Function integrated chitosan-based beads with throughout sorption sites and inherent diffusion network for efficient phosphate removal.

A novel, cost-effective and biomass-derived adsorbent was fabricated by coating polydopamine on lanthanum-chitosan hydrogel (La-CS@PDA), which were endowed with a plentiful of amine groups. The diffusion structure of channel-network of La-CS@PDA made it well used in phosphate removal in wastewater treatment. The Langmuir isotherm delivered the maximal adsorption capacity about 195.3 mg/g, which was superior to most reported phosphate removal materials. More significantly, in the presence of competitive anions Cl, SO, HCO, NO, F and HCrO, the resultant La-CS@PDA still conducted distinct selectivity for phosphate, which could be attributed to the selective binding sites of La species in the composite. Under continuous adsorption, the dynamic experimental data fitted well with Thomas model which imitates industrial practical application. By virtue of more fortes of high efficiency, ease of separation and expectable mechanical strength, as-prepared La-CS@PDA might be a promising candidate of dephosphorizing sorbent.