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Valencia, Spain

Serrano A.B.,Grupo Aguas de Valencia | Molina J.L.A.,Polytechnic University of Valencia | Bonora I.B.,Entitat de Sanejament dAigiies de la Comunitat Valenciana EPSAR | Martinez J.J.M.,Entitat de Sanejament dAigiies de la Comunitat Valenciana EPSAR | Amat G.C.,Polytechnic University of Valencia
Tecnologia del Agua | Year: 2011

The biological scum formation (foaming) in wastewater treatment plants (WWTP) reactors with the activated sludge system is associated to hydrophobic bacteria such as Microthri.x and Mycolata. Recent studies have shown other morphotypes associated to the foaming, among which Nostocoida limicola has been detected. In the hereby research, the morphotypes of N. limicola have been identified and quantified by means of the FISH technique in three WWTP with Microthrix foaming problems, associating its abundance with the parameters of temperature, dissolved oxygen and F/M ratio.

Martinez T.M.,Grupo Aguas de Valencia | Garcia D.A.,Universidad Politecnica de Ingenieria | Polo J.F.,Universidad Politecnica de Ingenieria | Borras-Falomir L.,University of Valencia | Torrecillas A.S.,University of Valencia
Tecnologia del Agua | Year: 2010

In this work, the effect of calcium concentration in wastewater on the polyphosphate accumulating organisms (PAO) is investigated as well as its influence in PAO metabolism, specifically in the YPO4 (ratio between phosphorus release and acetic acid uptake). For this study a sequencing batch reactor (SBR) anaerobic-aerobic was used, in which the PAO enriched biomass was exposed to different calcium concentrations in the influent wastewater. The results indicate that until a given calcium level in the influent wastewater (35 mg Ca/1) the metabolism is not affected, but higher calcium concentrations lead to significant YPO4 decline.

Arregui L.,Complutense University of Madrid | PErez-Uz B.,Complutense University of Madrid | Zornoza A.,Grupo Aguas de Valencia | Serrano S.,Complutense University of Madrid
Journal of Eukaryotic Microbiology | Year: 2010

Unusual prostomatid specimens were found in the biological reactor of a wastewater treatment plant in a health resort in Valencia, Spain. These ciliates were attached to flocs unlike other free-swimming prostomatid ciliates described to date in the mixed liquor of activated sludge plants. The morphological study of this species led to a typically different combination of characteristics: elongated cell shape, 20-30 somatic kineties, 2 perioral kineties, and 1 circumoral kinety, 1 large vacuole protruding at the terminal end, a lorica tapered toward the aperture with a smooth neck, and 11-16 annular ridges. These characteristics place this representative as a new species of the genus Metacystis - Metacystis galiani n. sp. This species became the dominant population within the biological reactor when high values of conductivity (4,244 mScm) and temperature (26.8 °C) were recorded. © 2010 by the International Society of Protistologists.

Lopez-Jimenez P.A.,Polytechnic University of Valencia | Escudero-Gonzalez J.,Polytechnic University of Valencia | Montoya Martinez T.,Grupo Aguas de Valencia | Fajardo Montanana V.,Grupo Aguas de Valencia | Gualtieri C.,University of Naples Federico II
Journal of Water Process Engineering | Year: 2015

In recent years, Computational Fluid Dynamics (CFD) methods have increasingly been used to characterize hydrodynamics and mass-transport in wastewater treatment units. Despite being a well-known and widely applied treatment method to stabilize sludge before final disposal, the hydrodynamics and mass transport in the anaerobic digester have been less studied than those of other treatment units. This paper presents the preliminary results of a 3D numerical study, investigating the characteristics of sludge flow inside the Ontinyent Wastewater Treatment Plant anaerobic digester (Valencia, Spain). An approach based upon the Reynolds Averaged Navier-Stokes (RANS) equation was applied, and closure was obtained using the classical standard k-ε model. In this particular case, a single-phase model was applied considering both Newtonian and Non Newtonian behavior for the sludge simulations. These single-phase preliminary results allowed the occurrence of dead zones to be identified as well as possible shortcuts inside the digester. The analysis was carried out considering the velocities and the flow patterns inside the digester as well as the sludge volume in the digester that had lower velocities than a determined settling velocity. The model was calibrated using available experimental pressure and temperature data. Finally, as well-mixed conditions are strongly desirable for effective anaerobic digestion, proposals to reduce the volume of dead zones are suggested and discussed. © 2015 Elsevier Ltd.

Mendoza J.A.,Universidad Politecnica de Ingenieria | Garcia J.L.,Universidad Politecnica de Ingenieria | Fayos G.,Grupo Aguas de Valencia | Hidalgo D.,Grupo Aguas de Valencia | And 2 more authors.
Tecnologia del Agua | Year: 2012

This paper shows the performance of an ultrafiltration membrane from a membrane bioreactor (MBR) which treats municipal wastewater with industrial discharges. For this purpose, permeate of the ultrafiltration membranes and the mixed liquor from a pilot scale MBR have been characterized, and the fouling of the membranes has been studied through the transmembrane pressure variation, operating at a constant permeate flow rate. The presence of industrial discharges makes necessary to work at low permeate flows and to perform membrane relaxation periods to avoid excessive chemical cleanings. Despite the industrial discharges, both the membranes resistance and the effluent quality were excellent.

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