木粉/壳聚糖接枝丙烯酸-丙烯酰胺吸附树脂对二元重金属离子溶液中Pb^(2+)的吸附

Selective adsorption of Pb^(2+) on wood flour/chitosan graft acrylic acid-acrylamide resins in two heavy metal ion solutions

采用自制木粉/壳聚糖接枝丙烯酸-丙烯酰胺吸附树脂R1、R2、R3对二元金属离子Cu2+/Pb2+和Zn2+/Pb2+溶液中的吸附性能进行了较系统考察。Pb2+离子溶液中存在竞争离子Cu2+、Zn2+时,随竞争离子浓度增加,3种吸附树脂R1、R2、R3对Pb2+的吸附量明显下降,而竞争离子吸附量显著增加。二元溶液中各金属离子浓度相同时,3种树脂对竞争离子Cu2+、Zn2+的吸附量大于对Pb2+的吸附量;各溶液中分别加入NaCl及NaNO3、尿素后,对Pb2+离子的吸附量下降迅速。随吸附树脂用量增加,竞争离子Cu2+、Zn2+的吸附量逐渐减小,Pb2+的吸附量在吸附树脂用量0.10 g/L(Zn2+/Pb2+溶液)或0.15 g/L(Cu2+/Pb2+溶液)时出现最大值。溶液pH值对树脂吸附性能有显著影响。3.0<pH<5.0时,3种树脂对竞争离子和Pb2+的吸附量快速增大;5<pH<9时,树脂对竞争离子和Pb2+的吸附量基本不变;9<pH<11时,树脂对Pb2+的吸附量减小,而对竞争离子的吸附量或增大或减小。

The adsorption properties of three self-made wood flour/chitosan graft acrylic acid-acrylamide copolymerization resins（note as adsorbing resin R1,R2 and R3） were explored in detail for two metal ions,Cu2＋/Pb2＋ and Zn2＋/Pb2＋ mixing solutions.While there were the competitive ions Cu2＋ and Zn2＋ in Pb2＋ solutions,the adsorption capacities of Pb2＋ for three adsorption resins R1,R2 and R3 decreased obviously and those of the competitive ions Cu2＋ and Zn2＋ increased fastly with an increase of the concentrations of Cu2＋ and Zn2＋.The adsorption capacities of the competitive ions Cu2＋ and Zn2＋ were larger than those of Pb2＋ when the concentration of each metal ions was equal in two metal ion solutions and those of Pb2＋ decreased after NaCl,NaNO3 and urea were added into the metal ion Zn2＋/Pb2＋ or Cu2＋/Pb2＋ solution.When the masses（usage） of the adsorbing resins increased,the adsorption capacities of the competitive ions Cu2＋ and Zn2＋ decreased gradually while those of Pb2＋ had a maximum at the mass concentration 0.10 g/L for Zn2＋/Pb2＋ solution or 0.15 g/L for Cu2＋/Pb2＋ solution with an increase of the usage of three types of the adsorption resins.The pH values of the Zn2＋/Pb2＋ or Cu2＋/Pb2＋ solution had an obvious effect on the adsorption properties of three resins R1,R2 and R3.The adsorption capacities of Cu2＋,Zn2＋ and Pb2＋ for three resins R1,R2 and R3 increased quickly when the pH value was between 3 and 5,and these hardly changed when the pH value was between 5 and 9,while the adsorption capacities of Pb2＋ for three resins R1,R2 and R3 decreased,and these of Cu2＋ and Zn2＋ for three resins R1,R2 and R3 either increased or decreased when the pH value was between 9 and 11.