改性活性炭对羽毛水解液中芳香族氨基酸的吸附

Adsorption of aromatic amino acids in feather hydrolysate by modified activated carbon

本文首先对吸附羽毛水解液中芳香族氨基酸(AA)的活性炭进行筛选,然后对筛选出的活性炭进行酸碱改性。在考察的杏壳、椰壳、果壳、木质和煤质活性炭中,杏壳活性炭对AA吸附、洗脱效果最佳。实验表明:碱改性后的活性炭吸附效果较好,经碱改性的杏壳活性炭的比表面积、总孔容、微孔容均增大,酸改性则相反。Boehm滴定和傅里叶红外光谱(FT-IR)表征结果表明:碱改性后含氧官能团比未改性活性炭大幅减少,酸改性则明显增加。通过单因素试验确定NaOH改性杏壳活性炭对AA的静态吸附-洗脱工艺优化条件:上样液pH为5.6、上样液中酪氨酸质量浓度为2.4 mg/mL、乙醇体积分数为60%。NaOH改性的杏壳活性炭对AA的动态吸附-洗脱工艺优化条件:上样量为320 mL、上样流速为2 mL/min、洗脱流速为1.5 mL/min、洗脱体积为660 mL。在优化条件下,酪氨酸和苯丙氨酸回收率分别为76.3%和73.9%,纯度分别为81.7%和82.9%,表明NaOH改性的杏壳活性炭对羽毛水解液中芳香族氨基酸具有良好的分离纯化效果。

Activated carbons for aromatic amino acids (AA) in feather hydrolysate was screened,and activated carbons were modified by acid-base solutions.Among five kinds of activated carbons (apricot shell,coconut shell,fruit shell,wood and coal) investigated,the activated carbon from apricot shell had the best AA adsorption and desorption.Results showed that the alkali modified activated carbon,with the increase in the surface area,the total pore volume and micropore volume,had better AA adsorption performance than that on the acid modified one.Boehm titration and Fourier transform infrared spectroscopy (FT-IR) showed that the content of acidic oxygenated function groups was significantly decreased with the alkali modified activated carbon,but was significantly increased with the acid modification.The optimum parameters for the static adsorption-desorption of AA on NaOH-modified apricot shell activated carbon were determined by single factor experiments with the concentration of 2.4 mg/mL,pH of 5.6,and desorption solvent of 60% ethanol.The best purification parameters optimized by dynamic adsorption and desorption tests were as follows: the sample loading amount of 320 mL,flow rate of 2 mL/min,and subsequent elution with an eluent volume of 660 mL at 1.5 mL/min flow rate.Under such conditions,the recoveries of tyrosine and phenylalanine were 76.3% and 73.9%,the purity of tyrosine and phenylalanine were 81.7% and 82.9% respectively,indicating that NaOH-modified apricot shell activated carbon had a good adsorption of aromatic amino acids in feather hydrolysate.