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Environmentally sustainable methods of waste disposal are a strategic priority. For organic waste management and innovative biological treatments present advantageous opportunities, although organic waste treatment also includes environmental drawbacks, such as bioaerosol production. This study aims to evaluate bioaerosol spread during an innovative experimental treatment. The process consists of two anaerobic steps: acidogenesis, which includes polyhydroxyalkanoate accumulation, followed by methanogenesis. Bioaerosol, PM10, and endotoxin concentrations were measured at three sampling points during different campaigns to evaluate: (1) the background levels, (2) the contamination produced in the pre-treatment stage, and (3) the residual contamination of the outgoing digested sludge. Environmental PM10 seemed to be generally quite contained, while the endotoxin determination was close to 90 EU/m3. Significant microbial concentrations were detected during the loading of the organic fraction of municipal solid waste (fungi > 1300 CFU/m3, Bacillus genus (≈103 CFU/m3), higher Clostridium spp. and opportunistic human pathogens such as Pseudomonas aeruginosa and Klebsiella pneumoniae), suggesting a significant contamination level. Such results are useful for hazard identification in the risk assessment of innovative processes, as they reveal contaminants potentially harmful to both workers’ health and the environment.
Erica Pascale; Elena Franchitti; Chiara Caredda; Stefania Fornasero; Giulia Carletto; Biancamaria Pietrangeli; Francesco Valentino; Paolo Pavan; Giorgio Gilli; Elisa Anedda; Deborah Traversi. Bioaerosol Emissions during Organic Waste Treatment for Biopolymer Production: A Case Study. Atmosphere 2021, 12, 1069 .
AMA StyleErica Pascale, Elena Franchitti, Chiara Caredda, Stefania Fornasero, Giulia Carletto, Biancamaria Pietrangeli, Francesco Valentino, Paolo Pavan, Giorgio Gilli, Elisa Anedda, Deborah Traversi. Bioaerosol Emissions during Organic Waste Treatment for Biopolymer Production: A Case Study. Atmosphere. 2021; 12 (8):1069.
Chicago/Turabian StyleErica Pascale; Elena Franchitti; Chiara Caredda; Stefania Fornasero; Giulia Carletto; Biancamaria Pietrangeli; Francesco Valentino; Paolo Pavan; Giorgio Gilli; Elisa Anedda; Deborah Traversi. 2021. "Bioaerosol Emissions during Organic Waste Treatment for Biopolymer Production: A Case Study." Atmosphere 12, no. 8: 1069.
Volatile fatty acids obtained from the fermentation of the organic fraction of municipal solid waste can be used as raw materials for non-toxic ethyl ester (EE) synthesis as well as feedstock for the production of polyhydroxyalkanoates (PHAs). Taking advantage of the concept of an integrated process of a bio-refinery, in the present paper, a systematic investigation on the extraction of intracellular poly(3-hydroxybutyrate-co-3-hydroxyvalerate), produced by mixed microbial culture by using EEs was reported. Among the tested EEs, ethyl acetate (EA) was the best solvent, dissolving the copolymer at the lowest temperature. Then, extraction experiments were carried out by EA at different temperatures on two biomass samples containing PHAs with different average molecular weights. The parallel characterization of the extracted and non-extracted PHAs evidenced that at the lower temperature (100 °C) EA solubilizes preferentially the polymer fractions richer in 3HV comonomers and with the lower molecular weight. By increasing the extraction temperature from 100 °C to 125 °C, an increase of recovery from about 50 to 80 wt% and a molecular weight reduction from 48% to 65% was observed. The results highlighted that the extracted polymer purity is always above 90 wt% and that it is possible to choose the proper extraction condition to maximize the recovery yield at the expense of polymer fractionation and degradation at high temperatures or use milder conditions to maintain the original properties of a polymer.
Sara Alfano; Laura Lorini; Mauro Majone; Fabio Sciubba; Francesco Valentino; Andrea Martinelli. Ethylic Esters as Green Solvents for the Extraction of Intracellular Polyhydroxyalkanoates Produced by Mixed Microbial Culture. Polymers 2021, 13, 2789 .
AMA StyleSara Alfano, Laura Lorini, Mauro Majone, Fabio Sciubba, Francesco Valentino, Andrea Martinelli. Ethylic Esters as Green Solvents for the Extraction of Intracellular Polyhydroxyalkanoates Produced by Mixed Microbial Culture. Polymers. 2021; 13 (16):2789.
Chicago/Turabian StyleSara Alfano; Laura Lorini; Mauro Majone; Fabio Sciubba; Francesco Valentino; Andrea Martinelli. 2021. "Ethylic Esters as Green Solvents for the Extraction of Intracellular Polyhydroxyalkanoates Produced by Mixed Microbial Culture." Polymers 13, no. 16: 2789.
The bio-based production of added-value products and energy from waste streams while minimizing environmental impacts is a crucial aspect within the circular economy’s principles. A two-phases anaerobic digestion process to produce volatile fatty acids (VFA) and biogas production in an energetically feasible manner from the organic fraction of municipal solid waste (OFMSW) has been investigated. Mesophilic temperature (T) coupled to 5.0 days as hydraulic retention time (HRT) gave a VFA-rich stream with an overall concentration of 24.4 ± 0.2 g CODVFA/L, dominated by propionic and valeric acids, and high acidification yield, being VFA close to 90% of the soluble COD. The pH was maintained around 7.0 by the digestate recirculation from the second methanation reactor (HRT of 20 days) where biogas production was quantified under mesophilic and thermophilic T. The assessment of energy balance showed the benefits to carry out the second methanation stage under thermophilic condition, having more income from electricity generation without losing the thermal sustainability of the two-phases process as a whole.
Francesco Valentino; Gianluca Munarin; Marco Biasiolo; Cristina Cavinato; David Bolzonella; Paolo Pavan. Enhancing volatile fatty acids (VFA) production from food waste in a two-phases pilot-scale anaerobic digestion process. Journal of Environmental Chemical Engineering 2021, 9, 106062 .
AMA StyleFrancesco Valentino, Gianluca Munarin, Marco Biasiolo, Cristina Cavinato, David Bolzonella, Paolo Pavan. Enhancing volatile fatty acids (VFA) production from food waste in a two-phases pilot-scale anaerobic digestion process. Journal of Environmental Chemical Engineering. 2021; 9 (5):106062.
Chicago/Turabian StyleFrancesco Valentino; Gianluca Munarin; Marco Biasiolo; Cristina Cavinato; David Bolzonella; Paolo Pavan. 2021. "Enhancing volatile fatty acids (VFA) production from food waste in a two-phases pilot-scale anaerobic digestion process." Journal of Environmental Chemical Engineering 9, no. 5: 106062.
Editorial on the Research Topic Biofuels and Bioproducts From Anaerobic Processes: Anaerobic Membrane Bioreactors (AnMBRs) New biodegradable waste treatment configurations and technologies have arisen to support the transition of treatment plants toward resource recovery facilities. The interest in Anaerobic Membrane Biological Reactor (AnMBR) technology is increasing due to the advantages related to combine anaerobic digestion with membrane filtration. Thanks to the complete retention of anaerobic microorganisms, AnMBRs have the capacity to efficiently recover most of the energy potential in biodegradable waste streams in the form of biogas and produce high-quality effluents with low biomass production. In both municipal and industrial wastewater treatment plants, a change of paradigm from aerobic treatment toward anaerobic treatment which uses the biodegradable organic carbon present in wastewaters to produce energy (as methane) and reduce the amount of sludge to be handled could find its practical application in AnMBR technology. Since the anaerobic treatment alone may not be enough to meet discharge limits and to hold low-rate anaerobic microorganisms, the utilisation of membrane technology coupled to anaerobic bioreactor is a promising solution to solve these issues. Fouling-related aspects are currently investigated since fouling mitigation can strongly contribute to energy saving, improving the economy for MBR-based wastewater treatment. In this perspective, different studies have been set up to address this issue, utilizing various reactor configurations and/or operating conditions. Other aspects to consider for the implementation of AnMBR are the effect of sulphate concentration in the influent wastewater that could be transformed to sulphide by sulphate-reducing bacteria while oxidizing biodegradable COD to CO2, the recovery of dissolved methane in the effluent, especially when working at psychrophilic temperatures, and the lack of nutrient removal in the treated effluent, among many others. When applied for organic waste streams treatment, AnMBRs also could offer several advantages when compared to conventional anaerobic digestion treatment, including the footprint reduction thanks to the effective decoupling of hydraulic retention time (HRT) and sludge retention time (SRT), while achieving efficient hydrolysis and methanogenesis processes. In this scenario, AnMBRs application is still challenging, especially for those cases in which the waste substrate is characterised by a high suspended solids content and salinity, possible presence of toxic compounds and a variable influent composition. In this Research Topic issue, the gathered contributions report successful applications of the AnMBR technology for the treatment of a wide variety of wastes and wastewaters. Depending on the studied case, the researchers selected suitable AnMBR configurations, Organic loading Rates (OLRs), initial inoculum and operating temperature ranges, among other parameters, yielding high COD removal efficiencies to produce methane-rich biogas and a high-quality effluent with reduced sludge production. Moreover, the published papers also take into consideration strategies devoted to alleviating membrane fouling and prevent flux decline, the modelling of the process performance and/or the study of the dynamics of the developed microbial communities under different operational conditions to better understand the biological process and the complex interactions of anaerobic microorganisms. For the treatment of low strength municipal wastewater under psychrophilic temperatures, Ribera-Pi et al. analysed the performance of three upflow anaerobic sludge blanket (UASB) reactors, using different reactor configurations and inocula (namely, an UASB inoculated with flocculent biomass and two UASB-type AnMBRs, equipped with submerged hollow fiber membranes and inoculated with flocculent and granular biomass, respectively). In this study, the application of AnMBR technology led to a higher effluent quality in terms of soluble and particulate COD, BOD5 and TSS. Furthermore, under the conditions tested in AnMBRs, a slightly higher hydrolysis rates were recorded when flocculent biomass was used. These authors also highlighted the crucial need of dissolved CH4 recovery when anaerobic digestion is applied at low temperature conditions. A sustainable treatment of concentrated industrial wastewaters could also be reached by means of AnMBR technology as reported by Muñoz Sierra et al., who studied the performance of an AnMBR equipped with a sidestream tubular membrane working at 55°C for the treatment of a high strength wastewater characterised by a phenol concentration up to 0.8 g phenol L−1 and a high salinity (18 g Na+ L−1). In this study, COD and phenol removal efficiencies of about 95% during long-term operation were recorded when the phenol loading rate did not exceed 20 mg phenol g−1 VSS d−1, which demonstrates the capability of AnMBR technology to convert organic pollutants into renewable methane energy under high saline conditions. As explained above, the AnMBR technology could also offer several advantages for the treatment of biodegradable organic wastes when compared to conventional anaerobic digestion treatment. Within this framework, Ariunbaatar et al. studied the application of an AnMBR consisting of an UASB coupled with 2 side-stream tubular membrane modules connected in parallel to treat diluted FW under mesophilic conditions reducing the HRT successfully from the typical 20 d to 1 d. These authors recorded a COD conversion to biomethane up to 76% and the effect of membrane filtration contributed to obtain an overall percentage of COD removal above 97%. Moreover, the study carried out by Iskander et al. demonstrates that codigestion of food waste with a suitable co-substrate (such as fats, oils and grease, FOG) could be successfully implemented in AnMBRs in both a...
Francesco Valentino; Paolo Pavan; Joan Dosta. Editorial: Biofuels and Bioproducts From Anaerobic Processes: Anaerobic Membrane Bioreactors (AnMBRs). Frontiers in Bioengineering and Biotechnology 2021, 9, 1 .
AMA StyleFrancesco Valentino, Paolo Pavan, Joan Dosta. Editorial: Biofuels and Bioproducts From Anaerobic Processes: Anaerobic Membrane Bioreactors (AnMBRs). Frontiers in Bioengineering and Biotechnology. 2021; 9 ():1.
Chicago/Turabian StyleFrancesco Valentino; Paolo Pavan; Joan Dosta. 2021. "Editorial: Biofuels and Bioproducts From Anaerobic Processes: Anaerobic Membrane Bioreactors (AnMBRs)." Frontiers in Bioengineering and Biotechnology 9, no. : 1.
The use of polyhydroxyalkanoates (PHA) as slow-release electron donors for environmental remediation represents a novel and appealing application that is attracting considerable attention in the scientific community. In this context, here, the fermentation pattern of different types of PHA-based materials has been investigated in batch and continuous-flow experiments. Along with commercially available materials, produced from axenic microbial cultures, PHA produced at pilot scale by mixed microbial cultures (MMC) using waste feedstock have been also tested. As a main finding, a rapid onset of volatile fatty acids (VFA) production was observed with a low-purity MMC-deriving material, consisting of microbial cells containing 56% (on weight basis) of intracellular PHA. Indeed, with this material a sustained, long-term production of organic acids (i.e., acetic, propionic, and butyric acids) was observed. In addition, the obtained yield of conversion into acids (up to 70% gVFA/gPHA) was higher than that obtained with the other tested materials, made of extracted and purified PHA. These results clearly suggest the possibility to directly use the PHA-rich cells deriving from the MMC production process, with no need of extraction and purification procedures, as a sustainable and effective carbon source bringing remarkable advantages from an economic and environmental point of view.
Neda Amanat; Bruna Matturro; Marta Rossi; Francesco Valentino; Marianna Villano; Marco Petrangeli Papini. Assessment of Long-Term Fermentability of PHA-Based Materials from Pure and Mixed Microbial Cultures for Potential Environmental Applications. Water 2021, 13, 897 .
AMA StyleNeda Amanat, Bruna Matturro, Marta Rossi, Francesco Valentino, Marianna Villano, Marco Petrangeli Papini. Assessment of Long-Term Fermentability of PHA-Based Materials from Pure and Mixed Microbial Cultures for Potential Environmental Applications. Water. 2021; 13 (7):897.
Chicago/Turabian StyleNeda Amanat; Bruna Matturro; Marta Rossi; Francesco Valentino; Marianna Villano; Marco Petrangeli Papini. 2021. "Assessment of Long-Term Fermentability of PHA-Based Materials from Pure and Mixed Microbial Cultures for Potential Environmental Applications." Water 13, no. 7: 897.
Polyhydroxyalkanoates (PHAs) are well-known biodegradable plastics produced by various bacterial strains, whose major drawback is constituted by the high cost of their synthesis. Producing PHAs from mixed microbial cultures and employing organic wastes as a carbon source allows us to both reduce cost and valorize available renewable resources, such as food waste and sewage sludge. However, different types of pollutants, originally contained in organic matrices, could persist into the final product, thus compromising their safety. In this work, the exploitation of municipal wastes for PHA production is evaluated from the environmental and health safety aspect by determining the presence of polycyclic aromatic hydrocarbons (PAHs) in both commercial and waste-based PHA samples. Quantification of PAHs by gas chromatography-mass spectrometry on 24 PHA samples obtained in different conditions showed very low contamination levels, in the range of ppb to a few ppm. Moreover, the contaminant content seems to be dependent on the type of PHA stabilization and extraction, but independent from the type of feedstock. Commercial PHA derived from crops, selected for comparison, showed PAH content comparable to that detected in PHAs derived from organic fraction of municipal solid waste. Although there is no specific regulation on PAH maximum levels in PHAs, detected concentrations were consistently lower than threshold limit values set by regulation and guidelines for similar materials and/or applications. This suggests that the use of organic waste as substrate for PHA production is safe for both the human health and the environment.
Chiara Cavaliere; Anna Capriotti; Andrea Cerrato; Laura Lorini; Carmela Montone; Francesco Valentino; Aldo Laganà; Mauro Majone. Identification and Quantification of Polycyclic Aromatic Hydrocarbons in Polyhydroxyalkanoates Produced from Mixed Microbial Cultures and Municipal Organic Wastes at Pilot Scale. Molecules 2021, 26, 539 .
AMA StyleChiara Cavaliere, Anna Capriotti, Andrea Cerrato, Laura Lorini, Carmela Montone, Francesco Valentino, Aldo Laganà, Mauro Majone. Identification and Quantification of Polycyclic Aromatic Hydrocarbons in Polyhydroxyalkanoates Produced from Mixed Microbial Cultures and Municipal Organic Wastes at Pilot Scale. Molecules. 2021; 26 (3):539.
Chicago/Turabian StyleChiara Cavaliere; Anna Capriotti; Andrea Cerrato; Laura Lorini; Carmela Montone; Francesco Valentino; Aldo Laganà; Mauro Majone. 2021. "Identification and Quantification of Polycyclic Aromatic Hydrocarbons in Polyhydroxyalkanoates Produced from Mixed Microbial Cultures and Municipal Organic Wastes at Pilot Scale." Molecules 26, no. 3: 539.
A combined two-levels control method has been developed and tested on a long term operation of a two-phases pilot-scale anaerobic process for the concurrent production of volatile fatty acids, hydrogen and methane. The latter was designed for the treatment of food waste of urban origin (namely, the organic fraction of municipal solid waste). The optimized control method was set on the base of the inputs of three online probes: a pH-meter in the fermentation reactor, a pH-meter and a conductivity probe in the digestion reactor. The first control level managed the pH in the fermentation reactor while the second control level managed the ammonia concentration in the digestion reactor. This combination established the volume of the digestate to be recycled from the digestion to the fermentation reactor, optimizing the yield of volatile fatty acid (0.31-0.32 kg CODVFA/kg CODfed) and the specific hydrogen production (SHP; 0.070-0.074 m3 H2/kg TVSfed) in the fermentation reactor and the specific methane production (SMP; 0.48-0.55 m3 CH4/kg TVSfed) in the digestion reactor. A new process configuration was also proposed and applied over the course of the long operation period. This configuration allowed to remove part of the volatile fatty acid-rich liquid stream from the fermenter effluent, maintaining the corresponding solid-rich effluent in the whole system (as feed for the digestion reactor) by using a solid/liquid separation unit. In this way, the concentration of volatile fatty acids in the digester was kept at a low level, even with high loading rates, so maintaining a satisfying efficiency of methane production and utilising the excess volatile fatty acids (out of the system) as building blocks for other purposes. The optimized two-levels control method for the anaerobic treatment of food waste provides new perspectives for the valorisation of such waste stream; the production of building blocks namely volatile fatty acids supports new innovative bio-refinery platforms for the production of bio-products.
Federico Micolucci; Marco Gottardo; David Bolzonella; Paolo Pavan; Mauro Majone; Francesco Valentino. Pilot-scale multi-purposes approach for volatile fatty acid production, hydrogen and methane from an automatic controlled anaerobic process. Journal of Cleaner Production 2020, 277, 124297 .
AMA StyleFederico Micolucci, Marco Gottardo, David Bolzonella, Paolo Pavan, Mauro Majone, Francesco Valentino. Pilot-scale multi-purposes approach for volatile fatty acid production, hydrogen and methane from an automatic controlled anaerobic process. Journal of Cleaner Production. 2020; 277 ():124297.
Chicago/Turabian StyleFederico Micolucci; Marco Gottardo; David Bolzonella; Paolo Pavan; Mauro Majone; Francesco Valentino. 2020. "Pilot-scale multi-purposes approach for volatile fatty acid production, hydrogen and methane from an automatic controlled anaerobic process." Journal of Cleaner Production 277, no. : 124297.
In this study, the performance of the selection process for polyhydroxyalkanoates (PHAs) production from mixed microbial cultures (MMCs) at pilot scale was deeply investigated with the solid retention time (SRT) to cycle length (CL) ratio as main affecting parameter. Four different runs were tested by varying the SRT/CL ratio maintaining the same organic loading rate (OLR). The pilot scale selection and accumulation reactors were fed with a fermented mixture of source selected organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS), refined with a centrifuge and membrane unit for the coarse solid removal. The selected biomass obtained in the most performing run was characterized by a specific storage rate of 375 mg CODP/g CODXa h and a storage yield of 0.46 CODP/CODSOL. Accumulations performed with the same biomass were characterized by a storage yield of 0.62 CODP/CODVFA. The microbiome composition was assessed. In the most performing run, putative PHA-storing bacteria affiliated with Paracoccus genus were found at high abundance (36.8%), in contrast to all other runs. An overall PHA yield of 110 g PHA/kg VS was estimated for the best scenario, revealing an interesting perspective for biorefinery technology chains based on the three-stage process for PHA production.
Giulia Moretto; Laura Lorini; Paolo Pavan; Simona Crognale; Barbara Tonanzi; Simona Rossetti; Mauro Majone; Francesco Valentino. Biopolymers from Urban Organic Waste: Influence of the Solid Retention Time to Cycle Length Ratio in the Enrichment of a Mixed Microbial Culture (MMC). ACS Sustainable Chemistry & Engineering 2020, 8, 1 .
AMA StyleGiulia Moretto, Laura Lorini, Paolo Pavan, Simona Crognale, Barbara Tonanzi, Simona Rossetti, Mauro Majone, Francesco Valentino. Biopolymers from Urban Organic Waste: Influence of the Solid Retention Time to Cycle Length Ratio in the Enrichment of a Mixed Microbial Culture (MMC). ACS Sustainable Chemistry & Engineering. 2020; 8 (38):1.
Chicago/Turabian StyleGiulia Moretto; Laura Lorini; Paolo Pavan; Simona Crognale; Barbara Tonanzi; Simona Rossetti; Mauro Majone; Francesco Valentino. 2020. "Biopolymers from Urban Organic Waste: Influence of the Solid Retention Time to Cycle Length Ratio in the Enrichment of a Mixed Microbial Culture (MMC)." ACS Sustainable Chemistry & Engineering 8, no. 38: 1.
The present study reports on the production and characterization of a new biopackaging material made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from municipal biowaste (MBW) and produced by the mixed bacterial culture technology. After purification and extraction, the MBW-derived PHBV was processed by electrospinning to yield defect-free ultrathin fibers, which were thermally post-treated. Annealing at 130 °C, well below the biopolymer’s melting temperature (Tm), successfully yielded a continuous film resulting from coalescence of the electrospun fibrillar morphology, the so-called biopaper, exhibiting enhanced optical and color properties compared to traditional melt compounding routes. The crystallinity and crystalline morphology were comprehensively studied as a function of temperature by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and combined time-resolved synchrotron small- and wide-angle X-ray scattering (SAXS and WAXS) experiments, which clearly indicated that the molecular order within the copolyester was improved up to a maximum at 130 °C, and then it decreased at the biopolymer’s Tm. It was hypothesized that by annealing at the temperature at which the thermally induced molecular order is maximized, the fibers generated sufficient mobility to align alongside, hence reducing surface energy and porosity. The data suggest that this material shows a good balance between enhanced mechanical and improved barrier properties to vapors and gases in comparison to traditional paper and other currently used petroleum-derived polymers, thus presenting significant potential to be part of innovative food biopackaging designs for the protection and preservation of foods in a circular bioeconomy scenario.
Beatriz Melendez-Rodriguez; Sergio Torres-Giner; Laura Lorini; Francesco Valentino; Chris Sammon; Luis Cabedo; Jose Maria Lagaron. Valorization of Municipal Biowaste into Electrospun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Biopapers for Food Packaging Applications. ACS Applied Bio Materials 2020, 3, 1 .
AMA StyleBeatriz Melendez-Rodriguez, Sergio Torres-Giner, Laura Lorini, Francesco Valentino, Chris Sammon, Luis Cabedo, Jose Maria Lagaron. Valorization of Municipal Biowaste into Electrospun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Biopapers for Food Packaging Applications. ACS Applied Bio Materials. 2020; 3 (9):1.
Chicago/Turabian StyleBeatriz Melendez-Rodriguez; Sergio Torres-Giner; Laura Lorini; Francesco Valentino; Chris Sammon; Luis Cabedo; Jose Maria Lagaron. 2020. "Valorization of Municipal Biowaste into Electrospun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Biopapers for Food Packaging Applications." ACS Applied Bio Materials 3, no. 9: 1.
The utilisation of urban organic waste as feedstock for polyhydroxyalkanoates (PHA) production is growing since it allows to solve the main concerns about their disposal and simultaneously to recover added-value products. A pilot scale platform has been designed for this purpose. The VFA-rich fermentation liquid coming from the anaerobic treatment of both source-sorted organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS) has been used as substrate for the aerobic process steps: a first sequencing batch reactor (SBR, 100 L) for the selection of a PHA-producing biomass, and a second fed-batch reactor (70 L) for PHA accumulation inside the cells. The SBR was operated at 2.0-4.4 kg COD/(m3 d) as OLR, under dynamic feeding regime (feast-famine) and short hydraulic retention time (HRT; 1 day). The selected biomass was able to accumulate up to 48% g PHA/g VSS. Both steps were performed without temperature (T) control, avoiding additional consumption of energy. In this regard, the applied OLR was tuned based on environmental T and, as a consequence, on biomass kinetic, in order to have a constant selective pressure. The latter was mainly quantified by the PHA storage yield (YP/Sfeast 0.34-0.45 CODP/CODS), which has been recognized as the main parameters affecting the global PHA productivity [1.02-1.82 g PHA/(L d)] of the process.
Francesco Valentino; Laura Lorini; Marco Gottardo; Paolo Pavan; Mauro Majone. Effect of the temperature in a mixed culture pilot scale aerobic process for food waste and sewage sludge conversion into polyhydroxyalkanoates. Journal of Biotechnology 2020, 323, 54 -61.
AMA StyleFrancesco Valentino, Laura Lorini, Marco Gottardo, Paolo Pavan, Mauro Majone. Effect of the temperature in a mixed culture pilot scale aerobic process for food waste and sewage sludge conversion into polyhydroxyalkanoates. Journal of Biotechnology. 2020; 323 ():54-61.
Chicago/Turabian StyleFrancesco Valentino; Laura Lorini; Marco Gottardo; Paolo Pavan; Mauro Majone. 2020. "Effect of the temperature in a mixed culture pilot scale aerobic process for food waste and sewage sludge conversion into polyhydroxyalkanoates." Journal of Biotechnology 323, no. : 54-61.
The utilization of food waste and sewage sludge as organic substrate from urban context for the synthesis of microbial polyhydroxyalkanoates (PHAs) has been only recently investigated at pilot scale. Within this context, two stabilization methods have been found for preserving the amount of PHA intracellularly produced by open mixed microbial culture (MMC): thermal drying and wet acidification of the biomass at the end of PHA accumulation process. The extracted PHA from the two differently stabilized biomasses was then characterized with regard to chemical composition, molecular weight, and thermal properties. The polymer contained two types of monomers, namely 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) at a relative percentage of 93.0–79.8 and 7.0–20.2 w/w, respectively. PHA extracted from wet-acidified biomass had higher average molecular weights (M w ) of 370–424 kDa while PHA recovered from thermally stabilized dried biomass had a 3-fold lower M w (on average). The PHA decomposition temperatures T d 10% and T d max were in the range 260–268 °C and 269–303 °C, respectively, not dependent on the monomeric composition or molecular weight. Thermal properties such as melting temperature (T m 1 132–150 °C; T m 2 155–167 °C) and melting enthalpy (26–70 J/g) were quantified in a relatively broad range according to the different stabilization-extraction method and obtained composition.
Laura Lorini; Andrea Martinelli; Paolo Pavan; Mauro Majone; Francesco Valentino. Downstream processing and characterization of polyhydroxyalkanoates (PHAs) produced by mixed microbial culture (MMC) and organic urban waste as substrate. Biomass Conversion and Biorefinery 2020, 11, 693 -703.
AMA StyleLaura Lorini, Andrea Martinelli, Paolo Pavan, Mauro Majone, Francesco Valentino. Downstream processing and characterization of polyhydroxyalkanoates (PHAs) produced by mixed microbial culture (MMC) and organic urban waste as substrate. Biomass Conversion and Biorefinery. 2020; 11 (2):693-703.
Chicago/Turabian StyleLaura Lorini; Andrea Martinelli; Paolo Pavan; Mauro Majone; Francesco Valentino. 2020. "Downstream processing and characterization of polyhydroxyalkanoates (PHAs) produced by mixed microbial culture (MMC) and organic urban waste as substrate." Biomass Conversion and Biorefinery 11, no. 2: 693-703.
The microbial synthesis of polyhydroxyalkanoates (PHA) from organic wastes is a valuable process to valorize available renewable resources, such as food wastes and biological sludge. Bioplastics find many applications in various sectors, from medical field to food industry. However, persistent organic pollutants could be transferred from wastes to the final product. The present paper demonstrates that the use of municipal wastes in PHA production is safe for the environment and human health and provides a polychlorinated biphenyl (PCB) profile in both commercial and waste-based PHA samples. PCB analysis in several PHA samples showed very low concentrations of the target analytes. Commercial PHA samples showed a similar PCB level with respect to PHA samples from municipal waste/sludge and higher than PHA samples from fruit waste. For all analyzed PCBs, detected concentrations were consistently lower than the ones reported in regulatory framework or guidelines.
Carmela Riccardi; Francesca Buiarelli; Federica Castellani; Patrizia Di Filippo; Laura Lorini; Mauro Majone; Mariana Matos; Donatella Pomata; Giulia Simonetti; Bruno Sommer Ferreira; Francesco Valentino. Polychlorinated Biphenyl Profile in Polyhydroxy-alkanoates Synthetized from Urban Organic Wastes. Polymers 2020, 12, 659 .
AMA StyleCarmela Riccardi, Francesca Buiarelli, Federica Castellani, Patrizia Di Filippo, Laura Lorini, Mauro Majone, Mariana Matos, Donatella Pomata, Giulia Simonetti, Bruno Sommer Ferreira, Francesco Valentino. Polychlorinated Biphenyl Profile in Polyhydroxy-alkanoates Synthetized from Urban Organic Wastes. Polymers. 2020; 12 (3):659.
Chicago/Turabian StyleCarmela Riccardi; Francesca Buiarelli; Federica Castellani; Patrizia Di Filippo; Laura Lorini; Mauro Majone; Mariana Matos; Donatella Pomata; Giulia Simonetti; Bruno Sommer Ferreira; Francesco Valentino. 2020. "Polychlorinated Biphenyl Profile in Polyhydroxy-alkanoates Synthetized from Urban Organic Wastes." Polymers 12, no. 3: 659.
In this study, polyhydroxyalkanoates (PHAs) production integrated with the via-nitrite nitrogen removal from anaerobic reject water was investigated at pilot scale under long-term period. The pilot plant was located in Carbonera wastewater treatment plant (WWTP) (Treviso, Italy) and comprised the following units: i) rotating belt dynamic filter (RBDF) for the recovery of cellulosic primary sludge (CPS); ii) fermentation unit for the production of volatile fatty acids (VFAs); iii) ultrafiltration unit (UF) for solid/liquid separation of the fermented sludge; iv) nitritation sequencing batch reactor (N-SBR) for the oxidation of ammonia to nitrite; v) selection SBR (S-SBR) where aerobic-feast and anoxic-famine conditions were established to select PHA-accumulating biomass and vi) an accumulation SBR (A-SBR) were intracellular PHA content was maximized through the feed-on-demand strategy. Results showed that around 80% of the influent ammonia was efficiently removed by the system when both N-SBR and S-SBR operated with volumetric nitrogen loading rate (vNLR) of 1.64–1.72 kgN/m3 d and 0.60–0.63 kgN/m3 d, respectively. Accumulation tests showed PHA yields ranging between 0.58 and 0.61 g CODPHA/g CODVFA, indicating an effective selection strategy. The overall mass balance assessment demonstrated that around 0.32 g of COD per gram of COD treated can be recovered as bio-based products. The integration of nitrogen removal and PHA production in the sidestream resulted in a methane recovery up to 4.0 m3CH4/PE y and a maximal PHA production of 1.2 kgPHA/PE y with a potential revenue for the WWTP up to 6.5 €/PE y.
Vincenzo Conca; Cinzia da Ros; Francesco Valentino; Anna Laura Eusebi; Nicola Frison; Francesco Fatone. Long-term validation of polyhydroxyalkanoates production potential from the sidestream of municipal wastewater treatment plant at pilot scale. Chemical Engineering Journal 2020, 390, 124627 .
AMA StyleVincenzo Conca, Cinzia da Ros, Francesco Valentino, Anna Laura Eusebi, Nicola Frison, Francesco Fatone. Long-term validation of polyhydroxyalkanoates production potential from the sidestream of municipal wastewater treatment plant at pilot scale. Chemical Engineering Journal. 2020; 390 ():124627.
Chicago/Turabian StyleVincenzo Conca; Cinzia da Ros; Francesco Valentino; Anna Laura Eusebi; Nicola Frison; Francesco Fatone. 2020. "Long-term validation of polyhydroxyalkanoates production potential from the sidestream of municipal wastewater treatment plant at pilot scale." Chemical Engineering Journal 390, no. : 124627.
This study focuses on the application of the concept of circular economy, with the creation of added-value marketable products and energy from organic waste while minimizing environmental impacts. Within this purpose, an urban biorefinery technology chain has been developed at pilot scale in the territorial context of the Treviso municipality (northeast Italy) for the production of biopolymers (polyhydroxyalkanoates, PHAs) and biogas from waste of urban origin. The piloting system (100–380 L) comprised the following units: a) acidogenic fermentation of the organic fraction of municipal solid waste (OFMSW) and biological sludge; b) two solid/liquid separation steps consisting of a coaxial centrifuge and a tubular membrane (0.2 μm porosity); c) a Sequencing Batch Reactor (SBR) for aerobic PHA-storing biomass production; d) aerobic fed-batch PHA accumulation reactor and e) Anaerobic co-digestion (ACoD). The thermal pre-treatment (72 °C, 48 h) of the feedstock enhanced the solubilization of the organic matter, which was converted into volatile fatty acids (VFAs) in batch mode under mesophilic fermentation conditions (37 °C). The VFA content increased up to 30 ± 3 g COD/L (overall yield 0.65 ± 0.04 g CODVFA/g VS(0)), with high CODVFA/CODSOL (0.86 ± 0.05). The high CODVFA/CODSOL ratio enhanced the PHA-storing biomass selection in the SBR by limiting the growth of the non-storing microbial population. Under fully aerobic feast-famine regime, the selection reactor was continuously operated for 6 months at an average organic loading rate (OLR) of 4.4 ± 0.6 g COD/L d and hydraulic retention time (HRT) of 1 day (equal to SRT). The ACoD process (HRT 15 days, OLR 3.0–3.5 kg VS/m3 d) allowed to recover the residual solid-rich overflows generated by the two solid/liquid separation units with the production of biogas (SGP 0.44–0.51 m3/kg VS) and digestate. An overall yield of 7.6% wt PHA/VS(0) has been estimated from the mass balance. In addition, a preliminary insight into potential social acceptance and barriers regarding organic waste-derived products was obtained.
Giulia Moretto; Ivan Russo; David Bolzonella; Paolo Pavan; Mauro Majone; Francesco Valentino. An urban biorefinery for food waste and biological sludge conversion into polyhydroxyalkanoates and biogas. Water Research 2019, 170, 115371 .
AMA StyleGiulia Moretto, Ivan Russo, David Bolzonella, Paolo Pavan, Mauro Majone, Francesco Valentino. An urban biorefinery for food waste and biological sludge conversion into polyhydroxyalkanoates and biogas. Water Research. 2019; 170 ():115371.
Chicago/Turabian StyleGiulia Moretto; Ivan Russo; David Bolzonella; Paolo Pavan; Mauro Majone; Francesco Valentino. 2019. "An urban biorefinery for food waste and biological sludge conversion into polyhydroxyalkanoates and biogas." Water Research 170, no. : 115371.
This study analyses the bacterial population dynamics of a mixed microbial community (MMC) selected in a pilot plant producing polyhydroxyalkanoate (PHA) from the fermentation of the organic fraction of urban waste (OFMSW) and sewage sludge (SS). 16S rRNA gene high-throughput sequencing revealed the occurrence of a variety of PHA accumulating bacteria that ensured a stable PHA production in an open system operating with real substrates and without temperature control. The Volatile Fatty Acids (VFA) changes in the feed and the temperature variation affected the dynamics of the PHA-accumulating bacteria over the plant operation. Remarkably, the higher PHA content was associated to a MMC largely comprising of Hydrogenophaga species during the operation at higher working temperature. The involvement of a heterogeneous PHA-accumulating MMC was associated with a high phaC synthase genes biodiversity confirming the occurrence of a functional redundancy.
Simona Crognale; Barbara Tonanzi; Francesco Valentino; Mauro Majone; Simona Rossetti. Microbiome dynamics and phaC synthase genes selected in a pilot plant producing polyhydroxyalkanoate from the organic fraction of urban waste. Science of The Total Environment 2019, 689, 765 -773.
AMA StyleSimona Crognale, Barbara Tonanzi, Francesco Valentino, Mauro Majone, Simona Rossetti. Microbiome dynamics and phaC synthase genes selected in a pilot plant producing polyhydroxyalkanoate from the organic fraction of urban waste. Science of The Total Environment. 2019; 689 ():765-773.
Chicago/Turabian StyleSimona Crognale; Barbara Tonanzi; Francesco Valentino; Mauro Majone; Simona Rossetti. 2019. "Microbiome dynamics and phaC synthase genes selected in a pilot plant producing polyhydroxyalkanoate from the organic fraction of urban waste." Science of The Total Environment 689, no. : 765-773.
Although the organic fraction of municipal solid waste (OFMSW) and sewage sludge (SS) originate from the same urban area and contain similar organic matter, they are collected separately and handled with different technologies. In this work, a combined treatment of OFMSW–SS mixture was investigated at pilot scale, by using a three-step mixed microbial culture (MMC) process in order to produce polyhydroxyalkanoate (PHA) as final high value biobased product. Biomass selection efficiency was quantified by PHA-specific storage rate that was 258 mg CODPHA/g CODXa/h under the optimized process condition. In fed-batch tests, PHA-storing MMC was able to accumulate up to 46 wt % PHA. In the perspective of a full-scale application and taking into account the mass flows in each process step, an overall yield of 65 g PHA/kg TVS was estimated.
Francesco Valentino; Giulia Moretto; Laura Lorini; David Bolzonella; Paolo Pavan; Mauro Majone. Pilot-Scale Polyhydroxyalkanoate Production from Combined Treatment of Organic Fraction of Municipal Solid Waste and Sewage Sludge. Industrial & Engineering Chemistry Research 2019, 58, 12149 -12158.
AMA StyleFrancesco Valentino, Giulia Moretto, Laura Lorini, David Bolzonella, Paolo Pavan, Mauro Majone. Pilot-Scale Polyhydroxyalkanoate Production from Combined Treatment of Organic Fraction of Municipal Solid Waste and Sewage Sludge. Industrial & Engineering Chemistry Research. 2019; 58 (27):12149-12158.
Chicago/Turabian StyleFrancesco Valentino; Giulia Moretto; Laura Lorini; David Bolzonella; Paolo Pavan; Mauro Majone. 2019. "Pilot-Scale Polyhydroxyalkanoate Production from Combined Treatment of Organic Fraction of Municipal Solid Waste and Sewage Sludge." Industrial & Engineering Chemistry Research 58, no. 27: 12149-12158.
The new “Bioeconomy Strategy” document, which was issued by the European Commission in October 2018, encourages the exploitation of organic wastes according to a pyramidal hierarchy in which the extraction of valuable biomolecules, which will be used as they are or as precursors of high added value compounds, is a priority in biofuel production. This review considers a biorefinery platform in which food waste and sewage sludge, are adopted to produce volatile fatty acids (VFAs) through a dark fermentation process. VFAs fermentation is optimized by slightly acid pH (6‐7), short HRT (1‐7 days) and high OLR (more than 10gTS/Ld). Attention has been focused on VFA exploitation for polyhydroxyalkanoate (PHA) production via a “feast and famine” strategy performed in sequencing batch reactors. The obtained PHA yields are around 0.4‐0.5 gPHA/gCOD. Moreover, VFAs allow for the production of biofuels, such as hydrogen and methane, through single or double‐staged anaerobic digestion. Innovative bioelectrochemical upgrade strategies for biogas helps producers to obtain biomethane for the automotive sector. Moreover, biogas has recently been tested for the production of polyhydroxybutyrate (PHB), a biodegradable and biocompatible thermoplastic made by microorganisms from C1 carbon sources (CO2 and CH4). Digestates from anaerobic bioreactors are still rich in nitrogen and phosphorus compounds. These latter compounds have been identified as critical raw materials due to their low availability in the EU and to increasing demand from the growing global population. Thus, the nutrient recovery from digestate allows users to close the loop of the “circular economy” approach. This article is protected by copyright. All rights reserved.
Federico Battista; Nicola Frison; Paolo Pavan; Cristina Cavinato; Marco Gottardo; Francesco Fatone; Anna Laura Eusebi; Mauro Majone; Marco Zeppilli; Francesco Valentino; Debora Fino; Tonia Tommasi; David Bolzonella. Food wastes and sewage sludge as feedstock for an urban biorefinery producing biofuels and added‐value bioproducts. Journal of Chemical Technology & Biotechnology 2019, 95, 328 -338.
AMA StyleFederico Battista, Nicola Frison, Paolo Pavan, Cristina Cavinato, Marco Gottardo, Francesco Fatone, Anna Laura Eusebi, Mauro Majone, Marco Zeppilli, Francesco Valentino, Debora Fino, Tonia Tommasi, David Bolzonella. Food wastes and sewage sludge as feedstock for an urban biorefinery producing biofuels and added‐value bioproducts. Journal of Chemical Technology & Biotechnology. 2019; 95 (2):328-338.
Chicago/Turabian StyleFederico Battista; Nicola Frison; Paolo Pavan; Cristina Cavinato; Marco Gottardo; Francesco Fatone; Anna Laura Eusebi; Mauro Majone; Marco Zeppilli; Francesco Valentino; Debora Fino; Tonia Tommasi; David Bolzonella. 2019. "Food wastes and sewage sludge as feedstock for an urban biorefinery producing biofuels and added‐value bioproducts." Journal of Chemical Technology & Biotechnology 95, no. 2: 328-338.
The problem of waste disposal has recently focused on practices for waste recycling and bio-resources valorization. Organic waste produced in urban context together with biological sludge produced in wastewater treatment plants (WWTPs) can be used as renewable feedstock for the production of building blocks of different products, from biopolymers to methyl esters. This paper deals with the optimization of the fermentation process in order to transform urban organic waste (a mixture of pre-treated food waste and biological sludge) into added-value volatile fatty acid (VFA) rich stream, useful for biological processes within a biorefinery technology chain. Different temperatures, pH, hydraulic retention times (HRTs) and organic loading rates (OLRs) were tested both in batch and continuous trials. Batch tests showed the best working conditions at 37 °C and pH 9, using the bio-waste feedstock thermally pre-treated (76 h at 72 °C). These conditions were applied in continuous process, where higher HRT (6.0 d) and lower OLR [7.7 kg VS/(m3 d)] gave the best performances in terms of process yield and maximum VFA level achieved: 0.77 CODVFA/VS(0) and 39 g CODVFA/L. An optimized fermentation process is crucial in a biorefinery perspective since it has to give a final stream of constant composition or tailored products suitable for further applications.
Giulia Moretto; Francesco Valentino; Paolo Pavan; Mauro Majone; David Bolzonella. Optimization of urban waste fermentation for volatile fatty acids production. Waste Management 2019, 92, 21 -29.
AMA StyleGiulia Moretto, Francesco Valentino, Paolo Pavan, Mauro Majone, David Bolzonella. Optimization of urban waste fermentation for volatile fatty acids production. Waste Management. 2019; 92 ():21-29.
Chicago/Turabian StyleGiulia Moretto; Francesco Valentino; Paolo Pavan; Mauro Majone; David Bolzonella. 2019. "Optimization of urban waste fermentation for volatile fatty acids production." Waste Management 92, no. : 21-29.
A combined acidic fermentation and anaerobic digestion (AD) treatment has been developed on pilot scale for urban bio-waste conversion into volatile fatty acid (VFA) and biogas. The specific waste mixture was composed by the pre-treated organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS), both produced inside the Treviso (northeast Italy) municipality. The effect of temperature (37 °C and 55 °C) was investigated in both steps. Only the mesophilic fermentation process provided a VFA-rich stream (19.5 g CODVFA/L) with stable physical-chemical features, with no need of chemicals addition for pH control. The sludge buffering capacity made this step technically feasible. The AD step was performed on the solid-rich fraction of fermented bio-waste, after dilution with excess WAS. No relevant differences were observed under the two investigated temperature: in the steady state (organic loading rate of 2.5 kg VS/m3 d), the specific biogas production was 0.40 and 0.45 m3/kg VS at 37 °C and 55 °C respectively, with similar CH4 content (63–64% v/v). The scaled-up version of the system (in an average urban municipality of 170,000 Person Equivalent) revealed that the whole process is thermally sustainable if both reactors are operated at mesophilic temperature: 36% of surplus thermal energy and 13,03 MWh/d of produced electricity, which corresponds to a revenue of 609,605 €/year. In addition, 2,262 kg CODVFA/d are available for parallel purposes, such as the synthesis of bio-products with higher added value than bio-methane (e.g. biopolymers).
Francesco Valentino; Giulia Moretto; Marco Gottardo; Paolo Pavan; David Bolzonella; Mauro Majone. Novel routes for urban bio-waste management: A combined acidic fermentation and anaerobic digestion process for platform chemicals and biogas production. Journal of Cleaner Production 2019, 220, 368 -375.
AMA StyleFrancesco Valentino, Giulia Moretto, Marco Gottardo, Paolo Pavan, David Bolzonella, Mauro Majone. Novel routes for urban bio-waste management: A combined acidic fermentation and anaerobic digestion process for platform chemicals and biogas production. Journal of Cleaner Production. 2019; 220 ():368-375.
Chicago/Turabian StyleFrancesco Valentino; Giulia Moretto; Marco Gottardo; Paolo Pavan; David Bolzonella; Mauro Majone. 2019. "Novel routes for urban bio-waste management: A combined acidic fermentation and anaerobic digestion process for platform chemicals and biogas production." Journal of Cleaner Production 220, no. : 368-375.
The integrated-multistage process proposed herein is a practical example of a biorefinery platform, where the organic fraction of municipal solid waste (OFMSW) is used as value source for polyhydroxyalkanoates (PHA) and biogas production. Technical and economical feasibility of this approach have been demonstrated at pilot-scale providing a possible upgrade to traditional biowaste management practices presently based on anaerobic digestion (AD). A pH-controlled OFMSW fermentation stage produced a liquid VFA-rich stream with high VFA/CODSOL ratio (0.90 COD/COD) that was easily used in following aerobic stages for biomass and PHA production. The solid fraction was valorized into biogas through AD, obtaining energy and minimizing secondary fluxes waste generation. The reliable aerobic biomass enrichment was demonstrated by stable feast-famine regime and supported by microbial community analysis. The selected consortium was able to accumulate PHA up to 55% wt. Compared to the traditional single stage AD process in an urban scenario of 900,000 AE, the integrated approach for OFMSW valorisation is preferable to biogas production only, being characterized by electrical energy production of 85.7 MWh/d and 1.976 t/d as PHA productivity. The proposed process has been also evaluated economically sustainable if PHA is marketed from 0.90 €/kg, as minimum threshold, to higher market price.
Francesco Valentino; Marco Gottardo; Federico Micolucci; Paolo Pavan; David Bolzonella; Simona Rossetti; Mauro Majone. Organic Fraction of Municipal Solid Waste Recovery by Conversion into Added-Value Polyhydroxyalkanoates and Biogas. ACS Sustainable Chemistry & Engineering 2018, 6, 16375 -16385.
AMA StyleFrancesco Valentino, Marco Gottardo, Federico Micolucci, Paolo Pavan, David Bolzonella, Simona Rossetti, Mauro Majone. Organic Fraction of Municipal Solid Waste Recovery by Conversion into Added-Value Polyhydroxyalkanoates and Biogas. ACS Sustainable Chemistry & Engineering. 2018; 6 (12):16375-16385.
Chicago/Turabian StyleFrancesco Valentino; Marco Gottardo; Federico Micolucci; Paolo Pavan; David Bolzonella; Simona Rossetti; Mauro Majone. 2018. "Organic Fraction of Municipal Solid Waste Recovery by Conversion into Added-Value Polyhydroxyalkanoates and Biogas." ACS Sustainable Chemistry & Engineering 6, no. 12: 16375-16385.