乌贼墨黑色素对Pb2+-Cu2+二元体系的吸附性能研究

为探索新型生物吸附剂,以乌贼墨黑色素（SIM）为吸附剂,研究Pb²⁺、Cu²⁺单组分溶液及Pb²⁺-Cu²⁺二元混合体系中SIM对Pb²⁺和Cu²⁺的吸附效果并构建等温吸附模型.结果表明,pH值、SIM添加量、吸附时间对SIM吸附Pb²⁺和Cu²⁺的吸附量影响较大,而吸附温度对吸附效果影响较小;单组分吸附与二元混合体系吸附对比表明,二元混合体系中Pb²⁺和Cu²⁺存在竞争吸附.应用L （Langmuir）和F （Freundlich）等温吸附模型拟合了SIM对Pb²⁺、Cu²⁺单组分金属离子的吸附过程,其中L模型与试验结果拟合度更高;应用Non-modified Langmuir、Modified Langmuir isotherm、Extended Langmuir、Extended Freundlich和SRS模型5种模型对Pb²⁺-Cu²⁺二元混合体系的等温吸附过程进行拟合,其中Extended Langmuir模型与试验结果拟合度最佳.应用红外光谱（FTIR）分析SIM吸附金属离子的原理时发现,SIM上羟基、-NH和不饱和键是金属离子的吸附位点,且SIM对Pb²⁺的吸附能力优于对Cu²⁺的吸附.

Adsorption performance of squid ink melanin (SIM) on Pb2+-Cu2+ binary system

Squid ink melanin (SIM) was used as a new biological adsorbent to investigate absorptive efficiency of SIM to Lead ions (Pb²⁺) and copper ions (Cu²⁺) from mono-component aqueous solution(Pb²⁺、Cu²⁺) and binary solution (Pb²⁺-Cu²⁺), and the isothermal adsorption model was established. The results indicated that the effects of pH, SIM addition and adsorption time on the adsorption of Pb²⁺ and Cu²⁺ by SIM were significant, except for adsorption temperature. The adsorption comparison between single component adsorption and binary mixed system shows, Pb²⁺ and Cu²⁺ have competitive adsorption in binary mixed system.The single-component of Pb²⁺ and Cu²⁺ adsorption by SIM were fitted to L (Langmuir) and F (Freundlich) isotherm adsorption models, and the L model has a higher fitting degree with the experimental results. The isotherm adsorption processes of Pb²⁺-Cu²⁺ binary system was fitted by using the Non-modified Langmuir, Modified Langmuir isotherm, Extended Langmuir, Extended Freundlich and SRS model. The result showed that Extended Langmuir model was the best fitted to the experimental results. The machanism of SIM adsorption of metal ions was analysed by FTIR. It was found that the hydroxyl, -NH and unsaturated bonds on SIM were the adsorption sites of metal ions, and the adsorption capacity of SIM to Pb²⁺ was superior to that of Cu²⁺.