Application of waste tyre-based powdered activated carbon for the adsorptive removal of cylindrospermopsin toxins from environmental matrices: Optimization using response surface methodology and desirability function.

Activated carbon (AC) derived from waste tyre was investigated for the removal of cylindrospermopsin (CYN) from aqueous solutions and spiked real water samples. Response surface methodology based on Box-Behnken design was used for the optimization of experimental conditions. Based on the desirability score of 1.0, the percentage recovery of CYN was optimized at 104% and the optimum conditions were found to be 50.0 mg for the mass of adsorbent, 60 min for contact time and sample pH value of 3. The experimental equilibrium data best fitted Langmuir isotherm model and the maximum monolayer adsorption uptake of the waste tyre-based AC (WTAC) was 107 µg g-1. Kinetic studies demonstrated that the adsorption data were best described by pseudo-second-order. Finally, the optimized adsorption process was applied for the removal of CYN from real samples.