The ability of several mesocosm-scale and full-scale constructed wetlands (CWs) to remove pharmac... more The ability of several mesocosm-scale and full-scale constructed wetlands (CWs) to remove pharmaceuticals and personal care products (PPCPs) from urban wastewater was assessed. The results of three previous works were considered as a whole to find common patterns in PPCP removal. The experiment took place outdoors under winter and summer conditions. The mesocosm-scale CWs differed in some design parameters, namely the presence of plants, the vegetal species chosen (Typha angustifolia versus Phragmites australis), the flow configuration (surface flow versus subsurface flow), the primary treatment (sedimentation tank versus HUSB), the feeding regime (batch flow versus continuous saturation) and the presence of gravel bed. The full-scale CWs consisted of a combination of various subsystems (ponds, surface flow CWs and subsurface flow CWs). The studied PPCPs were ketoprofen, naproxen, ibuprofen, diclofenac, salicylic acid, carbamazepine, caffeine, methyl dihydrojasmonate, galaxolide and...
ABSTRACT The influence of the loading rate and the seasonal environmental conditions on the bacte... more ABSTRACT The influence of the loading rate and the seasonal environmental conditions on the bacterial communities established in High Rate Algal Ponds (HRAPs) treating diluted swine manure was investigated using 16S rRNA Denaturing Gradient Gel Electrophoresis (DGGE) and further phylogenetic analysis. Two HRAPs were successfully operated at different loading rates (10 and 20 times diluted swine manure, resulting in average Surface Organic Loading Rates (SOLR) ranging from 13 to 99 g m−2 d−1 and from 21 to 180 g m−2 d−1, respectively) for 9 months. The DGGE analysis revealed a high diversity of bacteria symbiotically living with microalgae. The environmental conditions rather than the organic loading rate were the most significant factors determining the bacterial community structure. Hence, despite a higher biodiversity was recorded in summer, both HRAPs presented a similar community regardless of their different organic loading. Most of the species (≈54%) belonged to Verrucomicrobium, an ubiquitous phylum of aerobic bacteria commonly found in eutrophic environments. Firmicutes and Proteobacteria (Gammaproteobacteria) were the other dominant phyla. Some of the bacteria present in the HRAPs were highly resistant to UV radiation and floc-forming species, which might explain the reasonable good settling characteristics of the algal–bacterial biomass in the ponds. The present work provides new insights on the complex interactions between microalgae and bacteria in algal-based wastewater treatment systems.
Boletín de la Real Sociedad Española de Historia Natural, 2021
An Encyonema population collected in the Zambeze River near the Victoria Falls, Namibia, is here ... more An Encyonema population collected in the Zambeze River near the Victoria Falls, Namibia, is here described and illustrated in detail with the aid of LM and SEM microscopy. This taxon had already been presented in the literature under the name E. volkii, the reasons leading to treat this species as a new, independent taxon are here discussed. Encyonema ratpanati sp. nov. can be easily distinguished from E. volkii by its more linear outline (length-to-width ratio up to 4.3 vs. up to 3.5 in E. volkii), its lower degree of dorsiventrality, lack of rostrate apices throughout the whole diminution series, wider axial area and denser areolation (>26 lineolae per 10 µm and not 20–22 as in E. volkii) Se describe una población de Encyonema recogida en el río Zambeze, cerca de las cataratas Victoria, Namibia, y se ilustra en detalle con la ayuda de microscopía óptica y electrónica. Este taxón ya había sido presentado en la literatura bajo el nombre de E. volkii, se discuten aquí las razones que llevan a tratar esta especie como un nuevo taxón independiente. Encyonema ratpanati sp. nov. Puede ser fácilmente diferenciado de E. volkii por su contorno más lineal (cociente largo/ancho de hasta 4.3 vs. hasta 3.5 en E. volkii), su menor grado de dorsiventralidad, la ausencia de ápices rostrados a lo largo de toda la serie decreciente, el área central más ancha una areolación más densa (>26 lineolas cada 10 µm y no 20–22 como en E. volkii).
International Journal of Greenhouse Gas Control, Oct 1, 2015
Abstract This paper evaluates the effect of CO2 on protozoan communities, a neglected group in CO... more Abstract This paper evaluates the effect of CO2 on protozoan communities, a neglected group in CO2 related studies, despite their potential role in influencing bacterial communities, and vegetation growth. For this purpose, the effect of increased CO2 in the soil upon the abundance of protozoa (amoebae, flagellates, and ciliates) and diversity of ciliates was experimentally studied in two soils. Twelve mesocosms were created with 8 m2 cells filled with the upper layer of one of the two soils. The cells were equipped with systems that controlled injection of CO2 at different depths. Two different flows of CO2 (20 and 40 l/h) were studied simulating a potential CO2 leakage from early CSS sites. Water content and pH levels were measured by continuous monitoring systems. There were no clear patterns in the abundance of amoebae, ciliates, or flagellates in response to the injection of CO2. The analysis used to evaluate the community structure of ciliates, such as Equitability, Margalef index, or the Colpodea to Polyhymenophorea ratio showed significant differences with increases in CO2. The results of this study indicate that controlled increments of CO2 in the soil influence the composition of the ciliate community, but have no effect on their total abundance. This paper supports the use of ciliates as promising biological indicators of CO2 effects in Carbon Capture and Storage operations.
Diatoms are microalgae, known to present several characteristics that make them excellent bioindi... more Diatoms are microalgae, known to present several characteristics that make them excellent bioindicators. In this study, we analyzed the epiphytic diatom communities of shallow lakes, with the aim of exploring the genetic variability explained by physical, chemical or geographical variables. We selected 77 lakes within the Spanish part of the Duero River Basin characterized by wide chemical variability. In each lake, physical parameters were measured in situ and water samples were taken to determine nutrient levels in the laboratory. Diatom communities were collected and identified by both microscopy and DNA-metabarcoding, amplifying a genetic barcode of rbcL gene. We analyzed the phylogenetic signal for several environmental parameters at the genus level for the three most representative genera of these lakes. Our results indicate significant phylogenetic signals that differ from a genus to another. Processes related to spatial scales appear to be the main predictors controlling the...
In the ablation zone of glacier habitats, cryoconite holes are known to harbor diverse microbial ... more In the ablation zone of glacier habitats, cryoconite holes are known to harbor diverse microbial communities, including unique diatom floras distinct from those of surrounding aquatic and terrestrial systems. Besides descriptive studies, little is known about the diversity of cryoconite diatoms and their response to environmental stressors, particularly in low-latitude glaciers. This paper documents an extremely diversified diatom community in Antisana Glacier (Ecuador), reporting 278 taxa found in 54 surface holes, although with low individual abundances. Contrary to our expectations, assemblage structure did not respond to water physical or chemical characteristics, nor to cryoconite hole morphology, but to elevation. We demonstrate that elevation is a driver of diatom assemblages. Both alpha diversity (measured as Fisher's index) and species richness (corrected for unequal sample sizes) correlated negatively with elevation, suggesting a replacement toward simplified, poorer c...
The ability of several mesocosm-scale and full-scale constructed wetlands (CWs) to remove pharmac... more The ability of several mesocosm-scale and full-scale constructed wetlands (CWs) to remove pharmaceuticals and personal care products (PPCPs) from urban wastewater was assessed. The results of three previous works were considered as a whole to find common patterns in PPCP removal. The experiment took place outdoors under winter and summer conditions. The mesocosm-scale CWs differed in some design parameters, namely the presence of plants, the vegetal species chosen (Typha angustifolia versus Phragmites australis), the flow configuration (surface flow versus subsurface flow), the primary treatment (sedimentation tank versus HUSB), the feeding regime (batch flow versus continuous saturation) and the presence of gravel bed. The full-scale CWs consisted of a combination of various subsystems (ponds, surface flow CWs and subsurface flow CWs). The studied PPCPs were ketoprofen, naproxen, ibuprofen, diclofenac, salicylic acid, carbamazepine, caffeine, methyl dihydrojasmonate, galaxolide and...
ABSTRACT The influence of the loading rate and the seasonal environmental conditions on the bacte... more ABSTRACT The influence of the loading rate and the seasonal environmental conditions on the bacterial communities established in High Rate Algal Ponds (HRAPs) treating diluted swine manure was investigated using 16S rRNA Denaturing Gradient Gel Electrophoresis (DGGE) and further phylogenetic analysis. Two HRAPs were successfully operated at different loading rates (10 and 20 times diluted swine manure, resulting in average Surface Organic Loading Rates (SOLR) ranging from 13 to 99 g m−2 d−1 and from 21 to 180 g m−2 d−1, respectively) for 9 months. The DGGE analysis revealed a high diversity of bacteria symbiotically living with microalgae. The environmental conditions rather than the organic loading rate were the most significant factors determining the bacterial community structure. Hence, despite a higher biodiversity was recorded in summer, both HRAPs presented a similar community regardless of their different organic loading. Most of the species (≈54%) belonged to Verrucomicrobium, an ubiquitous phylum of aerobic bacteria commonly found in eutrophic environments. Firmicutes and Proteobacteria (Gammaproteobacteria) were the other dominant phyla. Some of the bacteria present in the HRAPs were highly resistant to UV radiation and floc-forming species, which might explain the reasonable good settling characteristics of the algal–bacterial biomass in the ponds. The present work provides new insights on the complex interactions between microalgae and bacteria in algal-based wastewater treatment systems.
Boletín de la Real Sociedad Española de Historia Natural, 2021
An Encyonema population collected in the Zambeze River near the Victoria Falls, Namibia, is here ... more An Encyonema population collected in the Zambeze River near the Victoria Falls, Namibia, is here described and illustrated in detail with the aid of LM and SEM microscopy. This taxon had already been presented in the literature under the name E. volkii, the reasons leading to treat this species as a new, independent taxon are here discussed. Encyonema ratpanati sp. nov. can be easily distinguished from E. volkii by its more linear outline (length-to-width ratio up to 4.3 vs. up to 3.5 in E. volkii), its lower degree of dorsiventrality, lack of rostrate apices throughout the whole diminution series, wider axial area and denser areolation (>26 lineolae per 10 µm and not 20–22 as in E. volkii) Se describe una población de Encyonema recogida en el río Zambeze, cerca de las cataratas Victoria, Namibia, y se ilustra en detalle con la ayuda de microscopía óptica y electrónica. Este taxón ya había sido presentado en la literatura bajo el nombre de E. volkii, se discuten aquí las razones que llevan a tratar esta especie como un nuevo taxón independiente. Encyonema ratpanati sp. nov. Puede ser fácilmente diferenciado de E. volkii por su contorno más lineal (cociente largo/ancho de hasta 4.3 vs. hasta 3.5 en E. volkii), su menor grado de dorsiventralidad, la ausencia de ápices rostrados a lo largo de toda la serie decreciente, el área central más ancha una areolación más densa (>26 lineolas cada 10 µm y no 20–22 como en E. volkii).
International Journal of Greenhouse Gas Control, Oct 1, 2015
Abstract This paper evaluates the effect of CO2 on protozoan communities, a neglected group in CO... more Abstract This paper evaluates the effect of CO2 on protozoan communities, a neglected group in CO2 related studies, despite their potential role in influencing bacterial communities, and vegetation growth. For this purpose, the effect of increased CO2 in the soil upon the abundance of protozoa (amoebae, flagellates, and ciliates) and diversity of ciliates was experimentally studied in two soils. Twelve mesocosms were created with 8 m2 cells filled with the upper layer of one of the two soils. The cells were equipped with systems that controlled injection of CO2 at different depths. Two different flows of CO2 (20 and 40 l/h) were studied simulating a potential CO2 leakage from early CSS sites. Water content and pH levels were measured by continuous monitoring systems. There were no clear patterns in the abundance of amoebae, ciliates, or flagellates in response to the injection of CO2. The analysis used to evaluate the community structure of ciliates, such as Equitability, Margalef index, or the Colpodea to Polyhymenophorea ratio showed significant differences with increases in CO2. The results of this study indicate that controlled increments of CO2 in the soil influence the composition of the ciliate community, but have no effect on their total abundance. This paper supports the use of ciliates as promising biological indicators of CO2 effects in Carbon Capture and Storage operations.
Diatoms are microalgae, known to present several characteristics that make them excellent bioindi... more Diatoms are microalgae, known to present several characteristics that make them excellent bioindicators. In this study, we analyzed the epiphytic diatom communities of shallow lakes, with the aim of exploring the genetic variability explained by physical, chemical or geographical variables. We selected 77 lakes within the Spanish part of the Duero River Basin characterized by wide chemical variability. In each lake, physical parameters were measured in situ and water samples were taken to determine nutrient levels in the laboratory. Diatom communities were collected and identified by both microscopy and DNA-metabarcoding, amplifying a genetic barcode of rbcL gene. We analyzed the phylogenetic signal for several environmental parameters at the genus level for the three most representative genera of these lakes. Our results indicate significant phylogenetic signals that differ from a genus to another. Processes related to spatial scales appear to be the main predictors controlling the...
In the ablation zone of glacier habitats, cryoconite holes are known to harbor diverse microbial ... more In the ablation zone of glacier habitats, cryoconite holes are known to harbor diverse microbial communities, including unique diatom floras distinct from those of surrounding aquatic and terrestrial systems. Besides descriptive studies, little is known about the diversity of cryoconite diatoms and their response to environmental stressors, particularly in low-latitude glaciers. This paper documents an extremely diversified diatom community in Antisana Glacier (Ecuador), reporting 278 taxa found in 54 surface holes, although with low individual abundances. Contrary to our expectations, assemblage structure did not respond to water physical or chemical characteristics, nor to cryoconite hole morphology, but to elevation. We demonstrate that elevation is a driver of diatom assemblages. Both alpha diversity (measured as Fisher's index) and species richness (corrected for unequal sample sizes) correlated negatively with elevation, suggesting a replacement toward simplified, poorer c...
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Papers by Eloy Becares