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John Wiley & Sons, Inc. eBooks, Aug 12, 2009
It has been estimated that around 5% of watersheds in industrialized countries have health-and en... more It has been estimated that around 5% of watersheds in industrialized countries have health-and environment-threatening sediments and that 10% of marine and estuarine sediments are potentially hazardous for the aquatic environment. Indeed, industrial activities are often located near the seashore; therefore, it is not unusual to find marine sediments heavily contaminated by either heavy metals or organic contaminants. Dredging and management operations on contaminated sediments are also related to marine trade routes maintenance; although contaminated sediments may be left in place covered by a low permeability and erosion-resistant capping, dredging may still be required for harbor/routes maintenance purposes. In such cases, huge amounts of (possibly) contaminated sediments need to be dredged, dewatered, and treated before reuse or final disposal. Around 500 million cubic meters of sediments are dredged each year for navigational purposes and roughly 1%-4% requires dewatering and treatment prior to disposal, increasing the cost of dredging by a factor of 300-500. Despite decades of research, surprisingly little is known about successful treatment of contaminated sediments. Presently, the most common approach to management of dredged sediment is generally limited to land (or aquatic) disposal. Confined aquatic disposal (CAD) involves underwater contaminated sediments capping with clean sediments or sand, geotextiles, liners, or even reactive barriers, either with or without lateral confinement. Sediments are deposited in natural or artificial depression, usually by means of a clamshell or a hydraulic pipeline. Capping may also shift 1
Bioresource Technology, Mar 1, 2019
Factorial fermentation experiments on food waste (FW) inoculated with activated sludge (AS) were ... more Factorial fermentation experiments on food waste (FW) inoculated with activated sludge (AS) were conducted to investigate the effects of pH and the inoculum-to-substrate ratio (ISR [g VS AS /g TOC FW ]) on biohydrogen production. The two parameters affected the H 2 yield, the fermentation rate and the biochemical pathways. The minimum and maximum yields were 41 L H 2 /kg TOC FW (pH = 7.5, ISR = 1.74) and 156160 L H 2 /kg TOC FW (pH = 5.5, ISR = 0.58 and 1.74). The range of carbohydrates conversion into H 2 was 0.371.45 mol H 2 /mol hexose, corresponding to 9.436.2% of the theoretical threshold. A second-order predictive model for H 2 production identified an optimum region at low pHs and high ISRs, with a theoretical maximum of 168 L H 2 /kg TOC FW at pH = 5.5 and ISR = 1.74. The Spearman's correlation method revealed several relationships between the variables, suggesting the potentially governing metabolic pathways, which turned out to involve both hydrogenogenic pathways and competing reactions.
1 ISPRA (Italian Institute for Environmental Protection and Research). Via Vitaliano Brancati, 60... more 1 ISPRA (Italian Institute for Environmental Protection and Research). Via Vitaliano Brancati, 60 00144 Rome (Italy) 2 Universita di Cagliari – Dipartimento di Geoingegneria e Tecnologie Ambientali. Piazza d’Armi, 1 – 09123 Cagliari (Italy) 3 ARPA Emilia Romagna (Agenzia Regionale Prevenzione e Ambiente). Largo Caduti del Lavoro, 6 40121 Bologna (Italy) 4 CNR (Consiglio Nazionale delle Ricerche) – Istituto di Geologia Ambientale e Geoingegneria. Piazza d’Armi, 19 – 09123 Cagliari (Italy) 5 Universita degli Studi di Roma “La Sapienza” – Dipartimento di Ingegneria Civile, Edile ed Ambientale. Via Eudossiana, 18 – 00184 Rome (Italy)
Dredging operations in harbour and marine coastal areas, usually performed to maintain operationa... more Dredging operations in harbour and marine coastal areas, usually performed to maintain operational waterdepth, might represent a viable option to mitigate environmental pollution if applied to remove contaminated sediments from the water body. Sediment landfilling could generate relevant environmental burdens due to the amounts of materials to be disposed of; however, the implementation of alternative management options aimed at re-use is hindered by the high cost of technology and the absence of a market for the recovered materials. The present project, named COAST BEST “CO-ordinated Approach for Sediment Treatment and BEneficial reuse in Small harbours networks” and funded in the framework of the LIFE08+ ENV European call, is aimed to find out a method to integrate all the phases (i.e., dredging, treatment, valorisation and disposal) of sediment management, through the creation of a network-based system including different small harbours which can be geographically interconnected
Journal of Environmental Management, Nov 1, 2022
Waste Management, 2007
Mechanical-biological pre-treatment (MBP) of municipal solid waste (MSW) has gained evidence as a... more Mechanical-biological pre-treatment (MBP) of municipal solid waste (MSW) has gained evidence as a practice capable of accomplishing the requirements for environmental sustainable landfilling. In particular, MBP is effective in reducing the ammoniacal nitrogen content in the leachate. However, few data are available on the modifications of the nitrogen forms occurring during MBP and on the role played by processes such as nitrification and generation of refractory organic compounds. The dynamic transformations of nitrogen were investigated during the MBP. MSW was mechanically and biologically pre-treated; samples were collected at different stages of the process and analysed to investigate the evolution of nitrogen forms; batch and column leaching tests were performed as well. The results indicate that nitrification is negligible and volatilization can only partially explain the low ammoniacal nitrogen content in the leachate. Incorporation of ammoniacal nitrogen into a refractory organic form was assessed and is likely to play an important role. The maximum content of refractory organic nitrogen in the solid waste was achieved after about 60 days of aerobic pre-treatment; therefore, the minimal duration of the MBP should be about 8-9 weeks in order to optimize the ammoniacal nitrogen incorporation, unless the waste is characterized by a low C/N ratio.
Sustainability, Nov 29, 2018
In this study, the influence of the inoculum-to-substrate ratio (ISR) on dark fermentative hydrog... more In this study, the influence of the inoculum-to-substrate ratio (ISR) on dark fermentative hydrogen production from food waste (FW) was evaluated. ISR values ranging from 0.05 to 0.25 g VS inoculum /g VS substrate were investigated by performing batch tests at T = 39 • C and pH = 6.5, the latter being the optimal value identified based on a previous study. The ISR was found to affect the fermentation process, clearly showing that an adequate ISR is essential in order to optimise the process kinetics and the H 2 yield. An ISR of 0.14 proved to optimum, leading to a maximum H 2 yield of 88.8 L H 2 /kg VS FW and a maximum production rate of 10.8 L H 2 /kg VS FW •h. The analysis of the fermentation products indicated that the observed highest H 2 production mostly derived from the typical acetate/butyrate-type fermentation.
Proceedings of the 16th International Conference on Environmental Science and Technology, Nov 19, 2022
In the present study, PHA production from ovine cheese whey (oCW) through a 3-step process (dark ... more In the present study, PHA production from ovine cheese whey (oCW) through a 3-step process (dark fermentation, biomass selection and PHA accumulation process) was investigated. Different operating pHs were adopted during the fermentation step and no external nutrients were supplied at any step of the process. Results showed that the production of PHA from oCW is a promising valorisation approach.
John Wiley & Sons, Inc. eBooks, Aug 12, 2009
It has been estimated that around 5% of watersheds in industrialized countries have health-and en... more It has been estimated that around 5% of watersheds in industrialized countries have health-and environment-threatening sediments and that 10% of marine and estuarine sediments are potentially hazardous for the aquatic environment. Indeed, industrial activities are often located near the seashore; therefore, it is not unusual to find marine sediments heavily contaminated by either heavy metals or organic contaminants. Dredging and management operations on contaminated sediments are also related to marine trade routes maintenance; although contaminated sediments may be left in place covered by a low permeability and erosion-resistant capping, dredging may still be required for harbor/routes maintenance purposes. In such cases, huge amounts of (possibly) contaminated sediments need to be dredged, dewatered, and treated before reuse or final disposal. Around 500 million cubic meters of sediments are dredged each year for navigational purposes and roughly 1%-4% requires dewatering and treatment prior to disposal, increasing the cost of dredging by a factor of 300-500. Despite decades of research, surprisingly little is known about successful treatment of contaminated sediments. Presently, the most common approach to management of dredged sediment is generally limited to land (or aquatic) disposal. Confined aquatic disposal (CAD) involves underwater contaminated sediments capping with clean sediments or sand, geotextiles, liners, or even reactive barriers, either with or without lateral confinement. Sediments are deposited in natural or artificial depression, usually by means of a clamshell or a hydraulic pipeline. Capping may also shift 1
Bioresource Technology, Mar 1, 2019
Factorial fermentation experiments on food waste (FW) inoculated with activated sludge (AS) were ... more Factorial fermentation experiments on food waste (FW) inoculated with activated sludge (AS) were conducted to investigate the effects of pH and the inoculum-to-substrate ratio (ISR [g VS AS /g TOC FW ]) on biohydrogen production. The two parameters affected the H 2 yield, the fermentation rate and the biochemical pathways. The minimum and maximum yields were 41 L H 2 /kg TOC FW (pH = 7.5, ISR = 1.74) and 156160 L H 2 /kg TOC FW (pH = 5.5, ISR = 0.58 and 1.74). The range of carbohydrates conversion into H 2 was 0.371.45 mol H 2 /mol hexose, corresponding to 9.436.2% of the theoretical threshold. A second-order predictive model for H 2 production identified an optimum region at low pHs and high ISRs, with a theoretical maximum of 168 L H 2 /kg TOC FW at pH = 5.5 and ISR = 1.74. The Spearman's correlation method revealed several relationships between the variables, suggesting the potentially governing metabolic pathways, which turned out to involve both hydrogenogenic pathways and competing reactions.
1 ISPRA (Italian Institute for Environmental Protection and Research). Via Vitaliano Brancati, 60... more 1 ISPRA (Italian Institute for Environmental Protection and Research). Via Vitaliano Brancati, 60 00144 Rome (Italy) 2 Universita di Cagliari – Dipartimento di Geoingegneria e Tecnologie Ambientali. Piazza d’Armi, 1 – 09123 Cagliari (Italy) 3 ARPA Emilia Romagna (Agenzia Regionale Prevenzione e Ambiente). Largo Caduti del Lavoro, 6 40121 Bologna (Italy) 4 CNR (Consiglio Nazionale delle Ricerche) – Istituto di Geologia Ambientale e Geoingegneria. Piazza d’Armi, 19 – 09123 Cagliari (Italy) 5 Universita degli Studi di Roma “La Sapienza” – Dipartimento di Ingegneria Civile, Edile ed Ambientale. Via Eudossiana, 18 – 00184 Rome (Italy)
Dredging operations in harbour and marine coastal areas, usually performed to maintain operationa... more Dredging operations in harbour and marine coastal areas, usually performed to maintain operational waterdepth, might represent a viable option to mitigate environmental pollution if applied to remove contaminated sediments from the water body. Sediment landfilling could generate relevant environmental burdens due to the amounts of materials to be disposed of; however, the implementation of alternative management options aimed at re-use is hindered by the high cost of technology and the absence of a market for the recovered materials. The present project, named COAST BEST “CO-ordinated Approach for Sediment Treatment and BEneficial reuse in Small harbours networks” and funded in the framework of the LIFE08+ ENV European call, is aimed to find out a method to integrate all the phases (i.e., dredging, treatment, valorisation and disposal) of sediment management, through the creation of a network-based system including different small harbours which can be geographically interconnected
Journal of Environmental Management, Nov 1, 2022
Waste Management, 2007
Mechanical-biological pre-treatment (MBP) of municipal solid waste (MSW) has gained evidence as a... more Mechanical-biological pre-treatment (MBP) of municipal solid waste (MSW) has gained evidence as a practice capable of accomplishing the requirements for environmental sustainable landfilling. In particular, MBP is effective in reducing the ammoniacal nitrogen content in the leachate. However, few data are available on the modifications of the nitrogen forms occurring during MBP and on the role played by processes such as nitrification and generation of refractory organic compounds. The dynamic transformations of nitrogen were investigated during the MBP. MSW was mechanically and biologically pre-treated; samples were collected at different stages of the process and analysed to investigate the evolution of nitrogen forms; batch and column leaching tests were performed as well. The results indicate that nitrification is negligible and volatilization can only partially explain the low ammoniacal nitrogen content in the leachate. Incorporation of ammoniacal nitrogen into a refractory organic form was assessed and is likely to play an important role. The maximum content of refractory organic nitrogen in the solid waste was achieved after about 60 days of aerobic pre-treatment; therefore, the minimal duration of the MBP should be about 8-9 weeks in order to optimize the ammoniacal nitrogen incorporation, unless the waste is characterized by a low C/N ratio.
Sustainability, Nov 29, 2018
In this study, the influence of the inoculum-to-substrate ratio (ISR) on dark fermentative hydrog... more In this study, the influence of the inoculum-to-substrate ratio (ISR) on dark fermentative hydrogen production from food waste (FW) was evaluated. ISR values ranging from 0.05 to 0.25 g VS inoculum /g VS substrate were investigated by performing batch tests at T = 39 • C and pH = 6.5, the latter being the optimal value identified based on a previous study. The ISR was found to affect the fermentation process, clearly showing that an adequate ISR is essential in order to optimise the process kinetics and the H 2 yield. An ISR of 0.14 proved to optimum, leading to a maximum H 2 yield of 88.8 L H 2 /kg VS FW and a maximum production rate of 10.8 L H 2 /kg VS FW •h. The analysis of the fermentation products indicated that the observed highest H 2 production mostly derived from the typical acetate/butyrate-type fermentation.
Proceedings of the 16th International Conference on Environmental Science and Technology, Nov 19, 2022
In the present study, PHA production from ovine cheese whey (oCW) through a 3-step process (dark ... more In the present study, PHA production from ovine cheese whey (oCW) through a 3-step process (dark fermentation, biomass selection and PHA accumulation process) was investigated. Different operating pHs were adopted during the fermentation step and no external nutrients were supplied at any step of the process. Results showed that the production of PHA from oCW is a promising valorisation approach.