title: Tertiary treatment for wastewater reuse based on the Daphnia magna filtration - comparison with conventional tertiary treatments.
abstract: Tertiary treatments are required to permit safe reuse of wastewater. The performance of a new biological tertiary treatment based on the filtration by a population of Daphnia magna was studied and compared with the performance of other conventional tertiary treatments such as coagulation-flocculation, settling tank, disc filtration, sand filtering and ultraviolet (UV) light. The analysis was based on the efficiency in the particle removal and Escherichia coli inactivation. The Daphnia magna treatment reduced the concentration of particles with diameters below 30 μm by 35%, depending on abiotic parameters such as water temperature and the hydraulic retention time (HRT). The Daphnia magna filtration increased with water temperature for water temperatures >20 °C, while it remained constant for water temperatures <20 °C. Lower HRTs induced the growth of the Daphnia magna population, maintaining the same water quality. Furthermore, the Daphnia magna treatment inactivated E. coli in 1.2 log units. This inactivation was six times larger than that obtained by the conventional macrofiltration systems analyzed, although lower than the inactivation attained by UV light, which ranged between 1.5 and 4 log units.
authors.affiliation: Department of Physics, University of Girona, Campus Montilivi, 17071-Girona, Spain E-mail: teresa.serra@udg.edu.
authors.forename: Teresa
authors.initials: T
authors.lastname: Serra
authors.affiliation: Department of Physics, University of Girona, Campus Montilivi, 17071-Girona, Spain E-mail: teresa.serra@udg.edu.
authors.forename: Jordi
authors.initials: J
authors.lastname: Colomer
authors.affiliation: Department of Physics, University of Girona, Campus Montilivi, 17071-Girona, Spain E-mail: teresa.serra@udg.edu.
authors.forename: Conxi
authors.initials: C
authors.lastname: Pau
authors.affiliation: Empresa Mixta Aigües Costa Brava, Condado del Jaruco s/n, 17310-Lloret de Mar, Spain.
authors.forename: Maribel
authors.initials: M
authors.lastname: Marín
authors.affiliation: Consorci Costa Brava, Plaça Josep Pla, 4, 17001-Girona, Spain.
authors.forename: Lluís
authors.initials: L
authors.lastname: Sala
mesh_terms: D000818:Animals; D003621:Daphnia; D004926:Escherichia coli / Q000302:isolation & purification* / Q000528:radiation effects; D005374:Filtration; D005427:Flocculation; D013696:Temperature; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater; D014873:Water Pollutants / Q000302:isolation & purification* / Q000528:radiation effects
chemical_list: D062065:Wastewater; D014873:Water Pollutants