Alessandra Polettini

Sapienza University of Rome | la sapienza

The present work investigates a two-stage process scheme for cheese whey valorization through energy recovery in different forms by means of bio-electrochemical systems. The first stage consisted of an integrated bio-electrochemical process for H2 and electricity production. This combined dark fermentation with an electrochemical system with the ai...

In the present study commercial Polylactic Acid-based disposable cups and plates were selected for lab scale anaerobic degradability tests. The experiments were carried out under thermophilic conditions at different inoculum to substrate ratios and test material sizes, and the specific biogas production and associated kinetics were evaluated. Maxim...

Despite having been widely investigated, dark fermentative H2 production from organic residues is still limited by process-related issues which may hamper the perspectives of full-scale process implementation. Such constraints are mainly due to the process complexity, which is largely affected by multiple and often mutually interacting factors. In...

Volatile fatty acids (VFAs) are high-value chemicals that are increasingly demanded worldwide. Biological production via food waste (FW) dark fermentation (DF) is a promising option to achieve the sustainability and environmental benefits typical of biobased chemicals and concurrently manage large amounts of residues. DF has a great potential to pl...

Continuous dark fermentation experiments for hydrogen production from synthetic cheese whey were conducted at different HRTs and OLRs. The study mainly aimed at developing a novel criterion to quantitatively assess stability and relating it to the evolution of microbial pathways and associated metabolic products. For HRTs = 6–8 h and OLRs = 65–97.5...

This study investigated the performance of a novel integrated bio-electrochemical system for synergistic hydrogen production from a process combining a dark fermentation reactor and a galvanic cell. The operating principle of the system is based on the electrochemical conversion of protons released upon dissociation of the acid metabolites of the b...

In this study, we investigate the combined production of biofuels H2 and biopolymers PHA using sheep cheese whey as the substrate. The results obtained shows that the peculiar characteristics of sheep cheese whey (high carbon and protein content) can be exploited to boost innovative valorisation scheme in the framework of waste biorefinery.

This study investigated the performance of a novel integrated bio-electrochemical system for synergistic hydrogen production from a process combining a dark fermentation reactor and a galvanic cell. The operating principle of the system is based on the electrochemical conversion of protons released upon dissociation of the acid metabolites of the b...

Cheese whey (CW) is the main by-product of the dairy industry and is often considered one of the main agro-industrial biowaste streams to handle, especially within the European Union, where the diary activities play an essential role in the agrarian economy. In the paper, Life Cycle Assessment (LCA) is used to analyse the feasibility of producing p...

The Circular and Green Economy principles is inspiring new approaches to municipal wastewater treatment plants (MWWTPs) design and operation. Recently, an ever-growing interest is devoted to exploring the alternatives for switching the WWTPs from being able to ‘simply’ removing contaminants from water to biorefinery-like plants where energy and mat...

The paper reports an investigation on the compositional characteristics and environmental behaviour of eight fractions deriving from an advanced separation process applied to waste incineration bottom ash to recover ferrous and non-ferrous metals. Specifically, five mineral fractions and three weakly magnetic mixed metal/mineral fractions were anal...

With an estimated worldwide production of 190 billion kg per year, and due to its high organic load, cheese whey represents a huge opportunity for bioenergy and biochemicals production. Several physical, chemical and biological processes have been proposed to valorise cheese whey by producing biofuels (methane, hydrogen, and ethanol), electric ener...

Anaerobic digestion (AD) of organic waste, although widely practiced, may require suitable accompanying treatments to enhance the degradability of complex materials. Since these may require significant efforts in terms of energy and chemical demand, careful assessment of their overall environmental sustainability is mandatory to evaluate their full...

The concept of biorefinery expands the possibilities to extract value from organic matter in form of either bespoke crops or organic waste. The viability of biorefinery schemes depends on the recovery of higher-value chemicals with potential for a wide distribution and an untapped marketability. The feasibility of biorefining organic waste is enhan...

This paper evaluates the effects of ultrasonication (US) applied, individually or in combination with a mechanical treatment, to the effluent of anaerobic digestion (AD) of lignocellulosic waste, on methane (CH 4 ) production. US of the substrate downstream of AD is a relatively novel concept aimed at improving the degradation of recalcitrant compo...

Batch dark fermentation tests were performed on sheep cheese whey without inoculum addition at different operating pHs, relating the type and production yields of the observed gaseous and liquid by-products to the evolution of fermentation. Cheese whey fermentation evolved over time in two steps, involving an initial conversion of carbohydrates to...

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 VSAS/g TOCFW]) on biohydrogen production. The two parameters affected the H2 yield, the fermentation rate and the biochemical pathways. The minimum and maximum yields...

Three different experimental sets of runs involving batch fermentation assays were performed to evaluate the influence of the experimental conditions on biological hydrogen production from the source-separated organic fraction of municipal solid waste collected through a door-to-door system. The fermentation process was operated with and without au...

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 VSinoculum/g VSsubstrate 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 st...

Cheese whey (CW) is the main by-product of the cheese making process and is composed mainly by lactose, proteins, lipids and mineral salts. The environmental impacts and other potential negative effects linked to the traditional management strategies of CW are no longer considered sustainable, therefore alternatives need to be explored. Dark fermen...

The great concern regarding food loss (FL) has been studied previously, but in an isolated way, disregarding interdependencies with other areas. This paper aims to go a step further by proposing a new procedure to assess different waste management alternatives based on the nexus approach by means of an integrated Water-Energy-Food-Climate Nexus Ind...

Considerable technical advances in the cleaning of flue gases from waste incineration have increasingly made solid residues from the process the main emission route for inorganic contaminants. Appropriate strategies to manage waste incineration residues are therefore required and have driven scientific research toward finding environmentally sound...

An assessment of the energetic requirements of slurry-phase accelerated carbonation for CO2 sequestration using steelmaking slag was conducted. The results of dedicated lab-scale carbonation experiments in which the CO2 sequestration yield of basic oxygen furnace slag was investigated at different operating conditions were used for the energy requi...

The present study evaluates the influence of alkaline (NaOH) pretreatment on anaerobic digestion of olive pomace. Batch hydrolysis experiments with different NaOH dosages, process durations and temperatures were conducted, in which the variation of olive pomace solubilization in the liquid phase was investigated. The effect of pretreatment on anaer...

The paper reports the results of slurry-phase accelerated carbonation experiments using basic oxygen surface steel slag as the source of alkalinity for CO2 sequestration. In particular, the effect of particle size distribution on the carbon sequestration performance was investigated in detail. To this aim, different size classes of the slag were se...

A factorial study was conducted on basic oxygen furnace slag from a steelmaking industry with the aim of systematically identifying the individual and joint effects of the operating parameters (total pressure, CO2 concentration in the gas phase and temperature) on the CO2 sequestration yield of a direct aqueous carbonation process. Each operating p...

This work presents the results of carbonation experiments performed on Basic Oxygen Furnace (BOF) steel slag samples employing gas mixtures containing 40 and 10% CO2 vol. simulating the gaseous effluents of gasification and combustion processes respectively, as well as 100% CO2 for comparison purposes. Two routes were tested, the slurry-phase (L/S...

This paper evaluates the effect of ultrasonication on anaerobic biodegradability of lignocellulosic residues. While ultrasonication has been commonly applied as a pre-treatment of the feed substrate, in the present study a non-conventional process configuration based on recirculation of sonicated digestate to the biological reactor was evaluated at...

In the present work the influence of accelerated mineral carbonation on the leaching behaviour of basic oxygen furnace steel slag was investigated. The environmental behaviour of the material as evaluated through the release of major elements and toxic metals under varying pH conditions was the main focus of the study. Geochemical modelling of the...

The preservation of marine and coastal areas requires a sustainable and environmentally friendly management of polluted sediments. In small harbours with low financial capabilities and limited technical and operational capacity, the application of full-scale treatment and valorisation of dredged sediments is often hampered by high investment and op...

This paper discusses the effects of accelerated carbonation on the leaching behaviour of two types of stainless steel slags (electric arc furnace and argon oxygen decarburisation slag). The release of major elements and toxic metals both at the natural pH and at varying pH conditions was addressed. Geochemical modelling of the eluates was used to t...

Hydrogen production from cheese whey through dark fermentation was investigated in this study in order to systematically analyse the effects of the operating pH. The effluents from pecorino cheese and mozzarella cheese production were the substrates used for the fermentation tests. Either CW only or a mixture of CW and heat-shocked activated sludge...

The results of direct aqueous accelerated carbonation of three types of steel manufacturing residues, including an electric arc furnace (EAF) slag and two basic oxygen furnace (BOF) steel slags, are reported. Batch accelerated carbonation tests were conducted at different temperatures and CO2 pressures applying the thin-film route (liquid to solid,...

The outcomes of a study on the valorization of dredged sediments from harbour areas are presented and discussed. The experimental activities were carried out in the framework of the COAST BEST project "CO-ordinated Approach for Sediment Treatment and BEneficial reuse in Small harbours neTworks" supported by the European LIFE+ financial tool. The pr...

The suitability of electrokinetic remediation for removing heavy metals from dredged marine sediments is under investigation within the SEKRET Life+ project (“Sediment ElectroKinetic REmediation Technology for heavy metal pollution removal”), by means of a demonstrative 150 m3 treatment basin to be built in an area of the port of Livorno (Italy). I...

This study evaluates the influence of alkaline (NaOH) pretreatment on the methane potential of olive pomace. Batch hydrolysis experiments with different NaOH doses, reaction periods and temperatures were conducted, in which the variation of olive pomace solubilization in the liquid phase was investigated. According to the results, higher solubilisa...

Site selection for waste disposal is a complex task that should meet the requirements of communities and stakeholders. In this article, three decision support methods (Boolean logic, index overlay and fuzzy gamma) are used to perform land suitability analysis for landfill siting. The study was carried out in one of the biggest metropolitan regions...

Batch dark fermentation experiments were performed on food waste and mixtures of food waste and wastewater activated sludge to evaluate the influence of pH on biological H2 production and compare the process performance with and without inoculum addition. The effect of a preliminary thermal shock treatment of the inoculum was also investigated as a...

This work reports the results of a combined accelerated carbonation and wet granulation treatment applied to Basic Oxygen Furnace (BOF) steel slag with the aim of producing secondary aggregates for civil engineering applications and of storing CO2 in a solid and thermodynamically stable form. The tests were carried out in a laboratory scale granula...

Sediment dredging operations in the harbours and/or along marine coastal areas, usually due to maintain their operational water-depth, might represent a viable option to mitigate their environmental pollution of the areas. At the same time, the dredged sediments could be directly, or after treatment activity, reused in beach nourishment. The presen...

Hydrogen is believed to play a potentially key role in the implementation of sustainable energy production, particularly when it is produced from renewable sources and low energy-demanding processes. In the present paper an attempt was made at critically reviewing more than 80 recent publications, in order to harmonize and compare the available res...

Dredging operations in harbour and marine coastal areas, usually performed to mantian operational water-depth, 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 amount of materials to be di...

Dredging operations in harbour and marine coastal areas, usually performed to maintain operational water-depth, 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...

Dredging operations in harbour and marine coastal areas, usually performed to maintain operational water-depth, 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...

The CO2 uptake and Ca-to-carbonate conversion yield attained by wet and slurry-phase carbonation of stainless steel slag are reported. A maximum CO2 uptake of 180 g CO2/kg slag was achieved under wet conditions (50 °C, 3 bar CO2, 0.4 l/kg), corresponding to a Ca-to-carbonate conversion yield of 50%. The slurry-phase process, even when adopting more...

IntroductionMaterials and Methods Results and DiscussionConclusions

Gli interventi di dragaggio dei sedimenti portuali e marino-costieri, originariamente eseguiti al solo fine di ottenere o ripristinare adeguate condizioni di navigabilità, hanno progressivamente assunto una connotazione di carattere ambientale in ragione della presenza di livelli di contaminazione da inquinanti organici e inorganici che ne complica...

Laboratory experiments on a lead-contaminated soil were carried out to test the effects of chelant addition on metal leachability using column tests. Tests were aimed at studying metal mobilisation upon application of two different chelating agents (ethylenediaminetetraacetic acid [EDTA] and ethylenediaminedisuccinic acid [EDDS]). Column operation...

In the present study the evolution of mechanical strength and the leaching behavior of major and trace elements from activated incinerator bottom ash/Portland cement mixtures were investigated. Chemical and mechanical activation were applied with the purpose of improving the reactivity of bottom ash in cement blends. Chemical activation made use of...

This paper examines the main results of an accelerated carbonation treatment applied to different types and size fractions of stainless steel slag. The objectives of this work were essentially to assess the CO2 uptake achievable by each type of slag under mild operating conditions and to investigate the effects of carbonation on the mineralogy and...

The investigation of the pilot-scale application of two different stabilisation/solidification (S/S) techniques was carried out at a former fireworks and low explosives manufacturing site in SE England. Cores and granular samples were recovered from uncovered accelerated carbonated (ACT) and cement-treated soils (S/S) after 4 years to evaluate fiel...

Dredged sediments contaminated by heavy metals and PAHs were subjected to both unenhanced and enhanced electrokinetic remediation under different operating conditions, obtained by varying the applied voltage and the type of conditioning agent used at the electrode compartments in individual experiments. While metals were not appreciably mobilized a...

This paper investigates the effects of accelerated carbonation on the characteristics of bottom ash from refuse derived fuel (RDF) incineration, in terms of CO(2) uptake, heavy metal leaching and mineralogy of different particle size fractions. Accelerated aqueous carbonation batch experiments were performed to assess the influence of operating par...

This work presents the results of a study on accelerated carbonation of incinerator air pollution control residues, with a particular focus on the modifications in the leaching behaviour of the ash. Aqueous carbonation experiments were carried out using 100% CO(2) at different temperatures, pressures and liquid-to-solid ratios, in order to assess t...

IntroductionContaminated Sediment Treatment OptionsElectrokinetic Treatment of SedimentsCase Study: Tests on Electrokinetic Remediation of Sea Harbor SedimentsSummaryReferences

Gas–solid carbonation of Air Pollution Control (APC) residues is a CO2 Capture and Storage (CCS) technology, where highly reactive Mg- or Ca-bearing materials adsorb CO2 and form stable Mg- or Ca-carbonates. The carbonation kinetics of this reaction have been studied at different temperatures, CO2 concentrations, and at atmospheric pressure in orde...

In the present study, the feasibility of recycling incinerator bottom ash in cementitious systems by means of chemical activation was investigated. Different Na-, K- and Ca-based hydroxides and salts were selected for the experiments on the basis of their recognized effects on activation of typical pozzolanic materials. The evolution of mechanical...

The main aims of this work were to assess the CO2 storage capacity of different particle size fractions of stainless steel slag subjected to accelerated carbonation under mild operating conditions, to study the influence on reaction kinetics of some of the main operating parameters (temperature, pressure and liquid to solid ratio) and to determine...

This paper analyses and compares the results of accelerated carbonation experiments for CO2 storage carried out on the air pollution control (APC) residues of a waste incineration plant, via both the dry and the wet route. The two routes achieved a similar maximum calcium conversion to carbonates (around 65%) corresponding to a potential CO2 storag...

PurposeThe fairly high amounts of sediments dredged in coastal or internal water bodies for navigational and/or environmental purposes claims for the identification of appropriate management strategies. Dredged sediments are frequently affected by organic and inorganic contamination, so that their reuse, as an alternative to final landfill disposal...

In the present study a chemical washing process was applied to dredged sea and river sediments. Five chelating agents (ethylenediaminetetraacetic, nitrilotriacetic, citric, [S,S]-ethylenediaminedisuccinic and oxalic acids), three surfactants (sodium dodecyl sulphate, cetylpyridinium chloride and saponin Q), as well as monobasic potassium phosphate...

In the present work, the application of an assisted electrokinetic process for the removal of heavy metals from real contaminated sediments was investigated. The process made use of both chemical and physical methods, including addition of chelating and acid agents, as well as application of a hydraulic gradient. Lab-scale electrokinetic runs were...

The aim of the study is to compare three different cogeneration systems, internal combustion engine, gas turbine and molten carbonate fuel cell (MCFC), combined with an anaerobic digester plant implementing a technical–economical analysis and a multicriteria analysis.Through the analysis it is possible to show the validity of integrating a MCFC in...