Evaluation of the performance of different materials to support the attached growth of algal biomass

Abstract

The attached microalgal biomass production in wastewater is promising for the development of biofilm reactors aimed at the economic separation and harvesting of biomass. However, the current impasse in the attached algal biomass production relies on the ability of materials to support such adherence. This study evaluated the effects of different support materials on the production and composition of algal biomass cultivated in domestic sewage. Durability and adherence of algal biomass to the threads of the support material were the most important criteria for choosing the material with the best performance. Three support materials were evaluated: cotton, nylon, and polyester. Polyester presented the best results in terms of durability; its resistance to friction tests was the highest, and even increased after its use in the experiment; this was associated with the high biomass production, mostly after the biomass inoculum (50.1 g∙m−2). This support also demonstrated greater development of nitrifying bacteria, which are essential for biofilm formation due to the presence of filaments in their cells. As for biomass characterization, it was observed that the different support materials did not interfere in the composition of the cells present in the attached biomass.