35 results on '"Roberta Ferrentino"'
Search Results
2. Rapid startup of aerobic granular sludge: Recent advances and future challenges
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Sajid Hussain, Roberta Ferrentino, Khakemin Khan, Zulfiqar Ali, Muhammad Yousuf, and Gianni Andreottola
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Aerobic granular sludge ,Inoculum ,Polymer ,Startup ,Technology - Abstract
Aerobic granular sludge (AGS) biotechnology has recently obtained considerable interest as a viable alternative to the activated sludge process (ASP) technique. This is because AGS can improve the performance of wastewater treatment and its significant capability for attaining sustainable growth. One of the main challenging issues for the aerobic granular sludge is the long startup time in wastewater treatment. This review presents a comprehensive analysis of AGS biotechnology, aiming specifically at its global adoption, startup duration, and granule stability. Aerobic granular sludge (AGS) is becoming more widespread globally. To ensure the successful implementation of AGS biotechnology, it is crucial to thoroughly identify the development of dense and stable granules, which is vital for the proper operation of wastewater treatment plants (WWTPs). Additionally, it offers a comprehensive summary of the latest advancements in the inoculum and polymer additives and their respective contributions to accelerate various processes through distinct mechanisms. In addition, this paper reviews the prevailing research patterns in the prompt initiation of rapid startup of AGS technology and outlines specific issues for future investigations.
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- 2024
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3. Full-Scale Sewage Sludge Reduction Technologies: A Review with a Focus on Energy Consumption
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Roberta Ferrentino, Michela Langone, Luca Fiori, and Gianni Andreottola
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sludge reduction ,energy consumption ,full scale ,wastewater treatment ,mechanical treatment ,biological treatment ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
In recent years, increasing attention has been paid to the problem of sewage sludge management and the relevant energy consumption, which represent the main cost items in wastewater treatment plants. Therefore, implementation of technologies that can reduce sludge production and ensure a positive impact on the energy of the entire sewage treatment plant has gained considerable importance in the scientific and technical community. The objective of this study was thus to screen full-scale sludge reduction technologies integrated into both the water line and the sludge line of a municipal sewage treatment plant with a sustainable impact on the overall balance of the plant. The results showed that, within the water line, ultrasound in the recirculation line of the activated sludge allowed for greater reductions in sludge production than the Cannibal and UTN systems, despite the higher energy consumption. CAMBITM, BioThelysTM, ExelysTM and TurboTec® enabled the greatest reductions in sludge production among the technologies integrated into the sludge line, and although they required a large amount of energy, this was partially offset by energy recovery in terms of additional biogas production.
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- 2023
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4. Sludge reduction by an anaerobic side-stream reactor process: A full-scale application
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Roberta Ferrentino, Michela Langone, and Gianni Andreottola
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Anaerobic side-stream reactor ,Full scale application ,Sludge minimization ,Sewage sludge ,Biological sludge reduction ,Environmental sciences ,GE1-350 - Abstract
In the present paper, a new process, whose acronym is UTN (University of Trento) system, is proposed and tested at full scale for reducing the amount of sludge of the wastewater treatment plant. The UTN system allows sludge reduction in conventional activated sludge (CAS) due to the cell lysis, the sludge decay and, above all, to the selection of slow growing microorganism. In this study, the first full-scale UTN system was tested by retrofitting an existing wastewater treatment plant located in Marmirolo (Lombardia, Italy) having a treatment capacity of 6,000 population equivalent (PE). Performances of the UTN system were evaluated in terms of sludge reduction, together with organic carbon and nutrients removal efficiencies. Results obtained over 10 month of monitoring period, divided in period I (7 months) and period II (3 months), characterized by different operative conditions, have reported a specific sludge production of 0.37 and 0.23 kg TSS per kg of COD removed, respectively; which is 50% and 69% lower than that observed in the reference period when the plant worked under conventional activated sludge process. Furthermore, results revealed that the UTN system allows a high removal of wastewater typical pollutants, without causing negative effects on the effluent quality, always ensuring compliance with the regulatory discharge limits.
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- 2021
- Full Text
- View/download PDF
5. Coupling Hydrothermal Carbonization with Anaerobic Digestion for Sewage Sludge Treatment: Influence of HTC Liquor and Hydrochar on Biomethane Production
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Roberta Ferrentino, Fabio Merzari, Luca Fiori, and Gianni Andreottola
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sewage sludge ,hydrothermal carbonization ,hydrochar ,HTC liquor ,anaerobic digestion ,biochemical methane potential ,Technology - Abstract
The present study addresses the coupling of hydrothermal carbonization (HTC) with anaerobic digestion (AD) in wastewater treatment plants. The improvement in biomethane production due to the recycling back to the anaerobic digester of HTC liquor and hydrochar generated from digested sludge is investigated and proved. Mixtures of different compositions of HTC liquor and hydrochar, as well as individual substrates, were tested. The biomethane yield reached 102 ± 3 mL CH4 g−1 COD when the HTC liquor was cycled back to the AD and treated together with primary and secondary sludge. Thus, the biomethane production was almost doubled compared to that of the AD of primary and secondary sludge (55 ± 20 mL CH4 g−1 COD). The benefit is even more significant when both the HTC liquor and the hydrochar were fed to the AD of primary and secondary sludge. The biomethane yield increased up to 187 ± 18 mL CH4 g−1 COD when 45% of hydrochar, with respect to the total feedstock, was added. These results highlight the improvement that the HTC process can bring to AD, enhancing biomethane production and promoting a sustainable solution for the treatment of the HTC liquor and possibly the hydrochar itself.
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- 2020
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6. Sewage Sludge Hydrochar: An Option for Removal of Methylene Blue from Wastewater
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Roberta Ferrentino, Riccardo Ceccato, Valentina Marchetti, Gianni Andreottola, and Luca Fiori
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hydrothermal carbonization ,HTC ,sewage sludge ,hydrochar ,methylene blue ,adsorption ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Municipal sewage sludge was subjected to a hydrothermal carbonization (HTC) process for developing a hydrochar with high adsorption capacity for water remediation in terms of dye removal. Three hydrochars were produced from municipal sewage sludge by performing HTC at 190, 220 and 250 °C, with a 3 h reaction time. Moreover, a portion of each hydrochar was subjected to a post-treatment with KOH in order to increase the adsorption capacity. Physicochemical properties of sludge samples, raw hydrochars and KOH-modified hydrochars were measured and batch adsorption studies were performed using methylene blue (MB) as a reference dye. Data revealed that both raw and modified hydrochars reached good MB removal efficiency for solutions with low MB concentrations; on the contrary, MB in high concentration solutions was efficiently removed only by modified hydrochars. Interestingly, the KOH treatment greatly improved the MB adsorption rate; the modified hydrochars were capable of capturing above 95% of the initial MB amount in less than 15 min. The physicochemical characterization indicates that alkali modification caused a change in the hydrochar surface making it more chemically homogeneous, which is particularly evident for the 250 °C hydrochar. Thus, the adsorption process can be regarded as a complex result of various phenomena, including physi- and chemi-sorption, acid–base and redox equilibria.
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- 2020
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7. Hydrothermal post-treatment of anaerobic digestate
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Donato Scrinzi, Roberta Ferrentino, Luca Fiori, and Gianni Andreottola
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- 2022
8. Investigating the Enhancement in Biogas Production by Hydrothermal Carbonization of Organic Solid Waste and Digestate in an Inter-Stage Treatment Configuration
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Roberta Ferrentino, Michela Langone, Davide Mattioli, Luca Fiori, and Gianni Andreottola
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anaerobic digestion ,hydrothermal carbonization ,organic fraction of municipal solid waste ,biogas production ,digestate ,Process Chemistry and Technology ,Chemical Engineering (miscellaneous) ,sludge reduction ,Bioengineering ,dewaterability - Abstract
In recent years, sewage sludge (SS) and bio-waste management have attracted increasing environmental attention. In this study, hydrothermal carbonization (HTC) technology is investigated in the framework of a co-treatment of sewage sludge digestate (SSD) and an organic fraction of municipal solid waste (OW). The proposed configuration integrates HTC with anaerobic digestion (AD) in an inter-stage configuration (AD1 + HTC + AD2). The effects of different percentages of OW added to SSD in the HTC treatment are evaluated in terms of characteristics and methane yield of the produced HTC liquor (HTCL) and HTC slurry (i.e., the mixture hydrochar-HTCL), as well as dewaterability of the HTC slurry. Results show that, with the increase in the percentage of OW in the OW-SSD mixture fed to the HTC process, production of biogas and biomethane of both HTC slurry and HTCL increases. The highest biogas production is achieved when a mixture consisting of half SSD and half OW is used, reaching 160 ± 10 and 240 ± 15 mL biogas g−1 CODadded, respectively, for HTCL and HTC slurry. Furthermore, sludge dewaterability is significantly improved by the combined AD1-HTC-AD2 process. Finally, an energy assessment allows estimating that the co-treatment of OW with SSD in HTC can cover up to 100% of the energy consumption of the system.
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- 2022
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9. Mathematical modelling of an intermittent anoxic/aerobic MBBR: Estimation of nitrification rates and energy savings
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Daniele Montecchio, Maria Rosaria Mattei, Gianni Andreottola, Giovanni Esposito, Roberta Ferrentino, Montecchio, D, Mattei, M R, Esposito, G, Andreottola, G, and Ferrentino, R
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Environmental Engineering ,Sewage ,Nitrogen ,Biofilm ,Bioreactor ,General Medicine ,Triacetoneamine-N-Oxyl ,Management, Monitoring, Policy and Law ,Wastewater ,Nitrification ,Waste Disposal, Fluid ,Bioreactors ,Ammonia ,Biofilms ,Denitrification ,Waste Water ,Waste Management and Disposal - Abstract
This study aimed at modelling the performance of a novel MBBR configuration, named A/O-MBBR, comprised of a pre-anoxic reactor, with an HRT of 4.5 h, coupled with an intermittent anoxic/aerobic MBBR (HRT = 6.8 h). The lab-scale system was fed with municipal wastewater with an average influent Total Ammonia Nitrogen (TAN) and total COD (TCOD) concentrations of 46 mg of TAN-N L-1 and 310 mg TCOD L-1. During the whole experimental period, TAN removal efficiency was always higher than 96%; denitrification was also very effective, achieving nitrate and nitrite concentrations in the effluent both lower than 5 mg NOx-N L-1 on average. Moreover, TCOD average removal efficiency was equal to 85%. Modelling was performed to investigate the nitrification efficacy enhancement; to this aim, a biofilm model was developed, adopting the equations for mixed-culture biofilms and the Activated Model Sludge n°1 (ASM1) for the biological processes rates. The model allowed to determine the maximum uptake rate for autotrophic growth (μA was 2.5 d-1) and the semisaturation constant (KOA was 0.2 mg O2 L-1), suggesting that the nitrification process was 3-fold faster than average and very effective at low oxygen concentrations. The model estimated that about 85% of TAN was removed by the biofilm and only the remaining part by suspended biomass in the bulk liquid. Finally, it was assessed that the A/O-MBBR configuration allowed for a 45-60% savings of the energy requirement compared to a Benchmark WWTP layout.
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- 2022
10. Biochemical Methane Potential Tests to Evaluate Anaerobic Digestion Enhancement by Thermal Hydrolysis Pretreatment
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Fabio Merzari, Luca Fiori, Roberta Ferrentino, and Gianni Andreottola
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0106 biological sciences ,Hydrolysis constant ,Renewable Energy, Sustainability and the Environment ,Chemistry ,020209 energy ,02 engineering and technology ,Thermal hydrolysis ,Pulp and paper industry ,01 natural sciences ,Anaerobic digestion ,Hydrolysis ,Biogas ,010608 biotechnology ,Yield (chemistry) ,0202 electrical engineering, electronic engineering, information engineering ,Sewage treatment ,Agronomy and Crop Science ,Energy (miscellaneous) ,Mesophile - Abstract
This study evaluates the effects of thermal hydrolysis (TH) pretreatment on anaerobic digestion (AD), through results obtained by biochemical methane potential (BMP) tests under mesophilic conditions (35 °C). Thickened sludge from a wastewater treatment plant (WWTP) was thermally treated under two different temperatures (150 and 170 °C) and reaction times (30 and 60 min). Results show a significant increase in soluble COD, compared with the untreated sludge, when sludge was treated at 170 °C for 60 min. Moreover, the following BMP tests point out that TH pretreatment of sludge accelerated the AD rate and increased the biogas yield contributing to an increase in methane production, ranging between 17 and 24% compared with the raw sludge. Furthermore, the hydrolysis constant was estimated and methane production and degree of disintegration of the TH pretreated sludge were correlated, in order to deep the knowledge on the hydrolysis as the AD rate-limiting step. Further, the combined effects of TH pretreatment and AD on sludge show a reduction of total and volatile solids up to 19% and 24%, respectively.
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- 2019
11. Optimisation of Fe2+/H2O2 ratio in Fenton process to increase dewaterability and solubilisation of sludge
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Fabio Merzari, Roberta Ferrentino, and Gianni Andreottola
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inorganic chemicals ,fungi ,0208 environmental biotechnology ,Oxide ,food and beverages ,02 engineering and technology ,General Medicine ,010501 environmental sciences ,Pulp and paper industry ,01 natural sciences ,020801 environmental engineering ,chemistry.chemical_compound ,chemistry ,Reagent ,Scientific method ,Environmental Chemistry ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
Fenton is one of the advanced oxidation processes that can oxide organic compounds efficiently increasing the dewaterability of sludge. This study reports the optimisation of two reagents, Fe2+ and...
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- 2019
12. Anaerobic digestion of blood serum water integrated in a valorization process of the bovine blood treatment
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Federico Freddi, Gianni Andreottola, Roberta Ferrentino, and Michela Langone
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Chromatography ,Renewable Energy, Sustainability and the Environment ,Chemistry ,020209 energy ,Forestry ,02 engineering and technology ,Anaerobic digestion ,Reaction rate constant ,Blood serum ,Biogas ,Yield (chemistry) ,0202 electrical engineering, electronic engineering, information engineering ,Anaerobic filter ,Saturation (chemistry) ,Waste Management and Disposal ,Agronomy and Crop Science ,Mesophile - Abstract
The present work aims to analyze the valorization of blood (Category 3 animal by-products). In this study, for the first time, blood serum water, obtained after a sterilization process and a solid/liquid separation unit, has been utilized as energy rich input material for anaerobic digestion. The performance of an up-flow anaerobic filter (UAF) for treating bovine blood serum water under mesophilic conditions was investigated. The reactor was loaded up to an organic loading rate of 2.5 kg m−3 d−1 of total COD, achieving total and soluble COD removal efficiencies of 90% and 92%, respectively. A maximum biogas yield of 0.56 m3 kg−1 of removed total COD was measured. According to the modified Stover-Kincannon kinetic model, maximum removal rate constant, Umax, and saturation value constant, KB, values were estimated as 18.8 g L−1 d−1 and 18.5 g L−1 d−1 for blood serum water, respectively. As the model gave high correlation coefficients (R2 = 97%), it could be used in both designing and predicting the behaviour of the UAF.
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- 2019
13. Progress toward full scale application of the anaerobic side-stream reactor (ASSR) process
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Gianni Andreottola, Roberta Ferrentino, and Michela Langone
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0106 biological sciences ,Environmental Engineering ,Nitrogen ,chemistry.chemical_element ,Bioengineering ,Sequencing batch reactor ,010501 environmental sciences ,Waste Disposal, Fluid ,01 natural sciences ,chemistry.chemical_compound ,Denitrifying bacteria ,Bioreactors ,Rivers ,010608 biotechnology ,Ammonium Compounds ,Anaerobiosis ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Bacteria ,Sewage ,biology ,Renewable Energy, Sustainability and the Environment ,Hydrolysis ,General Medicine ,Phosphate ,biology.organism_classification ,Pulp and paper industry ,Carbon ,Activated sludge ,chemistry ,Fermentation ,Sewage treatment ,Anaerobic exercise - Abstract
In order to reduce the investment costs of the anaerobic side-stream reactor (ASSR) process coupled with an activated sludge system and promote the full scale application, the impact of 1 d anaerobic solid retention time (SRTASSR) and 100% interchange ratio (IR) has been investigated on sludge reduction, carbon and nutrient removal efficiency and microbial community, in a sequencing batch reactor (SBR)-ASSR system. The SBR-ASSR achieved good removal efficiencies in COD (91.5 ± 3.4%), ammonium nitrogen (98.8 ± 0.5%), total nitrogen (87.9 ± 4.9%) and phosphate (92.8 ± 6.7). The sludge yield of the system was 0.1648 g TSS g−1COD; 54% lower compared to a conventional activated sludge (CAS) system. Real time quantitative polymerase chain reaction (q-PCR) showed an abundance of hydrolyzing and fermentative bacteria. Comparison at class and genus level confirmed an abundance of anaerobic hydrolyzing and fermentative bacteria, denitrifying bacteria able to simultaneous perform nitrogen and phosphate removal and phosphate accumulating organisms.
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- 2019
14. Coupling Hydrothermal Carbonization with Anaerobic Digestion for Sewage Sludge Treatment: Influence of HTC Liquor and Hydrochar on Biomethane Production
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Fabio Merzari, Gianni Andreottola, Luca Fiori, and Roberta Ferrentino
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HTC liquor ,anaerobic digestion ,Control and Optimization ,020209 energy ,Energy Engineering and Power Technology ,02 engineering and technology ,010501 environmental sciences ,Raw material ,biomethane ,01 natural sciences ,lcsh:Technology ,hydrothermal carbonization ,Hydrothermal carbonization ,Biogas ,0202 electrical engineering, electronic engineering, information engineering ,sewage sludge ,hydrochar ,biochemical methane potential ,Electrical and Electronic Engineering ,Engineering (miscellaneous) ,0105 earth and related environmental sciences ,Renewable Energy, Sustainability and the Environment ,Chemistry ,lcsh:T ,food and beverages ,equipment and supplies ,Pulp and paper industry ,digestive system diseases ,Anaerobic digestion ,Sewage sludge treatment ,Sewage treatment ,Sludge ,Energy (miscellaneous) - Abstract
The present study addresses the coupling of hydrothermal carbonization (HTC) with anaerobic digestion (AD) in wastewater treatment plants. The improvement in biomethane production due to the recycling back to the anaerobic digester of HTC liquor and hydrochar generated from digested sludge is investigated and proved. Mixtures of different compositions of HTC liquor and hydrochar, as well as individual substrates, were tested. The biomethane yield reached 102 ± 3 mL CH4 g−1 COD when the HTC liquor was cycled back to the AD and treated together with primary and secondary sludge. Thus, the biomethane production was almost doubled compared to that of the AD of primary and secondary sludge (55 ± 20 mL CH4 g−1 COD). The benefit is even more significant when both the HTC liquor and the hydrochar were fed to the AD of primary and secondary sludge. The biomethane yield increased up to 187 ± 18 mL CH4 g−1 COD when 45% of hydrochar, with respect to the total feedstock, was added. These results highlight the improvement that the HTC process can bring to AD, enhancing biomethane production and promoting a sustainable solution for the treatment of the HTC liquor and possibly the hydrochar itself.
- Published
- 2020
15. Application of real-time nitrogen measurement for intermittent aeration implementation in a biological nitrogen removal system: performances and efficiencies
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M. Vian, Roberta Ferrentino, Michela Langone, and Gianni Andreottola
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Nitrogen ,0208 environmental biotechnology ,Biomass ,chemistry.chemical_element ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,Waste Disposal, Fluid ,01 natural sciences ,Nitrogen removal ,Nitrogen measurement ,Bioreactors ,Environmental Chemistry ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,General Medicine ,Energy consumption ,Pulp and paper industry ,Nitrification ,020801 environmental engineering ,chemistry ,Denitrification ,Environmental science ,Sewage treatment ,Aeration ,Efficient energy use - Abstract
Several automatic strategies for aeration control have been investigated so far to favor a significant decrement of energy consumptions in biological processes in wastewater treatment plants (WWTPs). Above all, the intermittent aeration process has demonstrated to have several advantages. This work reports the results of a case study made in a small municipal WWTP where an intermittent aeration control strategy based on the online measurement of real-time nitrogen forms has been implemented to optimize the nitrogen removal and the energy consumption in an activated process. High organic removal efficiency was achieved during the whole experimental period. Results indicated that nitrogen removal efficiency has been improved, especially during winter months, by the control strategy adopted that helped to determine the perfect length for the nitrification and denitrification phases. The intermittent aeration process increased the activity of the biomass, further selecting phosphate-accumulating bacteria and improving the growth of bacteria able to internally store carbon source. Excellent effects were achieved on energy and chemical consumption, with a reduction of about 15% and 23%, respectively. Finally, a 12% reduction of sludge production was also detected.
- Published
- 2018
16. Hydrothermal carbonization liquor as external carbon supplement to improve biological denitrification in wastewater treatment
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E. Grigolini, Fabio Merzari, Roberta Ferrentino, Gianni Andreottola, and Luca Fiori
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Denitrification ,Chemistry ,Process Chemistry and Technology ,Sequencing batch reactor ,Pulp and paper industry ,Hydrothermal carbonization ,chemistry.chemical_compound ,Wastewater ,Nitrate ,Sewage treatment ,Safety, Risk, Reliability and Quality ,Waste Management and Disposal ,Kjeldahl method ,Sludge ,Biotechnology - Abstract
This study investigates the suitability of a sequencing batch reactor (SBR) for treating the liquor (HTCL) derived from hydrothermal carbonization (HTC) of sewage sludge in addition to the influent municipal wastewater. The SBR was fed for 80 days with an increasing mixing ratio HTCL/municipal wastewater. HTCL was used as external carbon source to enhance the denitrification process in the water line of the wastewater treatment plant (WWTP). The feeding of the HTCL caused an overloading in the COD and TKN concentration of the biological treatment equal to, respectively, 25% and 8% (Period II), 50% and 16% (Period III) and 100% and 32% (Period IV). Results revealed that good efficiencies of COD removal were obtained during the entire experimental test, accounting up to 91% in Period IV. Moreover, the removal of TN was improved increasing from 28% in the reference period (Period I), where no HTCL was fed, to 33%, 47% and 64% respectively in Period II, III and IV. Thus, an improvement in the denitrification process was obtained when HTCL was fed to the biological reactor in addition to the influent wastewater. The implementation of the SBR system was supported by nitrate uptake rate (NUR) tests and respirometric assays to evaluate the nitrate removal after the addition of HTCL and the fraction of readily biodegradable COD (RBCOD) and soluble biodegradable COD (sCODbio) on the total COD of the HTCL.
- Published
- 2021
17. Evaluation of the developmental profile in patients with autism spectrum disorders: P04-30
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Maria Pia, Riccio, Giuseppina, Borriello, Roberta, Maresca, Lucia, Russo, Roberta, Ferrentino, and Carmela, Bravaccio
- Published
- 2011
18. Stoichiometric evaluation of partial nitritation, anammox and denitrification processes in a sequencing batch reactor and interpretation of online monitoring parameters
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Michela Langone, Maria Cadonna, Roberta Ferrentino, and Gianni Andreottola
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Environmental Engineering ,Denitrification ,Carbon-to-nitrogen ratio ,Nitrogen ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,Inorganic chemistry ,chemistry.chemical_element ,Sequencing batch reactor ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,Online Systems ,01 natural sciences ,Water Purification ,chemistry.chemical_compound ,Bioreactors ,Reduction potential ,Ammonium Compounds ,Environmental Chemistry ,Ammonium ,Nitrites ,0105 earth and related environmental sciences ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Pollution ,Anoxic waters ,020801 environmental engineering ,chemistry ,Anammox ,Environmental chemistry ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
A laboratory-scale sequencing batch reactor (SBR) performing partial nitritation – anammox and denitrification was used to treat anaerobic digester effluents. The SBR cycle consisted of a short mixing filling phase followed by oxic and anoxic reaction phases. Working at 25 °C, an ammonium conversion efficiency of 96.5%, a total nitrogen removal efficiency of 88.6%, and an organic carbon removal efficiency of 63.5% were obtained at a nitrogen loading rate of 0.15 kg N m−3 d−1, and a biodegradable organic carbon to nitrogen ratio of 0.37. The potential contribution of each biological process was evaluated by using a stoichiometric model. The nitritation contribution decreased as the temperature decreased, while the contribution from anammox depended on the wastewater type and soluble carbon to nitrogen ratio. Denitrification improved the total nitrogen removal efficiency, and it was influenced by the biodegradable organic carbon to nitrogen ratio. The characteristic patterns of conductivity, oxidation-reduction potential (ORP) and pH in the SBR cycle were well related to biological processes. Conductivity profiles were found to be directly related to the decreasing profiles of ammonium. Positive ORP values at the end of the anoxic phases were detected for total nitrogen removal efficiency of lower than 85%, and the occurrence of bending points on the ORP curves during the anoxic phases was associated with nitrite depletion by the anammox process.
- Published
- 2016
19. Optimisation of Fe
- Author
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Roberta, Ferrentino, Fabio, Merzari, and Gianni, Andreottola
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Sewage ,Hydrogen Peroxide ,Oxidation-Reduction - Abstract
Fenton is one of the advanced oxidation processes that can oxide organic compounds efficiently increasing the dewaterability of sludge. This study reports the optimisation of two reagents, Fe
- Published
- 2019
20. Sludge reduction by an anaerobic side-stream reactor process: A full-scale application
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Michela Langone, Roberta Ferrentino, and Gianni Andreottola
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Pollutant ,Global and Planetary Change ,Environmental Engineering ,Full scale ,Management, Monitoring, Policy and Law ,Pulp and paper industry ,Pollution ,Environmental sciences ,Anaerobic side-stream reactor ,Nutrient ,Activated sludge ,Wastewater ,Sludge minimization ,Environmental science ,GE1-350 ,Sewage treatment ,Population equivalent ,Full scale application ,Sewage sludge ,Waste Management and Disposal ,Effluent ,Biological sludge reduction - Abstract
In the present paper, a new process, whose acronym is UTN (University of Trento) system, is proposed and tested at full scale for reducing the amount of sludge of the wastewater treatment plant. The UTN system allows sludge reduction in conventional activated sludge (CAS) due to the cell lysis, the sludge decay and, above all, to the selection of slow growing microorganism. In this study, the first full-scale UTN system was tested by retrofitting an existing wastewater treatment plant located in Marmirolo (Lombardia, Italy) having a treatment capacity of 6,000 population equivalent (PE). Performances of the UTN system were evaluated in terms of sludge reduction, together with organic carbon and nutrients removal efficiencies. Results obtained over 10 month of monitoring period, divided in period I (7 months) and period II (3 months), characterized by different operative conditions, have reported a specific sludge production of 0.37 and 0.23 kg TSS per kg of COD removed, respectively; which is 50% and 69% lower than that observed in the reference period when the plant worked under conventional activated sludge process. Furthermore, results revealed that the UTN system allows a high removal of wastewater typical pollutants, without causing negative effects on the effluent quality, always ensuring compliance with the regulatory discharge limits.
- Published
- 2021
21. Investigation of sludge solubilization and phosphorous release in anaerobic side-stream reactor with a low pressure swirling jet hydrodynamic cavitation treatment
- Author
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Gianni Andreottola and Roberta Ferrentino
- Subjects
Jet (fluid) ,Process Chemistry and Technology ,Side stream ,Biomass ,02 engineering and technology ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,Phosphate ,01 natural sciences ,Pollution ,chemistry.chemical_compound ,chemistry ,Solubilization ,Cavitation ,Chemical Engineering (miscellaneous) ,Uptake rate ,0210 nano-technology ,Waste Management and Disposal ,Anaerobic exercise ,0105 earth and related environmental sciences ,Nuclear chemistry - Abstract
In this study, the feasibility of a novel hydrodynamic cavitation (HC) system was evaluated to speed up the biological sludge reduction mechanisms of the anaerobic side-stream reactor (ASSR) process. In the first part of the research, HC was performed on ASSR sludge by using a low pressure swirling jet cavitation system, named Ecowirl – EW 25. The effects of the Ecowirl – EW 25 system, in terms of sludge solubilisation, disintegration degree and microbial activity, were investigated considering two different injection plates, respectively, with two and four injection slots and four different treatment times, from 10 to 80 minutes. The best results were achieved after 80 min of HC treatment, using the plate with two injection slots and with a specific supplied energy (SE) equal to 12670 kJ kg TSS-1. Respirometric tests showed an increase in the readily biodegradable COD through the HC treatment of sludge. Moreover, low endogenous decay rates (bH) were measured on the ASSR sludge for SE lower than 6340 kJ kg TSS-1 revealing that the sludge solubilization was due to a modification in the floc structure rather than a decrease in the biomass viability. In the second part of the research, the solubilized sludge, after HC treatment, was used as carbon substrate for the biological activity of bacteria into the ASSR, such as total phosphate accumulating organisms (TPAOs). Results revealed that the phosphorous releasing and uptake rate, obtained using the HC treated sludge as carbon source, were comparable with those obtained with the addition of a ready biodegradable carbon source such as acetate.
- Published
- 2020
22. A review of anaerobic side-stream reactor for excess sludge reduction: Configurations, mechanisms, and efficiency
- Author
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Laura Tramonte, Fabio Merzari, Michela Langone, Gianni Andreottola, and Roberta Ferrentino
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Environmental Engineering ,Waste management ,Side stream ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Pollution ,Anoxic waters ,020801 environmental engineering ,Mixed liquor suspended solids ,Activated sludge ,Environmental science ,Sewage sludge treatment ,Sewage treatment ,Waste Management and Disposal ,Anaerobic exercise ,Sludge ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
In the frame of a modern waste management, an important sector concerns the sewage sludge minimization. In recent years a lot of techniques have been developed to reduce the sludge production such as biological, thermal, thermochemical, high-temperature oxidation and mechanical treatments, ultrasonication and ozonation, or using chemical compounds. Among those, the use of an anaerobic side-stream reactor (ASSR) in the conventional activated sludge line is a challenging biological technology able to minimize sludge production in wastewater treatment plants. The ASSR can be easily realized in both new and existing plants as it consists of an ASSR for sludge treatment and reduction where a portion or, in some cases, all the return sludge of the activated sludge process is subjected to alternating aerobic, anoxic, and anaerobic conditions. Studies show that, combining a conventional activated process with an ASSR, sludge yield could be reduced by up to 40–60% without any negative effects, neither on t...
- Published
- 2015
23. Process performance optimization and mathematical modelling of a SBR-MBBR treatment at low oxygen concentration
- Author
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Alberto Ferraro, M.R. Mattei, Giovanni Esposito, Roberta Ferrentino, Gianni Andreottola, Ferrentino, Roberta, Ferraro, Alberto, Mattei, Maria Rosaria, Esposito, Giovanni, and Andreottola, Gianni
- Subjects
Low oxygen ,Chemistry ,0208 environmental biotechnology ,Mathematical model ,MBBR ,Nutrient removal ,Biomass ,Bioengineering ,02 engineering and technology ,010501 environmental sciences ,Simultaneous nitrification-denitrification ,Pulp and paper industry ,01 natural sciences ,Biochemistry ,Applied Microbiology and Biotechnology ,020801 environmental engineering ,Process conditions ,Yield (chemistry) ,Scientific method ,Process efficiency ,Nitrification ,0105 earth and related environmental sciences - Abstract
In this study, performances of a SBR-MBBR in terms of COD, TN removal efficiency and sludge production were compared to that of an A/O-MBBR. The SBR-MBBR (40% filling ratio) at 24, 18 and 12 h HRT had a COD and TN removal efficiencies of 88 and 75%, 92 and 72%, 90 and 47%. Increasing the filling ratio to 60% with 12 h HRT, the COD and TN removal efficiencies raised to 93% and 66%, respectively. Thus, increasing the filling ratio of the MBBR the TN removal was improved. The A/O-MBBR configuration achieved a COD and TN removal efficiencies, respectively, of 85% and 72%. This configuration obtained the highest sludge yield due to an increase of the sludge production. Nitrification and denitrification activity tests, performed on attached and suspended biomass, revealed a specialization of the microbial community with the suspended biomass responsible for the denitrification process while the attached biomass for the nitrification. Moreover, a mathematical model consisting of a system of impulsive ordinary differential equations was developed to simulate the SBR-MBBR process. The mathematical model was successfully calibrated and validated through the collected experimental data, resulting in a suitable tool for process efficiency prediction and optimization of operational process conditions.
- Published
- 2018
24. Correction to: Strict anaerobic side-stream reactor: effect of the sludge interchange ratio on sludge reduction in a biological nutrient removal process
- Author
-
Michela Langone, Roberta Ferrentino, Gianni Andreottola, and Roberta Villa
- Subjects
Waste management ,Health, Toxicology and Mutagenesis ,Microorganism ,Chemical oxygen demand ,Sequencing batch reactor ,02 engineering and technology ,General Medicine ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,Phosphate ,01 natural sciences ,Pollution ,Denitrifying bacteria ,Ammonia ,chemistry.chemical_compound ,Extracellular polymeric substance ,chemistry ,Environmental Chemistry ,Sewage treatment ,0210 nano-technology ,0105 earth and related environmental sciences - Abstract
In order to investigate the impact of the sludge interchange ratio (IR) on both the sludge reduction process and the carbon and nutrient removal efficiencies, an anaerobic side-stream reactor (ASSR) at 20 °C and − 400 mV was operated for 300 days coupled to a sequencing batch reactor (SBR) for urban wastewater treatment. It was found that a 100% interchange rate, corresponding to an anaerobic solid retention time (SRTASSR) of 2.5 days, was the most suitable case in terms of sludge reduction and wastewater treatment process, achieving a 66% sludge reduction compared to a control system simulated as an SBR. Chemical oxygen demand (COD), ammonium nitrogen, total nitrogen, and phosphate removal efficiencies of 86.1 ± 7.2, 82.5 ± 11.2, 81.7 ± 12.0, and 62.6 ± 15.0%, respectively, were achieved. When the interchange rate was increased, more ammonium nitrogen and soluble extracellular polymeric substance concentrations were released in the ASSR. This implies that cell lysis and hydrolysis of particulate organic matter in the ASSR were processes of fundamental importance with the increasing mass of sludge cycled to the ASSR. Compared to the release of ammonia, soluble COD release was detected to a lesser extent, due to its consumption by microorganisms in the ASSR. There was also a simultaneous increase in slow-growing microorganisms which use organic carbon for metabolic activities, above all sulfate-reducing bacteria and denitrifying phosphate-accumulating organisms. This increase contributed significantly to sludge reduction in the SBR–ASSR system.
- Published
- 2017
25. Strict anaerobic side-stream reactor: effect of the sludge interchange ratio on sludge reduction in a biological nutrient removal process
- Author
-
Roberta Ferrentino, Michela Langone, Roberta Villa, and Gianni Andreottola
- Subjects
Sewage ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,02 engineering and technology ,General Medicine ,010501 environmental sciences ,Wastewater ,01 natural sciences ,Pollution ,Waste Disposal, Fluid ,020801 environmental engineering ,Bioreactors ,Environmental Chemistry ,Anaerobiosis ,0105 earth and related environmental sciences - Abstract
In order to investigate the impact of the sludge interchange ratio (IR) on both the sludge reduction process and the carbon and nutrient removal efficiencies, an anaerobic side-stream reactor (ASSR) at 20 °C and - 400 mV was operated for 300 days coupled to a sequencing batch reactor (SBR) for urban wastewater treatment. It was found that a 100% interchange rate, corresponding to an anaerobic solid retention time (SRT
- Published
- 2017
26. Shift in microbial community structure of anaerobic side-stream reactor in response to changes to anaerobic solid retention time and sludge interchange ratio
- Author
-
Isabella Gandolfi, Roberta Ferrentino, Gianni Andreottola, Michela Langone, Valentina Bertolini, Andrea Franzetti, Ferrentino, R, Langone, M, Gandolfi, I, Bertolini, V, Franzetti, A, and Andreottola, G
- Subjects
0301 basic medicine ,Environmental Engineering ,030106 microbiology ,Microbial Consortia ,Bioengineering ,010501 environmental sciences ,Biology ,Wastewater ,01 natural sciences ,Waste Disposal, Fluid ,03 medical and health sciences ,Extracellular polymeric substance ,Bioreactors ,Microbial community ,Organic matter ,Anaerobiosis ,Waste Management and Disposal ,Phylogeny ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Waste management ,Bacteria ,Sewage ,Renewable Energy, Sustainability and the Environment ,General Medicine ,biology.organism_classification ,Pulp and paper industry ,BIO/19 - MICROBIOLOGIA GENERALE ,Anoxic waters ,Sludge reduction ,Archaea ,Taxonomic identification ,Anaerobic side-stream reactor ,DPAO ,Microbial population biology ,chemistry ,Fermentation ,Anaerobic exercise ,SRB - Abstract
A laboratory scale nutrient removal activated sludge system coupled with an anaerobic side-stream reactor was operated for 300 days treating real urban wastewater. A significant decrease in sludge production was obtained increasing the anaerobic solid retention time (SRTASSR) and decreasing the sludge interchange ratio (IR). In this study, the microbial community structure was analyzed and compared with the sludge reduction performance. Quantitative polymerase chain reaction analyses encoding 16 ribosomal RNA and functional genes revealed a wide diversity of phylogenetic groups in each experimental period, resulting from long solids retention time and recirculation of sludge under aerobic, anoxic and anaerobic conditions. However, decreasing SRTASSR from 10 to 2.5 d and increasing IR from 27 to 100%, an increasing selection of both fermenting bacteria able to release extracellular polymeric substances and hydrolyze organic matter and slow growing bacteria involved in nutrient removal were detected and linked to the sludge reduction mechanisms.
- Published
- 2016
27. Application of a Novel Hydrodynamic Cavitation System in Wastewater Treatment Plants
- Author
-
Michela Langone, Roberta Ferrentino, Trombino, Gabriella, Waubert Puiseau, D., Gianni Andreottola, Elena Cristina Rada, and Marco Ragazzi
- Subjects
Biodegradability ,Microbial cell disruption ,Hydrodynamic cavitation ,biodegradability ,solubilisation ,microbial cell disruption ,Solubilisation - Published
- 2015
28. Analysis of real-scale experiences of novel sewage sludge treatments in an Italian pilot region
- Author
-
Marco Ragazzi, Roberta Ferrentino, and Elena Cristina Rada
- Subjects
Co-combustion ,Waste management ,business.industry ,Scale (chemistry) ,Environmental engineering ,Biomass ,Sewage ,Ocean Engineering ,Wet oxidation ,Pollution ,Minimization ,Waste treatment ,Activated sludge ,Wastewater ,Pyrolysis ,Sewage sludge ,Environmental science ,Sewage treatment ,business ,Sludge ,Water Science and Technology - Abstract
Four case studies, related to real-scale novel solutions for sewage sludge management are presented. The described experiences concern an Italian region Trentino Alto Adige (TAA). In Italy, few years ago, solutions as landfilling of thermally dried sludge, composting and direct application on land were considered viable options. Today the sector is going quickly towards a crisis, as sludge is no longer accepted for landfilling (because of its biodegradability) and its direct or indirect application on land is more and more restricted in some regions. As a consequence of this situation, in Italy alternative options are studied, and TAA can be considered a pilot region thanks to the presence of multiple interesting case studies. Sludge minimization is widely studied, but in real scale the first Italian plant was constructed in TAA only recently: this plant is based on the principles of solid separation and biological cannibalization of the biomass. The target is the reduction of 50% of the solid loa...
- Published
- 2015
29. An anaerobic side-stream reactor in wastewater treatment: a review
- Author
-
Roberta Ferrentino, E. C. Rada, Gianni Andreottola, and Michela Langone
- Subjects
ASSR configurations ,Waste management ,Reduction mechanisms ,Sludge reduction ,Anoxic waters ,Anaerobic side-stream reactors (ASSR) ,Activated sludge ,Settling ,Sewage sludge treatment ,Environmental science ,Sewage treatment ,Effluent ,Anaerobic exercise ,Sludge - Abstract
In the frame of a modern waste management, an important sector concerns the sewage sludge minimisation. In recent years a lot of techniques have been developed to reduce the sludge production such as biological, thermal, thermochemical, high temperature oxidation and mechanical treatments, ultrasonication and ozonation or by using chemical compounds. Some of these have been proven to be not energy saving technologies, while others could negatively affect the effluent quality of the process due to the formation of byproducts. Among those, the use of an anaerobic side-stream reactor (ASSR) in the conventional activated sludge line is considered a challenging biological technology to minimize the sludge production in wastewater treatment plants. The whole process is mainly based on the waste activated sludge recirculation between aerobic, anoxic and anaerobic conditions. The ASSR can be easily realized in both new and existing plants as it consists of an anaerobic side-stream reactor for sludge treatment and reduction where a portion or, in some cases, all the excess sludge of the activated sludge process is recycled. Studies show that combining a conventional activated process with an ASSR could reduce the sludge yield by up to 40–60% without any negative effects, neither on the effluent quality nor on the settling characteristics of the activated sludge. The process has been applied by using various configurations. Further, different explanations about the reduction mechanism behind the process have been provided. This paper is a review of the existing application of the ASSR, in order to describe the configurations implemented, the mechanisms of sludge reduction observed and the main parameters involved.
- Published
- 2014
30. IMPIANTO E METODO PER LA RIDUZIONE DEI FANGHI NEL TRATTAMENTO DELLE ACQUE DI SCARICO - UTN (University of Trento) System
- Author
-
Gianni Andreottola, Roberta Ferrentino, and Michela Langone
31. Implementation of an anaerobic side-stream reactor in a CAS system
- Author
-
Roberta Ferrentino, Michela Langone, and Gianni Andreottola
32. Full-scale application of the UTN process to reduce sludge production in wastewater treatment
- Author
-
Roberta Ferrentino, Michela Langone, and Gianni Andreottola
33. Effects of Hydrodynamic Cavitation on Digested Sludge
- Author
-
Michela Langone, Roberta Ferrentino, Laura, Bruni, Claudio, Fabbri, Francesco, Pirozzi, and Gianni Andreottola
34. Temperature Effects on the Activity of Denitrifying Phosphate Accumulating Microorganisms and Sulphate Reducing Bacteria in Anaerobic Side-Stream Reactor
- Author
-
Roberta Ferrentino, Michela Langone, and Gianni Andreottola
35. Anaerobic side-stream reactor process to reduce sewage sludge production in wastewater treatment
- Author
-
Roberta Ferrentino, Michela Langone, and Gianni Andreottola
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