前可用的生物或非生物过程的降解动力学仍然很低，完全矿化还未彻底出现。
