Synthesis and application of an unprecedented bioadsorbent for removing arsenic from aqueous systems.

[Display omitted] • The SBTEA synthesis used renewable chemicals on a bio-based circular economy concept. • SBTEA efficiently removed As(V) from contaminated groundwater samples by ion-exchange. • SBTEA can be regenerated and reused with desorption efficiency higher than 90%. • SBTEA could be used to provide As(V) free drinking water in developing countries. • The estimated cost of production for SBTEA was USD 1.37 per gram of biosorbent. A quaternary ammonium anion exchanger (SBTEA) was prepared from sugarcane bagasse (SB) employing an improved two-step synthesis method by chemical modification with epichlorohydrin (EPI) and triethylamine (TEA) using N , N -dimethylformamide as a solvent without catalyst. Two multivariate optimizations were utilized to determine optimum conditions for SBTEA synthesis using Doehlert experimental designs. The optimum synthesis conditions were: V EPI = 12.8 mL g SB −1; V TEA = 22.0 mL g SB −1; and T 1 (etherification step) = T 2 (amination step) = 100 °C. The chlorine and nitrogen contents of the SBTEA produced under these conditions with a 21-fold increase in the synthesis scale (SBTEA -LS) were 4.2 ± 0.1% and 1.485 ± 0.007%, respectively. The 13C Multi-CP SS NMR revealed that 1.7 quaternary ammonium groups were introduced for 10 cellobiose units. SBTEA- LS was used to remove As(V) from contaminated groundwater samples with high removal efficiency (95 ± 4%), even with strong competitors such as SO 4 2−. The interactions involved in the adsorption were investigated through macroscopic and microscopic measurements, which suggested that the adsorption of As(V) on SBTEA -LS occurred mainly by ion exchange. Desorption experiments proved that SBTEA -LS could be efficiently regenerated (E des > 90%) using an HNO 3 solution, reducing operating costs and favoring technology upscaling. [ABSTRACT FROM AUTHOR]