Removal of Humic Acids (HAs) in Drinking Water by Adsorption onto Polysulfone/Fe2O3 Mixed Matrix Membrane: Study kinetics and Isotherm Analysis

The present study delineates the applicability of polysulfone/ X% Fe2O3 mixed matrix membranes as a low-cost and non-toxic natural adsorbent.  It was used to  remove humic acids (HAs)  rapidly from aqueous solutions. The polysulfone/ X% Fe2O3 mixed matrix membranes were characterized by BET, FT-IR, XRD, and SEM. The humic acids (HAs) removal by the developed adsorbent was investigated  using  the batch  adsorption  technique  and  all  parameters  influencing  the  removal efficiency such as dose of adsorbent and pH were considered. The optimal conditions for the humic acids (HAs) removal were found to be 5, 120-160 min, 10 mg/L, and 0.1 g for pH, contact time and adsorbent dosage respectively. The rapid adsorption of the humic acids (HAs) is an advantage of this adsorbent. The adsorption capacity of humic acids (HAs) onto polysulfone/ X% Fe2O3 mixed matrix membrane was reasonably constant in the pH range of 5–7 but decreased as the pH exceeded 5. Various isotherm models  were  used to  fit  the  experimental  equilibrium  data. Equilibrium  data obtained  have  been  fitted  to  the Langmuir,  Freundlich,  and  Dubinin–Radushkevich adsorption isotherms. Langmuir's model best fits the experimental results. Kinetic modeling showed that the pseudo-second-order equation was the most appropriate for the description of humic acids (HAs) for  PSF,  PSF/5%  Fe2O3, and PSF/10%  Fe2O3 mixed  matrix  membrane were  found  to  be  13.333, 10.309, and  7.874  mg/g,  respectively.  The  overall  results  confirmed  that polysulfone/  X%  Fe2O3 mixed matrix membrane could be a promising adsorbent material for humic acids (HAs) removal from aqueous solutions.