乌贼墨黑色素对贻贝蒸煮浓缩汁中镉的吸附特性研究

Study on the cadmium adsorption performance of Sepia ink melanin from Mussel cooking juice

研究了乌贼墨黑色素对贻贝蒸煮浓缩汁中重金属镉的吸附特性。以黑色素用量、p H、吸附时间及重金属镉初始浓度作为变量,进行动力学和热力学模型拟合;对镉吸附前后的黑色素进行扫描电镜及傅里叶变换红外光谱表征,并进行解吸再生实验。结果表明:黑色素能有效地降低浓缩汁中镉的含量,在25℃,酸性条件(p H3~6),反应45 min后,0.10 g黑色素对100 m L镉浓度为50 mg/L的浓缩汁达到吸附平衡,饱和吸附量为(46.47±0.12)mg/g,去除率达93.1%±0.1%;吸附反应符合准二级动力学(R^2=0.998)和Langmuir等温热力学模型;扫描电镜和红外光谱实验证实吸附反应发生在黑色素颗粒表层,主要活性基团为-OH,-NH,-COOH;黑色素在再生使用3次内活性稳定。由此可知,乌贼墨黑色素对贻贝蒸煮浓缩汁中的镉具有优良的吸附特性和再生性,可作为一种安全的食品吸附剂材料。

The performance of Cd adsorption of Sepia ink melanin from Mussel cooking juice was investigated in the present study.The effect of melanin content,p H,contact time and initial concentration of Cd on Sepia ink melanin from Mussel cooking juice was investigated.These parameters were fitted by using of the kinetic and thermodynamic model.The physical and chemical properties of melanin were characterized by using of scanning electron microscope and Fourier transform-infrared spectroscopy.Finally,the regeneration of Sepia ink melanin to cadmium adsorption was conducted. The results showed that the adsorption equilibrium of Cd was reached after reaction for 45 min at 25 ℃ when 0.10 g Sepia ink melanin was added into 100 m L p H3~6of Mussel cooking juice at an concentration of 50 mg/L Cd. The maximum cadmium adsorption capacity of was（ 46.47 ±0.12） mg/g and the removal rate of cadmium was 93.1% ± 0.1% under the optimum conditions.The equilibrium data were well explained by pseudo-second-order kinetic model（ R^2= 0.998） and fitted Langmuir isotherm. SEM and FT-IR confirmed that the adsorption reaction mainly existed on the surface of the melanin and the major functional groups involved in adsorption reaction was-OH,-NH,-COOH.The cadmium adsorption capacity did not significantly changed after regeneration three times.The present study suggested that Sepia ink melanin is good adsorbed material of cadmium and have good biological regeneration.