Fan Xiulei, Zou Yefeng, Geng Nan, Liu Jiaqiang, Hou Jun, Li Dandan, Yang Chengfang, Li Ying
Key Laboratory of Industrial Pollution Control and Resource Reuse of Jiangsu Province, College of Environmental Engineering, Xuzhou University of Technology, Xuzhou, 221018, China.
Key Laboratory of Industrial Pollution Control and Resource Reuse of Jiangsu Province, College of Environmental Engineering, Xuzhou University of Technology, Xuzhou, 221018, China.
J Hazard Mater. 2021 Jan 5;401:123363. doi: 10.1016/j.jhazmat.2020.123363. Epub 2020 Jul 2.
To assess the potential vector effects of degradable MPs (microplastics) on the coexisting pollutant, the adsorption-desorption behaviors of tetracycline (TC) and ciprofloxacin (CIP) by the original and aged polylactic acid (PLA) was investigated. Compared with PVC, the physicochemical properties of PLA changed more observably during the UV ageing. The original smooth surface of PLA appeared holes and cracks, and the S of PLA increased a 2.66-fold after the aging experiments. During the ageing processes, the hydrophily of aged MPs was also enhanced due to the increase of oxygen-containing functional groups. And the zeta potential of PLA decreased from -7.79 to -13.51 mV and PVC from -4.96 to -8.34 mV, respectively. In adsorption experiment, both the original and aged PLA showed better vector effects for antibiotics than PVC. The ageing factor increased the adsorption capacity of antibiotics on PLA 1.18-2.19 times. The desorption experiments showed that the desorption amount of antibiotics on MPs in simulated intestinal fluid was greater than that in Milli-Q water. On this basis, the desorption capacity of antibiotics with PLA was better than that of PVC, which proved that the potential negative impact of PLA on the aquatic environment and organisms might be more serious.
为评估可降解微塑料（MPs）对共存污染物的潜在载体效应，研究了四环素（TC）和环丙沙星（CIP）在原始及老化聚乳酸（PLA）上的吸附-解吸行为。与聚氯乙烯（PVC）相比，PLA的物理化学性质在紫外线老化过程中变化更为明显。PLA原本光滑的表面出现孔洞和裂缝，老化实验后PLA的比表面积（S）增加了2.66倍。在老化过程中，由于含氧官能团的增加，老化微塑料的亲水性也增强。PLA的zeta电位分别从-7.79 mV降至-13.51 mV，PVC的zeta电位从-4.96 mV降至-8.34 mV。在吸附实验中，原始及老化的PLA对抗生素均表现出比PVC更好的载体效应。老化因素使抗生素在PLA上的吸附容量提高了1.18至2.19倍。解吸实验表明，抗生素在模拟肠液中的解吸量大于在超纯水（Milli-Q水）中的解吸量。在此基础上，PLA对抗生素的解吸能力优于PVC，这证明PLA对水生环境和生物的潜在负面影响可能更严重。
