Imidazolium functionalized cellulose filter paper derived from waste newspaper and its application in removal of chromium(VI)

Abstract

Waste newspaper (WNP) is an abundant recyclable cellulose resource, which can be easily collected and purified to prepare high value-added bioadsorbents. In this study, a novel cellulosic filter paper (IMNP) was fabricated from WNP by ultrasonic deinking, wet-papermaking and chemical modification with a specific amino-based imidazolium salt. The prepared IMNP not only displayed good three-dimensional network interweaving structure, but also showed abundant imidazolium functional groups on its surface. Therefore, when IMNP was utilized to the treatment of the critical polluting agent Cr(VI) (hexavalent chromium), it could exhibit an excellent adsorption capacity of 129.3 ± 4.4 mg g−1. Moreover, a high removal rate of 97.9% after three filtrations was achieved. Besides, the adsorption mechanism was investigated by model fitting method of kinetic and isotherm. Meanwhile, by combining with the characterization analysis of materials after adsorption, the results demonstrated the separation of Cr(VI) by IMNP involving complex multiple interactions as well as redox process of transforming Cr(VI) into low-toxic trivalent chromium. Consequently, the application of this high-efficiency filter paper bioadsorbent conforms to the trend and requirement of sustainable development and environmental protection.