Investigation of the PES microfiltration membrane fouling characteristics for five substances
This article proposes two new concepts, adsorption and rejection accumulation and the membrane fouling efficiency per unit accumulation to quantitatively characterize the membrane fouling capacity of different single substances. The membrane fouling caused by bovine serum albumin (BSA), sucrose, glycerol triacetate, l-glutathione and maltodextrin on a polyethersulfone (PES) microfiltration membrane was studied. The real-time variations in filtrate concentration and transmembrane pressure were measured with an ultraviolet (UV) detector and pressure sensor during constant-flux filtration. The results showed that the PES membrane had rejection effects for the five substances. However, adsorption phenomena on the PES membrane were observed only for BSA and l-glutathione filtration. The membrane fouling capacity depended on the accumulation and fouling coefficient of the fouling component. The adsorption and rejection accumulation over 40 min followed the order of BSA (1441.39 µg·cm−2) > sucrose (908.53 µg·cm−2) > glycerol triacetate (290.29 µg·cm−2) > l-glutathione (145.18 µg·cm−2), while the membrane fouling efficiency per unit accumulation followed the order of l-glutathione (6.06 × 108 m−1·µg−1·cm2)>BSA (2.44 × 108 m−1·µg−1·cm2) > glycerol triacetate (2.08 × 108 m−1·µg−1·cm2) > sucrose (8.41 × 107m−1·µg−1·cm2). Based on these two factors, the membrane fouling was the most severe with BSA, followed by sucrose, l-glutathione and glycerol triacetate. The membrane fouling caused by maltodextrin was severe in the early stage and weakened in the later period due to the periodic formation and collapse of the maltodextrin cake layer on the membrane surface.