废弃烟梗制备细菌纤维素的最佳条件及其吸附性能研究OA北大核心CSTPCD

[Objective]To explore the optimal preparation conditions for bacterial cellulose derived from discarded tobacco stems and the adsorption performances of the prepared samples.[Method]Three types of bacterial cellulose(BC)were prepared using discarded tobacco stem water extracted from three production areas(Henan,Shaanxi,and Hunan)as fermentation media.The BC yield was used as an indicator to optimize six fermentation conditions:seed age,inoculation amount,initial pH value,triangular bottle liquid volume,temperature,and time.The structure of BC obtained from different discarded tobacco stem water extract media and conventional media was characterized,and the adsorption performances of heavy metal ions were compared.[Result]1)Without adding additional nutrients,tobacco stem water extract can be directly used as a fermentation medium to produce bacterial cellulose.2)The optimal conditions for fermenting bacterial cellulose are as follows:seed age of 18 hours,inoculation amount of 10%,initial pH value 5.5,liquid volume of 50 mL,temperature of 30℃,and time of 9-11 days.3)There is a positive correlation between bacterial cellulose production and sugar content in tobacco stem water extracts.4)The BC prepared from tobacco stem water extract was characterized by scanning electron microscopy(SEM),fourier transform infrared spectroscopy(FTIR),and X-ray diffraction(XRD),and it was found that it has a typical fine three-dimensional fiber network structure of BC.The fiber diameter is about 30-100 nm,with no significant difference,and the SX-BC crystallinity is relatively high.5)All four types of BC can adsorb Cu2+and Zn2+in solution,among which SX-BC has the best adsorption effect on Cu2+and Zn2+,reaching 36 mg·g-1 and 39 mg·g-1,respectively.[Conclusion]The SX-BC has the highest fermentation yield and the best adsorption effect on Cu2+and Zn2+.