白酒中乙醛和糠醛的吸附效果对比

Comparison of Adsorption Characteristics of Different Sorbents for Acetaldehyde and Furfural in Baijiu

本研究利用功能化聚苯乙烯树脂吸附白酒中的乙醛和糠醛,并与活性炭、硅藻土、AB-8大孔树脂等吸附剂进行吸附效果的对比,结果发现,在240 min、323 K时改性树脂对乙醛的吸附量能达到60.19 mg/g,对糠醛的吸附量能达到47.37 mg/g,远高于其他吸附剂。对市售3类主要香型的白酒样品进行了吸附实验,结果发现,吸附前后白酒中的总酯变化小于1%,达到了选择性吸附的目的。运用元素分析、傅里叶变换红外光谱、比表面积与孔结构分析、热重分析和扫描电子显微镜对改性树脂进行表征。通过吸附动力学、吸附等温线和吸附热力学探究改性树脂对乙醛和糠醛的吸附机理,结果显示,吸附过程与拟二级动力学模型和Freundlich模型吻合较好,ΔG^(0)>0、ΔH^(0)>0、ΔS>0,表明吸附过程是一个非自发的吸热过程,随着吸附的进行,溶液的有序性减小,其吸附过程主要受化学吸附调控。该研究为中国白酒品质化、健康化提供了借鉴。

The adsorption characteristics of functionalized polystyrene resin for acetaldehyde and furfural in Baijiu were evaluated in comparison with those of other sorbents including activated carbon,diatomite,and AB-8 macroporous resin.The adsorption capacity of the modified polystyrene resin was 60.19 and 47.37 mg/g for acetaldehyde and furfural at 240 min and 323 K,respectively,greatly exceeding that of the other sorbents.Adsorption experiments were conducted on three major commercial flavor types of Baijiu,revealing less than 1% change in the total ester content of Baijiu before and after adsorption,so selective adsorption could be achieved using this sorbent.Its structure was characterized through elemental analysis(EA),Fourier transform infrared spectroscopy(FTIR),Brunauer-Emmett-Teller(BET) surface area and pore structure analysis,thermogravimetric analysis(TGA),and scanning electron microscopy(SEM).The adsorption mechanism of aldehydes and furfural on the functionalized resin was investigated using adsorption kinetics,isotherms,and thermodynamics.The findings indicated that the adsorption process fitted well with the pseudo-second-order model and the Freundlich model.Based on the results of ΔG^(0) > 0,ΔH^(0) > 0,and ΔS > 0,the adsorption was a non-spontaneous endothermic process.As the adsorption process proceeded,the solution became less orderly,and the adsorption process was primarily governed by chemisorption.This research serves as a reference for the quality and health improvement of Baijiu.