Optimization of sodium alginate beads for the treatment of effluents from water recirculation systemsAutora: Ana Cecília Francio da Silva (Currículo Lattes)
Advisor: Dr. Ricardo Vieira Rodrigues
Abstract
The use of microalgae immobilized in alginate matrices for the remediation of effluents from recirculating aquaculture systems (RAS) has proven to be a viable alternative for aquaculture operations. The efficiency of certain microalgal species has already been tested; however, the methodology for producing the beads remains a recurring issue due to competition from sodium ions (Na⁺) present in the effluent with the cross-linking agent used for bead formation (CaCl₂). This study evaluated the optimization of the beads and the efficiency of Nannochloropsis oceanica in removing nitrate and phosphate from an effluent originating from a RAS, as well as the use of reinforcement CaCl₂ baths during the beads' exposure time in the medium. The results showed that N. oceanica successfully removed nutrients from the effluent, exhibiting growth rates superior to those of free cells. The study also demonstrated that the presence of naturally occurring microorganisms in these effluents compromised the structural stability of the beads.