目前,与塑料生产和废物相关的环境问题,例如世界范围内天然水域被微塑料污染的后果,已经导致寻求至少可以部分替代传统石油基塑料的替代材料。替代材料包括生物塑料和类似的基于植物的材料或其复合材料。然而,在非预期环境中处置时的命运(例如,水体)基本上是未知的,而在大规模开发这种材料之前,这种信息是非常需要的。本研究旨在填补这一知识空白。具体来说,19种不同类型的生物塑料和类似的基于植物的材料碎片(对应于微塑料的大小)与水长期接触,以模仿它们作为水污染物的行为,并对渗滤液进行了连续分析。19种研究材料中有18种释放出大量溶解的有机碳-浸出12周后,每克碎片最多34.0mg。每个渗滤液还包含以下元素中的一种或多种:Al,B,Ba,Ca,Fe,K,Mg,Mn,N,Na,P,Si,Ti,和Zn。非目标分析旨在提供对渗滤液成分的更具体了解,初步揭示了91种单独的化学物质,主要是脂肪酸和其他羧酸,邻苯二甲酸酯,对苯二甲酸酯,己二酸酯,酚类物质,酰胺,酒精,或有机磷酸酯。基于复合特性,它们可能是添加剂,非有意添加的物质,以及它们的降解产物。总的来说,目前的结果表明,生物塑料和类似的植物基材料应被视为复杂的材料,经过工业加工,并包含添加剂,而不是无害的天然物质。此外,当沉积在水中时,各种化合物可以从生物塑料和类似的基于植物的材料碎片中释放。这可能会对碳通量产生影响,金属和特定的有机污染物,它类似于传统石油基微塑料的一些特性。
Currently, the environmental problems associated with plastic production and waste, such as the consequences of worldwide pollution of natural waters with microplastics, have led to the seeking of alternative materials that can at least partially replace conventional petroleum-based plastics. Substitute materials include bioplastics and similar plant-based materials or their composites. However, their fate when disposed of in unintended environments (e.g., water bodies) remains largely unknown, while such information is highly desirable prior to massive expansion of exploiting such materials. This study aims to contribute filling this knowledge gap. Specifically, 19 different types of bioplastic and similar plant-based material debris (corresponding to the size of microplastics) were kept in long-term contact with water to mimic their behaviour as water pollutants, and the leachates were continuously analysed. Eighteen of the 19 investigated materials released significant amounts of dissolved organic carbon-up to 34.0 mg per g of debris after 12 weeks of leaching. Each leachate also contained one or more of the following elements: Al, B, Ba, Ca, Fe, K, Mg, Mn, N, Na, P, Si, Ti, and Zn. Non-targeted analysis aimed at providing more specific insight into the leachate composition tentatively revealed 91 individual chemicals, mostly fatty acids and other carboxylic acids, phthalates, terephthalates, adipates, phenols, amides, alcohols, or organophosphates. Based on the compound characteristics, they might be additives, non-intentionally added substances, as well as their degradation products. In general, the current results imply that bioplastics and similar plant-based materials should be considered complex materials that undergo industrial processing and comprise additives rather than harmless natural matter. Additionally, various compounds can release from the bioplastic and similar plant-based material debris when deposited in water. It might have consequences on the fluxes of carbon, metals and specific organic contaminants, and it resembles some properties of conventional petroleum-based microplastics.