| dc.description.abstract | In this work, the adsorptive features of water hyacinth (Eichhornia crassipes) derived biochar for sequestration of
ciprofloxacin and caffeine from aqueous solution is reported. The isothermal behaviour, adsorption kinetics, mechanisms and
thermodynamic parameters were investigated in batch mode. Langmuir and Freundlich models described the equilibrium adsorption
data with regression values > 0.9. The kineticsdata obeyed the pseudo-second-order kinetic law while intraparticle pore diffusion was
not the only rate controlling step. The computed thermodynamic parameters, namely change in Gibbs free energy (ΔG), change in
enthalpy (ΔH) and change in entropy (ΔS) indicated that the adsorption processes were spontaneous and exothermic with less
randomness. pH dependence studies depicted multi-mechanistic adsorption for both compounds and is hypothesized to involve
hydrophobic interactions besides other non-coulombic interactions. The findings demonstrate that water hyacinth biochar presents an
excellent low cost and environmentally benign adsorbent for mitigation of pharmaceuticals from water with a removal efficiency of
above 60 % for caffeine and ciprofloxacin. | en_US |
