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Julio Gómez

Independent Researcher, Mi casa, Faculty Member

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Norazian Mohamed Noor (PhD)

Universiti Malaysia Perlis (UniMAP)

University of East London

Estella Weiss-Krejci

Austrian Academy of Sciences

Dr.Subramaniam Karuppannan

Open University Malaysia (OUM),

University of the Basque Country, Euskal Herriko Unibertsitatea

Rasoul Mirabbasi

Shahrekord University

Gabriel Gutierrez-Alonso

University of Salamanca

Hong Kong Polytechnic University

Swansea University

The University of Newcastle

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CFIS PASSIVE SAMPLER

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Papers by Julio Gómez

Nearly Complete Genome Sequence of Raoultella ornithinolytica Strain MQB_Silv_108, Carrying an Uncommon Extended-Spectrum-β-Lactamase-like bla BEL Gene

Microbiology Resource Announcements

Raoultella ornithinolytica has become increasingly important in human diseases. Here, we report t... more Raoultella ornithinolytica has become increasingly important in human diseases. Here, we report the nearly complete genome sequence of a multidrug-resistant strain, R. ornithinolytica MQB_Silv_108, which was isolated from the effluent from a domestic wastewater treatment plant in Spain. Therefore, its release into the environment poses a possible exposure risk for humans and animals.

Incidencia y sensibilidad de la población microbiana aerobia en el Río Tambre

Dynamics of integron structures across a wastewater network – Implications to resistance gene transfer

Water Research, 2021

Highlights • Prevalence and types of integrons vary widely across a wastewater network.• Human-im... more Highlights • Prevalence and types of integrons vary widely across a wastewater network.• Human-impacted class 1 integrons carrying ARGs dominate, but are highest in hospital wastewater.• New qPCR assays are reported that segregate "anthropogenic" class 1 integrons that carry ARGs (aint1) vs empty structures (eaint1).• Recycled activated sludge has triple the “empty structures” per integron relative to WWTP liquid effluents.• Integron dynamics help identify wastewater compartments with elevated ARG transfer.

Spatial ecology of a wastewater network defines the antibiotic resistance genes in downstream receiving waters

Water Research, 2019

Wastewater treatment plants (WWTPs) are an effective barrier in the protection of human and envir... more Wastewater treatment plants (WWTPs) are an effective barrier in the protection of human and environment health around the world, although WWTPs also are suggested to be selectors and-or reservoirs of antibiotic resistance genes (ARGs) before entering the environment. The dogma about WWTPs as "ARG selectors" presumes that biotreatment compartments (e.g., activated sludge; AS) are single densely populated ecosystems with elevated horizontal gene transfer. However, recent work has suggested WWTP biotreatment compartments may be different than previously believed relative to antibiotic resistance (AR) fate, and other process factors, such as bacterial separation and specific waste sources, may be key to ARGs released to the environment. Here we combined 16S rRNA metagenomic sequencing and high-throughput qPCR to characterise microbial communities and ARGs across a wastewater network in Spain that includes both community (i.e., non-clinical urban) and hospital sources. Contrary to expectations, ARGs found in downstream receiving waters were not dominated by AS biosolids (RAS), but more resembled raw wastewater sources. In fact, ARGs and microbial communities in liquid-phase WWTP effluents and RAS were significantly different (BrayeCurtis dissimilarity index ¼ 0.66 ± 0.11), with a consequential fraction of influent ARGs and organisms passing directly through the WWTP with limited association with RAS. Instead, ARGs and organisms in the RAS may be more defined by biosolids separation and biophysical traits, such as flocculation, rather than ARG carriage. This explains why RAS has significantly lower ARG richness (47 ± 4 ARGs) than liquid-phase effluents (104 ± 5 ARGs), and downstream water column (135 ± 4 ARGs) and river sediments (120 ± 5 ARGs) (Tukey's test, p < 0.001). These data suggest RAS and liquid-phase WWTP effluents may reflect two parallel ecosystems with potentially limited ARG exchange. As such, ARG mitigation in WWTPs should more focus on removing bacterial hosts from the liquid phase, AR source reduction, and possibly disinfection to reduce ARG releases to the environment.

Anaerobic hydrolysis of a municipal wastewater in a pilot-scale digester

Water Science and Technology, 2003

Raw domestic wastewater from the city of Santiago de Compostela (Northwest Spain) was fed into a ... more Raw domestic wastewater from the city of Santiago de Compostela (Northwest Spain) was fed into a pilot-scale hydrolytic up flow sludge bed (HUSB) digester with an active volume of 25.5 m3. The total influent chemical oxygen demand (COD) ranged from 360 to 470 mg/l, the influent SS varied from 190 to 370 mg/l, and the temperature was between 17° and 20°C. The organic load rate (OLR) applied increased step by step from 1.2 to 3.9 kgCOD/m3.d, while the hydraulic retention time (HRT) decreased from 7.1 h to 2.9 h. A high suspended solids (SS) removal of about 82-85% from the influent was reached, most of which (81 to 88%) was eliminated by hydrolysis, while the rest remained in the purge stream. The total COD removal ranged from 46 to 59%. On the other hand, a high acidification of the COD remaining in the effluent was obtained, so the percent COD in the form of volatile fatty acids (VFACOD) with respect to total effluent COD was about 43% for the highest HRT applied, and about 27% for ...

Evaluation of fluorogenic TSC agar for recovering Clostridium perfringens in groundwater samples

Water Science and Technology, 2001

Clostridium perfringens is widely recognised as a reliable water pollution indicator. Since sever... more Clostridium perfringens is widely recognised as a reliable water pollution indicator. Since several media can be employed for the membrane filtration enumeration of this microorganism, the main aim of this work was to investigate the ability of fluorocult-supplemented TSC-agar (Merck) for recovering Cl. perfringens from public springs used for direct human consumption. Cl. perfringens recovery was also performed on mCP agar (Cultimed) according to Directive 98/83 as well as on TSC-Agar (Merck), TSN-Agar (Merck) and SPS-Agar (BBL) media. Variance analysis of data obtained showed no statistically significant differences in the counts obtained among all media employed in this work. However, the Cl. perfringens recovery efficiencies with TSC and fluorogenic TSC agars were significantly greater (P = &lt; 0.05) than the corresponding values of mCP and TSN media. On the other hand, the identification of typical and atypical colonies isolated from all media demonstrated that fluorogenic TSC agar was the most specific medium for Cl. perfringens recovery in groundwater samples (85.3% of typical colonies and 82.8% of atypical colonies confirmed). In summary, the membrane filtration technique with fluorogenic TSC agar showed the best performance characteristics of all the media tested as judged by their recovery efficiency and specificity in these water samples.

Tratamiento anaerobio de aguas residuales en digestores de simple y doble etapa

Tecnologia Del Agua, 2000

Los tratamientos anaerobios son una importante alternativa en la depuracion de las aguas residual... more Los tratamientos anaerobios son una importante alternativa en la depuracion de las aguas residuales, por su simplicidad y menor demanda energetica, si bien para que ello sea posible es necesario un mayor conocimiento de este proceso, y su tecnologia. Se definen los conceptos y parametros mas importantes desarrollados para tratar efluentes de media y alta carga, para los que se ha desarrollado varias tecnologias como: Filtro Anaerobio (FA), el Digestor de Lecho de Fango (UASB), el Digestor de Lecho Fluidizado (LE) y el Digestor de Lecho Expandido Granular (EGSB). Para determinar el rendimiento en la depuracion de aguas residuales de tipo urbano, se ha construido una planta piloto constituida por un reactor UASB en el que se han obtenido rendimientos del 60-65 / c en la eliminacion de la DQO total y del 5511c en los SST. Finalmente se define un cuadro comparativo entre el tratamiento aerobio y anaerobio, siendo de destacar las importantes posibilidades que ofrece este ultimo.

Waste water treatment plants as redistributors of resistance genes in bacteria

WIT Transactions on Ecology and the Environment, 2010

The aim of this study was to assess the number of both extended-spectrum -lactamases (ESBL) prod... more The aim of this study was to assess the number of both extended-spectrum -lactamases (ESBL) producing Enterobacteriaceae and vancomycin-resistant enterococci (VRE) present in the inflow (hospital and urban sewage) and effluent waste water treatment plant (WWPT) and receiving waters. The results show that the average counts of ESBL producing Enterobacteriaceae in hospital sewage were much higher (more than 2.5 logs) than those observed in urban waste water. On the other hand, the sewage treatment plant studied did not perform well in removing pathogenic microorganisms. Although Enterobacteriaceae concentrations were reduced in the final effluent by almost two log units as compared with the crude sewage concentrations, a high number of Enterobacteriaceae were detected in the effluent, representing a risk for microbiological pollution of water resources. A strong increase in ESBL-producing bacteria in the receiving water was detected after effluent discharge WWPT. vancomycin resistant enterococci, implying a potential risk of spreading these

Enumeration of Clostridium perfringens spores in groundwater samples: comparison of six culture media

Journal of Microbiological Methods, 2004

In order to investigate the ability of Fluorocult-supplemented TSC agar (TSCF (Fluorocult supplem... more In order to investigate the ability of Fluorocult-supplemented TSC agar (TSCF (Fluorocult supplemented TSC-agar): prepared from Tryptose Sulfite Cycloserine Agar Base (Merck), D-cycloserine (Fluka Chemika, USA), and fluorocult TSC-Agar supplement (Merck)) for detecting spores of Clostridium perfringens in water, we analyzed groundwater samples, pretreated by heating to 80 jC/5 min, using this fluorogenic medium together with five other media: mCP agar (Panreac; Cultimed), TSC agar (Merck, Germany), TSN agar (Merck), and SPS agar (BBL, USA) by the membrane filtration technique, and Wilson-Blair agar (WB) following the still-in-force Spanish official method. Variance analysis of the data obtained shows statistically significant differences in the counts obtained between media employed in this work. The C. perfringens spore counts on mCP agar were significantly lower (P<0.05) than the corresponding values of TSC, TSCF, SPS, and WB media. No statistically significant differences were found between C. perfringens spore counts on TSCF compared with those of other methods used. On the other hand, the identification of typical and atypical colonies isolated from all media demonstrated that fluorogenic TSC agar was the most specific medium for C. perfringens spore recovery in groundwater samples. Additionally, the results obtained indicate that mCP agar, which is the reference method in the European Union, is not suitable medium for recovering C. perfringens spores from groundwater samples.

Characterization of Paint Samples Used in Drinking Water Reservoirs: Identification of Endocrine Disruptor Compounds

Journal of Chromatographic Science, 2002

Several migration tests are performed from various epoxy paint samples that, according to the reg... more Several migration tests are performed from various epoxy paint samples that, according to the regulation, can be used in food reservoirs such as drinking water reservoirs. The level of the organic compounds capable of producing migrations to water with special attention to endocrine disruptor compounds (EDCs) are identified and estimated by closed loop-stripping analysis (CLSA) and liquid-liquid extraction (LLE) methods coupled with gas chromatography (GC)-mass spectrometry (MS). Bisphenol A, a strong endocrine disruptor, is found in all migration experiments. Its concentration level reaches between 0.02 and 0.03 mg/cm 2. The higher concentration corresponds with benzylic alcohol, which is used as a solvent and curing agent in epoxy paint. Other EDCs identified in the migration tests are phthalates, 4-nonylphenol, and t-butylphenol. The main non-EDCs identified are solvents, antioxidants, and rubber-like compounds. No great differences are found in the use of metallic plates or concrete slabs for migration experiments; only additional compounds related with the pretreatment of the concrete wall have been identified, too. In the study of a drinking water sample the same organic compounds identified in the migration test is not seen. This is probably because of the dynamic situation in a drinking water reservoir. Finally, a GC profile of a direct epoxy paint analysis is shown. The main peak identified is bisphenol A diglycidyl ether, monomer, and an active principle of the polymerization of epoxy resins based on bisphenol A. In addition, we report the recoveries of a selected group of EDCs using CLSA and LLE methods coupled with GC-MS.

Start-up alternatives and performance of an UASB pilot plant treating diluted municipal wastewater at low temperature

Bioresource Technology, 2006

Different start-up procedures of an upflow anaerobic sludge bed (UASB) digester were carried out.... more Different start-up procedures of an upflow anaerobic sludge bed (UASB) digester were carried out. Start-up without inoculum (experiment A) was delayed for about 120 day. The digester reached 75-85% total suspended solids (TSS) removal, 54-58% total chemical oxygen demand (TCOD) removal and 63-73% biological oxygen demand (BOD5) removal at influent concentrations of 240-340 mg TCODil-1, temperatures of 13.5-15 degrees C and hydraulic retention times (HRT) of 10-11 h. Digested sludge was used as inoculum in experiment B. After the start-up period of 75 days, digester efficiencies were 58%, 41% and 54% for TSS, TCOD and BOD5 removal, respectively, working at 169 mg TCODil-1, temperature of 14 degrees C and HRT of 11 h. The sludge bed developed and stabilised quickly when using a hydraulically adapted inoculum (experiment C), but TCOD and BOD5 removals remained low and volatile fatty acids (VFA) accumulated in the effluent.

Nearly Complete Genome Sequence of Raoultella ornithinolyticaStrain MQB_Silv_108, Carrying an Uncommon Extended-Spectrum-b-Lactamase-like blaBEL Gene

Microbiology Resource Announcements , 2022

Raoultella ornithinolytica has become increasingly important in human diseases.Here, we report th... more

Determinación de compuestos emergentes en efluentes hospitalarios

Revista de Salud Ambiental, 2015

Los bioensayos con plantas constituyen una excelente herramienta en la evaluacion del riesgo ambi... more Los bioensayos con plantas constituyen una excelente herramienta en la evaluacion del riesgo ambiental y, en particular, la utilizacion de semillas de plantas vasculares es recomendada debido a su mayor sensibilidad. El objetivo del presente trabajo fue evaluar el comportamiento de plantas nativas para ser utilizadas como indicador biologico de contaminacion ambiental con petroleo en relacion con un bioindicador estandarizado. Se analizo el Indice de Germinacion (IG) de Lactuca sativa L., Atriplex lampa (Moq.) D.Dietri. y Prosopis denudans Benth. en treinta muestras de suelo extraidas de un yacimiento petrolero a fin de detectar efectos fitotoxicos. El IG es un metodo economico, rapido y reproducible para determinar toxicidad de suelo, ayudando a caracterizar areas con suelos contaminados. La germinacion de Atriplex lampa (Moq.) D.Dietri. y Prosopis denudans resulto mas resistente en los suelos contaminados de un yacimiento petrolero que el bioindicador de referencia utilizado ( Lac...

Behaviour of pharmaceuticals and personal care products in a sewage treatment plant of northwest Spain

Water Science and Technology

Thirteen pharmaceutical and cosmetic compounds have been surveyed along the different units of a ... more Thirteen pharmaceutical and cosmetic compounds have been surveyed along the different units of a municipal sewage treatment plant (STP) to study their fate across each step and the overall removal efficiency. The STP studied corresponds to a population of approximately 100,000 inhabitants located in Galicia (northwest Spain), including three main sections: pre-treatment (coarse and fine screening, grit and fat removal); primary treatment (sedimentation tanks); and secondary treatment (conventional activated sludge). Among all the substances considered (galaxolide, tonalide, carbamazepine, diazepam, diclofenac, ibuprofen, naproxen, estrone, estradiol, ethinylestradiol, roxitromycin, sulfamethoxazole and iopromide), only significant concentrations were found for two musks (galaxolide and tonalide), two antiphlogistics (ibuprofen and naproxen), two natural estrogens (estrone, estradiol), one antibiotic (sulfamethoxazole) and the X-ray contrast media (iopromide), being the other compoun...

Evaluation of Coli-ID and MUG Plus media for recovering Escherichia coli and other coliform bacteria from groundwater samples

Water Science and Technology

Several chromogenic media for detecting coliform bacteria in water are commercially available inc... more Several chromogenic media for detecting coliform bacteria in water are commercially available including Coli ID medium (ID) (bioMérieux) and MUG Plus cefsulodin agar (MP) (Laboratorios Microkit, S.L.). Since little is known about the performance of these media, we have evaluated their usefulness for recovering Escherichia coli and other coliform organisms in groundwaters used for direct human consumption. Variance analysis of obtained data showed that no statistically significant differences in counts of E. coli and other coliforms on ID and MP media compared with reference methods. However, the evaluation of sensitivity and recovery efficiency of both media showed that the two chromogenic media were more sensitive and significantly more efficient (P = ļ0.05) than reference medium for detecting coliforms in groundwater. However, the identification of 400 typical and atypical colonies isolated from ID and MP media demonstrated a higher specificity when using ID for coliforms and E. c...

La Ría de Vigo. Una aproximación integral al ecosistema marino de la Ría de Vigo

Instituto de Estudios Vigueses Instituto Espanol de Oceanografia Instituto de Investigaciones Mar... more

El tratamiento secundario de aguas residuales como mecanismo redistribuidor de genes de resistencia en bacterias: análisis y evaluación de riesgo

ugr.es

El desarrollo y diseminación de propiedades de resistencia a antimicrobianos está generando una p... more

Performance of a UASB-Digester System Treating Domestic Wastewater

Environmental Technology, 2004

The anaerobic treatment of raw domestic wastewater by a novel technology consisting of an Up-flow... more The anaerobic treatment of raw domestic wastewater by a novel technology consisting of an Up-flow Anaerobic Sludge Bed (UASB) reactor combined with a completely mixed digester for the stabilisation of the UASB sludge was assessed. A pilot-scale plant of the so-called UASB-Digester system was located at the municipal wastewater treatment facility of Santiago de Compostela (Northwest of Spain). The main aim of the Digester was to enhance the biodegradation of influent solids retained in the UASB reactor at low temperatures, then increasing its specific methanogenic activity. The sludge drawn from the middle zone of the UASB entered the upper zone of the Digester and then circulated from the bottom of the Digester to the UASB bottom. Circulating in an automated semi-continuous way, the flow of this sludge stream was selected in order to set a previously defined hydraulic retention time (HRT) (16-27 d) in the digester. The Digester temperature was set at an optimum value ranging from 25 to 35 degrees C. The steady state efficiency of the UASB system, at 6-8 h of HRT, 15-16 degrees C of temperature and 330-360 mg l(-1) of influent total chemical oxygen demand (TCOD) was 79% of total suspended solids (TSS) removal, 52% of TCOD removal and 60% of biological oxygen demand (BOD5) removal. The hydrolysis of retained solids reached 85%, while excess sludge generation was only 7% of influent TCOD. A stable anaerobic (pre)treatment of diluted domestic wastewater was reached as the sludge concentration in the reactor remained mainly constant and the specific methanogenic activity showed a slight increase.

A review of the source, behaviour and distribution of arsenic in natural waters

Applied Geochemistry, 2002

kg−1. There appear to be two distinct 'triggers' that can lead to the release of As on a large sc... more kg−1. There appear to be two distinct 'triggers' that can lead to the release of As on a large scale. The first is the development of high pH (>8.5) conditions in semi-arid or arid environments usually as a result of the combined effects of mineral weathering and high evaporation rates. This pH change leads either to the desorption of adsorbed As (especially As(V) species) and a range of other anion-forming elements (V, B, F, Mo, Se and U) from mineral oxides, especially Fe oxides, or it prevents them from being adsorbed. The second trigger is the development of strongly reducing conditions at near-neutral pH values, leading to the desorption of As from mineral oxides and to the reductive dissolution of Fe and Mn oxides, also leading to As release. Iron (II) and As(III) are relatively abundant in these groundwaters and SO4 concentrations are small (typically 1 mg l−1 or less). Large concentrations of phosphate, bicarbonate, silicate and possibly organic matter can enhance the desorption of As because of competition for adsorption sites. A characteristic feature of high groundwater As areas is the large degree of spatial variability in As concentrations in the groundwaters. This means that it may be difficult, or impossible, to predict reliably the likely concentration of As in a particular well from the results of neighbouring wells and means that there is little alternative but to analyse each well. Arsenic-affected aquifers are restricted to certain environments and appear to be the exception rather than the rule. In most aquifers, the majority of wells are likely to be unaffected, even when, for example, they contain high concentrations of dissolved Fe.

CFIS PASSIVE SAMPLER

Explicación de funcionamiento del muestreador pasivo CFIS

Nearly Complete Genome Sequence of Raoultella ornithinolytica Strain MQB_Silv_108, Carrying an Uncommon Extended-Spectrum-β-Lactamase-like bla BEL Gene

Microbiology Resource Announcements

Raoultella ornithinolytica has become increasingly important in human diseases. Here, we report t... more Raoultella ornithinolytica has become increasingly important in human diseases. Here, we report the nearly complete genome sequence of a multidrug-resistant strain, R. ornithinolytica MQB_Silv_108, which was isolated from the effluent from a domestic wastewater treatment plant in Spain. Therefore, its release into the environment poses a possible exposure risk for humans and animals.

Incidencia y sensibilidad de la población microbiana aerobia en el Río Tambre

Dynamics of integron structures across a wastewater network – Implications to resistance gene transfer

Water Research, 2021

Highlights • Prevalence and types of integrons vary widely across a wastewater network.• Human-im... more Highlights • Prevalence and types of integrons vary widely across a wastewater network.• Human-impacted class 1 integrons carrying ARGs dominate, but are highest in hospital wastewater.• New qPCR assays are reported that segregate "anthropogenic" class 1 integrons that carry ARGs (aint1) vs empty structures (eaint1).• Recycled activated sludge has triple the “empty structures” per integron relative to WWTP liquid effluents.• Integron dynamics help identify wastewater compartments with elevated ARG transfer.

Spatial ecology of a wastewater network defines the antibiotic resistance genes in downstream receiving waters

Water Research, 2019

Wastewater treatment plants (WWTPs) are an effective barrier in the protection of human and envir... more Wastewater treatment plants (WWTPs) are an effective barrier in the protection of human and environment health around the world, although WWTPs also are suggested to be selectors and-or reservoirs of antibiotic resistance genes (ARGs) before entering the environment. The dogma about WWTPs as "ARG selectors" presumes that biotreatment compartments (e.g., activated sludge; AS) are single densely populated ecosystems with elevated horizontal gene transfer. However, recent work has suggested WWTP biotreatment compartments may be different than previously believed relative to antibiotic resistance (AR) fate, and other process factors, such as bacterial separation and specific waste sources, may be key to ARGs released to the environment. Here we combined 16S rRNA metagenomic sequencing and high-throughput qPCR to characterise microbial communities and ARGs across a wastewater network in Spain that includes both community (i.e., non-clinical urban) and hospital sources. Contrary to expectations, ARGs found in downstream receiving waters were not dominated by AS biosolids (RAS), but more resembled raw wastewater sources. In fact, ARGs and microbial communities in liquid-phase WWTP effluents and RAS were significantly different (BrayeCurtis dissimilarity index ¼ 0.66 ± 0.11), with a consequential fraction of influent ARGs and organisms passing directly through the WWTP with limited association with RAS. Instead, ARGs and organisms in the RAS may be more defined by biosolids separation and biophysical traits, such as flocculation, rather than ARG carriage. This explains why RAS has significantly lower ARG richness (47 ± 4 ARGs) than liquid-phase effluents (104 ± 5 ARGs), and downstream water column (135 ± 4 ARGs) and river sediments (120 ± 5 ARGs) (Tukey's test, p < 0.001). These data suggest RAS and liquid-phase WWTP effluents may reflect two parallel ecosystems with potentially limited ARG exchange. As such, ARG mitigation in WWTPs should more focus on removing bacterial hosts from the liquid phase, AR source reduction, and possibly disinfection to reduce ARG releases to the environment.

Anaerobic hydrolysis of a municipal wastewater in a pilot-scale digester

Water Science and Technology, 2003

Raw domestic wastewater from the city of Santiago de Compostela (Northwest Spain) was fed into a ... more Raw domestic wastewater from the city of Santiago de Compostela (Northwest Spain) was fed into a pilot-scale hydrolytic up flow sludge bed (HUSB) digester with an active volume of 25.5 m3. The total influent chemical oxygen demand (COD) ranged from 360 to 470 mg/l, the influent SS varied from 190 to 370 mg/l, and the temperature was between 17° and 20°C. The organic load rate (OLR) applied increased step by step from 1.2 to 3.9 kgCOD/m3.d, while the hydraulic retention time (HRT) decreased from 7.1 h to 2.9 h. A high suspended solids (SS) removal of about 82-85% from the influent was reached, most of which (81 to 88%) was eliminated by hydrolysis, while the rest remained in the purge stream. The total COD removal ranged from 46 to 59%. On the other hand, a high acidification of the COD remaining in the effluent was obtained, so the percent COD in the form of volatile fatty acids (VFACOD) with respect to total effluent COD was about 43% for the highest HRT applied, and about 27% for ...

Evaluation of fluorogenic TSC agar for recovering Clostridium perfringens in groundwater samples

Water Science and Technology, 2001

Clostridium perfringens is widely recognised as a reliable water pollution indicator. Since sever... more Clostridium perfringens is widely recognised as a reliable water pollution indicator. Since several media can be employed for the membrane filtration enumeration of this microorganism, the main aim of this work was to investigate the ability of fluorocult-supplemented TSC-agar (Merck) for recovering Cl. perfringens from public springs used for direct human consumption. Cl. perfringens recovery was also performed on mCP agar (Cultimed) according to Directive 98/83 as well as on TSC-Agar (Merck), TSN-Agar (Merck) and SPS-Agar (BBL) media. Variance analysis of data obtained showed no statistically significant differences in the counts obtained among all media employed in this work. However, the Cl. perfringens recovery efficiencies with TSC and fluorogenic TSC agars were significantly greater (P = &lt; 0.05) than the corresponding values of mCP and TSN media. On the other hand, the identification of typical and atypical colonies isolated from all media demonstrated that fluorogenic TSC agar was the most specific medium for Cl. perfringens recovery in groundwater samples (85.3% of typical colonies and 82.8% of atypical colonies confirmed). In summary, the membrane filtration technique with fluorogenic TSC agar showed the best performance characteristics of all the media tested as judged by their recovery efficiency and specificity in these water samples.

Tratamiento anaerobio de aguas residuales en digestores de simple y doble etapa

Tecnologia Del Agua, 2000

Los tratamientos anaerobios son una importante alternativa en la depuracion de las aguas residual... more Los tratamientos anaerobios son una importante alternativa en la depuracion de las aguas residuales, por su simplicidad y menor demanda energetica, si bien para que ello sea posible es necesario un mayor conocimiento de este proceso, y su tecnologia. Se definen los conceptos y parametros mas importantes desarrollados para tratar efluentes de media y alta carga, para los que se ha desarrollado varias tecnologias como: Filtro Anaerobio (FA), el Digestor de Lecho de Fango (UASB), el Digestor de Lecho Fluidizado (LE) y el Digestor de Lecho Expandido Granular (EGSB). Para determinar el rendimiento en la depuracion de aguas residuales de tipo urbano, se ha construido una planta piloto constituida por un reactor UASB en el que se han obtenido rendimientos del 60-65 / c en la eliminacion de la DQO total y del 5511c en los SST. Finalmente se define un cuadro comparativo entre el tratamiento aerobio y anaerobio, siendo de destacar las importantes posibilidades que ofrece este ultimo.

Waste water treatment plants as redistributors of resistance genes in bacteria

WIT Transactions on Ecology and the Environment, 2010

The aim of this study was to assess the number of both extended-spectrum -lactamases (ESBL) prod... more The aim of this study was to assess the number of both extended-spectrum -lactamases (ESBL) producing Enterobacteriaceae and vancomycin-resistant enterococci (VRE) present in the inflow (hospital and urban sewage) and effluent waste water treatment plant (WWPT) and receiving waters. The results show that the average counts of ESBL producing Enterobacteriaceae in hospital sewage were much higher (more than 2.5 logs) than those observed in urban waste water. On the other hand, the sewage treatment plant studied did not perform well in removing pathogenic microorganisms. Although Enterobacteriaceae concentrations were reduced in the final effluent by almost two log units as compared with the crude sewage concentrations, a high number of Enterobacteriaceae were detected in the effluent, representing a risk for microbiological pollution of water resources. A strong increase in ESBL-producing bacteria in the receiving water was detected after effluent discharge WWPT. vancomycin resistant enterococci, implying a potential risk of spreading these

Enumeration of Clostridium perfringens spores in groundwater samples: comparison of six culture media

Journal of Microbiological Methods, 2004

In order to investigate the ability of Fluorocult-supplemented TSC agar (TSCF (Fluorocult supplem... more In order to investigate the ability of Fluorocult-supplemented TSC agar (TSCF (Fluorocult supplemented TSC-agar): prepared from Tryptose Sulfite Cycloserine Agar Base (Merck), D-cycloserine (Fluka Chemika, USA), and fluorocult TSC-Agar supplement (Merck)) for detecting spores of Clostridium perfringens in water, we analyzed groundwater samples, pretreated by heating to 80 jC/5 min, using this fluorogenic medium together with five other media: mCP agar (Panreac; Cultimed), TSC agar (Merck, Germany), TSN agar (Merck), and SPS agar (BBL, USA) by the membrane filtration technique, and Wilson-Blair agar (WB) following the still-in-force Spanish official method. Variance analysis of the data obtained shows statistically significant differences in the counts obtained between media employed in this work. The C. perfringens spore counts on mCP agar were significantly lower (P<0.05) than the corresponding values of TSC, TSCF, SPS, and WB media. No statistically significant differences were found between C. perfringens spore counts on TSCF compared with those of other methods used. On the other hand, the identification of typical and atypical colonies isolated from all media demonstrated that fluorogenic TSC agar was the most specific medium for C. perfringens spore recovery in groundwater samples. Additionally, the results obtained indicate that mCP agar, which is the reference method in the European Union, is not suitable medium for recovering C. perfringens spores from groundwater samples.

Characterization of Paint Samples Used in Drinking Water Reservoirs: Identification of Endocrine Disruptor Compounds

Journal of Chromatographic Science, 2002

Several migration tests are performed from various epoxy paint samples that, according to the reg... more Several migration tests are performed from various epoxy paint samples that, according to the regulation, can be used in food reservoirs such as drinking water reservoirs. The level of the organic compounds capable of producing migrations to water with special attention to endocrine disruptor compounds (EDCs) are identified and estimated by closed loop-stripping analysis (CLSA) and liquid-liquid extraction (LLE) methods coupled with gas chromatography (GC)-mass spectrometry (MS). Bisphenol A, a strong endocrine disruptor, is found in all migration experiments. Its concentration level reaches between 0.02 and 0.03 mg/cm 2. The higher concentration corresponds with benzylic alcohol, which is used as a solvent and curing agent in epoxy paint. Other EDCs identified in the migration tests are phthalates, 4-nonylphenol, and t-butylphenol. The main non-EDCs identified are solvents, antioxidants, and rubber-like compounds. No great differences are found in the use of metallic plates or concrete slabs for migration experiments; only additional compounds related with the pretreatment of the concrete wall have been identified, too. In the study of a drinking water sample the same organic compounds identified in the migration test is not seen. This is probably because of the dynamic situation in a drinking water reservoir. Finally, a GC profile of a direct epoxy paint analysis is shown. The main peak identified is bisphenol A diglycidyl ether, monomer, and an active principle of the polymerization of epoxy resins based on bisphenol A. In addition, we report the recoveries of a selected group of EDCs using CLSA and LLE methods coupled with GC-MS.

Start-up alternatives and performance of an UASB pilot plant treating diluted municipal wastewater at low temperature

Bioresource Technology, 2006

Different start-up procedures of an upflow anaerobic sludge bed (UASB) digester were carried out.... more Different start-up procedures of an upflow anaerobic sludge bed (UASB) digester were carried out. Start-up without inoculum (experiment A) was delayed for about 120 day. The digester reached 75-85% total suspended solids (TSS) removal, 54-58% total chemical oxygen demand (TCOD) removal and 63-73% biological oxygen demand (BOD5) removal at influent concentrations of 240-340 mg TCODil-1, temperatures of 13.5-15 degrees C and hydraulic retention times (HRT) of 10-11 h. Digested sludge was used as inoculum in experiment B. After the start-up period of 75 days, digester efficiencies were 58%, 41% and 54% for TSS, TCOD and BOD5 removal, respectively, working at 169 mg TCODil-1, temperature of 14 degrees C and HRT of 11 h. The sludge bed developed and stabilised quickly when using a hydraulically adapted inoculum (experiment C), but TCOD and BOD5 removals remained low and volatile fatty acids (VFA) accumulated in the effluent.

Nearly Complete Genome Sequence of Raoultella ornithinolyticaStrain MQB_Silv_108, Carrying an Uncommon Extended-Spectrum-b-Lactamase-like blaBEL Gene

Microbiology Resource Announcements , 2022

Raoultella ornithinolytica has become increasingly important in human diseases.Here, we report th... more

Determinación de compuestos emergentes en efluentes hospitalarios

Revista de Salud Ambiental, 2015

Los bioensayos con plantas constituyen una excelente herramienta en la evaluacion del riesgo ambi... more Los bioensayos con plantas constituyen una excelente herramienta en la evaluacion del riesgo ambiental y, en particular, la utilizacion de semillas de plantas vasculares es recomendada debido a su mayor sensibilidad. El objetivo del presente trabajo fue evaluar el comportamiento de plantas nativas para ser utilizadas como indicador biologico de contaminacion ambiental con petroleo en relacion con un bioindicador estandarizado. Se analizo el Indice de Germinacion (IG) de Lactuca sativa L., Atriplex lampa (Moq.) D.Dietri. y Prosopis denudans Benth. en treinta muestras de suelo extraidas de un yacimiento petrolero a fin de detectar efectos fitotoxicos. El IG es un metodo economico, rapido y reproducible para determinar toxicidad de suelo, ayudando a caracterizar areas con suelos contaminados. La germinacion de Atriplex lampa (Moq.) D.Dietri. y Prosopis denudans resulto mas resistente en los suelos contaminados de un yacimiento petrolero que el bioindicador de referencia utilizado ( Lac...

Behaviour of pharmaceuticals and personal care products in a sewage treatment plant of northwest Spain

Water Science and Technology

Thirteen pharmaceutical and cosmetic compounds have been surveyed along the different units of a ... more Thirteen pharmaceutical and cosmetic compounds have been surveyed along the different units of a municipal sewage treatment plant (STP) to study their fate across each step and the overall removal efficiency. The STP studied corresponds to a population of approximately 100,000 inhabitants located in Galicia (northwest Spain), including three main sections: pre-treatment (coarse and fine screening, grit and fat removal); primary treatment (sedimentation tanks); and secondary treatment (conventional activated sludge). Among all the substances considered (galaxolide, tonalide, carbamazepine, diazepam, diclofenac, ibuprofen, naproxen, estrone, estradiol, ethinylestradiol, roxitromycin, sulfamethoxazole and iopromide), only significant concentrations were found for two musks (galaxolide and tonalide), two antiphlogistics (ibuprofen and naproxen), two natural estrogens (estrone, estradiol), one antibiotic (sulfamethoxazole) and the X-ray contrast media (iopromide), being the other compoun...

Evaluation of Coli-ID and MUG Plus media for recovering Escherichia coli and other coliform bacteria from groundwater samples

Water Science and Technology

Several chromogenic media for detecting coliform bacteria in water are commercially available inc... more Several chromogenic media for detecting coliform bacteria in water are commercially available including Coli ID medium (ID) (bioMérieux) and MUG Plus cefsulodin agar (MP) (Laboratorios Microkit, S.L.). Since little is known about the performance of these media, we have evaluated their usefulness for recovering Escherichia coli and other coliform organisms in groundwaters used for direct human consumption. Variance analysis of obtained data showed that no statistically significant differences in counts of E. coli and other coliforms on ID and MP media compared with reference methods. However, the evaluation of sensitivity and recovery efficiency of both media showed that the two chromogenic media were more sensitive and significantly more efficient (P = ļ0.05) than reference medium for detecting coliforms in groundwater. However, the identification of 400 typical and atypical colonies isolated from ID and MP media demonstrated a higher specificity when using ID for coliforms and E. c...

La Ría de Vigo. Una aproximación integral al ecosistema marino de la Ría de Vigo

Instituto de Estudios Vigueses Instituto Espanol de Oceanografia Instituto de Investigaciones Mar... more

El tratamiento secundario de aguas residuales como mecanismo redistribuidor de genes de resistencia en bacterias: análisis y evaluación de riesgo

ugr.es

El desarrollo y diseminación de propiedades de resistencia a antimicrobianos está generando una p... more

Performance of a UASB-Digester System Treating Domestic Wastewater

Environmental Technology, 2004

The anaerobic treatment of raw domestic wastewater by a novel technology consisting of an Up-flow... more The anaerobic treatment of raw domestic wastewater by a novel technology consisting of an Up-flow Anaerobic Sludge Bed (UASB) reactor combined with a completely mixed digester for the stabilisation of the UASB sludge was assessed. A pilot-scale plant of the so-called UASB-Digester system was located at the municipal wastewater treatment facility of Santiago de Compostela (Northwest of Spain). The main aim of the Digester was to enhance the biodegradation of influent solids retained in the UASB reactor at low temperatures, then increasing its specific methanogenic activity. The sludge drawn from the middle zone of the UASB entered the upper zone of the Digester and then circulated from the bottom of the Digester to the UASB bottom. Circulating in an automated semi-continuous way, the flow of this sludge stream was selected in order to set a previously defined hydraulic retention time (HRT) (16-27 d) in the digester. The Digester temperature was set at an optimum value ranging from 25 to 35 degrees C. The steady state efficiency of the UASB system, at 6-8 h of HRT, 15-16 degrees C of temperature and 330-360 mg l(-1) of influent total chemical oxygen demand (TCOD) was 79% of total suspended solids (TSS) removal, 52% of TCOD removal and 60% of biological oxygen demand (BOD5) removal. The hydrolysis of retained solids reached 85%, while excess sludge generation was only 7% of influent TCOD. A stable anaerobic (pre)treatment of diluted domestic wastewater was reached as the sludge concentration in the reactor remained mainly constant and the specific methanogenic activity showed a slight increase.

A review of the source, behaviour and distribution of arsenic in natural waters

Applied Geochemistry, 2002

kg−1. There appear to be two distinct 'triggers' that can lead to the release of As on a large sc... more kg−1. There appear to be two distinct 'triggers' that can lead to the release of As on a large scale. The first is the development of high pH (>8.5) conditions in semi-arid or arid environments usually as a result of the combined effects of mineral weathering and high evaporation rates. This pH change leads either to the desorption of adsorbed As (especially As(V) species) and a range of other anion-forming elements (V, B, F, Mo, Se and U) from mineral oxides, especially Fe oxides, or it prevents them from being adsorbed. The second trigger is the development of strongly reducing conditions at near-neutral pH values, leading to the desorption of As from mineral oxides and to the reductive dissolution of Fe and Mn oxides, also leading to As release. Iron (II) and As(III) are relatively abundant in these groundwaters and SO4 concentrations are small (typically 1 mg l−1 or less). Large concentrations of phosphate, bicarbonate, silicate and possibly organic matter can enhance the desorption of As because of competition for adsorption sites. A characteristic feature of high groundwater As areas is the large degree of spatial variability in As concentrations in the groundwaters. This means that it may be difficult, or impossible, to predict reliably the likely concentration of As in a particular well from the results of neighbouring wells and means that there is little alternative but to analyse each well. Arsenic-affected aquifers are restricted to certain environments and appear to be the exception rather than the rule. In most aquifers, the majority of wells are likely to be unaffected, even when, for example, they contain high concentrations of dissolved Fe.

Tratamiento anaerobio de aguas residuales urbanas en reactores de una y dos fases a baja temperatura

Endotoxinas, definición y determinación analítica

Máster en Enxeñaría Ambiental da USC, 2007

Las endotoxinas son un componente de la membrana exterior de las bacterias Gram negativas. Se tr... more Las endotoxinas son un componente de la membrana exterior de las bacterias Gram negativas. Se trata de agregados macromoleculares de alrededor de 1 millón de daltons (endotoxina libre). Las bacterias Gram negativas se presentan en el medio ambiente, principalmente contaminando los vegetales, y se detectan muy a menudo en las plantas de algodón. Estas bacterias se multiplican rápidamente en el agua estancada ya que requieren muy pocos nutrientes.

En forma pura, las endotoxinas son lipopolisacáridos (LPS); la porción lipídica del LPS, denominada lípido A, contiene ácidos grasos con el grupo 3-hidroxi. Químicamente es distinta a todos los demás lípidos de la membrana biológica; es la fracción más constante del LPS y es la responsable de la toxicidad característica de la molécula.

Curso verano USC Tratamiento Aguas 2010

El agua debe tratarse para que se pueda suministrar en condiciones de salubridad a la población. ... more

ANÁLISIS DE COMPUESTOS FARMACÉUTICO Y MERGENTES EN EFLUENTES HOSPITALARIOS UTILIZANDO MUESTREO PASIVO

PRESENCIA Y ELIMINACIÓN DE MICROCONTAMINANTES EN AGUA. 1 SIMPOSIO NOVEDAR, 2019

El objetivo de este trabajo es investigar la presencia de microcontaminantes en un efluente del C... more El objetivo de este trabajo es investigar la presencia de microcontaminantes en un efluente del Complejo Hospitalario Universitario de la USC que atiende a una población de aproximadamente 100,000 habitantes utilizando muestreo pasivo. Los compuestos que pertenecen a diferentes clases terapéuticas se han considerado y se mencionan en la introducción.

RESISTENCIA A ANTIMICROBIANOS EN AGUAS SUPERCIALES DESTINADAS A LA PRODUCCIÓN DE AGUA POTABLE

I CONGRESO Nacional de Laboratorios Agroalimentarios, 2004

Caracterizar de la población de bacterias heterótrofas presentes en las aguas destinadas a la pro... more Caracterizar de la población de bacterias heterótrofas presentes en las aguas destinadas a la producción de agua potable y en las aguas destinadas al consumo público.
Investigar la resistencia de las bacterias heterótrofas, presentes en las aguas analizadas, a agentes antimicrobianos empleados en sanidad humana, veterinaria y en alimentación animal.

Residuos zoosanitarios en aguas de consumo

V JORNADAS DE CONTROL DE RESIDUOS. EN ALIMENTOS: ANALÍTICA E INSPECCIÓN, 2009

El poder diferenciar el origen de los residuos zoosanitarios en aguas de consumo es importante. S... more

Performances of the Continuous Flow Integrative Sampler (CFIS) for monitoring hormones and pharmaceuticals in hospital effluents

by Julio Gómez and Lorena Sanjuan Tortosa

Conference Book. The 13th IWA Leading Edge Conference on Water and Wastewater Technologies, 2016

Passive sampling has recently emerged as an efficient alternative to conventional active sampling... more Passive sampling has recently emerged as an efficient alternative to conventional active sampling for the monitoring of organic pollutants in water. Labaqua developed and patented the Continuous Flow Integrative Sampler (CFIS), a fully submersible automated sampler, based on the passive sampling technique, for monitoring a wide range of organic micropollutants in various types of waters. The performances of the CFIS was compared with spot sampling for monitoring hormones and pharmaceuticals in influents of two hospitals effluents. The CFIS allowed integrating variations of concentrations of the target pollutants and achieving lower limits of detection than spot sampling, providing more accurate and more reliable contamination data.

ANÁLISIS DE COMPUESTOS FARMACÉUTICO Y EMERGENTES EN EFLUENTES HOSPITALARIOS UTILIZANDO MUESTREO PASIVO

by Julio Gómez, Adela Yañez, and Laura Díaz Esplá

Simposio Novedar, 2019

El objetivo de este trabajo es presentar la concentración de algunos PPCP en los efluentes de un ... more El objetivo de este trabajo es presentar la concentración de algunos PPCP en los efluentes de un complejo hospitalario que corresponde a una población de aproximadamente 100,000 habitantes-equivalentes. Se han considerado compuestos que pertenecen a diferentes clases terapéuticas, como los antiinflamatorios (naproxeno, diclofenaco); antiepilépticos (carbamazepina); hormonas (estrona, 17-β-estradiol, 17-α-etinilestradiol y estriol); desinfectantes (triclosán); Plaguicidas (diurón) y antibióticos (sulfametoxazol, trimetoprima, eritromicina). También se ha buscado con este proyecto saber si hay diferencias entre los PPCP que se utilizan en cada uno de los hospitales.

CONTAMINACIÓN DIFUSA “EL PROBLEMA DE LOS NUTRIENTES EN EL MEDIO RURAL

"VIII CONFERENCIA SOBRE GESTIÓN DEL AGUA" aqua doce, 2012

Las aguas residuales agrarias o agropecuarias son aguas procedentes de actividades agrícolas y ga... more Las aguas residuales agrarias o agropecuarias son aguas procedentes de actividades agrícolas y ganaderas. Se incluyen las aguas destinadas para riego (uso agrícola), los residuos líquidos del ganado (purines) y las agua utilizadas en explotaciones ganaderas, sobre todo en operaciones de limpieza que pueden arrastrar el estiércol y los purines, aunque, debido a su alta contaminación, deberían intentar eliminarse estos desechos como residuos

Molecular and physiological approaches to understand the ecology of methanol degradation during the biofiltration of air streams

Proceedings of the 2010 Duke-UAM Conference on Biofiltration for Air Pollution Control, Oct 28, 2010

A 13.4 L biofilter was used to treat a polluted air stream using methanol as a model pollutant. T... more A 13.4 L biofilter was used to treat a polluted air stream using methanol as a model pollutant. This unit was operated under two situations: i) with pine bark chips randomly packed with no pH control of the aqueous phase (P1) and; ii) with a structured packing formed by PVC rings and with a pH control system of the aqueous phase (P2). During P1 a continuous drop in pH was observed, from neutral values down to pH 2 after 60 days of operation. Biofilm developed in a homogeneous manner over all available areas of the support. Heterotrophic activity achieved 0.40.5 kg COD/kg VSS·d at the end of operation. The application of the FISH technique indicated that eukaryotic microorganisms were predominant over bacteria. Besides, the application of the PCR technique, by means of cloning and sequencing, allowed the identification of the main eukaryotes present: the fungi Candida boidinii, Nectria Mariannaeae, Scytalidium lignicola and Hydrocina chaetocladia. During the second period (P2), methanol removal observed was higher, close to 99.9%, after the first month of operation. In this case, biofilm was developed in a homogeneous manner over all rings, with much higher heterotrophic activity. The application of the FISH technique indicated in this case a clear predominance of eubacteria, although archaea and a minor presence of eukaryotic microorganisms were also present.

Eutrofización, consecuencia de la contaminación

Blog de Planckito, 2024

Dentro de los múltiples problemas a los que se enfrentan las masas de agua, algunos de los cuales... more Dentro de los múltiples problemas a los que se enfrentan las masas de agua, algunos de los cuales ya se han abordado en este blog, como la presencia de macro y microplásticos, la excesiva contaminación por sustancia químicas o la presencia de bacterias resistentes a antimicrobianos, existe uno que es inherente a la actividad humana y que, desgraciadamente, se expande cada vez más. Es la eutrofización.

La eutrofización es el proceso en el que un exceso de nutrientes, especialmente compuestos de nitrógeno y/o fósforo, provoca un crecimiento acelerado de algas y formas superiores de vida vegetal en el ecosistema acuático.