Removal of oxy-anions by liquid-phase polymer based retention technique

B. L. Rivas*, J. Sánchez, University of Concepción, Chile

This work is based on the retention oxy-anions with an impact on the environment, such as arsenate, chromate, molybdate, and vanadate using water-soluble polymers (WSPs) containing quaternary ammonium groups, coupled to ultrafiltration membranes of regenerated cellulose. This technique is known as liquid-phase polymer-based retention (LPR) technique. LPR can separate low molecular weight ionic species interacting with the functional groups of polyelectrolyte with high molecular weight, preventing its passage through the ultrafiltration membrane. The system used in LPR includes a ultrafiltration cell containing the regenerated cellulose membrane, a reservoir with water at pH of work, magnetic stirrer, and a pressure source.

In this study, the removal of oxy-anions was performed at different pHs (3, 6, and 9) using different concentrations of polymer and oxy-anions. Moreover, the separation capacity of these oxy-anionic species in presence of interfering ions was also studied. Finally, the maximum retention capacity of the WSP by the enrichment method was determined.

Arsenate retention by polymer at a high arsenate concentration (47.6 mg L−1) was 58% and this removal capacity increases gradually, reaching 100% retention when the arsenate concentration in the cell was at minimum (5.5 mg L−1) using molar ratio (20:1) polymer:As(V). The results related to chromium removal showed highest retention capacity....

Session: M2 - Ultrafiltration
Day: 12 October 2016
Time: 10:45 - 12:00 h

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