Lian-Jie Zhao,Jia-Ran Li,Yu Li,Li-Li Sun,Shao-Ni Sun,Xue-Fei Cao
The development of low-cost and high-performance water purification adsorbents has attracted increasingly attentions. In this work, corn stalk pith (CSP) and chitosan rich in amino groups were treated with ZnBr 2 ·4H 2 O to prepare lignocellulosic aerogels (LAs) and lignocellulose-chitosan composite aerogels (LCAs) for wastewater treatment. The effects of the ZnBr 2 ·4H 2 O treatment time and the addition of chitosan on the structure and adsorption performance of the aerogels were evaluated. The results showed that the lignocellulosic aerogel LA 15 had a three-dimensional porous structure and the optimal adsorption capacity of which reached 489.4 mg/g for Congo red. After the addition of chitosan, the adsorption performance and the adsorption behavior of LCA 10 for Congo red were evaluated in detail. The maximum adsorption capacity of the prepared LCA 10 for Congo red was up to 641.5 mg/g, which was 31 % higher than that of LA 15 . Adsorption kinetics suggested that the adsorption of Congo red on LCA 10 followed the pseudo-second-order kinetic and the Langmuir isotherm model, indicating that the adsorption was dominated by chemical adsorption and the adsorption of Congo red was mainly occurred on the surfaces of LCA 10 . This study provides a simple method for preparing high-performance dye adsorbents under mild conditions.
Wang Tao,Zhang Cailiang,Feng Hui,Zou Qingjun,Huang Wenrui,Wu Jiacong,Han Juan,Wang Yun
In this study, a green and effective stepwise catalytic system for cellulose conversion to 5-hydroxymethylfurfural (HMF) is reported. In a pretreatment process, very fast (15 min) dissolution of cellulose was achieved at a low temperature of 70 °C, utilizing ZnBr 2 ·4H 2 O as the best dissolution solvent, which to improve the reactivity of cellulase for raw cellulose and increase efficiency of cellulose degradation. Enzyme-inorganic hybrid nanoflowers (Cellulase@β-glucosidase/Zn 3 (PO 4 ) 2 -NF and Glucose isomerase@Zn 3 (PO 4 ) 2 -NF) with different morphological structures were prepared to act as biocatalyst in the sequential conversion of pretreated cellulose to glucose and glucose to fructose. HCl was applied catalyst for dehydration of fructose to 5-HMF in a water/tert-butanol biphasic system. Under optimal reaction conditions, the yield of 5-HMF for the overall reaction from cellulose was about 21.6%. A feasibility route for green conversion of cellulose to 5-HMF is reported. Graphical abstract
危险品化学品经营许可证（带存储）