Escola Superior de Biotecnologia
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Browsing Escola Superior de Biotecnologia by Sustainable Development Goals (SDG) "06:Água Potável e Saneamento"
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- Dynamics and interrelationships between antibiotic resistance, organic micropollutants and bacterial communities in full-scale rural constructed wetlandsPublication . Teixeira, A. Margarida; Matos, Diana; Coelho, Norberta; Halwatura, Lahiruni M.; Vaz-Moreira, Ivone; Castro, Paula M. L.; Aga, Diana S.; Manaia, Célia M.Constructed wetlands systems (CWs) are increasingly regarded as promising alternatives or complements to conventional wastewater treatment processes. However, the fate of chemical and biological contaminants in realworld treatment processes is understudied in this type of systems. This study aimed to fill this gap by evaluating the response of three horizontal subsurface flow CWs, in Northern Portugal, planted with Phragmites australis, in operation for >7 years, to reducing the load of fecal contamination, antibiotic resistance genes and organic micropollutants (OMPs). Influent, effluent and sediments samples (n = 36) were examined for abundance of cultivable Escherichia coli and total coliforms, total bacteria (16S rRNA gene), 10 genetic biomarkers associated with anthropogenic contamination (uidA, crAssphage, intI1, sul1, ermB, ermF, mefC, qacEΔ1, tetX and aph(3″)-Ib) by quantitative PCR, non-target LC-MS of OMPs and 16S rRNA gene-based bacterial community analysis. The three CWs showed reduction values (log-units/mL) up to 4.8 of E. coli and 3.6 of biomarkers, with the highest values observed in warmer periods. No evidence of for the accumulation microbiological contaminants in the sediments was observed. Among the 59 OMPs detected, reduction rates varied, and the concentration of the most abundant pharmaceutical compounds in the final effluent varied –reaching ng/L concentrations of ~36 000 for fenofibric acid, ~14 000 for acetaminophen, ~3000 for oxazepam and ~2000 for irbesartan, which can be considered high to discharge in the receiving environment. The bacterial community was dominated by members of the class Gammaproteobacteria, with treatment contributing to significant reduction of the relative abundance of members of the classes Clostridia, Bacilli and Actinomycetes. Compared with wastewater, sediments had significantly higher relative abundance of Alphaproteobacteria. The study confirms that CWs are an adequate alternative for the treatment of domestic wastewater in small communities, although it warns of the need for regular monitoring and adjustment of treatment conditions, especially during cooler periods.
- Shifts in aerobic granular sludge bacteriome driven by seawater intrusion in wastewaterPublication . Miranda, Catarina; Castro, Paula M. L.; Amorim, Catarina L.High salinity levels in wastewater treatment plants (WWTPs) can be attributed to multiple sources, including seawater intrusion in wastewater streams. In coastal WWTPs, this phenomenon is becoming more frequent, causing transient salinity shocks on the microbial populations involved in the treatment process. Aerobic granular sludge (AGS) has emerged as a revolutionary technology that has been adopted worldwide for treating several types of wastewater. Much of its success is related to its great tolerance to extreme environments, including high-saline wastewater. In this study, a laboratory-scale AGS reactor was exposed to different salinity stresses over 286 days. First, over 131 days, the seawater content in wastewater was gradually increased in the feeding regime (1.5 – 15 g/L). For the remainder of the operation, the AGS had to deal with daily salinity oscillations, ranging from high (7.5 g/L) to very high (22.5 g/L) seawater levels in wastewater. Throughout the operation, the removal performance of organic carbon, ammonium, and phosphate was consistently effective, despite the daily fluctuations in the seawater content of the wastewater. This was likely ensured by the nutrient removal-related taxa present in the AGS core microbiome, which was highly diverse and resilient to changes in wastewater composition. Over time, enrichment of the core microbiome with halotolerant taxa and extracellular polymeric substance producers proved crucial for maintaining the integrity and stability of the reactor’s performance. The findings of this work underscore the flexibility and robustness of AGS communities in thriving under diverse environmental challenges and adapting to sustain AGS reactor performance.
- Treating domestic wastewater towards freshwater quality: bacterial community and antibiotic resistance profiles highlight critical steps and improvement opportunitiesPublication . Leão, Inês; Antunes, Jorge; Baptista, Inês; Jorge, Ruben; Marinheiro, Luís; Löblich, Stefan; Vaz-Moreira, Ivone; Manaia, Célia M.Ideally, wastewater treatment aims to produce water indistinguishable from freshwater, especially for reuse. This study evaluated bacterial community and antibiotic resistance variations throughout treatment and benchmarked these with freshwater sources. Samples collected from six points of a full-scale wastewater treatment plant, pilot-scale advanced treatment options (non-thermal plasma - NTP, ultrafiltration - UF, UF followed by reverse osmosis- UF+RO), two rivers and a borehole were analyzed for quality parameters (BOD5, TSS, turbidity, Escherichia coli), antibiotic resistance genes (quantitative PCR), class 1 integron variable region composition (Oxford Nanopore sequencing), and bacterial community composition (16S rRNA Illumina sequencing). Secondary treatment followed by sand filters and coagulants caused the highest reduction (~2 log-unit/volume) of all analyzed parameters and the sharpest reduction of diversity of antibiotic resistance genes within class 1 integrons’ variable region. Ultraviolet disinfection triggered minimal bacterial or genes reduction, while among advanced treatments, UF+RO caused the highest, and NTP the lowest. Principal component analysis suggested significant associations between antibiotic resistance (n=32) and genetic recombination elements (n=12) and predominant bacterial families in raw wastewater (Aeromonadaceae, Moraxellaceae, Campylobacteraceae, Lachnospiraceae). For predominant freshwater families (Comamonadaceae, Chitinophagaceae, Flavobacteriaceae) no significant associations were observed. Freshwater differed from UF-treated water by a lower antibiotic resistance abundance, higher bacterial richness (~4000 vs.1200 operational taxonomic units) and distinct predominant families - Alcaligenaceae, Sphingomonadaceae, Chitinophagaceae, and Microbacteriaceae in UF water. The findings underscore the critical role of secondary/post-secondary treatments in shaping resistance and community profiles and suggest that advanced treatment should balance water quality with bacterial diversity preservation for sustainable reuse.