预辐射接枝改性无纺布制备铯离子吸附材料

摘要

采用预辐射接枝聚合方法制备了4-羟基丁基丙烯酸酯缩水甘油醚(4HBAG)接枝的聚乙烯/聚丙烯(PE/PP)皮芯结构无纺布.用Na2SO3对接枝4HBAG的无纺布(PE/PP-g-4HBAG)进行开环反应,改性得到磺酸型吸附材料.在环氧基物质的量转化率52%时获得了磺酸基密度1.4 mmol/g的吸附材料.采用批次吸附和流动吸附对Cs+的吸附性能进行研究.Cs+的吸附等温线和吸附动力学表明,吸附过程遵循Langmuir等温线模型和准二级动力学模型.在1000 SV/h高流速下,Cs+的最大吸附容量为1.35 mmol/g.在pH=4~10时,吸附率稳定在90%左右,该值随pH值的增加而降低.在Cs+初始浓度为1 mg/L和10 mg/L的溶液中研究了Na+对Cs+吸附率的影响,当Na+浓度从0增加到20 mmol/L时,Cs+的吸附率迅速降低.二价和三价金属离子Mg2+、Ca2+和Fe3+对Cs+吸附更具有阻碍作用.该磺酸型吸附材料在1000 SV/h的高流速下能快速去除Cs+.%Sulfonic-type adsorbent was prepared from radiation-induced graft polymerization of 4-hydroxybutyl acrylate glycidylether (4HBAG) on PE/PP non-woven fabric. Sulfonation of the 4HBAG grafted PE/PP non-woven fabric was carried out in a mixed solution of Na2SO3. The process of sulfonation was investigated by the morphology and weight of the material. A sulfonic group density of 1.4 mmol/g adsorbent with a 52% molar conversion of the epoxy group was obtained. The adsorption behavior of cesium was studied with batch and column model. The sorption isotherm and sorption kinetics of cesium indicated that the adsorption process followed the Langmuir isotherm model and pseudo second-order kinetic model. The maximum adsorption capacity of cesium was evaluated as 1.35 mmol/g at a high flow rate of 1000 SV/h. In the range of pH=4~10, the adsorption ratio remained stable at approximately 90%, and the value decreased with further increments of pH value. The effect of Na+ on the removal ratio of Cs+ was studied in its 1 mg/L and 10 mg/L solution. The removal ratio of Cs+ decreased quickly when the Na+ concentration increased from 0 to 20 mmol/L. Compared with the effects of Na+ and K+, bivalent ions such as Mg2+ and Ca2+and the trivalent metal ion Fe3+ were found to be more impeditive to Cs+ adsorption. This sulfonic-type adsorbent exhibited the extremely rapid removal of Cs+ with a high flow rate of 1000SV/h.