Efficient and Selective Adsorption of Cationic Dye Malachite Green by Kiwi-Peel-Based Biosorbents
Yanjun Zhao,
Xintong Liu,
Wenhui Li,
Suyun Pei,
Yifan Ren,
Xinyang Li,
Chen Qu,
Chuandong Wu,
Jiemin Liu
Affiliations
Yanjun Zhao
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, China
Xintong Liu
School of Light Industry, Beijing Technology and Business University, No. 33 Fucheng Road, Haidian District, Beijing 100048, China
Wenhui Li
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, China
Suyun Pei
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, China
Yifan Ren
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, China
Xinyang Li
China Testing & Certification International Group Co., Ltd., No. 1 Guanzhuang Road, Chaoyang District, Beijing 100024, China
Chen Qu
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, China
Chuandong Wu
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, China
Jiemin Liu
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, China
In this study, pristine kiwi peel (KP) and nitric acid modified kiwi peel (NA-KP) based adsorbents were prepared and evaluated for selective removal of cationic dye. The morphology and chemical structure of KP and NA-KP were fully characterized and compared, and results showed nitric acid modification introduced more functional groups. Moreover, the adsorption kinetics and isotherms of malachite green (MG) by KP and NA-KP were investigated and discussed. The results showed that the adsorption process of MG onto KP followed a pseudo-second-order kinetic model and the Langmuir isotherm model, while the adsorption process of MG onto NA-KP followed a pseudo-first-order kinetic model and the Freundlich isotherm model. Notably, the Langmuir maximum adsorption capacity of NA-KP was 580.61 mg g−1, which was superior to that of KP (297.15 mg g−1). Furthermore, thermodynamic studies demonstrated the feasible, spontaneous, and endothermic nature of the adsorption process of MG by NA-KP. Importantly, NA-KP showed superior selectivity to KP towards cationic dye MG against anionic dye methyl orange (MO). When the molar ratio of MG/MO was 1:1, the separation factor (αMG/MO) of NA-KP was 698.10, which was 5.93 times of KP. In addition, hydrogen bonding, π-π interactions, and electrostatic interaction played important roles during the MG adsorption process by NA-KP. This work provided a low-cost, eco-friendly, and efficient option for the selective removal of cationic dye from dyeing wastewater.
