CTAB/H2O2 modified biosorbent for anionic dye from aqueous solutions: biosorption parameters and mechanism

The study focused on improving the biosorption capability of kiwi peel (KW) for the removal of methyl orange (MO). For this purpose, KW having negligible biosorption capacity for MO was dual-modified with the CTAB/H2O2 solution to CTAB/H2O2 -KW biosorbent. The structure of CTAB/H2O2-KW before and after biosorption was determined with FTIR, SEM/EDX, thermal analysis, and zeta potential measurements. CTAB and H2O2 amounts were optimized in CTAB/H2O2-KW biosorbent and the optimum amounts of CTAB and H2O2 for KW modification were 0.15 M and 30%, respectively. MO molecules were removed from the solution in 98.70% efficiency after dual modification due to the electrostatic interaction between CTAB/H2O2 -KW and anionic dye. The pseudo-second-order kinetic (R-2 = 0.999) and Langmuir isotherm (R-2 =0.997) models had good fitting in the biosorption process. The calculated maximum biosorption capacity of CTAB/H2O2-KW was 561.337 mg g(-1) at pH = 3 and 20 degrees C. The results indicated that CTAB/H2O2-KW exhibited excellent application potentials as a biosorbent for the removal of methyl orange from aqueous solutions.