Preparation of High Concentration Polyaluminum Chloride with High Alc Content by Membrane Distillation

A direct contact membrane distillation (DCMD) process was applied to prepare high concentration polyaluminum chloride (PACl) with high Alc content. The changes in total Al concentration (AlT) and Al species distribution were investigated. The results showed that AlT increased but the flux decreased with operating time during the DCMD process. The Alc content increased from 65% to 81% while the Alb content decreased from 34% to 18%, and the Ala content was almost 1% in the process. 2.1 mol·L−1 PACl with 81% Alc was successfully prepared by DCMD method. Thus the DCMD is an effective method for preparing high concentration PACl with high Alc content.