Removal of reactive green KE-4BD and Congo red dyes in textile effluent by natural clinoptilolite particles on a biosorbent as a cheap and efficient adsorbent: experimental design and optimisation

Abstract

ABSTRACT In this study, corn silk/clinoptilolite (CS/Clino) was synthesised and used for the removal of Reactive green KE-4BD (RG) and Congo red (CR) dyes in textile effluent. CS/Clino composite was characterised by FT-IR, FESEM, BET, and XRD techniques. Effects of pH, amount of adsorbent, and contact time on RG and CR dyes adsorption were studied by central composite design (CCD). Optimal conditions for maximum Reactive green KE-4BD and Congo red dyes removal percentage (95.54% and 99.42%, respectively) process were as follows: pH = 4.50, adsorbent amount: 0.05 g, and contact time: 12.15 minfordyes concentration of 20.0 mg L−1. Also, the isotherms, adsorption kinetics, and thermody namics were examined. Adsorption isotherms (qmax: 245.51 and 319.91 mgg−1 for RG and CR dyes, respectively), and kinetics study were showed that the sorption processes were better fitted by Langmuir equation and pseudo-second-order equation.