Microbial fuel cells implemented in constructed wetlands (CW-MFCs), albeit a relatively new technology still under study, have shown to improve treatment efficiency of urban wastewater. So far the vast majority of CW-MFC systems investigated were designed as lab-scale systems working under rather unrealistic hydraulic conditions using synthetic wastewater. The main objective of this work was to quantify CW-MFCs performance operated under different conditions in a more realistic setup using meso-scale systems with horizontal flow fed with real urban wastewater. Operational conditions tested were organic loading rate (4.9±1.6, 6.7±1.4 and 13.6±3.2 g COD/m 2 .day) and hydraulic regime (continuous vs intermittent feeding) as well as different electrical connections: CW control (conventional CW without electrodes), opencircuit CW-MFC (external circuit between anode and cathode not connected) and closed-circuit CW-MFC (external circuit connected). Eight horizontal subsurface flow CWs were operated for about four months. Each wetland consisted of a PVC reservoir of 0.193 m 2 filled with 4/8 mm granitic riverine gravel (wetted depth 25 cm). All wetlands had intermediate sampling points for gravel and interstitial liquid sampling. The CW-MFCs were designed as three MFCs incorporated one after the other along the flow path of the CWs. Anodes consisted of gravel with an incorporated current collector (stainless steel mesh) and the cathode consisted of a graphite felt layer. Electrodes of closed-circuit CW-MFC systems were connected externally over a 220 Ω resistance.Results showed no significant differences between tested organic loading rates, hydraulic regimes or electrical connections, however, on average, systems operated in closed-circuit CW-MFC mode under continuous flow outperformed the other experimental conditions. Closedcircuit CW-MFC compared to conventional CW control systems showed around 5% and 22% higher COD and ammonium removal, respectively. Correspondingly, overall bacteria activity, as measured by the fluorescein diacetate technique, was higher (4% to 34%) in closed-circuit systems when compared to CW control systems. KeywordsConstructed wetlands, urban wastewater, microbial fuel cells, bacterial activity, hydraulic regime, organic loading rate removal. Microbial activity was higher in all three transects in closed-circuit mode when compared to control conditions, which could be one of the reasons for the observed enhancement of treatment performance. Differences between closed-circuit and control systems were not significant in the first transect but very significant in the second and extremely significant in the third, possibly indicating that the lower organic load along the flow path benefited the activity of electrogenic bacteria over competing non-electrogenic bacteria. ACKNOWLEDGEMENTSThis project has received funding from the European Union´s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 676070. This communication reflects only the authors' view...

Endocrine disruptors have been studied for their high occurrence in different environments including aquatic; however, in the context of developing countries, their occurrence, magnitude and potential threat have little information. This study involved the analysis of various components of the urban water cycle in the city of Bogotá, Colombia. As a result, it was found that the compounds with the highest occurrence are plasticizers such as phthalates and bisphenol A, whereas among the drugs, carbamazepine presented the highest concentrations (0.68-31.45 µg L); the analysis of the threat coefficient (HQ) showed the importance of bis(2-ethylhexyl) phthalate (BEHP) and estrone (E1) that can reach surface waters from domestic and industrial discharges.

Palabras clave: compuestos farmacéuticos, disruptores endocrinos, agua potable, agua residual, agua superficial RESUMEN Los microcontaminantes incluyen una amplia gama de compuestos presentes en el ambiente en concentraciones de µg/L o ng/L. En este estudio se analizó la presencia y concentración de microcontaminantes como compuestos farmacéuticos y disruptores endocrinos en el ciclo urbano del agua de la ciudad de Santiago de Cali, Colombia, donde se incluyeron cuatro puntos de monitoreo de agua superficial, tres de agua potable y uno de agua residual. Se realizaron cinco jornadas de muestreo: un muestreo preliminar en el cual se cuantificaron 92 compuestos clasificados en cinco grupos de compuestos farmacéuticos (I, II, III, IV y V) y un grupo de disruptores endocrinos (DE), a partir del cual se priorizaron tres grupos a ser determinados en los cuatro muestreos siguientes. Los criterios de presencia, concentración, efectos sobre la biota acuática y financiamiento de la investigación, se emplearon para seleccionar los grupos I, IV y DE, los cuales tuvieron una presencia superior al 48 % y una concentración media de hasta 11 000 ng/L. Se encontró que los compuestos más relevantes, en términos de presencia y concentración en el ciclo urbano del agua fueron 10,11-dihydro-10,11-dihidroxicarbamazepina, ibuprofeno, naproxeno, gemfibrozilo, paracetamol, sulfametoxazol, estronas, 4-iso-nonilfenol y bisfenol A. La presencia en el ciclo urbano del agua de Cali genera una alerta por la potencial amenaza sobre los organismos acuáticos y la salud humana.Key words: pharmaceutical compounds, endocrine disruptors, drinking water, wastewater, superficial water ABSTRACT Micropollutants includes a wide variety of compounds in environmental concentrations of µg/L or ng/L. The presence and concentration of micropollutants, as pharmaceutical and endocrine disruptors compounds, were studied throughout the urban water cycle of Santiago de Cali city, Colombia. In order to do this, samples were collected in four points of surface water, three of drinking water and one of wastewater. Five samplings were carried out: one screening with 92 compounds measured, classified in five pharmaceutical compounds groups (I, II, III, IV and V) and one endocrine disruptors group Rev. Int.

Recebido em 21/2/12; aceito em 23/8/12; publicado na web em 24/1/13 EFFECT OF THERMAL DRYING AND ALKALINE TREATMENT ON THE MICROBIOLOGICAL AND CHEMICAL CHARACTERISTICS OF BIOSOLIDS FROM DOMESTIC WASTEWATER TREATMENT PLANTS. We evaluated the effect of thermal drying (60 to 75 °C and times from 0 to 12.58 h) and alkaline treatment (Ca(OH) 2 and CaO at doses from 8 to 10%.) on the microbiological and chemical characteristics of biosolids from the Cañaveralejo WWTP. The results showed that in thermal drying all temperatures studied were sufficient to achieve the sanitation of biosolids. In the alkaline treatment the two types of lime showed the total elimination of fecal coliforms, E. coli and helminth eggs, however, the process of alkalization of biosolids had significant influences on organic carbon and calcium.Keywords: biosolid; thermal drying; alkaline treatment. INTRODUCCIÓNLos biosólidos son los lodos que pueden ser empleados bené-ficamente después de ser sometidos a procesos de estabilización como la digestión aerobia o anaerobia, 1 aunque éstos contienen una importante proporción de elementos fertilizantes de gran valor agronómico, la presencia de microorganismos implica que su aplicación directa sin tratamiento previo represente riesgos para la salud humana y biótica. 2Los niveles de microorganismos patógenos, protozoos, parásitos y otros contenidos en los biosólidos, pueden ser significativamente mayores a los presentes en las aguas residuales domésticas; 3 bacterias indicadoras de contaminación fecal se encuentran presentes en los lodos frescos en concentraciones de 10 6 a 10 8 coliformes totales, 10 5 -10 7 coliformes fecales y 10 4 a 10 6 streptococos fecales. 4En 1993 la Environmental Protection Agency (EPA) de los Estados Unidos expidió la norma para el manejo y disposición de lodos y biosólidos generados en el tratamiento de las aguas residuales, 5 esta norma estableció un precedente importante en cuanto al manejo de lodos y biosólidos, fijando límites de metales pesados, calidad microbiológica y atracción de vectores, además de recomendar tratamientos para su estabilización, de tal forma que puedan cumplir con dichas exigencias. En países como México, Brasil Chile, y Argentina también se ha logrado normatizar el uso y disposición de biosólidos tomando como referencia la norma de la EPA; en la mayoría de estas normas, los biosólidos se clasifican en clases A y B con excepción de la norma Mexicana que introduce una tercera categoría (clase C); la clase A corresponde a biosólidos que pueden utilizarse sin restricción en agricultura incluyendo todos los usos urbanos con contacto pú-blico directo; los de clase B pueden ser aplicados con restricciones, para contacto indirecto, revegetación, cultivos de alimentos que se procesen antes de ser consumidos o cobertura en rellenos sanitarios y los de clase C mostrados en la norma mexicana pueden emplearse para usos forestales o mejoramientos de suelos.Los lodos de Plantas de Tratamiento de Aguas Residuales-PTAR son generalmente sometidos a los procesos de espe...

In developing countries such as Colombia, information on the occurrence of endocrine disruptors is still incipient. Bogotá, the capital of Colombia, has a complexity at an anthropogenic and environmental level that makes it particularly important to determine the possible presence of this type of compounds and the risks associated with its presence in aquatic environments. During the present study, the occurrence of endocrine disruptors, mainly pharmaceuticals, plasticizers, and hormones in different aquatic matrices including wastewater, surface water, runoff water, and drinking water was evaluated; the results show that phthalates present the highest occurrence followed by bisphenol A, with an important participation of carbamazepine (0.68-31.45 μgL À1 ), the most commonly found compound is bis(2-ethylhexyl) phthalate (BEHP). It was also found in the drinking water, this leads to the conclusion that endocrine disruptors in Colombia and Bogotá are a reality and deserve attention from researchers to deepen their potential sources of generation and control strategies, as well as the provision must start generating policies in this regard.