磺酸基树脂对铜、铅、镉离子的吸附行为

The Adsorption Behavior of Sulfonate Resin to Copper,Lead and Cadmium Ions

微塑料降解缓慢,由于部分塑料带有特殊基团,会对重金属离子产生吸附作用。一旦微塑料被摄入人体,重金属离子会重新释放,危及人的健康。基于微塑料常见骨架组成中的PS(聚苯乙烯),及常在塑料中出现的官能团磺酸根,选择骨架结构为苯乙烯-二乙烯苯共聚的D101和S001(Seplite 001X7,含有磺酸根基团)为研究对象,初步模拟考察微塑料及其中的磺酸根基团对水体中铜、铅、镉离子的吸附行为。结果表明:通过对比D101和S001的吸附效果,聚苯乙烯-二乙烯苯骨架不吸附铜、铅、镉离子,磺酸根的存在是吸附铜、铅、镉离子的根本原因。水体动力混合效果是影响三种重金属离子吸附速率的最主要因素,当采用搅拌的方式获得良好水体混合效果时,5 h内可达到吸附平衡。与搅拌相比,升温对吸附速率的提升和平衡吸附量的改变不显著。Na+的存在削弱了铜、铅、镉离子与磺酸根之间的静电吸引作用,进而大幅抑制S001对三种重金属离子的吸附。离子交换是S001吸附铜、铅、镉离子的作用机制。对于研究微塑料在水体中吸附重金属离子的性能具有很好的借鉴意义。

Microplastics have a characteristic of slow degradation.They can adsorb heavy metal ions because of special functional groups.When ingested into human body,these ions would be released again,and endanger human’s health.On the basis of common skeleton composition of microplastics,PS(polystyrene)and common functional group,sulfonate,D101 and S001(Seplite 001X7,with sulfonate groups)resins with skeleton of polystyrene-divinylbenzene were selected as research objects.The adsorption behavior of copper,lead and cadmium ions in aqueous solution by microplastics and its sulfonate groups were preliminary stimulated studied.Results show that the skeleton polystyrene-divinylbenzene do not adsorb copper,lead and cadmium ions by comparing the adsorption effects of D101 and S001.The dynamic mixing effect of solution is the most important factor affecting the adsorption rate of the three heavy metal ions.When using agitation to obtain good mixing effect,adsorption equilibrium can be obtained within 5 h.However,compared with stirring,the acceleration and equilibrium capacity of adsorption process influenced by heating is not obvious.The existence of Na+weakens the electrostatic attraction between copper,lead,cadmium ions and sulfonate,then inhibiting the adsorption of these three heavy metal ions by S001.Ion exchange is attributed to the mechanism by which S001 adsorb copper,lead and cadmium ions.This work has a good reference meaning for studying the adsorption performance of microplastics in adsorbing heavy metal ions in water.