Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China.
Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; State Environmental Protection Key Laboratory of Monitoring for Heavy Metal Pollutants, Changsha, 410082, PR China.
Chemosphere. 2022 Jan;286(Pt 2):131777. doi: 10.1016/j.chemosphere.2021.131777. Epub 2021 Aug 4.
Plastic discharged into the environment would break down into microplastics (MPs). However, the possible impact of MPs on heavy metals in the aquatic sediment remains unknown. In order to evaluate the potential role of MPs as carriers of coexisting pollutants, the adsorption capacity of lead ions from sediment onto aged degradable and conventional MPs were investigated as a function of lead ions concentration, contact time, temperature, MPs dosage, aging time, and fulvic acid concentration. MPs were exposed to UV to obtain aged polyethylene (A-PE) and aged polylactic acid (A-PLA). The aging treatment increased the oxygen content, specific surface area and hydrophilicity of MPs. The adsorption capacity of A-PE for Pb(II) in sediment increased from 10.1525 to 10.4642 mg g with the increasing aging time. However, the adsorption capacity of A-PLA for Pb(II) in sediment decreased from 9.3199 to 8.7231 mg g with the increasing aging time. The adsorption capacity of MPs in sediment for Pb(II) was in the following order: A-PE > PLA > PE > A-PLA. Fulvic acid could promote the adsorption of Pb(II) by MPs in sediment. These results indicated that the aging process of the plastics in the environment would affect its role as a carrier of coexisting pollutants.
塑料排入环境后会分解成微塑料 (MPs)。然而， MPs 对水生生境中重金属的潜在影响尚不清楚。为了评估 MPs 作为共存污染物载体的潜在作用，研究了老化可降解和传统 MPs 从沉积物中吸附铅离子的能力，作为铅离子浓度、接触时间、温度、 MPs 用量、老化时间和富里酸浓度的函数。 MPs 暴露在紫外线下以获得老化的聚乙烯 (A-PE) 和老化的聚乳酸 (A-PLA)。老化处理增加了 MPs 的含氧量、比表面积和亲水性。 A-PE 对沉积物中 Pb(II) 的吸附能力从 10.1525 增加到 10.4642 mg g，随着老化时间的增加。然而， A-PLA 对沉积物中 Pb(II) 的吸附能力从 9.3199 降低到 8.7231 mg g，随着老化时间的增加。 MPs 在沉积物中对 Pb(II) 的吸附能力依次为：A-PE > PLA > PE > A-PLA。富里酸可以促进 MPs 从沉积物中吸附 Pb(II)。这些结果表明，环境中塑料的老化过程会影响其作为共存污染物载体的作用。
