Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Analytical and Testing Center, Guangdong Ocean University, Zhanjiang, 524088, China.
Environ Pollut. 2023 Apr 1;322:121158. doi: 10.1016/j.envpol.2023.121158. Epub 2023 Jan 27.
In recent years, microplastics (MPs) as emerging carriers for environmental pollutants have attracted increasing worldwide attention. However, the adsorption of heavy metals on MPs, especially for biodegradable MPs, has been still poorly understood in estuarine environments. In this study, we investigated the aging of biodegradable and conventional MPs in the Pearl River Estuary after long-term exposure and their impacts on the adsorption of heavy metals from seawater. The results showed that the changes in surface characteristics were more prominent on biodegradable MPs than on conventional MPs after aging. Both biodegradable and conventional MPs could adsorb heavy metals, and their adsorption capacities fluctuated greatly on different MPs and different exposure times. The adsorption capacities of Cu, Pb, and As on biodegradable MPs were higher than those on conventional MPs, whereas Mn, Cr, and Co had lower adsorption on biodegradable MPs after 9-12 months by inductively coupled plasma-mass spectrometry (ICP-MS). The aging characteristics (CI, O/C, and X) of MPs accounted for a contribution of 51.0% on heavy metal adsorption, while the environmental factors (temperature, salinity, pH, and heavy metal concentration) only contributed to 13.2%. Therefore, the present study can provide important evidence on the environmental behaviors and ecological risks of biodegradable and conventional MPs in estuarine systems.
近年来，作为环境污染物新兴载体的微塑料（MPs）引起了全世界越来越多的关注。然而，在河口环境中， MPs 对重金属的吸附作用，特别是可生物降解 MPs 对重金属的吸附作用，仍了解甚少。本研究调查了珠江口长期暴露后可生物降解和常规 MPs 的老化及其对海水重金属吸附的影响。结果表明，老化后可生物降解 MPs 的表面特征变化比常规 MPs 更为明显。可生物降解和常规 MPs 均可吸附重金属，其吸附能力在不同 MPs 和不同暴露时间上波动很大。与常规 MPs 相比，可生物降解 MPs 对 Cu、Pb 和 As 的吸附能力更高，而 9-12 个月后 ICP-MS 分析表明，Mn、Cr 和 Co 在可生物降解 MPs 上的吸附能力较低。 MPs 的老化特征（CI、O/C 和 X）对重金属吸附的贡献为 51.0%，而环境因素（温度、盐度、pH 和重金属浓度）仅贡献 13.2%。因此，本研究可为河口系统中可生物降解和常规 MPs 的环境行为和生态风险提供重要证据。
