Search results for "Aerobic"
showing 10 items of 760 documents
Laboratory investigations on co-digestion of energy crops and crop residues with cow manure for methane production: Effect of crop to manure ratio
2007
Abstract Anaerobic co-digestion of grass silage, sugar beet tops and oat straw with cow manure was evaluated in semi-continuously fed laboratory continuously stirred tank reactors (CSTRs). Co-digestion of manure and crops was shown to be feasible with feedstock volatile solids (VS) containing up to 40% of crops. The highest specific methane yields of 268, 229 and 213 l CH4 kg−1 VSadded in co-digestion of cow manure with grass, sugar beet tops and straw, respectively, were obtained with 30% of crop in the feedstock, corresponding to 85–105% of the methane potential in the substrates as determined by batch assays. Including 30% of crop in the feedstock increased methane production per digeste…
Designing an AnMBR-based WWTP for energy recovery from urban wastewater: The role of primary settling and anaerobic digestion
2015
The main objective of this paper is to assess different treatment schemes for designing a submerged anaerobic membrane bioreactor (AnMBR) based WWTP. The economic impact of including a primary settling (PS) stage and further anaerobic digestion (AD) of the wasted sludge has been evaluated. The following operating scenarios were considered: sulphate-rich and low-sulphate urban wastewater (UWW) treatment at 15 and 30 ºC. To this aim, the optimum combination of design/operating parameters that resulted in minimum total cost (CAPEX plus OPEX) for the different schemes and scenarios was determined. The AnMBR design was based on both simulation and experimental results from an AnMBR plant featuri…
Energy recovery from Municipal Solid Waste in EU: proposals to assess the management performance under a circular economy perspective
2017
In 2015 the European Commission issued a package of documents on Circular Economy concerning an integrated revision of legislative proposals on waste management. The aim was to stimulate a European transition towards a circular economy concept, which is expected to foster competitiveness, sustainable economic growth and new jobs generation. Three indicators are proposed in this paper to contribute to the assessment of the energy recovery management performance from MSW in a scenario of circular economy: a) referring to MSW directly used (RMSW) or indirectly used (SRF) as input of thermochemical plants, an indicator can be the percentage of waste having LHV > 13MJ/kg; b) referring to the MSW…
Assessment of organic waste management methods through energy balance
2014
In Italy, the Organic Fraction of Municipal Solid W aste (OFMSW) is nowadays landfilled or processed through aerobic composting. The Italian towns curre ntly support a high cost for OFMSW disposal and cause a high environmental impact, because of long distance s travelled from towns to a few available landfills and fewer treatment places, as well as the used waste m anagement methods. An interesting option for OFMSW is Anaerobic Digestion (AD), producing biogas and “digestate”. In this survey a theoretical biogas plant was placed near a town of Sicily Region (Italy), centra lised with reference to the area considered for pro ducing OFMSW. The distances travelled every year to transport OFMS…
Instrumentation, control, and automation for submerged anaerobic membrane bioreactors
2015
A submerged anaerobic membrane bioreactor (AnMBR) demonstration plant with two commercial hollow-fibre ultrafiltration systems (PURON® , Koch Membrane Systems, PUR-PSH31) was designed and operated for urban wastewater treatment. An instrumentation, control, and automation (ICA) system was designed and implemented for proper process performance. Several single-input-single-output (SISO) feedback control loops based on conventional on off and PID algorithms were implemented to control the following operating variables: flow-rates (influent, permeate, sludge recycling and wasting, and recycled biogas through both reactor and membrane tanks), sludge wasting volume, temperature, transmembrane pr…
Global sensitivity analysis of a filtration model for submerged anaerobic membrane bioreactors (AnMBR)
2014
The results of a global sensitivity analysis of a filtration model for submerged anaerobic MBRs (AnMBRs) are assessed in this paper. This study aimed to (1) identify the less- (or non-) influential factors of the model in order to facilitate model calibration and (2) validate the modelling approach (i.e. to determine the need for each of the proposed factors to be included in the model). The sensitivity analysis was conducted using a revised version of the Morris screening method. The dynamic simulations were conducted using long-term data obtained from an AnMBR plant fitted with industrial-scale hollow-fibre membranes. Of the 14 factors in the model, six were identified as influential, i.e…
Mathematical modelling of filtration in submerged anaerobic MBRs (SAnMBRs): long-term validation
2013
The aim of this study was the long-term validation of a model capable of reproducing the filtration process occurring in a submerged anaerobic membrane bioreactor (SAnMBR) system. The proposed model was validated using data obtained horn a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes. The validation was carried out using both lightly and heavily fouled membranes operating at different bulk concentrations, gas sparging intensities and transmembrane fluxes. Across a broad spectrum of operating conditions, the model correctly forecast the respective experimental data in the long term. The simulation results revealed the importance of controlling irreversible f…
Anaerobic digestion of organic solid poultry slaughterhouse waste – a review
2002
This work reviews the potential of anaerobic digestion for material recovery and energy production from poultry slaughtering by-products and wastes. First, we describe and quantify organic solid by-products and wastes produced in poultry farming and poultry slaughterhouses and discuss their recovery and disposal options. Then we review certain fundamental aspects of anaerobic digestion considered important for the digestion of solid slaughterhouse wastes. Finally, we present an overview of the future potential and current experience of the anaerobic digestion treatment of these materials.
Sicilian potential biogas production
2013
This study is aimed at predicting the Sicilian potential biogas production, using the Organic Fraction of Municipal Solid Waste (OFMSW), animal manure and food industry by-products, in a region where only one biogas plant using MSW and one co-digestion plant are nowadays available. The statistical data about OFMSW, the number of animals bred in medium and large farms and the amounts of by-products of food processing industries were evaluated, in order to compute the Sicilian potential biogas and energy production. The OFMSW produced in Sicily, that is 0.8 million tons ca. per year (37% of MSW), could be used in a bio-reactor, together with other raw materials, for Anaerobic Digestion (AD) p…
A fuzzy-logic-based controller for methane production in anaerobic fixed-film reactors
2017
The main objective of this work was to develop a controller for biogas production in continuous anaerobic fixed-bed reactors, which used effluent total volatile fatty acids (VFA) concentration as control input in order to prevent process acidification at closed loop. To this aim, a fuzzy-logic-based control system was developed, tuned and validated in an anaerobic fixed-bed reactor at pilot scale that treated industrial winery wastewater. The proposed controller varied the flow rate of wastewater entering the system as a function of the gaseous outflow rate of methane and VFA concentration. Simulation results show that the proposed controller is capable to achieve great process stability ev…