Fouling and Cake Behavior of Algal Organic Foulants on Microfiltration Membranes in Various Growth Phases

Abstract

This study investigated the fouling behavior of algal organic foulants in various growth phases during microfiltration. The characteristics of the algogenic organic matter (AOM) in various growth phases were also determined to identify the membrane foulants on fouled membranes. The results indicated the stationary phase of the Aphanizomenon flos‐aquae and Anabaena flos‐aquae AOMs resulted in the most serious filtration flux, followed by their late exponential and primary exponential phases. The amounts of protein/protein‐like substances, the neutral hydrophilic fraction, and the macromolecular organics (including molecular weight) increased with cultivation time, potentially attributed to increasing membrane fouling. Analysis of organic hydrophobicity, molecular weight distribution and fluorescence excitation–emission matrix indicated that algal organic accumulation is a dynamic process of algal activity, biopolymers such as protein‐like and polysaccharides‐like substances were the major components of membrane foulants for the three algal growth phases. Moreover, pore plugging and cake layer formation were the dominant fouling mechanisms in membrane filtration. Timely monitoring of algal growth in water can be important for effectively predicting membrane fouling in microfiltration.