新型吡啶基螯合树脂选择性分离强酸高铁溶液中镍钴的特性与机制  

SEPARATION PROPERTIES OF NICKEL AND COBALT FROM STRONG-ACIDIC AND FERROUS WASTEWATER BY A NOVEL PYRIDINE CHELATING RESIN

作　　者：凌晨[1] 刘福强[1] 宗黎丹 刘自成 李爱民[1] LING Chen;LIU Fuqiang;ZONG Lidan;LIU Zicheng;LI Aimin(State Key Laboratary of Pollution Control and Resource,School of the Environment Nanjing University,Nanjing 210023,China)

机构地区：[1]南京大学环境学院,污染控制与资源化研究国家重点实验室,南京210046

出　　处：《离子交换与吸附》2018年第5期390-400,共11页Ion Exchange and Adsorption

基　　金：国家自然科学基金(No.51878334,51708281).

摘　　要：本文以pH 2的Ni(Ⅱ)/Co(Ⅱ)/Fe(Ⅱ)混合溶液(摩尔比1:1:10)模拟酸洗废水,研究自合成新型吡啶基螯合树脂(PABPY)对Ni(Ⅱ)/Co(Ⅱ)的静态和动态分离特性。PABPY对Ni(Ⅱ)的吸附量高达1.0mmol/g,而对Co(Ⅱ)和Fe(Ⅱ)的吸附量小于0.2mmol/g,镍钴分离系数高达51.79,较国外商用吡啶基螯合树脂或其他类型螯合树脂提高了187%以上。Ni(Ⅱ)的吸附基本不受Co(Ⅱ)影响,而且显著抑制Co(Ⅱ)的吸附。双组分吸附动力学证明Ni(Ⅱ)的吸附量随着吸附时间的增加而增加,而Co(Ⅱ)的吸附量则先增加后降低,其主导机制是吡啶基与Ni(Ⅱ)具有更强的亲合力,表现出Ni(Ⅱ)对Co(Ⅱ)的替代效应。动态吸附实验表明,降低流速可提高PABPY对强酸高铁溶液中Ni(Ⅱ)/Co(Ⅱ)的分离效果。在优选的2.5BV/h流速下,前135BV出水中钴的纯度高达99.0%以上,进一步证明了PABPY适用于酸洗废水中典型重金属的分离提纯。Pickling wastewater was strongly acidic and contains various toxic metal ions and high concentration of Fe(Ⅱ). The separation properties of Ni(Ⅱ) and Co(Ⅱ) from a simulated pickling wastewater [the mixture solution with 1:1:10 mole ratio of Ni(Ⅱ)/Co(Ⅱ)/Fe(Ⅱ) and pH of 2.0] using a self-synthesized bi-pyridine resin(PABPY) were investigated with static and dynamic binary adsorption studies. In the same strong-acidic and ferrous system, the adsorption amounts of Ni(Ⅱ) onto PABPY was 1.0 mmol/g, while those of Co(Ⅱ) and Fe(Ⅱ) were lower than0.2 mmol/g. The separation coefficient of Ni(Ⅱ) and Co(Ⅱ) reached 51.79 which were much higher(>187%) than the counterparts of the commercial pyridine resins and other resins. The adsorption of Ni(Ⅱ) onto PABPY was little affected by Co(Ⅱ) while Ni(Ⅱ) markedly inhibited Co(Ⅱ) adsorption. With the increase of adsorption time, the loading of Ni(Ⅱ) onto PABPY increased, while the adsorption of Co(Ⅱ) increased first then reduced. The selective adsorption of Ni(Ⅱ) was attributed to higher affinity of Ni(Ⅱ) than Co(Ⅱ) toward pyridine group. Part of preloaded Co(Ⅱ) could be replaced by Ni(Ⅱ). Dynamic studies showed that reducing the flow rates could enhance the separation efficiencies of Ni(Ⅱ) and Co(Ⅱ) by PABPY in the strong-acidic and ferrous system. Under the 2.5 BV/h flow rate, the purity of Co(Ⅱ) was up to99.0% in the former 200 BV. The results show that PABPY could be potentially applied in the separation and purification of heavy metal resources from pickling wastewater.

关 键 词：吡啶基螯合树脂 强酸 高铁 重金属离子 分离特性 

分 类 号：TQ085[化学工程]