Deterioration Mechanism of a Tertiary Polyamide Reverse Osmosis Membrane by Hypochlorite.

A tertiary polyamide membrane was synthesized using ,'-dimethyl--phenylenediamine. The durability of this membrane to chlorination by hypochlorite treatment followed by sodium hydroxide treatment was examined, and then deterioration mechanisms were proposed. The tertiary polyamide membrane demonstrated better durability to free chlorine than a conventional secondary polyamide one; however, the former was deteriorated by hypochlorite for 24 h at 2000 ppm of free chlorine below pH 7.