Roles of membrane-foulant and inter/intrafoulant species interaction forces in combined fouling of an ultrafiltration membrane.

To explore better the combined organic-inorganic fouling mechanisms of ultrafiltration (UF) membranes, SiO and bovine serum albumin (BSA), humic acid (HA) were chosen as model inorganic and organic foulants, respectively. Fouling experiments with single and combined foulants, corresponding fouling layer structure, and the membrane-foulant and inter/intrafoulant species interaction forces were investigated. The results showed that the addition of SiO particles led to opposite fouling phenomena for BSA and HA, which could be explained by the membrane-foulant and interfoulant species interaction forces.

New insights into the humic acid fouling mechanism of ultrafiltration membranes for different Ca dosage ranges: results from micro- and macro-level analyses.

To reveal the mechanisms of the influence of Ca on membrane fouling with humic acid (HA), the adhesion forces of HA with both other HA molecules and the membrane, the HA fouling layer structure, HA fouling experiments, and the HA rejections at a wide range of Ca dosages were investigated. The results indicated that the effect of Ca on HA fouling can be divided into three stages. At lower ionic strength (IS) of CaCl, the change in electrostatic forces is the main factor in controlling HA fouling behavior; i.