CLAY AS A SUBSTRATUM MATERIAL FOR MICROALGAE BIOFILM CULTIVATION

Abstract

The production of microalgae faces several obstacles. The bioreactors and processes used today in microalgae cultivation are expensive or lack optimization to scale up. Furthermore, harvesting, concentrating and dewatering, while using a cheap and suitable photobioreactor are the main problems that we need to be overcome to achieve viability in the process. The Clay Ceramic Bioreactor (CCBR) was built using only clay and wood sawdust and was designed to grow an immobilized microalgal biofilm while having almost complete separation from the liquid culture medium, reducing the consumption of water and energy. Results showed that the wood sawdust particle size should be sifted in a mesh size 10 and mixed in a proportion of 33% of sawdust and 67% of red clay and a maximum firing temperature of 900oC. Maximum dry biomass production of 3.71 g.m-2.d-1 was achieved within 7 days of cultivation, with no CO2 addition and a low light intensity of 45 µmol.m?2.s?1. The biomass was harvested through simple scraping. Initial results indicate a great potential for the use of clay as substratum and further tests should be carried out to scale up and optimize microalgae production,