A new economical method to remove humic substances in water: adsorption onto a recycled polymeric material with surfactant addition

Cationic surfactants were used to enhance the adsorption of dissolved organic matter (DOM), contained in the effluent of municipal wastewater, onto polypropylene (PPL), a polymeric synthetic adsorbent made from recycled plastics. Both batch and continuous up-flow column experiments were carried out. The DOM, in the form of humic acid, was treated with a range of cationic surfactants, then, adsorption experiments were conducted to evaluate the adsorption of the mixture onto PPL in both its soluble and precipitated forms. This research validated the feasibility of the proposed system in which anionic humic acid is removed from the aqueous phase by forming neutral hydrophobic molecules with cationic surfactants and subsequently by adsorbing them on the hydrophobic surface of PPL.