聚丙烯腈纤维改性条件优化及其对模拟电镀废水的净化作用

为了寻求低价、环保的电镀废水处理方案,将廉价的聚丙烯腈(PAN)纤维与羟胺试剂反应对PAN纤维进行改性,使其上氰基螯合获得偕胺肟基纤维。通过改变各种改性条件,探讨了改性条件对PAN改性纤维在重金属单离子溶液和多离子混合溶液中吸附性能的影响。结果表明:最佳改性条件为21.2 g/L PAN纤维,27.0 g/L盐酸羟胺,pH值为7.0,70℃下反应2 h;改性PAN纤维对模拟电镀废水中的Cu2+,Zn2+,Ni2+,Pb2+,Cd2+等重金属离子均有较好吸附性能,其中对Cd2+吸附效果最好,吸附量为55 mg/g;在多离子混合溶液中优先选择吸附Cd2+;改性PAN纤维再生效果优良,可重复利用。

Adsorption Behavior of Modified Polyacrylonitrile Fiber for Heavy Metallic Ions in Simulated Electroplating Wastewater

Inexpensive polyacrylonitrile(PAN) fiber was allowed to react with hydroxylamine agent,realizing modification of PAN fiber via cyano chelating to form amidoxime-group fiber.The effect of modification conditions on the adsorption behavior of modified PAN fiber for single heavy metallic ions or mixed heavy metallic ions in aqueous solution was investigated.It was found that the optimized reactant system consisted of 21.2 g/L modified PAN fiber and 27.0 g/L hydroxylamine chloride.The optimal reaction conditions were determined as pH=7.0,temperature of 70 ℃ and reaction for 2 h.The modified PAN fiber had good adsorption capacity for heavy metallic ions including Cu 2+,Zn 2+,Ni 2+,Pb 2+ and Cd 2+ in simulated electroplating wastewater.Particularly,it possessed the best adsorption capability for Cd 2+,showing an adsorption capacity of 55 mg/g.In the aqueous solution containing several mixed metallic ions,it preferentially adsorbed Cd 2+.As-prepared modified PAN fiber could be well recycled.