Percorrer por autor "Pablos, Cristina"
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- Assessment of full-scale tertiary wastewater treatment by UV-C based-AOPs: removal or persistence of antibiotics and antibiotic resistance genes?Publication . Rodríguez-Chueca, Jorge; Giustina, Saulo Varella della; Rocha, Jaqueline; Fernandes, Telma; Pablos, Cristina; Encinas, Ángel; Barceló, Damià; Rodríguez-Mozaz, Sara; Manaia, Célia M.; Marugána, JavierAOPs based on the photolytic decomposition of H2O2 and peroxymonosulfate tested at low dosages (0.05-0.5 mM) and with very low UV-C contact time (4-18 s) demonstrated to be more efficient than UV-C radiation alone on the removal of the analyzed ABs. PMS (0.5 mM) combined with UV-C (7 s contact time) was the most efficient treatment in terms of AB removal: 7 out of 10 ABs detected in the waste water were removed more efficiently than using the other oxidants. In terms of ARGs removal efficiency, UV-C alone seemed the most efficient treatment, although H2O2/UV-C, PMS/UV-C and PMS/Fe(II)/UV-C were supposed to generate higher concentrations of free radicals. The results show that treatments with the highest removal of ABs and ARGs did not coincide, which could be attributed to the competition between DNA and oxidants in the absorption of UV photons, reducing the direct photolysis of the DNA. Whereas the photolytic ABs removal is improved by the generation of hydroxyl and sulfate radicals, the opposite behavior occurs in the case of ARGs. These results suggest that a compromise between ABs and ARGs removal must be achieved in order to optimize wastewater treatment processes.
- Study of bacterial microbiota over the course of tilapia growth cycle in an aquaponics systemPublication . Pablos, Cristina; Molina, Maria Dolores; Vaz-Moreira, Ivone; Silva, Maria Inês Leão; Nunes, Olga; Manaia, Célia; Marugán, JavierAquaponics combines hydroponic crop production with recirculating aquaculture. These systems comprise various compartments ( in this case: fish tank, biofilter, sump, hydroponic floating raft, settler, and aerobic digester provided by Green in Blue ). Efficient developing of aquaponics in terms of water quality, fish welfare, plant health and food safety requires a thorough understanding of the microbial composition for each compartment of the system . In this study 1m3 dechlorinated tap water aquaponic system stocked with 50 Nile tilapia ( Oreochromisniloticus L., stocked at 5.7 kg per system) and 72 lettuce plants (Lactuca sativa Batavian Red) for 22lettuce cycles of 5 weeks. The experiment was conducted in a small scale, closed-loop, simple recirculating aquaculture system (RAS) running for six months from 18 January ended on 21 July2023. Several physico -chemical water parameters were monitored throughout the cycle to follow the general evolution of the system and correlate potential microbiota variations with water parameters and establish connection to the nitrogen cycle. DNA sequencing results in Figure 1 clearly displays that aquaponics microbiome is complex and each compartment possesses its own bacterial community (p<0.05). An important genus in the biofilter is Nitrospira . This highlights its crucial role in nitrification as no Nitrobacter or Nitrosomonas is detected in the biofilter. Nocardia. A substantial proportion of denitrifying Flavobacterium genus common in soil, aquatic systems and plant-associated habitats were detected in sump. Also, Cetobacterium genus related to fish gut. As conclusion, metagenomics allows optimization of the operational parameters of aquaponics system to prevent pathogen proliferation and pathogen cross transfer among compartments, as well as to enhance efficient functioning of aquaponics biofilters.