聚多巴胺/海藻酸钠(SA-PDA)凝胶球的制备及其对水中Cu²⁺的吸附研究

Preparation of Polydopamine/Sodium Alginate (SA-PDA) Gel Ball and Its Adsorption of Cu²⁺ in Water

本研究制备了聚多巴胺/海藻酸钠(SA-PDA)凝胶球,用以研究其在水环境中对Cu2+的吸附影响,分别考察了pH、吸附时间和离子强度对Cu2+的吸附效果。对样品进行了傅立叶变换红外线光谱(FTIR)测试和扫描电子显微镜(SEM)的表征观察。研究显示,实验最佳的吸附条件为:pH值为6,吸附平衡时间为1600 min。SA-PDA在同等实验条件下的吸附效果明显优于PDA。此过程更符合准二级动力学方程,表明该吸附速率是由化学反应速率控制。通过Langmuir和Freundlich吸附等温式拟合,计算出SA-PDA凝胶球对水中Cu2+的最大吸附量为116.14 mg/g,吸附行为单分子层吸附,显著高于相同条件下单纯PDA对Cu2+约23.78 mg/g的吸附量。

The poly-dopamine/sodium alginate gel ball was prepared for studying the adsorption efficiency of Cu2+in water environment.It was observed that the adsorption process could be affected by pH,adsorption time and ionic strength.The characterization of the sample was conducted with Fourier Transform infrared spectroscopy(FTIR)test and scanning electron microscope(SEM)test,showing the best adsorption condition of the experiment:pH=6,adsorption equilibrium time 1600 min.SA-PDA had a better adsorption efficiency than PDA under the same experiment condition.This process could be fitted much better with the pseudo-second-order reaction kinetics than that with the pseudo-first order,suggesting that the adsorption rate was dominated by chemical reaction.According to the R2 value of fitted Langmuir and Freundlich model,the monolayer adsorption was investigated and the maximum adsorption capacity of Cu2+was 116.14 mg/g by SA-PDA,remarkably higher than that by the simple PDA(23.78 mg/g).