Chitosan/functionalized fruit stones as a highly efficient adsorbent biomaterial for adsorption of brilliant green...

In this research, a highly efficient adsorbent biomaterial (hereinafter, CTS/PPS-HS) of chitosan/functionalized fruit stones (peach and plum) with H₂SO₄ was produced for the adsorption of brilliant green (BG) dye from aquatic systems. The developed biomaterial was characterized by several techniques like SEM-EDX, FTIR, XRD, BET, and pH_pzc. To systematically optimize the adsorption performance of CTS/PPS-HS, the Box-Behnken design (BBD) based on response surface methodology (RSM) was attained. The factors considered for optimization included A: CTS/PPS-HS dosage (0.02-0.08 g), B: pH (4-10), and C: removal time (10-60 min). The pseudo-first-order and Langmuir isotherm models exhibited excellent agreement with the experimental results of BG adsorption by CTS/PPS-HS. The outstanding adsorption capacity (409.63 mg/g) of CTS/PPS-HS was obtained. The remarkable adsorption of BG onto CTS/PPS-HS can be primarily attributed to electrostatic forces between the acidic sites of CTS/PPS-HS and the BG cations, accompanied by interactions such as π-π, Yoshida H-bonding, n-π, and H-bond interactions. The current data underscores the significant potential inherent in combining biomass with CTS polymer to create an exceptionally effective adsorbent biomaterial tailored for the elimination of cationic dyes.