The equilibrium Cr binding on the biosorbent was well explained using Freundlich isotherm (R 2 = 0.97), which indicated the indirect interactions between Cr (VI) and the biosorbent. 
THERM
Process parameters (pH, dose, contact time, temperature, and initial concentration) were optimized for efficient Cr VI adsorption using a response surface methodology-based Box-Behnken design (BBD) employing Design-software 6.0.8. 
Design-software 6.0.8