Experimental studies and statistical analysis of membrane fouling behavior and performance in microfiltration of microalgae by a gas sparging assisted process

Ultrafiltration of non-axenic microalgae cultures: Energetic requirements and filtration performance

“…Moreover, fouling during microalgae filtration has been strongly related to exo-polysaccharides (EPS) excretion by microalgae and debris [25,26], which may be associated with the shear stress resulting from high CFV. In this sense, Javadi (2014) [18] reported an increase of EPS excretion in membrane filtration of Chlorella sp. operated when surface velocities increased until 0.4 m/s.…”

“…Obviously, biomass concentration changed during concentration, and concentration may affect cake formation by changing the convective flow of particles and solutes towards the membrane. Furthermore, mechanical stress derived from pumping of the culture has been identified as a negative factor for membrane concentration of microalgae, due to release of EPS or intracellular components [18,26,27]. This may affect particle size, a key factor determining particle back-transport mechanisms and deposition during crossflow filtration [28,29].…”

“…Most of the reports dealing with membrane-based microalgae harvesting are based on TMP constant experiments. However, most of them also show rapid decrease of flux during the first hours or even minutes of filtration [18,19]. Flux decline in membrane filtration is normally the result of the combination of phenomena such as cake formation, concentration-polarization and fouling.…”

“…Indeed, membrane filtration is characterized by complete biomass retention, does not need the addition of chemicals and can be easily scaled-up [10,16,17]. Despite the reported advantages of membrane filtration, the main drawback is flux reduction as result of membrane fouling [18,19]. Operational flux is indeed a key parameter, since it determines membrane requirements.…”

Influence of coagulation process on the ultrafiltration performance – The roles of Al species and characteristics of algae-laden water

“…Especially for the algae-laden source water, algal cells could secrete extracellular organic matter (EOM) and mucilaginous slime material, which could cement particulates on the membrane surface and increase the resistance to filtration [10,11]. Some researches had demonstrated the influence of different hydrophobic/hydrophilic fractions of EOM on ultrafiltration membrane fouling [12][13][14]. In the membrane fouling process, the deposited layer formation, pore plugging and hydrophobic adhesion were the main mechanisms for the membrane fouling caused by algal EOM [15].…”