Waste polystyrene foam – Chitosan composite materials as high-efficient scavenger for the anionic dyes

Abstract

The highly toxic organic dyes and white foam waste are difficult to degrade in the ecological environment, posing a series of serious threats to natural beauty and human health, and the design of a functional material to solve these problems together has become a huge challenge. Herein, we introduced a facile strategy to link chitosan (CS) onto waste packaging polystyrene foam (PS) to serve (PS-CS) as high efficient adsorbents of anionic dyes in wastewater. Influencing factors such as dosage (0.4–1.4 g/L), pH (2–12), dye concentration (100–1500 mg/L), contact time (10–120 min) and temperature (298.15–318.15 K) on the adsorption of Congo red (CR) and Reactive red 24 (RR24) were systematically investigated. Enormous efforts have indicated that the adsorption capacity of as-prepared PS-CS composites toward CR and RR24 were 1081.1 and 1107.5 mg/g, respectively; the adsorption kinetics confirmed to the pseudo second-order linear model better; thermodynamics showed that the adsorption of CR and RR24 on PS-CS were a spontaneous endothermic process. After 6 adsorption-desorption cycles, the removal rate of the two dyes still remained above 90%. Moreover, the adsorption experiments on methyl blue and methyl orange confirmed that PS-CS had good absorbability, wide applicability to anionic dyes, strong ability to resist ion interference. In brief, As-synthesized chitosan-based composites exhibit a great practical prospect in complex wastewater treatment. • Treating the wastes with wastes, increasing the plastic of the value innovation. • A chitosan-based material PS-CS was prepared by using waste polystyrene foam. • Langmuir adsorption capacity was 1081.1 mg/g for CR and 1107.5 mg/g for RR24. • PS-CS showed good applicability to a variety of anionic dyes. • In the sixth reusability cycle, the removal rate was still above 90%.