SiO_(2)@松香基阳离子交换树脂对水中微量Cd吸附

Study on adsorption of trace of Cd^(2+) in water with SiO_(2)@rosin-based cationic exchange resin

以硅胶为核,马来海松酸丙烯酸乙二醇酯和甲基丙烯酸为功能单体,采用涂覆悬浮聚合法合成了核壳型SiO_(2)@松香基阳离子交换树脂(SiO_(2)@RCER),研究了其对水中微量Cd^(2+)的静态吸附性能。结果表明,在Cd^(2+)溶液浓度为0.5 mg·L^(-1),pH=6.0,温度为303 K,吸附剂用量为10 g·L^(-1)时,Cd^(2+)去除率可达到100%;SiO_(2)@RCER对Cd^(2+)的吸附符合准二级动力学方程以及Langmuir吸附等温线,表明吸附过程为单分子层化学吸附。吸附前后材料的XPS图谱表明:SiO_(2)@RCER对Cd^(2+)吸附主要涉及Na^(+)以及溶液中的Cd^(2+)的阳离子交换。该吸附剂在对Cd^(2+)、Pb^(2+)浓度超标的矿区废水吸附处理后,高毒重金属浓度均达到国家生活饮用水水源水质一级标准(CJ3020-93),其他离子浓度也有所降低。

The adsorption behavior of the core-shell silica@rosin-based cationic exchange resin for Cd^(2+) was studied.The core-shell SiO_(2)@rosin-based cationic exchange resin(SiO_(2)@RCER)was synthesized from glycol maleated rosinate modified acrylic acid and methacrylic acid as functional monomer by coating-suspension polymerization method.The results show that when the concentration of Cd^(2+) is 0.5 mg·L^(-1),the solution pH=6.0,the temperature is 303 K and the amount of adsorbent is 10 g·L^(-1),the Cd^(2+)removal rate can reach 100%.The adsorption of Cd^(2+) by SiO_(2)@RCER conforms to the Pseudo-second-order kinetic model and Langmuir adsorption isotherm,indicating that the adsorption process is monolayer chemisorption.The XPS characterization of the materials before and after adsorption show that the adsorption of Cd^(2+) by SiO_(2)@RCER which is mainly related to the cation exchange of Na^(+)in SiO_(2)@RCER and Cd^(2+) in solution.After the adsorption of the adsorbent on the mining wastewater with Cd^(2+) and Pb^(2+) exceeding the standard,the concentrations of highly toxic heavy metals all reached the national standard of water quality of drinking water sources(CJ3020-93),and the concentration of other ions also decreased.