铅离子印迹聚合物对Pb2+的选择性吸附研究

Adsorption and Recognition Performance of Lead Ion imprinted Micro beads

摘要:

针对日益严重的水体重金属污染及工业废水处理问题，利用一种由1,12十二烷O,O′二苯基磷酸（DDDPA）和4 乙烯基吡啶作为双功能单体得到新型铅离子印迹聚合物微球，对其吸附及识别性能展开研究，结果表明，铅离子印迹聚合物微球对水中Pb2+有着良好的吸附性能，当溶液pH> 5时，就能保持很高的吸附效率.选择性吸附试验研究发现，当共存金属阳离子为Zn2+，Co2+，Ni2+时，铅离子印迹聚合物微球对目标Pb2+的选择性较好，试验条件下的选择吸附系数分别为86.6，53.0和46.5;铅离子印迹聚合物对Cr3+和Cu2+具有一定的吸附能力，试验条件下的选择吸附系数分别为20.8和9.5.对铅离子印迹聚合物微球的洗脱试验结果表明，洗脱含微量Pb2+的吸附剂时使用低浓度的HNO3就能达到100%脱附.经HNO3脱附后的吸附剂对水中Pb2+的单位饱和吸附量仍然可达90.9 mg·g-1，为吸附剂的重复使用提供了依据.

Abstract:

As to the problem of the heavy metal pollution in the water environment and the wastewater treatment, a lead ion imprinted micro beads, with two functional monomers 1,12 dodecanediol o,o’ diphenyl phosphonic acid(DDDPA) and 4 vinylpyridine, were synthesized. Its adsorption and recognition performance were investigated. The lead ion imprinted micro beads were efficient for lead ions removal from the aqueous solutions in a broad pH range (pH> 5). In the presence of competitive ions Zn2+, Co2+, Ni2+, it shows a high selectivity for lead ions. The selectivity coefficient of Pb2+/Zn2+, Pb2+/Co2+ and Pb2+/Ni2+ are 86.6, 53.0 and 46.5, respectively. Meanwhile it shows a certain adsorption capacity for Cr3+ and Cu2+, the selectivity coefficient of Pb2+/ Cr3+ and Pb2+/ Cu2+ are 20.8 and 9.5, respectively. The desorption experiments indicate that the lower concentration of nitric acid has almost 100% removal efficiency for the low quantity of lead ions. After the recycle of adsorption desorption experiment, the lead ion imprinted polymer still shows a high adsorption capacity of 90.9 mg·g-1.