Simulation of cake layer topography in heterotrophic microalgae harvesting based on interface modified diffusion-limited-aggregation (IMDLA) and its implications for membrane fouling control

Membrane technology, as an effective method for heterotrophic microalgae harvesting, is still restricted by the inevitable fouling and unclear fouling mechanisms. Accordingly, in this study, IMDLA model was developed to simulate the cake layer topography and predicate the local fouling tendency. A series of experiments and characterizations were designed to certify the feasibility of this model. The findings indicate that the cake layer formation and growth at the microscopic level was a sequential evolution process: rivet seed-cluster-mobile seeds interact with cluster-cluster horizontal growth-monolayer cake-multilayer cake formation-cake layer condensation. The formation of one uniform cake layer was delayed with fewer rivet seeds. Coverage can reflect the change in cake layer topography versus time in both the horizontal and vertical directions. Furthermore, by imputing the typical parameters of a one-setting filtration process, the cake layer topography in any filtration time was rapidly obtained. With the assistance of model-based visualized images, the fouling tendency was quickly confirmed, thereby improving the efficiency of providing precise control strategies. This model provides new insight into understanding local fouling behavior and works well as a useful tool to predict the algae-related membrane fouling.

Automated summary

The study developed the IMDLA model to simulate membrane fouling processes and confirmed its feasibility through a series of experiments. It was found that the formation and growth of cake layers follow a sequential evolution process, where the number of rivet seeds affects the formation rate of the cake layer.