聚氯乙烯和橡胶中化学成分的浸出行为及生态毒性

为探究塑料中化学成分的浸出行为及其生态毒性,以环境中广泛存在的聚氯乙烯(PVC)和橡胶(CTR)为研究对象,筛选25种有机塑化剂和15种金属作为目标物质,分析其在PVC和CTR材料中的浸出潜能,利用大型溞的急性致死效应和慢性亚致死效应(心率、胸肢跳动和游泳活性)表征了PVC和CTR浸出液的生态毒性效应。结果表明,PVC和CTR浸出液中共检出21种化学成分,其中邻苯二甲酸二异丁酯(DiBP)、邻苯二甲酸二(2-甲氧基)乙酯(DMEP)、双酚A(BPA)、双酚F(BPF)、Ca和Zn的浸出浓度较高。CTR中浸出的塑化剂和金属总浓度分别是PVC的8.8倍和1.2倍,且CTR中浸出的新型塑化剂BPF浓度达到3.51μg/g,显著高于BPA的浸出浓度。对比不同条件下浸出的物质量差异,发现光照能够加速PVC和CTR中DiBP、Zn和Ca等物质的释放,其赋存状态还受到细菌作用的干扰。CTR浸出液对大型溞的急性致死效应明显,48h半数致死浓度(LC₅₀)为浸出原液的19.1%。慢性暴露条件下,PVC浸出液对大型溞心率、胸肢跳动和游泳活性产生明显抑制作用,并造成大型溞肢体肥大。PVC和CTR等塑料颗粒不断排放,并在环境中累积,其生物毒害效应不容忽视。

Leaching behavior and ecotoxicity of chemical composition in polyvinyl chloride and rubber

To investigate the leaching behavior and ecotoxicity of chemical composition in plastics, polyvinyl chloride (PVC) and rubber (CTR) widely existed in the environment were selected as the subjects of the study. Leaching potential of 25 organic plasticizers and 15 metals as the target substances were analyzed for PVC and CTR materials. The acute lethal effects and chronic sublethal effects (heart rate, thoracic limb activity and swimming activity) of Daphnia magna were used to characterize the ecotoxicological effects of PVC and CTR leachates. The results showed that 21 chemical compositions were detected in PVC and CTR leachates, with higher leaching concentrations of diisobutyl phthalate (DiBP), di (2-methoxy) ethyl phthalate (DMEP), bisphenol A (BPA), bisphenol F (BPF), Ca and Zn. The total concentrations of plasticizers and metals leached from CTR were 8.8 times and 1.2 times higher than those from PVC, respectively. The concentration of the new plasticizer BPF leached from CTR reached 3.51μg/g, which was significantly higher than that of BPA. Comparing the concentration of substances leached under different conditions, it was found that light can accelerate the release of DiBP, Zn and Ca from PVC and CTR, and their occurrence characteristics were affected by bacteria. Acute toxicity of CTR leachate to Daphnia magna is obvious, with the 48h-LC₅₀ of 19.1% of the leaching solution. For chronic toxicity, the PVC leachate significantly inhibited the heart rate, thoracic limb activity and swimming activity of Daphnia magna, and caused body hypertrophy of Daphnia magna. The biological toxic effects caused by the continuous discharge of PVC and CTR in the aquatic environment should not be ignored.