Ecotoxicity characterization assisted performance assessment of electro-bioremediation reactors for nitrate and arsenite elimination.

The performance of combined reduction of nitrate (NO3 - ) to dinitrogen gas (N2 ) and oxidation of arsenite (As[III]) to arsenate (As[V]) by a bioelectrochemical system was assessed, supported by ecotoxicity characterization. For the comprehensive toxicity characterization of the untreated model groundwater and the treated reactor effluents, a problem-specific ecotoxicity test battery was established. The performance of the applied technology in terms of toxicity and target pollutant elimination was compared and analyzed. The highest toxicity attenuation was achieved under continuous flow mode with hydraulic retention time (HRT) = 7.5 h, with 95%, nitrate removal rate and complete oxidation of arsenite to arsenate. Daphnia magna proved to be the most sensitive test organism. The results of the D. magna lethality test supported the choice of the ideal operational conditions based on chemical data analysis. The outcomes of the study demonstrated that the applied technology was able to improve the groundwater quality in terms of both chemical and ecotoxicological characteristics. The importance of ecotoxicity evaluation was also highlighted, given that significant target contaminant elimination did not necessarily lower the environmental impact of the initial, untreated medium, in addition, anomalies might occur during the technology operational process which in some instances, could result in elevated toxicity levels.

Microbial electricity driven anoxic ammonium removal.

Removal of nitrogen, mainly in form of ammonium (NH4+), in wastewater treatment plants (WWTPs) is a highly energy demanding process, mainly due to aeration. It causes costs of about half a million Euros per year in an average European WWTP. Alternative, more economical technologies for the removal of nitrogen compounds from wastewater are required. This study proves the complete anoxic conversion of ammonium (NH4+) to dinitrogen gas (N2) in continuously operated bioelectrochemical systems at the litre-scale. The removal rate is comparable to conventional WWTPs with 35 ± 10 g N m-3 d-1 with low accumulation of NO2-, NO3-, N2O. In contrast to classical aerobic nitrification, the energy consumption is considerable lower (1.16 ± 0.21 kWh kg-1 N, being more than 35 times less than for the conventional wastewater treatment). Biotic and abiotic control experiments confirmed that the anoxic nitrification was an electrochemical biological process mainly performed by Nitrosomonas with hydroxylamine as the main substrate (mid-point potential, Eox = +0.67 ± 0.08 V vs. SHE). This article proves the technical feasibility and reduction of costs for ammonium removal from wastewater, investigates the underlying mechanisms and discusses future engineering needs.

External Resistances Applied to MFC Affect Core Microbiome and Swine Manure Treatment Efficiencies.

Microbial fuel cells (MFCs) can be designed to combine water treatment with concomitant electricity production. Animal manure treatment has been poorly explored using MFCs, and its implementation at full-scale primarily relies on the bacterial distribution and activity within the treatment cell. This study reports the bacterial community changes at four positions within the anode of two almost identically operated MFCs fed swine manure. Changes in the microbiome structure are described according to the MFC fluid dynamics and the application of a maximum power point tracking system (MPPT) compared to a fixed resistance system (Ref-MFC). Both external resistance and cell hydrodynamics are thought to heavily influence MFC performance. The microbiome was characterised both quantitatively (qPCR) and qualitatively (454-pyrosequencing) by targeting bacterial 16S rRNA genes. The diversity of the microbial community in the MFC biofilm was reduced and differed from the influent swine manure. The adopted electric condition (MPPT vs fixed resistance) was more relevant than the fluid dynamics in shaping the MFC microbiome. MPPT control positively affected bacterial abundance and promoted the selection of putatively exoelectrogenic bacteria in the MFC core microbiome (Sedimentibacter sp. and gammaproteobacteria). These differences in the microbiome may be responsible for the two-fold increase in power production achieved by the MPPT-MFC compared to the Ref-MFC.

[Ten-year retrospective study of rotavirus infection in the province of Castellón (Spain)]. / Estudio retrospectivo de 10 años de la infección por rotavirus en la provincia de Castellón.

OBJECTIVE: To determine the percentage of rotavirus infection in children aged less than 14 years old and the epidemiology in area 02 of the province of Castellón (Spain). MATERIAL AND METHODS: We performed a retrospective study from January 1995 to December 2004 in which 14,068 stool samples from pediatric patients with acute gastroenteritis were analyzed. The variables analyzed were sex, age, origin, diagnosis of rotavirus, and date of diagnosis. Differences were considered statistically significant if p<0.05. RESULTS: Rotavirus was detected in 11.9% of the samples (1687 cases) in the 10 years of the study, 12.14 % corresponded to boys and 11.81% to girls (p=0.5459). The mean age of the population was 2.63 years. The highest percentage of cases occurred in the group aged 1- 4 years old (14.1%; p<0.001) and in outpatients (12.76%; p<0.05). In this geographical region, there was a significant tendency (p<0.001) for rotavirus to occur in the winter months. CONCLUSION: Rotavirus is one of the main causes of morbidity in children both in the hospital and the outpatient setting. Children aged less than 4 years old are most frequently affected, especially those aged 1 year. The infection appears mainly in winter.

[Infectious diarrhea study in Castellón, Spain (EDICS): population incidence of sporadic cases in 2004 and comparison with the year 2000]. / Estudio de la diarrea infecciosa en Castellón (EDICS): incidencia poblacional de casos esporádicos en 2004 y comparación con el año 2000.

BACKGROUND AND OBJECTIVE: Infectious intestinal diseases are highly prevalent, and among them sporadic cases are the most common processes. The aim of this study was to estimate the incidence of sporadic cases diagnosed in a healthcare district of Castellón (Spain) in the year 2004, and to compare them with those of the year 2000. MATERIAL AND METHOD: Based on routine coprocultures and individual demographic data of each patient, we calculated the population rates by age for the more frequent microorganisms, especially detailed for children up to 5 years of age. We report the results of the year 2004, and compare these with the previous study of the year 2000. RESULTS: Campylobacter showed the highest rate (1.01 x 103), followed by Salmonella (0.75), each without significant differences regarding the year 2000. The rate of rotavirus cases (0.65) was smaller than in 2000; and for adenovirus 2004 was an atypical seasonal year. In children younger than 3 years, rates were 26.54; 10.23 and 11.75. As in the previous study, the age-distribution in children < 5 years was very particular. An U inverted shape was seen for Campylobacer, and the rates for rotavirus decreased after the peak observed in the youngest group (< 6 months). Among hospitalized patients rotavirus was the most common and Campylobacter the less common. CONCLUSIONS: The epidemiological traits of the rates by age until the age of five are characteristic for each microorganism, as are the proportions of hospitalization. Rates of Campylobacter and Salmonella in the year 2004 were similar to the year 2000, but a decrease in the rotavirus rates was observed.

Estudio de la diarrea infecciosa en Castellón (EDICS): incidencia poblacional de casos esporádicos en 2004 y comparación con el año 2000 / Infectious diarrhea study in Castellón, Spain (EDICS): population incidence of sporadic cases in 2004 and comparison with the year 2000

Fundamento y objetivo: Las infecciones intestinales son procesos muy frecuentes y la mayor parte de ellas son casos esporádicos. Se pretende estimar su incidencia poblacional en un área de Castellón durante el año 2004 y compararla con la del año 2000. Material y método: A partir de los coprocultivos habituales se calcularon las tasas por edades para los microorganismos más frecuentes, prestando especial atención a los niños menores de 5 años de edad. Se presentan los resultados de 2004 y su comparación con el año 2000. Resultados: Campylobacter presentó las tasas globales más altas (1,01 ƒ 103), seguido de Salmonella (0,75), sin diferencias significativas con el año 2000. Rotavirus, con una tasa de 0,65, disminuyó respecto a 2000 y adenovirus presentó un año atípico. En menores de 3 años las tasas fueron, respectivamente, de 26,54, 10,23 y 11,75. La distribución por edades en menores de 5 años fue muy diferente en cada microorganismo, con forma de U invertida para Campylobacter y perfil decreciente continuo desde el máximo en menores de 6 meses de edad para rotavirus. En hospitalizados destacan las elevadas tasas de Rotavirus, ya desde los menores de 6 meses de edad, y los escasos ingresos por campilobacteriosis. Conclusiones: Los rasgos epidemiológicos que reflejan las distribuciones por edad desde los menores de 6 meses hasta los niños de 5 años son peculiares para cada germen, como lo son las proporciones de hospitalización. Las tasas de Campylobacter y Salmonella fueron estables, pero rotavirus experimentó una disminución de incidencia

Background and objective: Infectious intestinal diseases are highly prevalent, and among them sporadic cases are the most common processes. The aim of this study was to estimate the incidence of sporadic cases diagnosed in a healthcare district of Castellón (Spain) in the year 2004, and to compare them with those of the year 2000. Material and method: Based on routine coprocultures and individual demographic data of each patient, we calculated the population rates by age for the more frequent microorganisms, especially detailed for children up to 5 years of age. We report the results of the year 2004, and compare these with the previous study of the year 2000. Results: Campylobacter showed the highest rate (1.01 ƒ 103), followed by Salmonella (0.75), each without significant differences regarding the year 2000. The rate of rotavirus cases (0.65) was smaller than in 2000; and for adenovirus 2004 was an atypical seasonal year. In children younger than 3 years, rates were 26.54; 10.23 and 11.75. As in the previous study, the age-distribution in children < 5 years was very particular. An U inverted shape was seen for Campylobacer, and the rates for rotavirus decreased after the peak observed in the youngest group (< 6 months). Among hospitalized patients rotavirus was the most common and Campylobacter the less common. Conclusions: The epidemiological traits of the rates by age until the age of five are characteristic for each microorganism, as are the proportions of hospitalization. Rates of Campylobacter and Salmonella in the year 2004 were similar to the year 2000, but a decrease in the rotavirus rates was observed