Facile fabrication of lignocellulose-chitosan composite aerogel using ZnBr2·4H2O for dye adsorbent

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.