A biogenic tunable sorbent produced from upcycling of aquatic biota-based materials functionalized with methylene blue dye for the removal of chromium(VI) ions

The valorization of algal biomass and bi-valve shells allows synthesizing, in the presence urea, a sorbent highly efficient for methylene blue (MB) sorption (sorption capacity: 1.5 mmol MB g?1 at pH 5.8). dye-functionalized shows enhanced properties Cr(VI) recovery 3. isotherm is fitted by Langmuir equation: maximum capacity reaches 8.53 Cr (for MB-loading: g?1). Different mechanisms may be involved such as electrostatic attraction anionic species, chelation on reactive groups, reduction into Cr(III). Under selected experimental conditions, achieved within less than 60 m. kinetic profiles are controlled pseudo-second order rate equation. Alkaline NaCl solutions effciently desorb chromate while maintaining good stability dye (negligible release). Therefore, desorption performances maintained remarkably stable least 5 sorption/desorption cycles. successfully applied from Cr(VI)–spiked (tap water wastewater petrochemical unit) with limited loss performances. characterized BET, TGA, FTIR, SEM, EDX zetametry to help understanding binding