Examinando por Autor "Puyol, Daniel"

Mostrando 1 - 6 de 6

A novel photoanaerobic process as a feasible alternative to the traditional aerobic treatment of refinery wastewater
(Elsevier, 2022) San Martín, Javier; Puyol, Daniel; Segura, Yolanda; Melero, Juan A.; Martínez, Fernando
Refinery wastewater (RWW) treatment is outdated since new wastewater management and reuse challenges require more environmental-friendly and cheap alternatives. Conventional biological treatments focused on activated sludge are highly energy-intensive and resource-dissipating processes. However, anaerobic treatments are an excellent alternative to reduce costs derived from aeration and carbon footprint. This work proposes a novel strategy for the treatment of RWW involving a photoanaerobic membrane bioreactor (PAnMBR) with a mixed culture of purple phototrophic bacteria (PPB). PPB upcycles the organic matter, nitrogen, and phosphorus in an assimilative way, leading to a much higher biomass yield and nutrient removal than aerobic cultures. The enriched PPB culture was generated from the RWW as the sole substrate without specific PPB inoculation. The RWW (exempted from sufficient nutrients) was successfully treated with additional ammonium and phosphates provided by domestic wastewater (DWW). Preliminary batch tests determined the best DWW/RWW volumetric mixing ratio at 25:75. The PAnMBR was operated for 144 days under different specific loading rates (SLR) by modifying hydraulic and solid retention times. The maximum specific loading rate (SLR) for the efficient RWW/ DWW mix treatment was 0.3 mgCODinlet/mgCODbiomass⋅d. The COD consumption was mainly mediated by Rhodopseudomonas sp. and Rhodobacter sp. PPB genera. The PPB-based photo-anaerobic membrane reactor was able to comply with regulated parameters for wastewater discharge for the more restrictive use of reclaimed water according to the European legislation in force.
Biodiesel and biogas production from Isochrysis galbana using dry and wet lipid extraction: A biorefinery approach
(Elsevier, 2020) Sánchez-Bayo, Alejandra; López-Chicharro, Daniel; Morales, Victoria; Espada, Juan José; Puyol, Daniel; Martínez, Fernando; Astals, Sergi; Vicente, Gemma; Bautista, Luis Fernando; Rodríguez, Rosalía
Wet lipid extraction combined with residual biomass anaerobic digestion are alternatives to reduce the overall energy consumption of biodiesel production from microalgae. Solvents with different polarities have been studied to assess dry and wet lipid extraction process from Isochrysis galbana microalga. Ethyl acetate (EA) and a chloroform:methanol (CM) mixture yielded the best lipid extraction results in the dry and wet route with suitable lipid compositions. Fatty acid methyl esters (FAMEs) conversion of dry and wet extracted lipids with these solvents was performed by using both homogeneous (H2SO4) and heterogeneous (resin CT 269) catalysts. FAME production from wet extracted lipids with the EA solvent using the CT-269 resin constitutes an advantageous process because it avoids the water elimination step, and the CT-269 is a heterogeneous commercial catalyst, readily to separate after reaction. Lipid-spent microalga was anaerobically digested, obtaining that waste biomass from the wet extraction with EA had the highest methane yield (310 mL CH4/g volatile solids (VS). Energy balance analysis for FAMEs production with EA solvent (wet route) and heterogeneous catalyst yielded an energy recovery of about 80% in terms of biodiesel and biogas. Therefore, this process constitutes a promising route under an energy-driven microalga biorefinery.
Contamination of N-poor wastewater with emerging pollutants does not affect the performance of purple phototrophic bacteria and the subsequent resource recovery potential
(2020) Martínez, Fernando; de las Heras, Igor; Molina, Raúl; Segura, Yolanda; Hülsen, Tim; Molina, María Carmen; Gonzalez-Benítez, Natalia; Melero, Juan Antonio; Mohedano, Ángel F.; Puyol, Daniel
Propagation of emerging pollutants (EPs) in wastewater treatment plants has become a warning sign, especially for novel resource-recovery concepts. The fate of EPs on purple phototrophic bacteria (PPB)-based systems has not yet been determined. This work analyzes the performance of a photo-anaerobic membrane bioreactor treating a low-N wastewater contaminated with 25 EPs. The chemical oxygen demand (COD), N and P removal efficiencies were stable (76 ± 8, 62 ± 15 and 36 ± 8 %, respectively) for EPs loading rate ranging from 50 to 200 ng L-1 d-1. The PPB community adapted to changes in both the EPs concentration and the organic loading rate (OLR) and maintained dominance with >85 % of total 16S gene copies. Indeed, an increment of the OLR caused an increase of the biomass growth and activity concomitantly with a higher EPs removal efficiency (30 ± 13 vs 54 ± 11 % removal for OLR of 307 ± 4 and 590 ± 8 mgCOD L-1 d-1, respectively). Biodegradation is the main mechanism of EPs removal due to low EPs accumulation on the biomass, the membrane or the reactor walls. Low EPs adsorption avoided biomass contamination, resulting in no effect on its biological methane potential. These results support the use of PPB technologies for resource recovery with low EPs contamination of the products.
Environmental life cycle assessment of polyhydroxyalkanoates production by purple phototrophic bacteria mixed cultures
(Elsevier, 2023) Martin-Gamboa, Mario; Allegue, Luis D.; Puyol, Daniel; Melero, Juan Antonio; Dufour, Javier
Bioplastics offer a promising sustainable alternative to petroleum-based plastics due to their biodegradability as well as favourable thermal and mechanical properties. Among different types of biobased polymers, the production of polyhydroxyalkanoates (PHA) using purple phototrophic bacteria (PPB) and low-value substrates has gained increasing interest. Despite the momentum, challenges regarding the scalability and environmental feasibility of this biopolymer production pathway remain. In response, this study employs an exploratory LCA approach to quantitatively assesses the potential environmental implications of PHA production in powder form and the joint management of the organic fraction of municipal solid waste (OFMSW) through a novel photobiorefinery system that uses PPB mixed cultures. Environmental impacts were tested under multiple improvement scenarios and benchmarked against the production of conventional fossil-based granulate or unprocessed plastics, including low density polyethylene (LDPE), polyethylene terephthalate (PET) and polyurethane (PU). The photobiorefinery stage was found to have the greatest contribution to the impact categories, particularly due to direct emissions, consumption of electricity and production of extractive chemical agents used. These factors accounted for over 70% of the photobiorefinery impact in all cases. Avoided impacts provided net favourable outcomes in terms of carbon footprint and fossil resources when comparing PHA production to conventional plastics, especially PET and PU, with impact reductions ranging from 30% to 60%, respectively. However, when considering other impact categories like eutrophication, this situation was less favourable. The exploration of alternative scenarios offered significant impact reductions, especially when renewable electricity or an environmentally friendly extraction agent is used. Moreover, minimizing methane losses or co-producing hydrogen in the photobiorefinery had a notably positive effect on the carbon footprint, reducing the impact by more than 2 t of CO2 eq per t of PHA powder compared to the base case. Therefore, the implementation of feasible improvement measures in the short term can position PHA produced by mixed cultures as a sustainable alternative to petroleum-based plastics.
Exploring the effects of ZVI addition on resource recovery in the anaerobic digestion process
(2018) Puyol, Daniel; Flores Alsina, Xavier; Segura, Yolanda; Molina, Raúl; Padrino, Beatriz; Fierro, Jose Luis G.; Gernaey, Krist V.; Melero, Juan Antonio; Martínez, Fernando
The influence of Zero Valent Iron (ZVI) addition on the potential resource recovery during the anaerobic digestion (AD) of domestic waste sludge is assessed. Potentially recoverable resources analyzed were nutrients such as struvite to recover P, and energy as biogas to recover C. Short term (biochemical methane potential tests, BMP) and long term (AD1, AD2) experiments are conducted using two types of set-up (batch, continuous). Process data (influent, effluent and biogas) is continuously collected and the dry digested sludge is analyzed by XPS. A mathematical model is developed based on a modified version of the Anaerobic Digestion Model No 1 upgraded with an improved physicochemical description, ZVI corrosion, propionate uptake enhancement and multiple mineral precipitation. The results of all experiments show that ZVI addition increases methane production and promotes the formation of siderite (FeCO3) and vivianite (Fe3(PO4)2), which causes changes in the biogas composition (%CH4 versus %CO2) and reduces P release. The model can satisfactorily reproduce the dynamics of AD processes, nutrient release, pH and methanogenesis in AD1. The proposed approach also describes the changes in the overall performance of the process because of ZVI addition in AD2. A model-based scenario analysis is included balancing chemical-ZVI addition and increased methane production/struvite precipitation. This scenario analysis allows concluding that: (a) the improvement of methane production does not compensate the costs of ZVI purchase, and (b) ZVI dramatically decreases the P recovery potential in the digestate of the AD systems. This is the first study to experimentally and mathematically describe the effect of ZVI on biogas production/composition and on the fate of phosphorus compounds, and its potential implications for potential energy and phosphorus recovery in AD systems.
Using inorganic acids to stop purple phototrophic bacteria metabolism improves PHA recovery at a large scale
(Springer, 2023) Srivastava, Pratiksha; Villamil, John A.; Melero, Juan A.; Martínez, Fernando; Puyol, Daniel
Polyhydroxyalkanoate (PHA) production at a large scale by purple phototrophic bacteria (PPB) is hindered due to high production costs and limited recovery due to its consumption during starvation periods. The present study identifed costefective inorganic acids as inactivation methods for PPB to obtain higher PHA recovery. The study was performed on reactors of diferent scales (10 L and 0.5 L) to grow PPB and recover PHA subsequently. The permanent feast strategy was adopted to obtain higher PHA in an anaerobic environment. As a result, the study achieved 33% (dry weight) PHA recovery using inorganic acid inactivation, while formaldehyde inactivation (traditional method) achieved signifcantly lower PHA recovery (20% only). The results from inorganic acid inactivation were further examined for their stability. The samples were stable even after day 14, and the PHA recovery was the same as on day 0. This pioneering study shows that inorganic acids can be used to inactivate the PPB metabolism to obtain higher PHA recovery; inorganic acid inactivation could be economical for large-scale PHA production.