Abstract
Hydrolysis rate of cellulose acetate in the active surface layer may be accelerated by the action of nascent oxygen generated from NaOCl. The decreasing rate of acetyl content may be expressed as a function of the square of the concentration of NaOCl. Activation energy of the rate constant is found to be 70.7 kJ ·mol-1. Concentration of NaOCl in the membrane depends on membrane permeability, which is a function of acetyl content and heat treatment. Change of R.O. separation with time is well anticipated, using heat treatment factor and data of pure water and solute permeabilities corresponding to each acetyl content obtained by Lonsdale et al. This anticipation method can well explain the decrease of separation of sea water R.O. desalination, using Toray's SC-5000 spiral wound modules at the Water Reuse Promotion Center Laboratory at Chigasaki Beach.
