Abstract:
Plastics are now the dominant fraction of anthropogenic marine debris and as a result of their long residence times, it is important to determine the threats that plastics present to marine ecosystems including their ability to sorb a diversity of environmental pollutants such as trace metals. To address this knowledge gap, this study examined the sorption of cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn) by macro- and microplastics of polyethylene terephthalate (PETE) and high-density polyethylene (HDPE) within marine intertidal sediments in a human-impacted area of Burrard Inlet (British Columbia, Canada). Trace metal sorption by macro- and microplastics was dependent on 1) polymer characteristics, notably the aging of the plastic over the duration of the field experiment as shown by the formation of new peaks via FTIR spectra; and 2) amounts of sediment organic matter, where the sorption of trace metals by the plastic particles decreased with increasing organic matter content (from 2.8 % to 15.8 %). Plastic particles play a minor role in trace metals sorption in the presence of organic matter at high concentrations as a result of competitive adsorption. Overall, the interaction of trace metals with sediment plastics was highly dynamic and to understand the key processes controlling this dynamic requires further study. This work contributed to our understanding on metal-plastic interactions in coastal intertidal sediments from urban environments and serve to support plastic pollution risk management and bioremediation studies.
摘要:
塑料现在是人为海洋垃圾的主要部分,由于它们的停留时间长,重要的是要确定塑料对海洋生态系统的威胁,包括它们吸收各种环境污染物如痕量金属的能力。为了解决这个知识差距,这项研究检查了镉(Cd)的吸附,铜(Cu),汞(Hg),铅(Pb),和锌(Zn),由聚对苯二甲酸乙二醇酯(PETE)和高密度聚乙烯(HDPE)在海洋潮间带沉积物中的宏观和微塑料在BurrardInlet受人类影响的地区(不列颠哥伦比亚省,加拿大)。宏观和微塑料对痕量金属的吸附取决于1)聚合物特性,特别是在现场实验期间塑料的老化,如通过FTIR光谱形成新峰所示;和2)沉积物有机质的量,其中塑料颗粒对痕量金属的吸附随有机物含量的增加而减少(从2.8%增加到15.8%)。由于竞争性吸附,在高浓度有机物存在下,塑料颗粒在痕量金属吸附中起着次要作用。总的来说,痕量金属与沉积物塑料的相互作用是高度动态的,要了解控制这种动态的关键过程需要进一步研究。这项工作有助于我们了解城市环境中沿海潮间带沉积物中的金属-塑料相互作用,并有助于支持塑料污染风险管理和生物修复研究。