Ethylparaben adsorption onto activated carbon and sugarcane bagasse in addition to toxicologic bioassays with freshwater planktonic species

Author(s)

Rodrigo Maia Valença

• Document type: Master's Dissertation
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD)
• Defense date: 2020-07-08

Examining board members

Eny Maria Vieira; Silvia Helena Govoni Brondi; Raquel Aparecida Moreira

• Advisor: Eny Maria Vieira

Abstract

Along with contemporary technological advances came the concern with emerging micropollutants, which are substances that are present in small concentrations on aquatic environments, that can resist conventional sewage treatment and even in such small concentrations can harm affected biotic systems. Parabens, a widely used group of preservatives, threaten human and aquatic biota health due to their toxicity and their endocrine disruption potential. This work evaluated the removal of ethylparaben in aqueous phase by adsorption on activated carbon and sugarcane bagasse and the sensibility of the freshwater cladocerans Daphnia similis and Ceriodaphnia silvestrii to its exposure. To detect ethylparaben in water a HPLC/DAD analytical method was developed and validated therefore chromatografic separation was achieved with a reverse phase column Agilent Zorbax C8 maintained at 30 °C, with methanol and water (80:20, v/v) on isocratic elution for five minutes, flow rate of 1 mL min-1, wavelength of 257 nm and injection volume of 20 μL. Acute exposures to ethylparben generated EC50 of 23.70 mg L-1 and 25.01 mg L-1 for D. similis and C. silvestrii and chronic effects in reproduction and mortality were significant when Ceriodaphnias were exposed to 8 mg L-1 of ethylparaben. Both adsorbents displayed satisfactory ethylparaben removal potential but the activated carbon demonstrated more affinity with the adsorbate. In tests with 10 mg L-1 of ethylparaben, 30 minutes of contact time and doses of 0.5 g L-1 of activated carbon and 16 g L-1 of sugarcane bagasse these materials removed respectively 62.51% and 37.05% of the paraben in aqueous solution. Environmental concentrations of ethylparaben in freshwater are usually in the order of 10 μg L-1 and although these concentrations and effect concentrations found in this study are not even in the same magnitude, toxicologic potential of ethylparaben should not be neglected considering parabens toxicity data are still scarce specially ones that relates them to tropical species. (AU)

• FAPESP's process: 17/20490-3 - Evaluation of the removal efficiency of ethylparaben by adsorption on activated carbon and on alternative adsorbents and toxicity tests with zooplanktonic freshwater organisms
• Grantee: Rodrigo Maia Valença
• Support Opportunities: Scholarships in Brazil - Master