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- 2-Fluorophenol degradation by aerobic granules in a sequencing batch reactorPublication . Duque, A. F.; Bessa, V. S.; Carvalho, M. F.; De Kreuk, M. K.; Loosdrecht, M. C. M. van; Castro, P. M. L.
- Isolation and characterization of a bacterial strain able to degrade 2-FluorophenolPublication . Duque, A. F.; Carvalho, M. F.; Janssen, D. B.; Castro, P. M. L.
- Bioaugmentation of a rotating biological contactor with a bacterial strain able to degrade fluorinated phenolsPublication . Duque, A. F.; Bessa, Vânia S.; Carvalho, M. F.; Castro, P. M. L.
- Biological treatment of a contaminated gaseous emission from a leather industry in a suspended-growth bioreactorPublication . Carvalho, M. F.; Duque, A. F.; Moura, S. C.; Amorim, Catarina L.; Ferreira Jorge, R. M.; Castro, Paula M. L.A suspended-growth bioreactor (SGB) was operated for the treatment of a gaseous stream mimicking emissions generated at a leather industrial company. The main volatile organic compounds (VOCs) present in the gaseous stream consisted of 1-methoxy-2-propanol, 2,6-dimethyl-4-heptanone, 2-butoxyethanol, toluene and butylacetate. A microbial consortium able to degrade these VOCs was successfully enriched. A laboratory- scale SGB was established and operated for 210-d with an 8 h cycle period and with shutdowns at weekends. Along this period, the SGB was exposed to organic loads (OL) between 6.5 and 2.3 £ 102 g h¡1 m¡3. Most of the compounds were not detected at the outlet of the SGB. The highest total VOC removal efficiency (RE) (ca 99%) was observed when an OL of 1.6 £ 102 g h¡1 m¡3 was fed to the SGB. The maximum total VOC elimination capacity (1.8 £ 102 g h¡1 m¡3) was achieved when the OL applied to the SGB was 2.3 £ 102 g h¡1 m¡3. For all the operating conditions, the SGB showed high levels of degradation of toluene and butylacetate (RE t 100%). This study also revealed that recirculation of the gaseous effluent improved the performance of the SGB. Overall, the SGB was shown to be robust, showing high performance after night and weekend shutdown periods.
- Treatment of wastewaters contaminated with heavy metals using aerobic granules in a sequencing batch reactorPublication . Marques, Ana P. G. C.; Duque, Anouk F.; Castro, Paula M. L.
- Long term performance of constructed wetlands for tannery wastewater treatmentPublication . Calheiros, Cristina S. C.; Duque, Anouk F.; Moura, Alexandra; Henriques, Isabel S.; Correia, António; Rangel, António O. S. S.; Castro, Paula M. L.
- A two-stage process for conversion of brewer’s spent grain into volatile fatty acids through acidogenic fermentationPublication . Guarda, Eliana C.; Oliveira, Ana Catarna; Antunes, Sílvia; Freitas, Filomena; Castro, Paula M. L.; Duque, Anouk F.; Reis, Maria A. M.This work is focused on the valorization of brewer’s spent grains (BSG) into volatile fatty acids (VFA) through acidogenic fermentation. VFAs are building blocks for several applications, such as bioplastics’ production. Using acid hydrolysis as pre-treatment, several batch assays were performed and the impact of organic load (OL) and pH on VFA production from BSG hydrolysate was assessed. Regardless of the condition, the produced acids were mainly butyric and acetic acids followed by propionic acid. The OL had a direct impact on the total organic acid concentration with higher concentrations at the highest OL (40 gCOD L-1). pH affected the concentration of individual organic acid, with the highest fermentation products (FP) diversity attained at pH 5.0 and OL of 40 gCOD L-1. To assess the potential application of organic acids for biopolymers (such as polyhydroxyalkanoates) production, the content in hydroxybutyrate (HB) and hydroxyvalerate (HV) monomers was estimated from the respective precursors produced at each pH and OL. The content in HV precursors increased with pH, with a maximum at pH 6.0 (ca. 16% C-mol basis). The acidogenic fermentation of BSG hydrolysate was also assessed in continuous operation, using an expanded granular sludge bed reactor (EGSB). It was shown that the BSG hydrolysate was successfully converted to VFAs without pH control, achieving higher productivities than in the batch operation mode.
- Biodegradation of 2-fluorophenol in a rotating biological contactorPublication . Duque, A. F.; Bessa, V. S.; Franco, A. R.; Carvalho, M. F.; Castro, P. M. L.
- HPLC-FD method to follow biodegradation of four fluoroquinolonesPublication . Maia, Alexandra; Duque, Anouk F.; Ribeiro, Ana L.; Castro, Paula M. L.; Tiritan, Maria E.
- Performance of an aerobic granular sequencing batch reactor fed with wastewaters contaminated with Zn2+Publication . Marques, Ana P. G. C.; Duque, Anouk F.; Bessa, Vânia S.; Mesquita, Raquel B. R.; Rangel, António O. S. S.; Castro, Paula M. L.The main aim of this study was to investigate the performance of an aerobic granular sludge sequencing batch reactor (AGS-SBR) receiving water streams supplied with different loads of Zn2+ (50 and 100 mg L-1) during an operation of 866 cycles (ca. 109 days). When the metal was not fed, chemical oxygen demand (COD), PO43- and NH4+ were efficiently removed, with efficiencies of 56, 23 and 72% respectively. DGGE profiles showed that Zn2+ supply negatively affected the bacterial diversity and community structure of the granules. Consequently, the shock loadings with Zn2+, particularly at the higher levels (100 mg L-1), affected the nutrient removal in the AGS-SBR, although the reactor still generally complied with admissible legal values concerning organic matter, nitrogen and Zn. Simultaneous removal of PO43- and TSS in such conditions needs further refining but the application of aerobic granular SBR in the treatment of Zn2+ contaminated wastewaters seems viable.