Desenvolvimento de um sistema de filtração do ar ambiente utilizando a microalga Arthrospira platensis

Abstract

Indoor Air Quality (IAQ) is extremely important because in addition to providing greater well-being, it helps in the productivity of employees and students in closed and air-conditioned environments. One of the elements that most harm this quality is carbon dioxide, a gas that does not pollute outdoors, but which indoors causes some harm, such as discomfort, reduced learning, lower productivity, among others. Carbon dioxide can be absorbed directly by photosynthesis, and an alternative that has been extensively studied is the use of microalgae during this process, since microalgae have a higher absorption rate compared to other plants studied so far. Considering the importance of IAQ, the present work aims to compose a biofilter containing the microalgae Arthrospira platensis to promote the improvement of air quality in a closed environment. This microalgae was chosen because of its easy handling and high CO2 absorption rates. Thus, two culture media with different concentrations of nutrients were evaluated, where little discrepancy was obtained in relation to the amount of algal biomass. CO2 biofixation was also measured over five days using two liters of Arthrospira sp. cultivation, which showed an average absorption of 488 ppm of carbon dioxide present in a BOD kiln that remained closed throughout the experiment. Considering the stoichiometric calculation, it is necessary to cultivate 118 liters of microalgae at a concentration of 40% of the salts in the Zarrouk medium. However, there is a difference taking into account the analysis using the gas meter, because analyzing the concentration of carbon dioxide inside the greenhouse during the 4 hours of the experiment, it was verified the need for a cultivation with 9,4 liters. This difference in the amount of microalgae cultivation is due to some factors, such as the difference in relation to the size of the site of each analysis.