1、Eco-EnvironmentalKnowledge Web环 境 科 学Environmental Science第44卷第4期 2023年4月Vol44,No4 Apr,2023典型雌激素在微塑料上的吸附特征及位点能量分布刘姜艳1,2,郑密密1,2,胡嘉梧2,柳王荣2,贺德春2*,潘杰1*(1 重庆三峡学院环境与化学工程学院,重庆404000;2 生态环境部华南环境科学研究所,广州510530)摘要:微塑料(MPs)和雌激素是目前备受关注的新型污染物,MPs 可作为环境中雌激素的载体而产生复合污染 为了解聚乙烯(PE)为代表的 MPs 对典型雌激素的吸附特性,采用批平衡吸附实验法,借助 X
2、 射线光电子能谱(XPS)和傅里叶红外光谱(FTI)等研究不同体系下 PE 对 6 种典型雌激素的吸附行为和位点能量分布情况 结果表明,在不同初始浓度(100 g L1和1000 g L1),PE 对目标雌激素的吸附过程更符合准二级动力学模型,初始浓度的增加会影响吸附平衡时间和雌激素吸附量占比 在单一体系(单一雌激素)和复合体系(6 种雌激素共存)中,雌激素在 PE 上的吸附更符合 Freundlich 模型(20.94)等温吸附实验结果及 XPS 和 FTI 表征结果表明,吸附过程主要受范德华力和疏水分配作用影响;单一己烯雌酚(DES)体系中出现的 COC 官能团和单一炔雌醇(17-EE2)
3、体系中出现的 COC 及 O=CO 官能团,表明化学键合作用对合成雌激素在 MPs 上的吸附有一定的影响,而对天然雌激素基本没有影响 与单一体系相比,复合体系中各雌激素的吸附位点能量整体向高位能区偏移,位点能量增加了 2.15%40.98%,其中,己烯雌酚(DES)的位点能量变化最为显著,说明其在复合体系中具有竞争优势 以上研究结果可以为有机污染物和微塑料共存情况下的吸附行为、作用机制和环境风险研究提供参考关键词:聚乙烯(PE);雌激素;吸附;位点能量;微塑料(MPs)中图分类号:X131文献标识码:A文章编号:0250-3301(2023)04-2158-10DOI:1013227/j hj
4、kx202205050收稿日期:2022-05-06;修订日期:2022-07-11基金项目:广州市基础研究计划项目(PM-zx913-202204-137);国家自然科学基金青年科学基金项目(42107437)作者简介:刘姜艳(1998 ),女,硕士研究生,主要研究方向为新型污染物控制技术,E-mail:liujiangyan114163 com*通信作者,E-mail:hedechun scies org;18116901 qq comSorption Characteristics and Site Energy Distribution Theory of Typical Estrog
5、ens onMicroplasticsLIU Jiang-yan1,2,ZHENG Mi-mi1,2,HU Jia-wu2,LIU Wang-rong2,HE De-chun2*,PAN Jie1*(1 College of Environmental and Chemical Engineering,Chongqing Three Gorges University,Chongqing 404000,China;2 South China Institute of Environmental Sciences,Ministry of Ecology and Environment,Guang
6、zhou 510530,China)Abstract:Microplastics(MPs)and estrogens are high-profile emerging contaminants at present,and MPs might become the carrier of estrogens in the environment and inducecombined pollution To study the adsorption behavior of polyethylene(PE)microplastics to typical estrogens,the adsorp
7、tion isothermal properties of the six estrogensestrone(E1),17-estradiol(17-E2),17-estradiol(17-E2),estriol(E3),diethylstilbestrol(DES),and ethinylestradiol(17-EE2)in single-solute and mixed-solutesystems were studied through batch equilibrium adsorption experiments,in which the PE microplastics befo
8、re and after adsorption were characterized by X-ray photoelectronspectroscopy(XPS)and Fourier transform infrared spectroscopy(FTI)Then,the site energy distribution theory of the adsorption of six estrogens on PE microplastics wasfurther analyzed based on the Freundlich model The results showed that
9、the adsorption process of selected estrogens with two concentrations(100 g L1and 1 000g L1)on PE were more consistent with the pseudo-second order kinetic model The increase in initial concentration reduced the equilibrium time of adsorption andincreased the adsorbing capacity of estrogens on PE In
10、the single system(one estrogen)or mixed system(six estrogens)with different concentrations(10 g L1-2 000g L1),the Freundlich model showed the best fitting effect for the adsorption isotherm data(20.94)The results of isothermal adsorption experiments and XPS andFTI spectra showed that the adsorption
11、of estrogens on PE in the two systems was heterogeneous adsorption,and hydrophobic distribution and van der Waals forces were theprincipal factors in the process of adsorption The occurrence of COC(in only the DES and 17-EE2 systems)and O=CO(in only the 17-EE2 system)indicatedthat the adsorption of
12、synthetic estrogens on PE was affected slightly by chemical bonding function,but no obvious effects were observed for natural estrogens The results of siteenergy distribution analysis showed that,compared with the single system,the adsorption site energy of each estrogen shifted to the high-energy r
13、egion in its entirety in themixed system,and the site energy increased by 2.15%-40.98%The energy change in DES was the most significant among all of the estrogens,indicating its competitiveadvantage in the mixed system The above results of this study can provide some reference for the study of adsor
14、ption behavior,mechanism of action,and environmental risksunder the coexisting condition of organic pollutants and MPsKey words:polyethylene(PE);estrogens;adsorption;energy distribution;microplastics(MPs)微塑料(microplastics,MPs)和雌激素均是近年来备受关注的新型污染物1 MPs 是指粒径 5 mm的塑料颗粒2,有研究发现其在水体3 5 和土壤6 等环境介质中已普遍存在 MPs
15、 进入动物体内后,会造成胃肠道堵塞而减少进食7、引发炎症8 和影响生长发育9 等危害 雌激素是由内分泌系统产生的一种环境内分泌干扰物(environmental endocrinedisrupting chemicals,EDCs)10,11,已在土壤、河道和地下水等环境介质中广泛检出12,13 研究表明环境中的雌激素仅在ng L1水平就会干扰生物体内分泌系统14 18,对生物体的生殖系统功能和正常性分化产生影响19 21,同时还会致癌致突变11 MPs 因其粒径小、比表面积大和疏水性强等特性,使有机污染物很容易吸附在 MPs 上22 有研究发现 MPs 是4 期刘姜艳等:典型雌激素在微塑料上
16、的吸附特征及位点能量分布海洋环境中双酚 A(BPA)的潜在汇和迁移媒介23 Liu 等24 研究表明,雌二醇(E2)在不同 MPs 上的吸附能力有明显差异,蒋晖等25 研究证实了 17-EE2和 BPA 在聚酰胺树脂(PA)上存在一定的竞争吸附,且 17-EE2 处于竞争优势位 Wu 等26 研究发现,PE 对 17-EE2 的吸附能力与 17-EE2 自身的疏水性有关目前关于 MPs 对雌激素的吸附行为研究,大多是研究单一雌激素体系下微塑料对其的吸附解吸行为,而环境中 MPs 与多种雌激素共存的现象较为普遍,因此,研究多种雌激素共存体系中 MPs 对其的吸附特性,对于科学评价雌激素在现实环境中的行为具有重要意义 本文研究了单一雌激素(单一体系)及多种雌激素共存(复合体系)情形下在典型微塑料(PE)上的吸附行为,并讨论在单一和复合体系下的竞争吸附及位点能量变化,以期为研究环境中有机污染物和微塑料共存情况下的吸附行为特征、作用机制和环境风险评价等提供参考1材料与方法1.1主要仪器和试剂主要仪器:Ulti Mate 3000 高效液相色谱仪(美国 Thermo);TSQ Vantage 三