Characterization of the Algal Colonization of Mortar Surfaces Using Image Analysis

This research work aims to characterize the algal colonization of mortar surfaces using image analysis. The resistance of mortars to the biofouling is studied by means of an accelerated lab-scale test. A suspension of green algae Klebsormidium flaccidum, was performed to periodically sprinkle the mortar surfaces and digital images were acquired thanks to a scanner. The colonization rate of the surface follows a sigmoid type curve as a function of time that can be modeled thanks to Avrami’s model. It is described by a two-process mechanism: attachment and growth of algal stains. To identify the parameters of the algal colonization model, the images were segmented thanks to a random forest algorithm to obtain pixel information on the presence of algae. These processes were then represented with a morphological min-tree and information such as the number of new germs or their growth have been exploited to feed the Avrami’s model. The results show a good agreement between the modeling and the experimental data.