Passos, Fabiana Lopes del Rei; Ferrer Martí, Ivet
Microalgal biomass grown in wastewater treatment raceway ponds may be valorised producing bioenergy through anaerobic digestion. However, pretreatment techniques seem to be necessary for enhancing microalgae methane yield. In this study, hydrothermal pretreatment was studied prior to batch and continuous reactors. The pretreatment increased organic matter solubilisation (8-13%), anaerobic digestion rate (30-90%) and final methane yield (17-39%) in batch tests. The highest increase was attained with the pretreatment at 130 degrees C for 15 min, which was attested in a laboratory-scale continuous reactor operated at a hydraulic retention time of 20 days with an average organic loading rate of 0.7...
Garfi, Marianna; Ferrer Martí, Laia; Villegas, V.; Ferrer Martí, Ivet
Guinea pig is one of the most common livestock in rural communities of the Andes. The aim of this research was to study the anaerobic digestion of guinea pig manure in low-cost unheated tubular digesters at high altitude. To this end, the performance of two pilot digesters was monitored during 7 months; and two greenhouse designs were compared. In the dome roof digester the temperature and biogas production were significantly higher than in the shed roof digester. However, the biogas production rate was low (0.04 View the MathML sourcembiogas3View the MathML sourcemdigester-3 d−1), which is attributed to the low organic...
Garfi, Marianna; Ferrer Martí, Laia; Velo García, Enrique; Ferrer Martí, Ivet
Low-cost household digesters are a promising appropriate technology which can help reducing the pressure on the environment due to deforestation and greenhouse gases emissions. The biogas and biofertilizer produced can alleviate poverty, by improving health conditions, increasing crops productivity and saving working time and burden for women and children. The aim of this study is to evaluate low-cost digesters technical, environmental and socio-economic impacts in rural communities of the Peruvian Andes, where a pilot project was developed during the last 3 years. Although the benefits are restricted by the performance of anaerobic digestion at high altitude, the results show that...
Garfi, Marianna; Gelman, Pau; Comas Angelet, Jordi; Carrasco, W.; Ferrer Martí, Ivet
This research aimed at assessing the properties of guinea pig manure digestate from low-cost tubular digesters for crops fertilization in rural Andean communities. To this end, field trials were carried out to evaluate the effect of the digestate on two common Andean crops: potato (Solanum tuberosum) and forage (Lolium multiflorum and Trifolium pratense L.). The potato yield (20–25 t ha−1) increased by 27.5% with digestate, by 15.1% with pre-compost and by 10.3% with the mixture, compared to the control. The forage yield (20–21 t ha−1) increased by 1.4% with digestate – 50% dose, and by 8.8% with digestate – 100%...
Ferrer Martí, Ivet; Garfi, Marianna; Uggetti, Enrica; Ferrer Martí, Laia; Calderón, Arcadio; Velo García, Enrique
Low-cost tubular digesters originally developed in tropical regions have been adapted to the extreme weather conditions of the Andean Plateau (3000e4000 m.a.s.l.). The aim of this study was to characterise biogas production in household digesters located at high altitude, operating under psychrophilic conditions. To this end, two pilot digesters were monitored and field campaigns were carried out in two representative digesters of rural communities. Digesters’ useful volume ranged between 2.4 and 7.5m3, and hydraulic residence time (HRT) between 60 and 90 days. The temperature inside the digester’s greenhouse ranged between 20 and 25 ºC. Treating cow manure, a specific biogas...
Morató Farreras, Jordi; Codony Iglesias, Francesc; Sánchez Lorente, Olga; Martín Pérez, Leonardo; García Serrano, Joan; Mas Herrero, Jordi
Constructed wetlands constitute an interesting option for wastewater reuse since high concentrations of contaminants and pathogenic microorganisms can be removed with these natural treatment systems. In this work, the role of key design factors which could affect microbial removal and wetland performance, such as granular media, water depth and season effect was evaluated in a pilot system consisting of eight parallel horizontal subsurface flow (HSSF) constructed wetlands treating urban wastewater from Les Franqueses del Valles (Barcelona, Spain). Gravel biofilm as well as influent and effluent water samples of these systems were taken in order to detect the presence of bacterial...
Passos, Fabiana Lopes del Rei; Uggetti, Enrica; Carrère, Helene; Ferrer Martí, Ivet
Microalgae have been intensively studied as a source of biomass for replacing conventional fossil fuels in the last decade. The optimization of biomass production, harvesting and downstream processing is necessary for enabling its full-scale application. Regarding biofuels, biogas production is limited by the characteristics of microalgae, in particular the complex cell wall structure of most algae species. Therefore, pretreatment methods have been investigated for microalgae cell wall disruption and biomass solubilization before undergoing anaerobic digestion. This paper summarises the state of the art of different pretreatment techniques used for improving microalgae anaerobic biodegradability. Pretreatments were divided into 4 categories: (i)...
Passos, Fabiana Lopes del Rei; Astals, Sergi; Ferrer Martí, Ivet
High rate algal ponds are an economic and sustainable alternative for wastewater treatment, where microalgae and bacteria grow in symbiosis removing organic matter and nutrients. Microalgal biomass produced in these systems can be valorised through anaerobic digestion. However, microalgae anaerobic biodegradability is limited by the complex cell wall structure and therefore a pretreatment step may be required to improve the methane yield. In this study, ultrasound pretreatment at a range of applied specific energy (16-67. MJ/kg. TS) was investigated prior to microalgae anaerobic digestion. Experiments showed how organic matter solubilisation (16-100%), hydrolysis rate (25-56%) and methane yield (6-33%) were improved...
Passos, Fabiana Lopes del Rei; Ferrer Martí, Ivet
Microalgal biomass harvested from wastewater treatment high rate algal ponds may be valorised through anaerobic digestion producing biogas. However, microalgae anaerobic biodegradability is limited by their complex cell wall structure. Thus, pretreatment techniques are being investigated to improve microalgae methane yield. In the current study, thermal pretreatment at relatively low temperatures of 75-95 °C was effective at enhancing microalgae anaerobic biodegradability; increasing the methane yield by 70% in respect to nonpretreated biomass. Microscopic images showed how the pretreatment damaged microalgae cells, enhancing subsequent anaerobic digestion. Indeed, digestate images showed how after pretreatment only species with resistant cell walls, such as...
Samsó Campà, Roger; García Serrano, Joan
Despite the fact that horizontal subsurface flow constructed wetlands have been in operation for several decades now, there is still no clear understanding of some of their most basic internal functioning patterns. To fill this knowledge gap, on this paper we present what we call
Ávila Martín, Cristina; Matamoros, Victor; Reyes, Carolina; Pina, Benjamin; Casado, Marta; Mita, Luigi; Rivetti, Claudia; Barata Martí, Carlos; García Serrano, Joan; Bayona, Josep Maria
The capacity of a hybrid constructed wetland (CW) system consisting of two vertical flow (VF) CWs working alternatively (3 m(2)), one horizontal flow (HF) CW (2 m(2)) and one surface flow (FWS) CW (2 m(2)) in series to eliminate 13 emerging organic contaminants (EOCs) under three different hydraulic loading rates (HLRs) (0.06, 0.13 and 0.18 m d(-1) considering the area of the two VF beds) was studied through a continuous injection experiment General toxicity, dioxin-like activity, antimicrobial activity and estrogenicity were also measured under the highest hydraulic loading rate. The hybrid system was highly efficient on the removal of total...
Ávila Martín, Cristina; Nivala, Jaime; Olsson, Linda; Kassa, Kinfe; Headley, Tom; Mueller, Roland A.; Bayona, Josep Maria; García Serrano, Joan
Four side-by-side pilot-scale vertical flow (VF) constructed wetlands of different designs were evaluated for the removal of eight widely used emerging organic contaminants from municipal wastewater (i.e. ibuprofen, acetaminophen, diclofenac, tonalide, oxybenzone, triclosan, ethinylestradiol, bisphenol A). Three of the systems were free-draining, with one containing a gravel substrate (VGp), while the other two contained sand substrate (VS1p and VS2p). The fourth system had a saturated gravel substrate and active aeration supplied across the bottom of the bed (VAp). All beds were pulse-loaded on an hourly basis, except VS2p, which was pulse-loaded every 2h. Each system had a surface area of...
Pérez Bort, Irene; Garfi, Marianna; Cadena, Erasmo; Ferrer Martí, Ivet
This study was carried out in response to the growing interest on household biogas digesters in Latin America, particularly in rural Andean communities. The aim was to compare the fixed dome and plastic tubular digester in terms of biogas production, cost and environmental impact, using the life cycle assessment methodology. Design and operational parameters, construction materials and implementation costs were based on our previous research and literature results for plastic tubular and fixed dome digesters, respectively. According to this analysis, the main advantage of the plastic tubular digester was
its ease of implementation and handling, and lower investment cost compared to...
Ávila Martín, Cristina; Reyes, Carolina; Bayona, Josep Maria; García Serrano, Joan
This study aimed at assessing the influence of primary treatment (hydrolytic upflow sludge blanket (HUSB) reactor vs. conventional settling) and operational strategy (alternation of saturated/ unsaturated phases vs. permanently saturated) on the removal of various
emerging organic contaminants (i.e. ibuprofen, diclofenac, acetaminophen, tonalide, oxybenzone, bisphenol A) in horizontal subsurface flow constructed wetlands. For that purpose, a continuous injection experiment was carried out in an experimental treatment plant for 26 days. The plant had 3 treatment lines: a control line (settler-wetland permanently
saturated), a batch line (settler-wetland operated with saturate/unsaturated phases)
and an anaerobic line (HUSB reactor-wetland permanently saturated). In each line,
wetlands had a...
Pedescoll Albacar, Anna; Samsó Campà, Roger; Romero Morales, Enrique Edgar; Puigagut Juárez, Jaume; García Serrano, Joan
The aim of this study was to verify under lab conditions the reliability, repeatability and accuracy of the
falling head method (FHM) for hydraulic conductivity measurements. TheFHMis a reliable procedure that has slight variations (less than 10%) in repeated measurements and turns out to be a reliable technique to record the hydraulic conductivities typically described for clogged and unclogged subsurface-flow
constructed wetlands (from 4 to ca. 360 m/day). The accuracy of the method is acceptable considering difficulties in the measurement of hydraulic conductivity in highly conductive media. Accordingly, results
show measurement deviations of 20% when compared with a laboratory constant head method for...
Uggetti, Enrica; Ferrer Martí, Ivet; Castellnou, Roger; Molist, Jordi; García Serrano, Joan
Hoy en día la gestión del lodo de depuradora es un tema clave dentro del tratamiento del agua residual, representando hasta el 60% de los costes de operación de una depuradora urbana. El elevado contenido de agua del lodo encarece su gestión, justificando la necesidad de desarrollar métodos simples y económicos para reducir su volumen. Durante las últimas décadas, se ha adaptado la
tecnología de los humedales construidos o lechos de macrófitos a la deshidratación del lodo. Como principales ventajas destacan una demanda energética, costes de operación y mantenimiento reducidos, y una buena integración en el paisaje. Sin embargo, el número...
Seguí Amórtegui, Luis Alberto; Alfranca Burriel, Òscar; García Serrano, Joan
The main interest of the methodology for the investigation of wastewater reclamation and reuse systems which
is proposed in this paper is that all costs and benefits (social and private) are considered in the economic and technological
analysis. This general concern allows an improvement in the design of investment decisions.
Traditionally, an economic-financial analysis of wastewater reclamation and reuse systems focuses exclusively
on the study of costs and private benefits. The methodology that is presented in this paper takes into account
not only the private impacts but also the project spillovers which could have relevance on the project.
In this research, the use value of the...
Uggetti, Enrica; Ferrer Martí, Ivet; Llorens Ribes, Esther; García Serrano, Joan
Sludge management has become a key issue in wastewater treatment, representing some 20–60% of the operational costs of conventional wastewater treatment plants. The high water content of the sludge
results in large daily flow rates to be handled and treated. Thus, the search for methods to improve sludge volume reduction continues to be of major interest. The technology known as sludge treatment wetlands
has been used for sludge dewatering since the late 1980s. Major advantages include its low energy requirements, reduced operating and maintenance costs, and a reasonable integration in the environment. However, the number of plants in operation is still low...
Poggio, Davide; Ferrer Martí, Ivet; Batet Miracle, Lluís; Velo García, Enrique
Farmers in the Andean Plateau strongly demand for household biodigesters due to the lack of clean fuels and agricultural
fertilizers, and the abundance of livestock residues. The diffusion of rural biodigesters in cold climate or mountainous rural zones has been traditionally scarce. The unfavorable relationship between low temperatures and the kinetics of biogas
production poses a technological barrier to the implementation of low cost biodigesters.
Since 2006, the Research Group on Development Cooperation and Human Development (GRECDH) from the Technical
University of Catalonia (UPC), in collaboration with the Peruvian NGO Institute for an Alternative Agriculture (IAA), investigates on the development of household biodigesters adapted...
Catalán, Jordi; Pla, S; García Serrano, Joan; Camarero, L
This study shows that diatom sediment records can be used to investigate the long-term inorganic carbon dynamics in oligotrophic and poorly acid-buffered lakes. Using a training set of 115 high-mountain lakes in the Pyrenees, we found that both alkalinity and potential hydrogen (pH) independently explained some of the variability in diatom assemblages. Transfer functions for both variables were developed and applied to a Holocene record from Lake Redon and CO2 changes calculated. CO2 saturation broadly followed alkalinity,
which in turn was related to summer and autumn air-temperature fluctuations. In general, warmer climate during the ice-free period led to higher supersaturation, due...