CLAY AS A SUBSTRATUM MATERIAL FOR MICROALGAE BIOFILM CULTIVATION

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,

CLAY AS A SUBSTRATUM MATERIAL FOR MICROALGAE BIOFILM CULTIVATION

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,

Understanding the Reactivity of Geminal P/B and P/Al Frustrated Lewis Pairs in CO2 Addition and H2 Activation

Understanding CO2 addition and H2 activation by geminal P/Z (Z = B, Al) frustrated Lewis pairs (FLPs) is crucial for the development of transition metal-free catalysts for hydrogenation of unsaturated...

The effect of CO2 addition and hydraulic retention time on pathogens removal in HRAPs

The influence of CO2 addition and hydraulic retention time (5 and 7 days) on removal of Pseudomonas aeruginosa, Clostridium perfringens, Staphylococcus sp., Enterococcus sp., and Escherichia coli was evaluated in a system with three parallel 21 L high rate algal ponds. Both the addition of CO2 and an increase in HRT had no significant influence on bacterial removal, but bacterial removal was higher than found in previous studies. The removal was 3.4–3.8, 2.5–3.7, 2.6–3.1, 2.2–2.6 and 1.3–1.7 units log for P. aeruginosa, E. coli, Enterococcus sp., C. perfringens, and for Staphylococcus sp., respectively. Although CO2 addition did not increase disinfection, it did significantly increase biomass productivity (by ≈60%) and settleability (by ≈350%). Additionally, even at the lower 5-day hydraulic retention time, CO2 addition improves removal of chemical oxygen demand (COD), total organic carbon (TOC), total organic nitrogen and phosphorus by 97, 91, 12 and 50%, respectively.