Study on the cleaning of new ultrafiltration spiral-wound modules to prevent membrane fouling (including biological fouling)

摘要

A study of cleaning a Bulgarian UF 60 PAN spiral-wound module was carried out on an ultrafiltration unit (Millipore,USA).Chemical cleaning of the membrane with a 0.25% solution of sodium metabisulfite did not prevent biological fouling.When treated with a 1% solution of formaldehyde,membrane fouling was diminished and the ultrafiltrate obtained contained a significantly lower number of microorganisms and colloid formations including iron and humic acids.After treatment with the two cleaning agents,the membrane maintained its flux for the water studied within a range of 1.58 to 1.64 m~3/m~2/d.The effect on the contaminants to be removed was also found to be comparatively constant.Membrane selectivity remained constant at different permeate yields.