As(V) removal from water using the La(III)- Montmorillonite hydrogel beads.

The porous La(III)- montmorillonite hydrogel beads (La-MMT_hb) with stable structure were fabricated via hydrogen-bond and electrostatic interactions for arsenic removal from water. The structural characteristics of La-MMT_hb and its sorption performances for As(V) were evaluated. The results showed that porous La-MMT_hb were clearly observed by scanning electron microscopy, and the addition of lanthanum significantly increased the specific surface area. The maximum adsorption capacity of La-MMT_hb for As(V) was 58.75 mg/g, reached within 4 h, at the optimum pH of 4 with optimum La dosage of 1%. The mechanism of adsorption can be attributed to the electrostatic forces between La(III) and H 2 AsO 4 − at pH 4, ion exchange of O H groups on the surface of adsorbent with H 2 AsO 4 − and complex chelate formation as.-NH 3 -H 2 AsO 4 and -La-O-As. • Enhancement of As(V) adsorption capacity by montmorillonite hydrogel beads with addition of lanthanum • Increase in specific surface area of hydrogel beads result from changes of microstructure owing to lanthanum loaded • Electrostatic forces, ion exchange and complex chelate formation with lanthanum and arsenic contribute to the larger sorption [ABSTRACT FROM AUTHOR]