Effect of cleaning protocol on membrane permeability recovery: A sensitivity analysis

Abstract

Results are presented for a four‐year study of chemical cleaning of ultrafiltration/microfiltration membranes for inland potable water treatment are presented. The study made use of a bespoke test cell in which sample membrane fibers extracted from modules in full‐scale operating membrane plants were examined. The test entailed cleaning—with the reagents used at each of the nine sites—under controlled conditions of reagent concentration (C), soak period (P), and temperature (T). Data were analyzed using a standard response surface model to identify optimum cleaning protocol parameter values. Results showed the effect and order of importance of C, P, and T to vary both between sites and temporally, making identification of the most appropriate prescriptive cleaning protocols extremely challenging. Optimization of plant operation and maintenance requires methods for recording and tracking changes in cleaning efficacy, such as the one used in this study, as an adjunct to assessing the tendency for initial fouling through pilot‐testing.