Browsing by Author "Alves, Marta"
Now showing 1 - 10 of 15
Results Per Page
Sort Options
- Adaptative biological response of aerobic granular sludge to events of single or combined wastewater related stressorsPublication . Alves, Marta; Henriques, Isabel; Castro, Paula M. L.; Amorim, Catarina L.Wastewater comprises various stressors and their individual and combined immediate effects on aerobic granular sludge (AGS) are still underexplored. In this study, the AGS was exposed for 24 hours to wastewater with varying salt concentrations (up to 30 g NaCl L⁻¹) alongside pharmaceuticals (diclofenac, DCF or carbamazepine, CBZ). Differences in extracellular polymeric substances (EPS) production and composition were observed between single and combined stressor exposures. The removal of pharmaceuticals was influenced by the wastewater salinity level and the type of pharmaceutical, with a positive correlation found between the EPS polysaccharides content and the removal efficiency at salinity levels up to 10 g NaCl L⁻¹ . The combination of salinity and pharmaceuticals in wastewater also impacted the AGS bacteriome composition, with the bacteriome of the AGS not-exposed to stressors showing greater similarity to that of AGS exposed to DCF than to that exposed to CBZ, at each wastewater salinity level. Functional profiling suggested that short-term exposure to stressors slightly increased the relative abundance of mismatch repair, cell motility, and homologous recombination functions in the AGS microbiome. Summing up, the stressors impact on AGS bacteriome structure and EPS production varies depending on the pharmaceutical and whether it is combined with salt or not. This study unveiled the immediate AGS response to both single and combined stressors exposure, but a more thoughtful characterization of the bacteriome composition over the early adaptation period to stressors is needed to understand the community succession and to identify key microbial groups.
- Bioprospecting microalgae for treatment of marine aquaculture wastewaterPublication . Alves, Marta; Cardador, Martim; Castro, Paula M.L.; Amorim, Catarina L.
- Bioremediation of coastal aquaculture effluents spiked with florfenicol using microalgae-based granular sludge – a promising solution for recirculating aquaculture systemsPublication . Oliveira, Ana S.; Alves, Marta; Leitão, Frederico; Tacão, Marta; Henriques, Isabel; Castro, Paula M. L.; Amorim, Catarina L.Aquaculture is a crucial industry in the agri-food sector, but it is linked to serious environmental problems. There is a need for efficient treatment systems that allow water recirculation to mitigate pollution and water scarcity. This work aimed to evaluate the self-granulation process of a microalgae-based consortium and its capacity to bioremediate coastal aquaculture streams that sporadically contain the antibiotic florfenicol (FF). A photo-sequencing batch reactor was inoculated with an autochthonous phototrophic microbial consortium and was fed with wastewater mimicking coastal aquaculture streams. A rapid granulation process occurred within ca. 21 days, accompanied by a substantially increase of extracellular polymeric substances in the biomass. The developed microalgae-based granules exhibited high and stable organic carbon removal (83-100%). Sporadically wastewater contained FF which was partially removed (ca. 5.5-11.4%) from the effluent. In periods of FF load, the ammonium removal slightly decreased (from 100 to ca. 70%), recovering 2 days after FF feeding ceased. A high-chemical quality effluent was obtained, complying with ammonium, nitrite, and nitrate concentrations for water recirculation within a coastal aquaculture farm, even during FF feeding periods. Members belonging to the Chloroidium genus were predominant in the reactor inoculum (ca. 99%) but were replaced from day-22 onwards by an unidentified microalga from the phylum Chlorophyta (>61%). A bacterial community proliferated in the granules after reactor inoculation, whose composition varied in response to feeding conditions. Bacteria from the Muricauda and Filomicrobium genera, Rhizobiaceae, Balneolaceae, and Parvularculaceae families, thrived upon FF feeding. This study demonstrates the robustness of microalgae-based granular systems for aquaculture effluent bioremediation, even during periods of FF loading, highlighting their potential as a feasible and compact solution in recirculation aquaculture systems.
- Effect of bioinoculants and biochar on grapevine-associated soil microbial communitiesPublication . Pereira, Sofia I. A.; Moreira, Helena; Vega, Alberto; Cunha, Joaquim; Alves, Marta; Graça, António; Fontes, Natacha; Porto, João; Castro, Paula M. L.
- Efficient ammonium removal from marine aquaculture wastewater with microalgal-bacterial granular sludge technologyPublication . Alves, Marta; Oliveira, Ana Sofia; Castro, Paula Maria Lima; Amorim, Catarina LeiteWater recirculation in marine aquaculture is fundamental for the protection of water resources and for the sector sustainability as it enables to reduce water usage 1. Microalgal-bacterial granular sludge (MBGS) has the potential to increase the removal efficiency of pollutants from wastewaters benefiting from the diverse metabolism allowing water recirculation. Moreover, MBGS would allow costs reduction both in biomass separation from the treated water given the rapid settling properties and in aeration due to microalgae oxygen production 2.This study aimed to develop MBGS able to treat marine aquaculture effluents. For that, a lab-scale photo sequencing batch reactor was inoculated with activated sludge, previously adapted to salty wastewater, and a microalgae consortium enriched from water collected at a marine aquaculture. Feeding composition was established to simulate marine aquaculture streams. The aggregation of microalgal and bacterial biomass to form granular structures occurred rapidly. Throughout the operation, dark green granules with a dense and compact structure became predominant together with an increase in chlorophyll and carotenoids content in biomass. Ammonia was absent from the reactor effluent, but the nitrite levels were often above the toxicity levels for fish. Nevertheless, the dissolved oxygen concentration in the treated water was high (> 8.63 mg/L). The microalgal-bacterial granules proved to be efficient in producing streams with high dissolved oxygen levels, lowering the needed of water oxygenation before reuse and without ammonium ions. However, for water recirculation, improvement of the nitrite removal is needed to maintain the levels below the fish toxicity levels.
- Exopolysaccharides production by aerobic granular sludge upon exposure to dual anthropogenic stressesPublication . Alves, Marta; Castro, Paula M.L.; Amorim, Catarina L.
- The long-term impact of antibiotic exposure in zebrafish bacterial communitiesPublication . Almeida, Ana Rita; Alves, Marta; Domingues, Inês; Henriques, Isabel
- Microalgae granular systems feasible for the treatment of marine aquaculture streams containing florfenicol antibioticPublication . Oliveira, Ana S.; Alves, Marta; Castro, Paula M. L.; Amorim, Catarina L.Land-based aquaculture industries generate high volumes of wastewater containing low concentration of carbon and nutrients that, if not properly handled, can pose a major environmental impact on the receiving water bodies and ecosystems. To face the current water scarcity and mitigate the pollution triggered by the rapid expansion of these industries, the development of treatment systems that allow water recirculation is of utmost importance. Florfenicol (FF), a broad-spectrum antibiotic, is sporadically present in aquaculture streams which may cause deleterious effects on the biological wastewater treatment systems and on the receiving ecosystems. This work aimed to evaluate the granulation of microalgae biomass with marine aquaculture effluents, without the need of any carrier, and its ability to remove nutrients in streams containing FF. A photo-sequencing batch reactor was inoculated with a suspended microalgae consortium enriched from water collected at a marine aquaculture facility and was fed with synthetic wastewater mimicking marine aquaculture streams. Rapid granulation occurred, with microalgae granules representing ca. 49% of the total reactor biomass around day-21. Overall, the microalgae granules exhibited high and stable organic carbon and ammonium removal efficiencies of more than 40 and 90%, respectively. During FF shock loads, ammonium removal efficiency slightly decreased to ca. 80% while carbon removal was unaffected. Nitrate was the main N species in the reactor effluent, but nitrite concentration exceeds the fish toxicity limit for adequate water recirculation. Up to 11% of the fed FF was removed in the reactor. Production of pigments, biomarkers of cell viability, increased exponentially until day-64, ca. 23 times, stabilizing thereafter. This study emphasizes the robustness of microalgae granules to remove carbon and ammonium from marine aquaculture streams, even in periods of FF load. The implementation of such systems in marine aquaculture facilities is a feasible and compact solution, however further improvement of the removal performance is needed to reduce nitrite levels if water recirculation is aimed for.
- Microalgae-bacterial granular sludge systems - on the road for more sustainable processes in the aquaculture sectorPublication . Oliveira, Ana S.; Alves, Marta; Castro, Paula M. L.; Amorim, Catarina L.With population growth and stagnation of capture fisheries, the aquaculture sector has been challenged to achieve remarkable production targets to meet the ever-increasing fish demand. However, land-based aquaculture industries need to capture high water volumes from nearby water bodies to ensure an adequate production and, consequently, high wastewater volumes, containing organic carbon, nutrients, and often contaminants of emerging concern, are produced. If not properly handled, aquaculture effluents pose a threat to receiving aquatic ecosystems. The rapid expansion of these industries, facing the increased demand for food worldwide, is only possible if more sustainable practices are adopted. To face the current water shortages and protect water resources, the development of environmentally friendly treatment systems that allow water recirculation is of utmost importance. This work aimed to develop a microalgae-bacteria granular sludge system able to efficiently treat marine aquaculture effluents so they can meet the requirements for recirculation. A photo-sequencing batch reactor was inoculated with a phototrophic microbial consortium obtained from water streams in a marine aquaculture facility and was fed with wastewater mimicking marine aquaculture streams. The aggregation of the microbial biomass occurred rapidly and, on day-21, ca. 49% of the total reactor biomass was in the form of granules. The system exhibited high and stable organic carbon removal (>80%), even when florfenicol, an antibiotic widely used in aquaculture, was present in the wastewater. Concerning the nitrogen content, a high-chemical quality effluent was obtained, complying with ammonium, nitrite, and nitrate concentrations for water recirculation within a marine aquaculture farm, even in periods where florfenicol was present in the wastewater. In addition, the dissolved oxygen levels in the treated effluents where within the ideal range for fish growth thus reducing the need for oxygenation and, consequently, the farms operational costs. Additionally, the coexistence of microalgae and bacteria within the granules allowed to treat wastewater at low air flow rates potentially reducing the energy needed for system’s aeration. Microalgae-bacterial granular sludge systems can contribute for the aquaculture sector sustainability as they enable to reduce energy and water usage whilst ensuring environmental protection.
- Microbial consortia selection for the development of an innovative nature-based solution for air pollutants remediationPublication . Moreira, Irina S.; Novo, Beatriz; Monteiro, Pedro; Pinto, Glória; Castro, Paula M. L.; Alves, Artur; Tacão, Marta; Alves, MartaAir pollutants, like benzene, toluene, and xylene (BTX), pose significant health and environmental risks being associated with 6.7 million premature deaths annually. Despite plants natural air purification capabilities in green infrastructures, high pollution levels in cities can hinder urban greening when tolerance levels are exceeded. Therefore, this study aimed to develop plant-beneficial microbial consortia with the capacity to degrade air pollutants envisioning their application as plant inoculants to promote plants’ resilience and their efficiency in air purification.Leaves and rhizosphere samples from Tilia sp., Rhododendron sp. and Euonymus sp. were collected in Porto city (Portugal), in an area with high traffic-derived air pollution (NOx, benzene – as in Qualar database). Total pigments concentration showed low variability among plants genera (from 3.24 ± 0.45 to 3.57 ± 0.30 µmol g-1). The neutral to alkaline pH of leaf extracts and high relative water content results indicated good tolerance of the sampled plant genera to pollutants. To select BTX-degrading microbial consortia, leaves and rhizosphere samples were incubated with 300ppm of BTX as the only carbon source, far exceeding EU limits. BTX concentration was monitored through GC-FID. Microbial strains within BTX degrading consortia were identified through sequencing of microbial phylogenetic markers.While leaf samples showed no BTX degradation, rhizosphere samples from all three plant genera displayed significant degradation after 7 to 14 days. Remarkably, in a Rhododendron sp. sample, only 3.8% of the initial BTX concentration remained after 14 days, indicating efficient pollutant removal. Among the fungi genera detected were Penincillium sp., Umbelopsis sp, Fusarium sp. and Clonostachys sp. with species known for their role in plant growth promotion. The obtained microbial consortia have the potential to be used as plant inoculants to promote air remediation.