Preparation of activated carbon with high nitrogen content from agro-industrial waste for efficient treatment of chromium (VI) in water

Abstract

Effective extermination of chromium (VI) from water is a major issue because of the hazardous and toxic nature of chromium (VI). Therefore, the development of highly capable and economical adsorbents is a key challenge to eliminating Cr (VI) from water for environmental restoration. Herein, sugarcane bagasse-based activated carbons (SBACs) were synthesized by one-step activation and functionalization of urea phosphate and utilized for Cr (VI) remediation. The outcomes found that the SBACs activated at 400 ℃ (SBAC400) had a porous structure with a specific surface of 608.44 m2/g and pore volume of 0.301 cm3/g. The Cr (VI) adsorption kinetic and equilibrium data fit well with pseudo-second-order kinetic models (R2 = 0.999–1) and Langmuir isotherm (R2 = 0.993–0.998), respectively. The SBAC400 showed a substantial quantitative removal with theoretical maximum adsorption of 227.27 mg/g (adsorbent dosage 2 g/L, pH=2). In terms of the mechanism, the adsorptions were controlled by physical adsorption (diffusion and pore filling), electrostatic attraction, chemical reduction, and surface complexation, which was dominated by chemisorption. Moreover, the coexisting ions do not affect the adsorption behavior of SBAC400. The SBAC material in this study showed promise for practical application to remove Cr (VI).