Equilibrium, kinetic and thermodynamic studies of the removal of triphenyl methane dyes from wastewater using iodopolyurethane powder

The removal and recovery of rosaniline and brilliant green were studied using batch and dynamic processes. The maximum sorption of these dyes (∼100%) was obtained in a pH range of 6–10 with a shaking time of 2–5 min. The sorption kinetics were best described by the pseudo-second-order model (R2 = 0.993). The variation in the sorption of rosaniline and brilliant green with temperature results in average values of ΔH and ΔG (i.e., −65.7 kJ mol−1 and −8.1 kJ mol−1, respectively). The sorption capacity of iodo-polyurethane powder (Iodo-PUP) was 106.8 and 154.4 mg g−1 for rosaniline and brilliant green, respectively. The dye removal percentage and detection limit were 99.5% and 20 ng mL−1, respectively. The isotherms exhibit good correlation (R2 = 0.9985) with a zero intercept (0.0045). Successful application was achieved for environmental samples (i.e., industrial, laundry and sewage wastewater). The average recovery and RSD were 85.2% and 4.9%, respectively.