Kostas Matis - Academia.edu (original) (raw)

Papers by Kostas Matis

Research paper thumbnail of Sorption of Metal Ions From Aqueous Solution on Fixed-Beds of Iron-Based Adsorbents

NATO Science for Peace and Security Series C: Environmental Security, 2009

ABSTRACT

Research paper thumbnail of Iron-Based Nanoadsorbents for the Removal of Metal Ions from Water

NATO Security through Science Series

Research paper thumbnail of Bonding of Toxic Metal Ions

Water Encyclopedia, 2005

Worldwide environmental problems are becoming more and more acute. It is known that many specific... more Worldwide environmental problems are becoming more and more acute. It is known that many specific industrial wastewater streams with large flows contain toxic metals in concentrations up to 500 mg/L, which have to be removed prior to water recycling, indirect discharge into a sewage system, or direct discharge into surface waters. Some examples are (1) rinse water in metal working enterprises, containing Cu, Ni, Zn, Sn, Cd, Pd, Ag, Al, Au, Cr, Mo, etc.; (2) rinse water in the semiconductor industry, containing Cu, Sn, Pb, Sb; (3) wastewater from the copper industry, containing As, Se; (4) other types of water in which the presence of toxic metals causes problems; (5) drinking water from ground water contaminated with As; and (6) mine water contaminated with different toxic metals (e.g., U, Ra, As). Keywords: precipitation; ion exchange; sorption; sorbents; flocculation; filtration; regeneration; electrodialysis

Research paper thumbnail of Bioremoval of Metal Ion and Water Treatment in a Hybrid Unit

Separation Science and Technology, 2009

ABSTRACT

Research paper thumbnail of Effect of Cationic Surfactant on the Adsorption of Arsenites onto Akaganeite Nanocrystals

Separation Science and Technology, 2007

The current research focuses on removal of arsenite ions from aqueous solutions by a new adsorben... more The current research focuses on removal of arsenite ions from aqueous solutions by a new adsorbent, surfactant modified akaganeite (Akm), prepared after the adsorption of the cationic surfactant, hexadecyl trimethyl ammonium bromide (N‐Cetyl‐N,N,N‐Trimethylammonium Bromide) onto akaganeite. The new adsorbent was investigated with Fourier transform infrared spectra and X‐ray photoelectron spectroscopy methods for a better understanding of the effects of surface

Research paper thumbnail of Alternative Flotation Techniques for Wastewater Treatment: Focus on Electroflotation

Separation Science and Technology, 2010

ABSTRACT

Research paper thumbnail of Air sparging during the solid/liquid separation by microfiltration: application of flotation

Separation and Purification Technology, 2004

A large number of techniques have been used today to limit the membranes fouling and among them, ... more A large number of techniques have been used today to limit the membranes fouling and among them, certainly is air bubbling constituting also the transport medium in flotation, as applied in wastewater treatment; flotation is suitable as a pretreatment stage for microfiltration. Ceramic flat-sheet membrane modules were used in this paper, of multi-channel geometry and mainly their fouling tendency and

Research paper thumbnail of Modeling the sorption of metal ions from aqueous solution by iron-based adsorbents

Journal of Hazardous Materials, 2009

The possibility of using iron-based adsorbents (i.e. akaganéite or goethite) to remove heavy meta... more The possibility of using iron-based adsorbents (i.e. akaganéite or goethite) to remove heavy metal ions from aqueous solutions was the aim of the present review paper. Synthesized material was used in two forms, i.e. in fine powder of nanocrystals and in the form of grains (as granular). The main examined parameters were the quantity of sorbent, the presence of ionic strength, the pH value of solution and the metals speciation, including the presence of complexing agents. The removal efficiency of the packed-bed column was examined and compared. Typical adsorption models were discussed and the bed depth-service time equation has been applied to the sorption results in order to model the column operation.

Research paper thumbnail of Removal of zinc ion from water by sorption onto iron-based nanoadsorbent

Journal of Hazardous Materials, 2007

Research paper thumbnail of The recovery of copper from a copper mine effluent in a hybrid flotation/microfiltration cell

International Journal of Environment and Pollution, 2007

Research paper thumbnail of Water Separation Processes and Sustainability

Industrial & Engineering Chemistry Research, 2011

Research paper thumbnail of Copper removal from effluents by various separation techniques

Research paper thumbnail of A New Hybrid Flotation—Microfiltration Cell

Separation Science and Technology, 2006

Research paper thumbnail of Wastewater Treatment Processes: Part I

Processes

Cheap and plentiful, water was for centuries a manufacturing tool that industry took for granted ... more Cheap and plentiful, water was for centuries a manufacturing tool that industry took for granted [...]

Research paper thumbnail of Flotation in Water and Wastewater Treatment

Processes

Flotation constitutes a separation process that originated from mineral processing. Nowadays, wid... more Flotation constitutes a separation process that originated from mineral processing. Nowadays, wider applications have been found and compared to flotation for water and wastewater treatment. Stress in the present review paper was mainly applied to heavy metal ions recovery by flotation and the respective mechanism followed, being either ion, precipitate, or sorptive flotation. In the latter case, the use of adsorbents is included (such as powdered activated carbon, zeolites, and goethite), as well as various biosorbents. The flotation of the following metals was reviewed: copper, zinc, nickel, lead, iron, chromium, arsenic, gold, and others. The bubble generation method could be applied for typical dispersed-air flotation column, electroflotation, or dissolved-air flotation; the latter being the most appropriate established technique in water treatment. The role of particle size (for example, studying flotation of salt-type mineral fines) was also examined.

Research paper thumbnail of The Flotation Process Can Go Green

Processes

In today’s world of environmental strain, wastewater treatment has become a, more or less, conven... more In today’s world of environmental strain, wastewater treatment has become a, more or less, conventional application of flotation—as for instance, in the oil, food, or chemical industries, and in potable water treatment. In this paper, different flotation methods (such as ion, adsorbing colloid, and adsorptive flotation, including biosorption) and techniques will be reviewed; and, in order to explain them further, several applications of these from the laboratory (General and Inorganic Chemical Technology) at Aristotle University of Thessaloniki, Greece (AUTh) will be presented and analyzed, with the main focus on sustainability. The application of flotation as a separation process, when applied in pollution control or during water treatment, was often criticized due to the possible toxicity of the applied collectors; however, the use of biosurfactants may alleviate this concern and enhance its further acceptability.

Research paper thumbnail of Increasing the efficiency of lignocellulosic biomass enzymatic hydrolysis:Hydrothermal pretreatment,extraction of surface lignin, wet milling and production of cellulolytic enzymes

ChemSusChem

Acetone and ethanol extraction of lignin deposits from the surface of hydrothermally (liquid hot ... more Acetone and ethanol extraction of lignin deposits from the surface of hydrothermally (liquid hot water) pretreated beech wood biomass alleviates the lignin inhibitory effects during enzymatic hydrolysis of cellulose to glucose and boosts the enzymatic digestibility to high values (≈70 %). Characterization of the extracted lignins (FTIR, pyrolysis/GC-MS, differential thermogravimetry, gel permeation chromatography) indicated high purity, low molecular weight, and features that suggest that it consists mainly of fragments of the native wood lignin partially depolymerized and recondensed on the biomass surface during the hydrothermal pretreatment. The pyrolysis products of the extracted surface lignins suggest their high potential as a feedstock for the production of high added value phenolic compounds. When the enzymatic hydrolysis of the pretreated and extracted biomass solids was assisted by mild wet milling, near complete cellulose digestibility (≥95 %) could be achieved. In the context of the biorefinery and whole-biomass valorization concept, it was also shown that the hydrothermally (hemicellulose-deficient) pretreated and delignified biomass solids could be also successfully used for the production of crude cellulase from Trichoderma reesei cultures, providing a simple and low-cost method for the complementary production of cellulases by utilizing fractions of the integrated hydrolysis process.

Research paper thumbnail of Hydrodynamic aspects of flotation separation

Open Chemistry, 2016

Flotation separation is mainly used for removing particulates from aqueous dispersions. It is wid... more Flotation separation is mainly used for removing particulates from aqueous dispersions. It is widely used for ore beneficiation and recovering valuable materials. This paper reviews the hydrodynamics of flotation separations and comments on selected recent publications. Units are distinguished as cells of ideal and non-ideal flow. A brief introduction to hydrodynamics is included to explain an original study of the hybrid flotation-microfiltration cell, effective for heavy metal ion removal.

Research paper thumbnail of Flotation process and apparatus containing a membrane

Research paper thumbnail of Arsenates Sorption by Nanocrystalline Hybrid Surfactant-Akagan�ite

Separ Sci Technol, 2012

ABSTRACT The scope of this study was to evaluate an innovative adsorbent, nanocrystalline hybrid ... more ABSTRACT The scope of this study was to evaluate an innovative adsorbent, nanocrystalline hybrid surfactant-akaganéite (denoted as Akh), for arsenate ions removal from dilute solution. Akh was synthesized in the laboratory using FeCl3 as the precursor and a cationic surfactant, hexadecyl-trimethylammonium bromide, as modifier. Akh presented a significantly higher arsenate adsorption capacity (about 180 mg As(V)/g) than the pure nanocrystalline akaganéite (denoted as Ak, about 120 mg As(V)/g). The kinetics of adsorption obeyed a pseudo-second-order rate equation. Higher ionic strength results in higher arsenate adsorption. The new adsorbent was investigated with X-ray powder diffraction, N2 adsorption-desorption (BET), Fourier transform infrared spectra and X-ray photoelectron spectroscopy methods for better understanding the effects of surface properties on arsenate adsorption.

Research paper thumbnail of Sorption of Metal Ions From Aqueous Solution on Fixed-Beds of Iron-Based Adsorbents

NATO Science for Peace and Security Series C: Environmental Security, 2009

ABSTRACT

Research paper thumbnail of Iron-Based Nanoadsorbents for the Removal of Metal Ions from Water

NATO Security through Science Series

Research paper thumbnail of Bonding of Toxic Metal Ions

Water Encyclopedia, 2005

Worldwide environmental problems are becoming more and more acute. It is known that many specific... more Worldwide environmental problems are becoming more and more acute. It is known that many specific industrial wastewater streams with large flows contain toxic metals in concentrations up to 500 mg/L, which have to be removed prior to water recycling, indirect discharge into a sewage system, or direct discharge into surface waters. Some examples are (1) rinse water in metal working enterprises, containing Cu, Ni, Zn, Sn, Cd, Pd, Ag, Al, Au, Cr, Mo, etc.; (2) rinse water in the semiconductor industry, containing Cu, Sn, Pb, Sb; (3) wastewater from the copper industry, containing As, Se; (4) other types of water in which the presence of toxic metals causes problems; (5) drinking water from ground water contaminated with As; and (6) mine water contaminated with different toxic metals (e.g., U, Ra, As). Keywords: precipitation; ion exchange; sorption; sorbents; flocculation; filtration; regeneration; electrodialysis

Research paper thumbnail of Bioremoval of Metal Ion and Water Treatment in a Hybrid Unit

Separation Science and Technology, 2009

ABSTRACT

Research paper thumbnail of Effect of Cationic Surfactant on the Adsorption of Arsenites onto Akaganeite Nanocrystals

Separation Science and Technology, 2007

The current research focuses on removal of arsenite ions from aqueous solutions by a new adsorben... more The current research focuses on removal of arsenite ions from aqueous solutions by a new adsorbent, surfactant modified akaganeite (Akm), prepared after the adsorption of the cationic surfactant, hexadecyl trimethyl ammonium bromide (N‐Cetyl‐N,N,N‐Trimethylammonium Bromide) onto akaganeite. The new adsorbent was investigated with Fourier transform infrared spectra and X‐ray photoelectron spectroscopy methods for a better understanding of the effects of surface

Research paper thumbnail of Alternative Flotation Techniques for Wastewater Treatment: Focus on Electroflotation

Separation Science and Technology, 2010

ABSTRACT

Research paper thumbnail of Air sparging during the solid/liquid separation by microfiltration: application of flotation

Separation and Purification Technology, 2004

A large number of techniques have been used today to limit the membranes fouling and among them, ... more A large number of techniques have been used today to limit the membranes fouling and among them, certainly is air bubbling constituting also the transport medium in flotation, as applied in wastewater treatment; flotation is suitable as a pretreatment stage for microfiltration. Ceramic flat-sheet membrane modules were used in this paper, of multi-channel geometry and mainly their fouling tendency and

Research paper thumbnail of Modeling the sorption of metal ions from aqueous solution by iron-based adsorbents

Journal of Hazardous Materials, 2009

The possibility of using iron-based adsorbents (i.e. akaganéite or goethite) to remove heavy meta... more The possibility of using iron-based adsorbents (i.e. akaganéite or goethite) to remove heavy metal ions from aqueous solutions was the aim of the present review paper. Synthesized material was used in two forms, i.e. in fine powder of nanocrystals and in the form of grains (as granular). The main examined parameters were the quantity of sorbent, the presence of ionic strength, the pH value of solution and the metals speciation, including the presence of complexing agents. The removal efficiency of the packed-bed column was examined and compared. Typical adsorption models were discussed and the bed depth-service time equation has been applied to the sorption results in order to model the column operation.

Research paper thumbnail of Removal of zinc ion from water by sorption onto iron-based nanoadsorbent

Journal of Hazardous Materials, 2007

Research paper thumbnail of The recovery of copper from a copper mine effluent in a hybrid flotation/microfiltration cell

International Journal of Environment and Pollution, 2007

Research paper thumbnail of Water Separation Processes and Sustainability

Industrial & Engineering Chemistry Research, 2011

Research paper thumbnail of Copper removal from effluents by various separation techniques

Research paper thumbnail of A New Hybrid Flotation—Microfiltration Cell

Separation Science and Technology, 2006

Research paper thumbnail of Wastewater Treatment Processes: Part I

Processes

Cheap and plentiful, water was for centuries a manufacturing tool that industry took for granted ... more Cheap and plentiful, water was for centuries a manufacturing tool that industry took for granted [...]

Research paper thumbnail of Flotation in Water and Wastewater Treatment

Processes

Flotation constitutes a separation process that originated from mineral processing. Nowadays, wid... more Flotation constitutes a separation process that originated from mineral processing. Nowadays, wider applications have been found and compared to flotation for water and wastewater treatment. Stress in the present review paper was mainly applied to heavy metal ions recovery by flotation and the respective mechanism followed, being either ion, precipitate, or sorptive flotation. In the latter case, the use of adsorbents is included (such as powdered activated carbon, zeolites, and goethite), as well as various biosorbents. The flotation of the following metals was reviewed: copper, zinc, nickel, lead, iron, chromium, arsenic, gold, and others. The bubble generation method could be applied for typical dispersed-air flotation column, electroflotation, or dissolved-air flotation; the latter being the most appropriate established technique in water treatment. The role of particle size (for example, studying flotation of salt-type mineral fines) was also examined.

Research paper thumbnail of The Flotation Process Can Go Green

Processes

In today’s world of environmental strain, wastewater treatment has become a, more or less, conven... more In today’s world of environmental strain, wastewater treatment has become a, more or less, conventional application of flotation—as for instance, in the oil, food, or chemical industries, and in potable water treatment. In this paper, different flotation methods (such as ion, adsorbing colloid, and adsorptive flotation, including biosorption) and techniques will be reviewed; and, in order to explain them further, several applications of these from the laboratory (General and Inorganic Chemical Technology) at Aristotle University of Thessaloniki, Greece (AUTh) will be presented and analyzed, with the main focus on sustainability. The application of flotation as a separation process, when applied in pollution control or during water treatment, was often criticized due to the possible toxicity of the applied collectors; however, the use of biosurfactants may alleviate this concern and enhance its further acceptability.

Research paper thumbnail of Increasing the efficiency of lignocellulosic biomass enzymatic hydrolysis:Hydrothermal pretreatment,extraction of surface lignin, wet milling and production of cellulolytic enzymes

ChemSusChem

Acetone and ethanol extraction of lignin deposits from the surface of hydrothermally (liquid hot ... more Acetone and ethanol extraction of lignin deposits from the surface of hydrothermally (liquid hot water) pretreated beech wood biomass alleviates the lignin inhibitory effects during enzymatic hydrolysis of cellulose to glucose and boosts the enzymatic digestibility to high values (≈70 %). Characterization of the extracted lignins (FTIR, pyrolysis/GC-MS, differential thermogravimetry, gel permeation chromatography) indicated high purity, low molecular weight, and features that suggest that it consists mainly of fragments of the native wood lignin partially depolymerized and recondensed on the biomass surface during the hydrothermal pretreatment. The pyrolysis products of the extracted surface lignins suggest their high potential as a feedstock for the production of high added value phenolic compounds. When the enzymatic hydrolysis of the pretreated and extracted biomass solids was assisted by mild wet milling, near complete cellulose digestibility (≥95 %) could be achieved. In the context of the biorefinery and whole-biomass valorization concept, it was also shown that the hydrothermally (hemicellulose-deficient) pretreated and delignified biomass solids could be also successfully used for the production of crude cellulase from Trichoderma reesei cultures, providing a simple and low-cost method for the complementary production of cellulases by utilizing fractions of the integrated hydrolysis process.

Research paper thumbnail of Hydrodynamic aspects of flotation separation

Open Chemistry, 2016

Flotation separation is mainly used for removing particulates from aqueous dispersions. It is wid... more Flotation separation is mainly used for removing particulates from aqueous dispersions. It is widely used for ore beneficiation and recovering valuable materials. This paper reviews the hydrodynamics of flotation separations and comments on selected recent publications. Units are distinguished as cells of ideal and non-ideal flow. A brief introduction to hydrodynamics is included to explain an original study of the hybrid flotation-microfiltration cell, effective for heavy metal ion removal.

Research paper thumbnail of Flotation process and apparatus containing a membrane

Research paper thumbnail of Arsenates Sorption by Nanocrystalline Hybrid Surfactant-Akagan�ite

Separ Sci Technol, 2012

ABSTRACT The scope of this study was to evaluate an innovative adsorbent, nanocrystalline hybrid ... more ABSTRACT The scope of this study was to evaluate an innovative adsorbent, nanocrystalline hybrid surfactant-akaganéite (denoted as Akh), for arsenate ions removal from dilute solution. Akh was synthesized in the laboratory using FeCl3 as the precursor and a cationic surfactant, hexadecyl-trimethylammonium bromide, as modifier. Akh presented a significantly higher arsenate adsorption capacity (about 180 mg As(V)/g) than the pure nanocrystalline akaganéite (denoted as Ak, about 120 mg As(V)/g). The kinetics of adsorption obeyed a pseudo-second-order rate equation. Higher ionic strength results in higher arsenate adsorption. The new adsorbent was investigated with X-ray powder diffraction, N2 adsorption-desorption (BET), Fourier transform infrared spectra and X-ray photoelectron spectroscopy methods for better understanding the effects of surface properties on arsenate adsorption.