TREATMENT OF WASTEWATER FROM BIODIESEL GENERATION AND ITS TOXICITY EVALUATION BY Raphidocelis subcapitata

• Main Authors: Nádia Hortense Torres, Álvaro Silva Lima, Luiz Fernando Romanholo Ferreira, Joyce de Andrade Oliveira, Eliane Bezerra Cavalcanti
• Format: Article
• Language: English
• Published: Brazilian Society of Chemical Engineering
• Series: Brazilian Journal of Chemical Engineering
• Subjects: Waste treatment; advanced oxidative process; ecotoxicology; biodiesel residue; toxicity
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66322018000200563&lng=en&tlng=en

ABSTRACT Biodiesel was developed to solve vast economic and environmental problems related to the use of petroleum as fuel. However, large quantities of water are necessary for biodiesel production, generating a high volume of effluent waste. Therefore, it is important to treat this wastewater in order to meet the environmental legislations according to the Brazilian Resolution Number 430/2011 (CONAMA). This work aimed to treat this effluent by coagulation/flocculation (CF) and an electrochemical advanced oxidation process. The combination of CF techniques (pH = 6.5) and electrochemical oxidation (boron doped diamond - BDD - electrode with NaCl) led to 78.5% removal of total organic carbon. The evaluation of the toxicity with Raphidocelis subcapitata indicated that the treated samples (IC5072h = 1.66%) had higher chronic toxicity when compared to raw effluent samples (IC5072h = 0.17%). This indicates that the proposed treatment was effective to decrease the organic load and reduce the environmental impact of these effluents in water bodies.