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Fortunata Lombardi - One of the best experts on this subject based on the ideXlab platform.

  • characterisation of major component leaching and buffering capacity of rdf incineration and gasification bottom ash in relation to reuse or disposal scenarios
    Waste Management, 2012
    Co-Authors: S Rocca, J J Dijkstra, Andre Van Zomeren, Rob N. J. Comans, Fortunata Lombardi
    Abstract:

    Thermal treatment of refuse derived fuel (RDF) in Waste-to-energy (WtE) plants is considered a promising solution to reduce Waste volumes for disposal, while improving material and energy recovery from Waste. Incineration is commonly applied for the energetic valorisation of RDF, although RDF gasification has also gained acceptance in recent years. In this study we focused on the environmental properties of bottom ash (BA) from an RDF incineration (RDF-I, operating temperature 850-1000 degrees C) and a RDF gasification plant (RDF-G, operating temperature 1200-1400 degrees C), by evaluating the total composition, mineralogy, buffering capacity, leaching behaviour (both at the material's own pH and as a function of pH) of both types of slag. In addition, buffering capacity results and pH-dependence leaching concentrations of major components obtained for both types of BA were analysed by geochemical modelling. Experimental results showed that the total content of major components for the two types of BA was fairly similar and possibly related to the characteristics of the RDF feedstock. However, significant differences in the contents of trace metals and salts were observed for the two BA samples as a result of the different operating conditions (i.e. temperature) adopted by the two RDF thermal treatment plants. Mineralogy analysis showed in fact that the RDF-I slag consisted of an assemblage of several crystalline phases while the RDF-G slag was mainly made up by amorphous glassy phases. The leached concentrations of major components (e.g. Ca, Si) at the natural pH of each type of slag did not reflect their total contents as a result of the partial solubility of the minerals in which these components were chemically bound. In addition, comparison of total contents with leached concentrations of minor elements (e.g. Pb, Cu) showed no obvious relationship for the two types of BA. According to the compliance leaching test results, the RDF-G BA would meet the limits of the Italian legislation for reuse and the European acceptance criteria for inert Waste landfilling. RDF-I BA instead would meet the European acceptance criteria for non hazardous Waste landfilling. A new geochemical modelling approach was followed in order to predict the leaching behaviour of major components and the pH buffering capacity of the two types of slags on the basis of independent mineralogical information obtained by XRD analysis and the bulk composition of the slag. It was found that the combined use of data regarding the mineralogical characterization and the buffering capacity of the slag material can provide an independent estimate of both the identity and the amount of minerals that contribute to the leaching process. This new modelling approach suggests that only a limited amount of the mineral phases that control the pH, buffering capacity and major component leaching from the solid samples is available for leaching, at least on the time scale of the applied standard leaching tests. As such, the presented approach can contribute to gain insights for the identification of the types and amounts of minerals that control the leaching properties and pH buffering capacity of solid residues such as RDF incineration and gasification bottom ash.

  • characterisation of major component leaching and buffering capacity of rdf incineration and gasification bottom ash in relation to reuse or disposal scenarios
    Waste Management, 2012
    Co-Authors: S Rocca, J J Dijkstra, Andre Van Zomeren, Rob N. J. Comans, Fortunata Lombardi
    Abstract:

    Thermal treatment of refuse derived fuel (RDF) in Waste-to-energy (WtE) plants is considered a promising solution to reduce Waste volumes for disposal, while improving material and energy recovery from Waste. Incineration is commonly applied for the energetic valorisation of RDF, although RDF gasification has also gained acceptance in recent years. In this study we focused on the environmental properties of bottom ash (BA) from an RDF incineration (RDF-I, operating temperature 850-1000 degrees C) and a RDF gasification plant (RDF-G, operating temperature 1200-1400 degrees C), by evaluating the total composition, mineralogy, buffering capacity, leaching behaviour (both at the material's own pH and as a function of pH) of both types of slag. In addition, buffering capacity results and pH-dependence leaching concentrations of major components obtained for both types of BA were analysed by geochemical modelling. Experimental results showed that the total content of major components for the two types of BA was fairly similar and possibly related to the characteristics of the RDF feedstock. However, significant differences in the contents of trace metals and salts were observed for the two BA samples as a result of the different operating conditions (i.e. temperature) adopted by the two RDF thermal treatment plants. Mineralogy analysis showed in fact that the RDF-I slag consisted of an assemblage of several crystalline phases while the RDF-G slag was mainly made up by amorphous glassy phases. The leached concentrations of major components (e.g. Ca, Si) at the natural pH of each type of slag did not reflect their total contents as a result of the partial solubility of the minerals in which these components were chemically bound. In addition, comparison of total contents with leached concentrations of minor elements (e.g. Pb, Cu) showed no obvious relationship for the two types of BA. According to the compliance leaching test results, the RDF-G BA would meet the limits of the Italian legislation for reuse and the European acceptance criteria for inert Waste landfilling. RDF-I BA instead would meet the European acceptance criteria for non hazardous Waste landfilling. A new geochemical modelling approach was followed in order to predict the leaching behaviour of major components and the pH buffering capacity of the two types of slags on the basis of independent mineralogical information obtained by XRD analysis and the bulk composition of the slag. It was found that the combined use of data regarding the mineralogical characterization and the buffering capacity of the slag material can provide an independent estimate of both the identity and the amount of minerals that contribute to the leaching process. This new modelling approach suggests that only a limited amount of the mineral phases that control the pH, buffering capacity and major component leaching from the solid samples is available for leaching, at least on the time scale of the applied standard leaching tests. As such, the presented approach can contribute to gain insights for the identification of the types and amounts of minerals that control the leaching properties and pH buffering capacity of solid residues such as RDF incineration and gasification bottom ash.

Harald Weigand - One of the best experts on this subject based on the ideXlab platform.

  • accelerated carbonation of Waste incinerator bottom ash in a rotating drum batch reactor
    Journal of environmental chemical engineering, 2018
    Co-Authors: Felix Bruck, Kevin Schnabel, Harald Weigand
    Abstract:

    Abstract Accelerated carbonation is known to improve the leaching behaviour and geotechnical properties of Waste incineration bottom ash (BA). Regarding process implementation on the industrial scale dynamic reactor configurations may be particularly suited since they enhance the mass exchange between gas and solid. Here we evaluated the influence of fundamental parameters on accelerated carbonation of BA in a rotating drum batch reactor equipped with an automated CO2 supply at close to atmospheric pressure conditions. Firstly, the effect of rotation speed and reactor fill level on the solids motion was studied. Secondly, the effects of CO2-concentration, fill level, and moisture on BA carbonation were investigated. Evaluation was based on the observed CO2 uptake, self-heating, and BA leachability. The bed behaviour of BA strongly differed from that of standard materials and was more affected by fill level than by rotation speed. The fill level was not a limiting factor for BA carbonation within the tested range (7–45 vol.-%). Both the CO2 uptake rate and the final level of carbonation increased as the CO2-concentration was raised from 15 to 75 vol.-%. A close relationship between CO2 uptake and reactor temperature was confirmed by benchmarking a heat balance model against the carbonation enthalpy. Carbonated BA exhibited a strongly decreased mobility of Pb and Zn as compared to fresh BA. The leaching behaviour of BA could be improved such as to comply with the German landfill ordinance for Non-Hazardous Waste.

S Rocca - One of the best experts on this subject based on the ideXlab platform.

  • characterisation of major component leaching and buffering capacity of rdf incineration and gasification bottom ash in relation to reuse or disposal scenarios
    Waste Management, 2012
    Co-Authors: S Rocca, J J Dijkstra, Andre Van Zomeren, Rob N. J. Comans, Fortunata Lombardi
    Abstract:

    Thermal treatment of refuse derived fuel (RDF) in Waste-to-energy (WtE) plants is considered a promising solution to reduce Waste volumes for disposal, while improving material and energy recovery from Waste. Incineration is commonly applied for the energetic valorisation of RDF, although RDF gasification has also gained acceptance in recent years. In this study we focused on the environmental properties of bottom ash (BA) from an RDF incineration (RDF-I, operating temperature 850-1000 degrees C) and a RDF gasification plant (RDF-G, operating temperature 1200-1400 degrees C), by evaluating the total composition, mineralogy, buffering capacity, leaching behaviour (both at the material's own pH and as a function of pH) of both types of slag. In addition, buffering capacity results and pH-dependence leaching concentrations of major components obtained for both types of BA were analysed by geochemical modelling. Experimental results showed that the total content of major components for the two types of BA was fairly similar and possibly related to the characteristics of the RDF feedstock. However, significant differences in the contents of trace metals and salts were observed for the two BA samples as a result of the different operating conditions (i.e. temperature) adopted by the two RDF thermal treatment plants. Mineralogy analysis showed in fact that the RDF-I slag consisted of an assemblage of several crystalline phases while the RDF-G slag was mainly made up by amorphous glassy phases. The leached concentrations of major components (e.g. Ca, Si) at the natural pH of each type of slag did not reflect their total contents as a result of the partial solubility of the minerals in which these components were chemically bound. In addition, comparison of total contents with leached concentrations of minor elements (e.g. Pb, Cu) showed no obvious relationship for the two types of BA. According to the compliance leaching test results, the RDF-G BA would meet the limits of the Italian legislation for reuse and the European acceptance criteria for inert Waste landfilling. RDF-I BA instead would meet the European acceptance criteria for non hazardous Waste landfilling. A new geochemical modelling approach was followed in order to predict the leaching behaviour of major components and the pH buffering capacity of the two types of slags on the basis of independent mineralogical information obtained by XRD analysis and the bulk composition of the slag. It was found that the combined use of data regarding the mineralogical characterization and the buffering capacity of the slag material can provide an independent estimate of both the identity and the amount of minerals that contribute to the leaching process. This new modelling approach suggests that only a limited amount of the mineral phases that control the pH, buffering capacity and major component leaching from the solid samples is available for leaching, at least on the time scale of the applied standard leaching tests. As such, the presented approach can contribute to gain insights for the identification of the types and amounts of minerals that control the leaching properties and pH buffering capacity of solid residues such as RDF incineration and gasification bottom ash.

  • characterisation of major component leaching and buffering capacity of rdf incineration and gasification bottom ash in relation to reuse or disposal scenarios
    Waste Management, 2012
    Co-Authors: S Rocca, J J Dijkstra, Andre Van Zomeren, Rob N. J. Comans, Fortunata Lombardi
    Abstract:

    Thermal treatment of refuse derived fuel (RDF) in Waste-to-energy (WtE) plants is considered a promising solution to reduce Waste volumes for disposal, while improving material and energy recovery from Waste. Incineration is commonly applied for the energetic valorisation of RDF, although RDF gasification has also gained acceptance in recent years. In this study we focused on the environmental properties of bottom ash (BA) from an RDF incineration (RDF-I, operating temperature 850-1000 degrees C) and a RDF gasification plant (RDF-G, operating temperature 1200-1400 degrees C), by evaluating the total composition, mineralogy, buffering capacity, leaching behaviour (both at the material's own pH and as a function of pH) of both types of slag. In addition, buffering capacity results and pH-dependence leaching concentrations of major components obtained for both types of BA were analysed by geochemical modelling. Experimental results showed that the total content of major components for the two types of BA was fairly similar and possibly related to the characteristics of the RDF feedstock. However, significant differences in the contents of trace metals and salts were observed for the two BA samples as a result of the different operating conditions (i.e. temperature) adopted by the two RDF thermal treatment plants. Mineralogy analysis showed in fact that the RDF-I slag consisted of an assemblage of several crystalline phases while the RDF-G slag was mainly made up by amorphous glassy phases. The leached concentrations of major components (e.g. Ca, Si) at the natural pH of each type of slag did not reflect their total contents as a result of the partial solubility of the minerals in which these components were chemically bound. In addition, comparison of total contents with leached concentrations of minor elements (e.g. Pb, Cu) showed no obvious relationship for the two types of BA. According to the compliance leaching test results, the RDF-G BA would meet the limits of the Italian legislation for reuse and the European acceptance criteria for inert Waste landfilling. RDF-I BA instead would meet the European acceptance criteria for non hazardous Waste landfilling. A new geochemical modelling approach was followed in order to predict the leaching behaviour of major components and the pH buffering capacity of the two types of slags on the basis of independent mineralogical information obtained by XRD analysis and the bulk composition of the slag. It was found that the combined use of data regarding the mineralogical characterization and the buffering capacity of the slag material can provide an independent estimate of both the identity and the amount of minerals that contribute to the leaching process. This new modelling approach suggests that only a limited amount of the mineral phases that control the pH, buffering capacity and major component leaching from the solid samples is available for leaching, at least on the time scale of the applied standard leaching tests. As such, the presented approach can contribute to gain insights for the identification of the types and amounts of minerals that control the leaching properties and pH buffering capacity of solid residues such as RDF incineration and gasification bottom ash.

F Fernandezmartinez - One of the best experts on this subject based on the ideXlab platform.

  • a mixed separation immobilization method for soluble salts removal and stabilization of heavy metals in municipal solid Waste incineration fly ash
    Journal of Environmental Management, 2019
    Co-Authors: Evangelina Atanes, Blanca Cuestagarcia, Antonio Nietomarquez, F Fernandezmartinez
    Abstract:

    This work presents the results of a treatment process of municipal solid Waste incineration (MSWI) fly ash using a solution of sodium carbonate as a stabilizing agent. The effectiveness of the treatment was evaluated by means of leaching test for Waste characterization according to European Standard, with special focus on soluble chlorides and heavy metals (Zn, Cd, Pb and Cu). Chemical, XRD and DTA/DTG analysis were used to gain insight into the chemical changes induced in the fly ash by the treatment. In the fresh fly ash, the total dissolved solids and chloride concentration exceed the acceptance limits for hazardous Waste whereas fresh fly ash was classified as hazardous Waste concerning Pb. The carbonated fly ash was considered as Non-Hazardous Waste according to all studied parameters. XRD and DTA/DTG analysis of treated fly ash showed that chlorine compounds have been transferred into the liquid phase during the stabilization process. The chloride removal from the ash was complete and fast irrespective of the sodium carbonate concentration and solid/liquid ratio in the stabilization process within the range studied. The treated fly ash was mainly composed by calcite and portlandite and the chemical analysis after the leaching test demonstrated that more than 98% of heavy metals remained in the treated fly ash. Therefore, the stabilization procedure of MSWI fly ash with a solution of carbonate ions achieved the separation of soluble salts and the leaching stabilization of heavy metals simultaneously in one step.

Kostis Magoulas - One of the best experts on this subject based on the ideXlab platform.

  • process development for chemical stabilization of fly ash from municipal solid Waste incineration
    Chemical Engineering Research & Design, 2017
    Co-Authors: Chrisanthi Vavva, Epaminondas Voutsas, Kostis Magoulas
    Abstract:

    Abstract Α detailed characterization of fly ash collected from a municipal solid Waste incinerator, which involves both its physicochemical properties and its leaching behavior, is presented. For the classification of the fly ash, the European standard leaching test EN 12457/2 was carried out and the leaching test results indicate that leachate concentration of Pb, TDS, chloride and sulfate ions, exceed the legal limit values for Non-Hazardous Waste landfilling, according to Council Decision 2003/33/EC. Two techniques, phosphoric acid stabilization and water washing were used for the treatment of fly ash. Several parameters that affect the two processes were tested. Phosphoric acid proved to be very effective for the stabilization of Pb. Water washing reduced effectively the soluble fraction but attention was given to the mobilization of toxic heavy metals and to the Wastewater which is produced. The combination of phosphoric acid stabilization and water washing was investigated, aiming to the successful stabilization of fly ash and the production of the best Wastewater quality. The effect of various parameters, such as phosphoric acid to ash ratio, pH, the sequence of the two processes and different phosphate sources, was examined. The results indicate that using phosphoric acid with an acid to ash ratio of 7% w/w followed by water washing, successfully stabilizes the fly ash and produces a Non-Hazardous Waste. In addition, the Wastewater produced from this treatment method is less polluted with heavy metals than the other tested methods.