Sant Cugat del Vallès, Spain
Sant Cugat del Vallès, Spain

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Ferrera I.,CSIC - Institute of Marine Sciences | Mas J.,Autonomous University of Barcelona | Taberna E.,Veolia Water Technologies | Sanz J.,Veolia Water Technologies | Sanchez O.,Autonomous University of Barcelona
Biofouling | Year: 2015

The diversity of the bacterial community developed in different stages of two reverse osmosis (RO) water reclamation demonstration plants designed in a wastewater treatment plant (WWTP) in Tarragona (Spain) was characterized by applying 454-pyrosequencing of the 16S rRNA gene. The plants were fed by secondary treated effluent to a conventional pretreatment train prior to the two-pass RO system. Plants differed in the material used in the filtration process, which was sand in one demonstration plant and Scandinavian schists in the second plant. The results showed the presence of a highly diverse and complex community in the biofilms, mainly composed of members of the Betaproteobacteria and Bacteroidetes in all stages, with the presence of some typical wastewater bacteria, suggesting a feed water origin. Community similarities analyses revealed that samples clustered according to filter type, highlighting the critical influence of the biological supporting medium in biofilm community structure. © 2015 Taylor & Francis.

Gal Z.,Desalitech | Septon J.,Desalitech | Efraty A.,Desalitech | Lee A.-M.,Veolia Water Technologies
Desalination and Water Treatment | Year: 2016

This study describes the application of closed circuit desalination (CCD) as a first pass for boiler-feed supplies with high recovery (96%) and low energy (0.34 kWh/m3) from a municipal source (553 μS/cm) comprising the scaling constituents Ca (65 ppm), SO4 (180 ppm), SiO2 (32 ppm), F (1.2 ppm), Ba (0.022 ppm), and Sr (0.295 ppm) in addition to modest amounts of Na (65 ppm) and Cl (18.8 ppm). The 96% recovery trials were performed using a pilot comprised of a single module (8″) with three elements (ESPA2-MAX) under fixed flow and variable pressure consecutive sequential CCD conditions at flux of 27.5 lmh and feed temperature of 20.7°C. Under the specified trial conditions, average permeates of 13 μS/cm electric conductivity (~6.5 ppm) are produced with energy consumption of 0.59 kWh/m3 which translates 0.34 kWh/m3 at 25°C and pressurizing means efficiency of 75%. The process proceeds at pH 5.0 in the presence of an antiscalant (Hydrex-4192 and 4102) with recycled concentrates of high super-saturated silica (max. 800 ppm) without any signs of scaling and/or fouling. The module performance results of this study are scalable to larger CCD systems of similar process design. © 2016 Balaban Desalination Publications. All rights reserved.

Salgado B.,Dow Water and Process Solutions | Ortega J.M.,Veolia Water Technologies | Blazheska J.,Rovira i Virgili University | Sanz J.,Veolia Water Technologies | Garcia-Molina V.,Dow Water and Process Solutions
Desalination and Water Treatment | Year: 2015

Abstract: Reverse osmosis (RO) has developed into one of the most commonly applied technologies for the reduction of the salt content of a feed stream. While it is a widely applied purification process, the market is continuously challenging suppliers for innovation to increase the economics and sustainability. This paper will review and analyse the field performance of Dow FILMTEC™ new high-flow/low-energy seawater reverse osmosis elements—SEAMAXX™. This new seawater RO membrane, which has the highest permeability currently available, is based on innovation related to membrane chemistry. SEAMAXX can be used to increase the recovery of an existing system or to decrease the energy consumption. In either case, the final cost of water is estimated to be between 10 and 15% lower compared to previously available state of the art RO elements. This paper will focus on three different cases studies where the expected performance of SEAMAXX has been validated. Two of these cases correspond to small-size and medium-size pilot trials completed at the Water Technology Center of Dow Water and Process Solutions in Tarragona, Spain. The third experience is a commercial installation which has been in operation with SEAMAXX elements since May 2013. In this particular facility, a retrofit of the RO system was undertaken such that existing 11-year-old FILMTEC membranes were replaced with next generation SWRO membranes. This commercial installation, located in the Canary Islands (Spain) treats the seawater (Atlantic Ocean) well to produce drinking water. In this third case, the performance of the desalination plant will be compared with the performance of the previous elements as well as with the predicted or expected performance of SEAMAXX according to ROSA™ (reverse osmosis system analysis) simulation software and DOW™ FT-NORM normalization tool. Rejection of dissolved salts and in particular, rejection of Boron has been carefully monitored by regular analysis in Dow’s R&D Lab and in external certified laboratories. After almost one year in operation, the performance of SEAMAXX has been validated through different seasons and different sets of operating conditions, confirming the expected savings in energy consumption. © 2014 Balaban Desalination Publications. All rights reserved.

Lopez J.,University of Los Andes, Colombia | Moreau A.,Veolia Water Technologies | Gil J.A.,Grundfos A S | van der Graaf J.H.J.M.,WitteveenBos | And 2 more authors.
Journal of Water Process Engineering | Year: 2015

Viscosity measurements play an important role in activated sludge (AS) characterization, especially with respect to Membrane BioReactor (MBR) operation where low and high shear rates (velocity gradients) occur near the membrane surface and on the bioreactor tank due to the mixing, respectively. Moreover, viscosity plays a role in terms of energy consumption (e.g. pumping and mixing). Therefore, an accurate viscosity relationship as a function of total suspended solids (TSS) and temperature can help to model the behavior of the AS. A total number of 10 municipal and 11 industrial MBR plants throughout Europe were investigated during the period 2007-2009 using the Delft Filtration Characterization method (DFCm). Unlike other literature studies, AS rheology was measured on site, exploiting the resemblance of the DFCm to a tubular rheometer and compared against the results of a rotational rheometer. A new rheological model for the viscosity of AS was developed maintaining the same mathematical structure as previous rheological models made for MBRs. The model proposed in this study is valid for TSS and temperature ranges of 5-20gL-1 and 10-25°C, respectively. This model proves that the DFCm unit can be used as a 'cheap' rheometer and produce the same results as a rotational rheometer for AS viscosity characterization. © 2014 Elsevier Ltd.

A process was developed for biological treatment of municipal wastewater for carbon and nitrogen removal while producing added-value polyhydroxyalkanoates (PHAs). The process comprised steps for pre-denitrification, nitrification and post-denitrification and included integrated fixed-film activated sludge (IFAS) with biofilm carrier media to support nitrification. In a pilot-scale demonstration (500-800L), wastewater treatment performance, in line with European standards, were achieved for total chemical oxygen demand (83% removal) and total nitrogen (80% removal) while producing a biomass that was able to accumulate up to 49% PHA of volatile suspended solids with acetic acid or fermented organic residues as substrates. Robust performance in wastewater treatment and enrichment of PHA-producing biomass was demonstrated under realistic conditions including influent variability during 225days of operation. The IFAS system was found to be advantageous since maintaining nitrification on the biofilm allowed for a relatively low (2days) solids retention time (SRT) for the suspended biomass in the bulk phase. Lower SRT has advantages in higher biomass yield and higher active fraction in the biomass which leads to higher PHA productivity and content. The outcomes show that production of added-value biopolymers may be readily integrated with carbon and nitrogen removal from municipal wastewater.

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