Agata Gallipoli - Academia.edu (original) (raw)
Papers by Agata Gallipoli
Séminaire sur les technologies et pratiques d'une agriculture durable.-ACTEURS ET FACTEURS DE CHA... more Séminaire sur les technologies et pratiques d'une agriculture durable.-ACTEURS ET FACTEURS DE CHANGEMENT. Compte rendu du Séminaire OCDE sur le technologies et pratiques d'une agriculture durable. 11-13 février 1992. OCDE/GD (92), 49, p. 1-19. Odegaard, H. (2004). "Sludge minimization technologies-an overview". Water Science and Technology, 49(10), p. 31-40 OECD ,(2001), " Environmental indicators for agriculture", Volume 3: methods and results, OECD, Paris; EC (2002a) Implementation of council directive 91/676/EEC concerning protection of water against pollution caused by nitrates from agricultural sources, European communities, Luxembourg
Journal of Cleaner Production, 2021
Journal of Environmental Chemical Engineering, 2020
Abstract Future sustainable technological solutions need to balance the development of sewage slu... more Abstract Future sustainable technological solutions need to balance the development of sewage sludge as resource against the paramount necessity to protect human health and environment. Nutrients, high value metals, embedded energy, and the avoidance of sludge handling costs are important examples of recoverable assets. Aim of this study was to assess the feasibility of sludge pre-treatments as ultrasound and thermal hydrolysis to promote the release of metals due to organics disintegration, and to investigate the efficiency of the anaerobic process to leach out metals from municipal sludge through an enhanced hydrolysis/acidification step. A preliminary deep analysis of elements concentration (Al, As, Ca, Cd, Co, Cr, Cu, Fe, Ga, Mg, Mn, Na, Ni, Pb, Se, V and Zn) in solid residue and water phase of waste activated sludge and anaerobic digestate sampled at full scale wastewater treatment plant (WWTP) allowed to calculate partitioning coefficients and equilibrium concentrations, in order to predict metal mobility and bioavailability. The gradual sludge disintegration and organics hydrolysis significantly contribute to the leaching of toxic elements as As, Ga, Se and Zn, increasing their removal potential. A new anaerobic bioleaching approach will be presented, aiming to develop a sustainable platform to recover metals, together with methane and a clean recyclable digestate.
Environmental Engineering and Management Journal, 2012
Ultrasounds pretreatment aims to convert waste activated sludge, characterized by recalcitrant pa... more Ultrasounds pretreatment aims to convert waste activated sludge, characterized by recalcitrant particulate organics, into a soluble, more biodegradable form, maximizing anaerobic stabilization and biogas recovery. Objective of this work was the assessment of the efficiency of high frequency ultrasounds, as 200 kHz, to improve sludge anaerobic digestion performances. Parallel batch anaerobic digestion tests were performed to evaluate anaerobic biodegradability of 20 or 200 kHz sonicated secondary sludge, operating at food/inoculum ratio of 0.5 and 1. Ultrasound pretreatments, independent on the frequency, accelerated the initial hydrolysis phase, and the effect was more marked working at high inoculum content. Moreover, the biogas produced by the sonicated sludge was always higher than that produced by the untreated one. This gain seemed to be independent on the F/I ratio for the digestion of the 20 kHz pretreated sludge, while, in the case of sludge treatment at 200 kHz, the biogas improvement was particularly high (about 40%) at F/I=0.5. In fact, at F/I=1, the biogas gain was only +4% due to an evident slowdown of the biogas production of the sonicated sludge, due to the accumulation of soluble organic substances, evidenced by the soluble COD pattern, suggesting discoupling between hydrolysis and methanogenesis. Fluorescence In Situ Hybridization (FISH) analysis allowed to highlight the establishment in the anaerobic biomass of different methanogens responsible for the biogas production depending on the extent of readily biodegradable substrates availability for the methanogenesis or on the amount of inoculum utilised at the start up of the anaerobic digestion process.
Chemosphere, 2020
Quorum sensing signals regulate various functions within activated sludge processes such as forma... more Quorum sensing signals regulate various functions within activated sludge processes such as formation of microbial aggregates. Disturbance of this signaling system, known as quorum quenching (QQ), provides opportunities for eliminating some problems related to biological wastewater treatment (e.g., biofouling and excess sludge production). However, it is poorly understood how and to what extent QQ systems can affect the microbial aggregation processes and the following floc formation. In particular, an in-depth structural characterization at the scale of microbial aggregate while considering nutrient conditions in the reactor is still largely disregarded. Here, we evaluated the QQ effects at the short-term time scale (i.e., after 4 h for the exogenous period and 19 h for exogenous/endogenous period), by combining advanced techniques for microbial characterization (flow cytometry, CARD-FISH, and confocal laser scanning microscopy) and conventional physical-chemical assessments. The results indicated that by implementing QQ agents (immobilized Acylase I enzyme in porous alginate beads) the abundance of single cells and suspended microbial aggregates in the supernatant did not show significant changes during the exogenous period. Conversely, at the end of the exogenous/endogenous period a significant increase of single prokaryotic cells, small and large microbial aggregates favored the growth of grazers, including free-living nanoflagellates and ciliates. Flocs became looser and thinner than those in the control reactor, thus affecting the sludge settling behavior. Inability of microbial community in degradation of soluble protein during the endogenous period confirmed that the QQ agents are likely to inhibit the secretion of protease enzyme within microbial communities of activated sludge.
New Biotechnology, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Bioresource Technology, 2018
Brønsted acid catalysed ethanolysis of the organic fraction of municipal solid waste for efficien... more Brønsted acid catalysed ethanolysis of the organic fraction of municipal solid waste for efficient production of biofuels,
International Biodeterioration & Biodegradation, 2017
A system using a two-phase anaerobic configuration (mesophilic/thermophilic) was tested by feedin... more A system using a two-phase anaerobic configuration (mesophilic/thermophilic) was tested by feeding waste activated sludge (WAS). The first acidogenic stage presented a hydraulic retention time (HRT) of 3 days, while the second methanogenic stage had an HRT of 10 days. Both raw and ultrasonically pretreated WAS samples were utilized for the experiment. Previous Fluorescence in Situ Hybridization (FISH) observations, revealed that in the thermophilic phase, the acetoclastic methanogenesis was likely replaced by a nonacetoclastic pathway, namely, syntrophic acetate oxidation (SAO). A modified version of Anaerobic Digestion Model n 1 (ADM1), accounting for the SAO pathway, was implemented and calibrated. The proposed model addressed the relationship between the hydrogen concentration and Gibbs free energy and showed the thermodynamic feasibility of the SAO pathway, while simultaneously highlighting the role played by hydrogenotrophic methanogens in maintaining a sufficiently low hydrogen partial pressure so that the SAO was energetically feasible. The estimated energy loss was estimated to be approximately 20% due to the switch of the microbial pathway from acetoclastic methanogenesis to SAO.
Biomass and Bioenergy, 2018
Stability and performance of long term semi-continuous Anaerobic Digestion of food waste at semi-... more Stability and performance of long term semi-continuous Anaerobic Digestion of food waste at semi-pilot scale is here evaluated based on the integration of multiple lines of evidence. In order to elucidate the main microbial components, the core microbiome dynamics were assessed by high-throughput 16 S rRNA gene sequencing over the reactor operation together with the data related to the AD performances. The experimental reactor, after a successful start-up, was operated for more than 200 days at a moderate OLR (Organic Loading Rate) of 1.6 ± 0.4 g VS L −1 d −1. The availability of readily biodegradable substrate, in particular carbohydrates, favored the fermentative functional redundancy of bacteria promoting the rapid accumulation of acetate first, and propionate afterwards, due to limited methanogenesis. The prolonged operation, despite the moderate OLR, nurtured propionate accumulation, because H 2 concentration exceeded the level capable to render the reaction endergonic, hampering the propionate uptake process. The application of a Pulsed Feeding strategy increased the hydrogenotrophic Methanomicrobiales favoring the consumption of propionate most likely through hydrogen utilization.
Environmental Technology, 2017
Methanogenic biomass plays a key role with regards methane production during anaerobic bioconvers... more Methanogenic biomass plays a key role with regards methane production during anaerobic bioconversion of organic substrates. In this study, the effect of two different acclimated inocula on digestion performances was investigated by means of anaerobic batch tests on untreated and sonicated waste activated sludge. Organics solubilisation and removal kinetics, the abundance and physiological conditions of archaeal cells on ultimate methane yield were evaluated. The simultaneous presence of Methanosarcina and Methanosaeta in the archaeal biomass, the higher initial archaeal cells relative abundance and their occurrence in the aggregated forms were the main factors positively affecting the conversion into methane. The presence of the acclimated inoculum at the start up influenced positively the methane improvement due to sonication, and the methane specific production increased from 0.335±0.03 to 0.420±0.05 Nm 3 /kg VS fed. Moreover, the better physiological state of methanogens permitted to appreciate the effect of hydrolysis improvement by ultrasound pretreatment.
DESCRIPTION Novel processing routes for effective sewage sludge management - Enhanced stabilizati... more DESCRIPTION Novel processing routes for effective sewage sludge management - Enhanced stabilization processes
This study give a preliminary survey of pharmaceutical contamination and accumulation in surface ... more This study give a preliminary survey of pharmaceutical contamination and accumulation in surface waters and sediments along the river Po basin (74,000 km 2 , the largest in Italy), a strategic region for the Italian economy: it collects sewage from a vast industrialized area of Italy (Autorità di Baciono del fiume Po, 2006, 2009). 10 pharmaceuticals (atenolol, propanolol, metoprolol, nimesulide, furosemide, carbamazepine, ranitidine, metronidazole, paracetamol, and atorvastatin) from several therapeutic classes were searched in 54 sampling points along the river Po from the source to the delta, and at the mouth of its major effluents. In water samples were found pharmaceuticals in the range of 0.38-0.001 μg/L, except for furosemide (max conc. 0.605 μg/L), paracetamol (max conc. 3.59 μg/L), metoprolol (never detected) and for atenolol (not analysed). In sediment samples, only paracetamol was not detected, while the others were generally found in the range of 0.4-0.02 μg/kg ww with high concentrations for atenolol (max conc. 284 μg/kg ww) and furosemide (max conc. 98.4 μg/kg ww). The findings confirm also STPs as point sources of contamination. Despite of the much evidence for the adverse effects of pharmaceuticals in the aquatic environment, the observed low levels cannot be considered to pose a serious risk to human health; further studies are necessary for a comprehensive risk assessment.
Ultrasonics Sonochemistry, 2012
Ultrasounds represent an effective technology in many research fields. In sewage sludge treatment... more Ultrasounds represent an effective technology in many research fields. In sewage sludge treatment, lowfrequency ultrasound, particularly at 20 kHz, are widely used for sludge disintegration before the anaerobic digestion, while in the last years novel application of high-frequency ultrasound regards the decontamination of water and wastewater through sonochemical reactions. The innovative approach presented in this paper is the treatment of sewage sludge with ultrasound at 200 kHz for obtaining efficient sludge disintegration and the removal of the linear alkylbenzenesulphonates (LAS) at the same time. Results of the sonolysis experiments showed that native LAS degradation up to 40% can be achieved with low power input in less than 1 h. The degradation pattern was different for each LAS homologue (from C10 to C13), because of their physical-chemical properties, in particular as regards the alkyl chain length. This highfrequency ultrasound irradiation resulted effective also in terms of floc disintegration and soluble organic matter release, in particular for energy inputs higher than 30,000 kJ/kg TS. The disrupting effect of the 200 kHz treatment was also evaluated by microscope analyses and determination of the extracellular polymeric substances release in the liquid phase.
Plant and Soil, 2008
An ombrotrophic peat core was collected in 2005 from Etang de la Gruère, Jura Mountains, Switzerl... more An ombrotrophic peat core was collected in 2005 from Etang de la Gruère, Jura Mountains, Switzerland. The concentrations of nine among the U.S. Environmental Protection Agency priority polycyclic aromatic hydrocarbons (PAHs) (i.e., acenaphthene, phenanthrene, fluorene, pyrene, fluoranthene, benzo[jbk]fluoranthene, benzo[a]pyrene, benzo[ghi]perylene, and indeno[1,2,3-cd]pyrene) were determined in both bulk peat and corresponding humic acids (HA) samples by gas chromatography equipped with a
Journal of Inorganic Biochemistry, 2006
Three new asymmetric platinum(II) complexes comprising an isopropylamine ligand trans to an azole... more Three new asymmetric platinum(II) complexes comprising an isopropylamine ligand trans to an azole ligand were synthesized and fully characterized by 1 H NMR, 195 Pt NMR, IR and elemental analysis. In addition the X-ray crystal structure of all three complexes was determined. The reaction kinetics of the complexes with DNA model base guanosine-5 0-monophosphate (GMP) was studied, revealing reaction kinetics comparable to cisplatin. To gain insight in the complexes as potential antitumor agents, cytotoxicity assays were performed on a variety of human tumor cell lines. These assays showed the complexes all to possess cytotoxicity profiles comparable to cisplatin. Furthermore, the complexes largely retain their activity in a human ovarian carcinoma cell line resistant to cisplatin, A2780R, compared to the cisplatin sensitive parent cell line A2780. These results are of fundamental importance, illustrating how platinum complexes of trans geometry can show improved activity compared to cisplatin in both cisplatin sensitive and cisplatin resistant cell lines.
![Research paper thumbnail of In vitro antitumor activity and interaction with DNA model bases of cis-[PtCl2(iPram)(azole)] complexes and comparison with their trans analogues](https://attachments.academia-assets.com/94610816/thumbnails/1.jpg)
](Inorganica Chimica Acta, 2006
Asymmetric cis-platinum(II) complexes with isopropylamine and two different azole ligands were sy... more Asymmetric cis-platinum(II) complexes with isopropylamine and two different azole ligands were synthesized and characterized with different techniques. In addition, for one of the complexes the X-ray structure was determined. Cytotoxicity tests using several human tumor cell lines, including the cisplatin-sensitive cell line A2780 and its cisplatin-resistant analogue. These results were compared with the results obtained for the trans isomers of the presented complexes and a relation between the structure and the activity was established. It was found that complexes with cis geometry are less active than their trans analogues, in particular in the resistant cell line A2780R. However, complex 1 can overcome cisplatin resistance to a certain extent. In the interaction with GMP, the asymmetric cis-Pt(II) complexes react with similar rates as their trans analogues and they behave as bifunctional species.
Detritus
This innovative Biorefinery platform is based on the integration of a mild thermal pre-treatment ... more This innovative Biorefinery platform is based on the integration of a mild thermal pre-treatment and a solid/liquid separation unit to parallel-integrated bioprocesses specifically selected on food waste distinctive chemical composition: a liquid fraction, rich in readily fermentable sugars, to be transformed into valuable biobased products, and a solid organic residue to enhance biomethane production generating a fully hygienized digestate to be recycled. The preliminary results in terms of VFAs yields and composition from the acidogenic stage, and the methane conversion rate from the anaerobic digestion of the solid residue, are here presented
Anaerobic digestion of Food Wastes (FW) was investigated in batch mesophilic tests. Scope of this... more Anaerobic digestion of Food Wastes (FW) was investigated in batch mesophilic tests. Scope of this work was to evaluate the efficiency of thermal pretreatment on the solubilisation degree of FW, alone or mixed with typical Mediterranean agro-wastes as olive husks (OH), and to evaluate the digestion enhancement potential of pretreatment and co-digestion strategy in terms of methane and hydrogen conversion rates of FW. Co-digestion was carried out by mixing FW and olive husks, untreated or thermal pre-treated. Thermal pretreatment was efficient in solubilising the organic material of FW (soluble COD increase up to 35%) and of the mixture FW and OH (up to +96%), in particular carbohydrates. After 30 days of digestion, an overall good anaerobic biodegradability of FW alone was observed, with methane yields in the range 0.350 – 0.592 Nm3/kgVSfed, overshadowing the effect of pretreatment, that affected positively only the hydrogenogenic phase. Moreover, also co-digestion with OH was a succ...
Journal of Environmental Chemical Engineering
Bioresource Technology, 2021
A novel biorefinery platform integrating thermal pretreatment and solid-liquid separation unit is... more A novel biorefinery platform integrating thermal pretreatment and solid-liquid separation unit is here proposed to fully exploit food waste (FW) potential for production of valuable chemicals and energy through semi-continuous anaerobic bioconversion. The liquid fraction deriving from raw or pretreated FW, was fermented into volatile fatty acids (VFAs, from acetic to caproic acid) while the residual fraction was converted into biomethane. Thermal pretreatment effectively extracted a portion of the macromolecular organics, especially starch, to the liquid phase, promoting acidogenic fermentation and chain elongation pathways (0.43 gVFA g-1VSfed and 0.58 gVFA g-1VSfed with raw and pretreated extract, respectively). In parallel, anaerobic digestion of solid residue in 10 L reactors showed process stability and higher conversion rate for the pretreated residue (0.31 against 0.26 Nm3CH4 kg-1VSfed). The mass-transfer balance coupled with the economic assessment, calculated in terms of direct gross added value, indicated promising revenues by integrating the thermal upstream treatment.
Séminaire sur les technologies et pratiques d'une agriculture durable.-ACTEURS ET FACTEURS DE CHA... more Séminaire sur les technologies et pratiques d'une agriculture durable.-ACTEURS ET FACTEURS DE CHANGEMENT. Compte rendu du Séminaire OCDE sur le technologies et pratiques d'une agriculture durable. 11-13 février 1992. OCDE/GD (92), 49, p. 1-19. Odegaard, H. (2004). "Sludge minimization technologies-an overview". Water Science and Technology, 49(10), p. 31-40 OECD ,(2001), " Environmental indicators for agriculture", Volume 3: methods and results, OECD, Paris; EC (2002a) Implementation of council directive 91/676/EEC concerning protection of water against pollution caused by nitrates from agricultural sources, European communities, Luxembourg
Journal of Cleaner Production, 2021
Journal of Environmental Chemical Engineering, 2020
Abstract Future sustainable technological solutions need to balance the development of sewage slu... more Abstract Future sustainable technological solutions need to balance the development of sewage sludge as resource against the paramount necessity to protect human health and environment. Nutrients, high value metals, embedded energy, and the avoidance of sludge handling costs are important examples of recoverable assets. Aim of this study was to assess the feasibility of sludge pre-treatments as ultrasound and thermal hydrolysis to promote the release of metals due to organics disintegration, and to investigate the efficiency of the anaerobic process to leach out metals from municipal sludge through an enhanced hydrolysis/acidification step. A preliminary deep analysis of elements concentration (Al, As, Ca, Cd, Co, Cr, Cu, Fe, Ga, Mg, Mn, Na, Ni, Pb, Se, V and Zn) in solid residue and water phase of waste activated sludge and anaerobic digestate sampled at full scale wastewater treatment plant (WWTP) allowed to calculate partitioning coefficients and equilibrium concentrations, in order to predict metal mobility and bioavailability. The gradual sludge disintegration and organics hydrolysis significantly contribute to the leaching of toxic elements as As, Ga, Se and Zn, increasing their removal potential. A new anaerobic bioleaching approach will be presented, aiming to develop a sustainable platform to recover metals, together with methane and a clean recyclable digestate.
Environmental Engineering and Management Journal, 2012
Ultrasounds pretreatment aims to convert waste activated sludge, characterized by recalcitrant pa... more Ultrasounds pretreatment aims to convert waste activated sludge, characterized by recalcitrant particulate organics, into a soluble, more biodegradable form, maximizing anaerobic stabilization and biogas recovery. Objective of this work was the assessment of the efficiency of high frequency ultrasounds, as 200 kHz, to improve sludge anaerobic digestion performances. Parallel batch anaerobic digestion tests were performed to evaluate anaerobic biodegradability of 20 or 200 kHz sonicated secondary sludge, operating at food/inoculum ratio of 0.5 and 1. Ultrasound pretreatments, independent on the frequency, accelerated the initial hydrolysis phase, and the effect was more marked working at high inoculum content. Moreover, the biogas produced by the sonicated sludge was always higher than that produced by the untreated one. This gain seemed to be independent on the F/I ratio for the digestion of the 20 kHz pretreated sludge, while, in the case of sludge treatment at 200 kHz, the biogas improvement was particularly high (about 40%) at F/I=0.5. In fact, at F/I=1, the biogas gain was only +4% due to an evident slowdown of the biogas production of the sonicated sludge, due to the accumulation of soluble organic substances, evidenced by the soluble COD pattern, suggesting discoupling between hydrolysis and methanogenesis. Fluorescence In Situ Hybridization (FISH) analysis allowed to highlight the establishment in the anaerobic biomass of different methanogens responsible for the biogas production depending on the extent of readily biodegradable substrates availability for the methanogenesis or on the amount of inoculum utilised at the start up of the anaerobic digestion process.
Chemosphere, 2020
Quorum sensing signals regulate various functions within activated sludge processes such as forma... more Quorum sensing signals regulate various functions within activated sludge processes such as formation of microbial aggregates. Disturbance of this signaling system, known as quorum quenching (QQ), provides opportunities for eliminating some problems related to biological wastewater treatment (e.g., biofouling and excess sludge production). However, it is poorly understood how and to what extent QQ systems can affect the microbial aggregation processes and the following floc formation. In particular, an in-depth structural characterization at the scale of microbial aggregate while considering nutrient conditions in the reactor is still largely disregarded. Here, we evaluated the QQ effects at the short-term time scale (i.e., after 4 h for the exogenous period and 19 h for exogenous/endogenous period), by combining advanced techniques for microbial characterization (flow cytometry, CARD-FISH, and confocal laser scanning microscopy) and conventional physical-chemical assessments. The results indicated that by implementing QQ agents (immobilized Acylase I enzyme in porous alginate beads) the abundance of single cells and suspended microbial aggregates in the supernatant did not show significant changes during the exogenous period. Conversely, at the end of the exogenous/endogenous period a significant increase of single prokaryotic cells, small and large microbial aggregates favored the growth of grazers, including free-living nanoflagellates and ciliates. Flocs became looser and thinner than those in the control reactor, thus affecting the sludge settling behavior. Inability of microbial community in degradation of soluble protein during the endogenous period confirmed that the QQ agents are likely to inhibit the secretion of protease enzyme within microbial communities of activated sludge.
New Biotechnology, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Bioresource Technology, 2018
Brønsted acid catalysed ethanolysis of the organic fraction of municipal solid waste for efficien... more Brønsted acid catalysed ethanolysis of the organic fraction of municipal solid waste for efficient production of biofuels,
International Biodeterioration & Biodegradation, 2017
A system using a two-phase anaerobic configuration (mesophilic/thermophilic) was tested by feedin... more A system using a two-phase anaerobic configuration (mesophilic/thermophilic) was tested by feeding waste activated sludge (WAS). The first acidogenic stage presented a hydraulic retention time (HRT) of 3 days, while the second methanogenic stage had an HRT of 10 days. Both raw and ultrasonically pretreated WAS samples were utilized for the experiment. Previous Fluorescence in Situ Hybridization (FISH) observations, revealed that in the thermophilic phase, the acetoclastic methanogenesis was likely replaced by a nonacetoclastic pathway, namely, syntrophic acetate oxidation (SAO). A modified version of Anaerobic Digestion Model n 1 (ADM1), accounting for the SAO pathway, was implemented and calibrated. The proposed model addressed the relationship between the hydrogen concentration and Gibbs free energy and showed the thermodynamic feasibility of the SAO pathway, while simultaneously highlighting the role played by hydrogenotrophic methanogens in maintaining a sufficiently low hydrogen partial pressure so that the SAO was energetically feasible. The estimated energy loss was estimated to be approximately 20% due to the switch of the microbial pathway from acetoclastic methanogenesis to SAO.
Biomass and Bioenergy, 2018
Stability and performance of long term semi-continuous Anaerobic Digestion of food waste at semi-... more Stability and performance of long term semi-continuous Anaerobic Digestion of food waste at semi-pilot scale is here evaluated based on the integration of multiple lines of evidence. In order to elucidate the main microbial components, the core microbiome dynamics were assessed by high-throughput 16 S rRNA gene sequencing over the reactor operation together with the data related to the AD performances. The experimental reactor, after a successful start-up, was operated for more than 200 days at a moderate OLR (Organic Loading Rate) of 1.6 ± 0.4 g VS L −1 d −1. The availability of readily biodegradable substrate, in particular carbohydrates, favored the fermentative functional redundancy of bacteria promoting the rapid accumulation of acetate first, and propionate afterwards, due to limited methanogenesis. The prolonged operation, despite the moderate OLR, nurtured propionate accumulation, because H 2 concentration exceeded the level capable to render the reaction endergonic, hampering the propionate uptake process. The application of a Pulsed Feeding strategy increased the hydrogenotrophic Methanomicrobiales favoring the consumption of propionate most likely through hydrogen utilization.
Environmental Technology, 2017
Methanogenic biomass plays a key role with regards methane production during anaerobic bioconvers... more Methanogenic biomass plays a key role with regards methane production during anaerobic bioconversion of organic substrates. In this study, the effect of two different acclimated inocula on digestion performances was investigated by means of anaerobic batch tests on untreated and sonicated waste activated sludge. Organics solubilisation and removal kinetics, the abundance and physiological conditions of archaeal cells on ultimate methane yield were evaluated. The simultaneous presence of Methanosarcina and Methanosaeta in the archaeal biomass, the higher initial archaeal cells relative abundance and their occurrence in the aggregated forms were the main factors positively affecting the conversion into methane. The presence of the acclimated inoculum at the start up influenced positively the methane improvement due to sonication, and the methane specific production increased from 0.335±0.03 to 0.420±0.05 Nm 3 /kg VS fed. Moreover, the better physiological state of methanogens permitted to appreciate the effect of hydrolysis improvement by ultrasound pretreatment.
DESCRIPTION Novel processing routes for effective sewage sludge management - Enhanced stabilizati... more DESCRIPTION Novel processing routes for effective sewage sludge management - Enhanced stabilization processes
This study give a preliminary survey of pharmaceutical contamination and accumulation in surface ... more This study give a preliminary survey of pharmaceutical contamination and accumulation in surface waters and sediments along the river Po basin (74,000 km 2 , the largest in Italy), a strategic region for the Italian economy: it collects sewage from a vast industrialized area of Italy (Autorità di Baciono del fiume Po, 2006, 2009). 10 pharmaceuticals (atenolol, propanolol, metoprolol, nimesulide, furosemide, carbamazepine, ranitidine, metronidazole, paracetamol, and atorvastatin) from several therapeutic classes were searched in 54 sampling points along the river Po from the source to the delta, and at the mouth of its major effluents. In water samples were found pharmaceuticals in the range of 0.38-0.001 μg/L, except for furosemide (max conc. 0.605 μg/L), paracetamol (max conc. 3.59 μg/L), metoprolol (never detected) and for atenolol (not analysed). In sediment samples, only paracetamol was not detected, while the others were generally found in the range of 0.4-0.02 μg/kg ww with high concentrations for atenolol (max conc. 284 μg/kg ww) and furosemide (max conc. 98.4 μg/kg ww). The findings confirm also STPs as point sources of contamination. Despite of the much evidence for the adverse effects of pharmaceuticals in the aquatic environment, the observed low levels cannot be considered to pose a serious risk to human health; further studies are necessary for a comprehensive risk assessment.
Ultrasonics Sonochemistry, 2012
Ultrasounds represent an effective technology in many research fields. In sewage sludge treatment... more Ultrasounds represent an effective technology in many research fields. In sewage sludge treatment, lowfrequency ultrasound, particularly at 20 kHz, are widely used for sludge disintegration before the anaerobic digestion, while in the last years novel application of high-frequency ultrasound regards the decontamination of water and wastewater through sonochemical reactions. The innovative approach presented in this paper is the treatment of sewage sludge with ultrasound at 200 kHz for obtaining efficient sludge disintegration and the removal of the linear alkylbenzenesulphonates (LAS) at the same time. Results of the sonolysis experiments showed that native LAS degradation up to 40% can be achieved with low power input in less than 1 h. The degradation pattern was different for each LAS homologue (from C10 to C13), because of their physical-chemical properties, in particular as regards the alkyl chain length. This highfrequency ultrasound irradiation resulted effective also in terms of floc disintegration and soluble organic matter release, in particular for energy inputs higher than 30,000 kJ/kg TS. The disrupting effect of the 200 kHz treatment was also evaluated by microscope analyses and determination of the extracellular polymeric substances release in the liquid phase.
Plant and Soil, 2008
An ombrotrophic peat core was collected in 2005 from Etang de la Gruère, Jura Mountains, Switzerl... more An ombrotrophic peat core was collected in 2005 from Etang de la Gruère, Jura Mountains, Switzerland. The concentrations of nine among the U.S. Environmental Protection Agency priority polycyclic aromatic hydrocarbons (PAHs) (i.e., acenaphthene, phenanthrene, fluorene, pyrene, fluoranthene, benzo[jbk]fluoranthene, benzo[a]pyrene, benzo[ghi]perylene, and indeno[1,2,3-cd]pyrene) were determined in both bulk peat and corresponding humic acids (HA) samples by gas chromatography equipped with a
Journal of Inorganic Biochemistry, 2006
Three new asymmetric platinum(II) complexes comprising an isopropylamine ligand trans to an azole... more Three new asymmetric platinum(II) complexes comprising an isopropylamine ligand trans to an azole ligand were synthesized and fully characterized by 1 H NMR, 195 Pt NMR, IR and elemental analysis. In addition the X-ray crystal structure of all three complexes was determined. The reaction kinetics of the complexes with DNA model base guanosine-5 0-monophosphate (GMP) was studied, revealing reaction kinetics comparable to cisplatin. To gain insight in the complexes as potential antitumor agents, cytotoxicity assays were performed on a variety of human tumor cell lines. These assays showed the complexes all to possess cytotoxicity profiles comparable to cisplatin. Furthermore, the complexes largely retain their activity in a human ovarian carcinoma cell line resistant to cisplatin, A2780R, compared to the cisplatin sensitive parent cell line A2780. These results are of fundamental importance, illustrating how platinum complexes of trans geometry can show improved activity compared to cisplatin in both cisplatin sensitive and cisplatin resistant cell lines.
Inorganica Chimica Acta, 2006
Asymmetric cis-platinum(II) complexes with isopropylamine and two different azole ligands were sy... more Asymmetric cis-platinum(II) complexes with isopropylamine and two different azole ligands were synthesized and characterized with different techniques. In addition, for one of the complexes the X-ray structure was determined. Cytotoxicity tests using several human tumor cell lines, including the cisplatin-sensitive cell line A2780 and its cisplatin-resistant analogue. These results were compared with the results obtained for the trans isomers of the presented complexes and a relation between the structure and the activity was established. It was found that complexes with cis geometry are less active than their trans analogues, in particular in the resistant cell line A2780R. However, complex 1 can overcome cisplatin resistance to a certain extent. In the interaction with GMP, the asymmetric cis-Pt(II) complexes react with similar rates as their trans analogues and they behave as bifunctional species.
Detritus
This innovative Biorefinery platform is based on the integration of a mild thermal pre-treatment ... more This innovative Biorefinery platform is based on the integration of a mild thermal pre-treatment and a solid/liquid separation unit to parallel-integrated bioprocesses specifically selected on food waste distinctive chemical composition: a liquid fraction, rich in readily fermentable sugars, to be transformed into valuable biobased products, and a solid organic residue to enhance biomethane production generating a fully hygienized digestate to be recycled. The preliminary results in terms of VFAs yields and composition from the acidogenic stage, and the methane conversion rate from the anaerobic digestion of the solid residue, are here presented
Anaerobic digestion of Food Wastes (FW) was investigated in batch mesophilic tests. Scope of this... more Anaerobic digestion of Food Wastes (FW) was investigated in batch mesophilic tests. Scope of this work was to evaluate the efficiency of thermal pretreatment on the solubilisation degree of FW, alone or mixed with typical Mediterranean agro-wastes as olive husks (OH), and to evaluate the digestion enhancement potential of pretreatment and co-digestion strategy in terms of methane and hydrogen conversion rates of FW. Co-digestion was carried out by mixing FW and olive husks, untreated or thermal pre-treated. Thermal pretreatment was efficient in solubilising the organic material of FW (soluble COD increase up to 35%) and of the mixture FW and OH (up to +96%), in particular carbohydrates. After 30 days of digestion, an overall good anaerobic biodegradability of FW alone was observed, with methane yields in the range 0.350 – 0.592 Nm3/kgVSfed, overshadowing the effect of pretreatment, that affected positively only the hydrogenogenic phase. Moreover, also co-digestion with OH was a succ...
Journal of Environmental Chemical Engineering
Bioresource Technology, 2021
A novel biorefinery platform integrating thermal pretreatment and solid-liquid separation unit is... more A novel biorefinery platform integrating thermal pretreatment and solid-liquid separation unit is here proposed to fully exploit food waste (FW) potential for production of valuable chemicals and energy through semi-continuous anaerobic bioconversion. The liquid fraction deriving from raw or pretreated FW, was fermented into volatile fatty acids (VFAs, from acetic to caproic acid) while the residual fraction was converted into biomethane. Thermal pretreatment effectively extracted a portion of the macromolecular organics, especially starch, to the liquid phase, promoting acidogenic fermentation and chain elongation pathways (0.43 gVFA g-1VSfed and 0.58 gVFA g-1VSfed with raw and pretreated extract, respectively). In parallel, anaerobic digestion of solid residue in 10 L reactors showed process stability and higher conversion rate for the pretreated residue (0.31 against 0.26 Nm3CH4 kg-1VSfed). The mass-transfer balance coupled with the economic assessment, calculated in terms of direct gross added value, indicated promising revenues by integrating the thermal upstream treatment.