Ndayishimiye Jean Claude, Nyirajana Jacqueline, Nyirabuhoro Pascaline, Nacumuyiki Patrick Irakoze, Coker Akinwale Oladotun, Akintayo Folake Olubunmi, Mazei Yuri, Saldaev Damir, Nkinahamira François, Habumugisha Théogène, Murwanashyaka Theophile, Hishamunda Valens
Faculty of Biology, Shenzhen MSU-BIT University, Shenzhen, 518172, China.
The Center for Earth and Natural Resource Sciences, Kigali, P.O. Box 4285, Rwanda.
Heliyon. 2024 Sep 30;10(19):e38738. doi: 10.1016/j.heliyon.2024.e38738. eCollection 2024 Oct 15.
Plastic pollution poses a significant threat to ecosystem health worldwide. This study examines the determinants of environmental changes in human-modified ecosystems through a quantitative-qualitative system dynamics modeling approach: field experiments conducted on a 310 m unsaturated clay-rich bed and a 2.5 m clay-rich shore of a plastic-impacted pond in Shenzhen, China, and a 1.17 ha plastic-impacted clay pit in Musanze, Rwanda; laboratory experiments involving Modified Proctor (MP) and California Bearing Ratio (CBR) tests on natural clay reinforced with polyethylene terephthalate (PET) microplastics, with diameters ranging from 0.25 to 5 mm and at concentrations of 1.25 %, 2.5 %, 3.75 %, 5 %, and 10 % by weight of clay; and plastic dynamic flows analyzed by modeling the life cycle of PET. Field experiments showed that mulch type and thickness were critical factors influencing crack distribution in a plastic-impacted pond bed. Specifically, cracks were dominant in areas with pronounced desiccation and lacking filamentous green algae and PET-dominated plastic waste. Along the 2.5 m moisture gradient in a plastic-impacted pond bed, temperature and moisture significantly influenced nutrients, particularly in pronounced desiccation zones. Laboratory experiments showed that microplastics altered the structural properties of natural clay, decreasing moisture content while increasing dry density and load-bearing capacity. The plastic life cycle underscored the roles of industrial and consumer practices, environmental conditions, and waste management and recycling inefficiencies in driving environmental changes in human-modified ecosystems. The findings underscore the need for effective plastic waste management and recycling to mitigate the ecological impacts of plastic pollution in ecosystems.
塑料污染对全球生态系统健康构成重大威胁。本研究通过定量-定性系统动力学建模方法，研究了人类改造生态系统中环境变化的决定因素：在中国深圳一个受塑料影响的池塘310米不饱和富粘土地床和2.5米富粘土岸边，以及卢旺达穆桑泽一个1.17公顷受塑料影响的粘土坑进行了实地实验；进行了实验室实验，对用直径0.25至5毫米、浓度为粘土重量的1.25%、2.5%、3.75%、5%和10%的聚对苯二甲酸乙二醇酯（PET）微塑料增强的天然粘土进行改良普氏（MP）和加州承载比（CBR）测试；并通过对PET生命周期建模分析塑料动态流。实地实验表明，覆盖物类型和厚度是影响受塑料影响的池塘床裂缝分布的关键因素。具体而言，在明显干燥且缺乏丝状绿藻和以PET为主的塑料垃圾的区域，裂缝占主导地位。在受塑料影响的池塘床2.5米的湿度梯度上，温度和湿度显著影响养分，尤其是在明显干燥的区域。实验室实验表明，微塑料改变了天然粘土的结构特性，降低了含水量，同时提高了干密度和承载能力。塑料生命周期强调了工业和消费行为、环境条件以及废物管理和回收效率低下在推动人类改造生态系统环境变化方面的作用。研究结果强调了有效管理和回收塑料垃圾以减轻塑料污染对生态系统生态影响的必要性。
