Highly adsorptive removal of anionic azo dye new coccine using inorganic nanohybrid of lysozyme protein functionalized nanosilica rice husk

In this study, we investigated the adsorptive removal of anionic dye new coccine (NCC) using bio-material, lysozyme-functionalized nanosilica (LFNS). We identified the optimal conditions for NCC removal using LFNS; the selected parameters were determined to be a pH of 3 and an adsorbent dosage of 10 mg/mL. Under these optimal conditions, the adsorptive removal of NCC dramatically improved, increasing from 21.9 % to 96.2 %. The isothermal adsorption of NCC on LFNS was accurately described by Langmuir and Freundlich models, while the pseudo-second-order model achieved the best fit for the adsorption kinetic of NCC. The maximum adsorption capacity of NCC on LFNS reached 18.9 mg/g while after four regeneration cycles, the removal of NCC remained above 77 %, illustrating the effectiveness of LFNS in NCC removal. From zeta potential and FT-IR measurements, the interactions governing the removal of NCC were influenced by both electrostatic and hydrophobic forces. The LFNS is demonstrated as a great adsorbent for removing dyes from water environment. • Removal of NCC increased from 21.9 to 91.6 % using LFNS compared with nanosilica without protein. • The selected parameters for NCC removal using LFNS were pH 3 and adsorbent dosage of 10 mg/mL. • Adsorption isotherms of NCC on LFNS were well fitted by Langmuir model and kinetics agreed with the pseudo-second-order model. • Adsorption of LFX was controlled by electrostatic and hydrophobic interaction with maximum adsorption capacity of 18.9 mg/g. • Removal efficiency of NCC using LFNS was greater than 77 % after four regenerations.