Ficorremediação de compostos orgânicos e inorgânicos por três espécies de microalgas em água mineral

Abstract

Phycoremediation has already been recognized as an alternative and promising approach to wastewater treatment and has been receiving wastewater treatment in recent years. The ability to remove organic and inorganic contaminants in wastewater and under environmental conditions makes it as extreme excellent microalgae for use in a final step of wastewater polishing. The objective of this study was to evaluate three species of unicellular photosynthetic microalgae (Chlorella vulgaris, Desmodesmus subcapitata and Raphidocelis subcapitata) in monocultures, regarding their ability to remove and biotransform organic and inorganic organisms, usually in domestic effluents, for future applications as a polishing step. in decentralized wastewater treatment systems. The microalgae were exposed to a solution with 600 mg/L COD, 24 mg/L of total seaweed and 10 mg of water/L of phosphate, in mineral at two initial population densities (105 and 107/mL), with constant aeration, temperature of 23-27°C and photoperiod of 16: 8h (light: dark). After 96h, biomass production was observed as a comparison of microalgae, with a 17.3-fold increase in the density of 105 algae/mL and 11.4-fold increase in the initial density of 107 algae/mL, in two controls defined with mineral water and medium of cultivation, which had a biomass production of 2.0 and 8.7 times the initial values, respectively. The reduction in COD observed (greater than 78% in all assays) was related to the density of algae, being higher in bioassays with 107 algae/mL. The highest algae removal of phosphate1 (80% or 91 mg/L) was observed in biophosphate107/mL), while D. subspicatus promoted the highest removal of 3.8 mg/EU). However, considering all bioassays, the removal of ideal and phosphate reached an average of 68% and 21%, respectively. results These are the potential for using microalgae as a polishing step in decentralized wastewater treatment systems.