Manasis Mitrakas

Manasis Mitrakas
Aristotle University of Thessaloniki | AUTH · Department of Chemical Engineering

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179
Publications
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Publications

Publications (179)
Article
Full-text available
High quantities of mining wastes (considered by-products) are stock-pilled in mines, and since zero-waste production is examined, as an important management concept for industrial activities (and also mines), it is of particular importance to find solutions for further exploitation of these wastes. Aiming to attain these targets, the optimum MgO ad...
Article
Fine rejected fraction run of mine (ROM) material, which is rich in magnesite and cannot be further exploited, was mixed with mining wastes by-products of magnesite mine “Grecian Magnesites SA” (Gerakini, Chalkidiki, N. Greece), to produce refractories. The exploitation of the ROM in combination with mining wastes was investigated with the applicat...
Article
Full-text available
The aim of this study was to investigate the correlation between solid materials and micropollutants, aiming to enhance the removal of the latter during the application of the ozonation process. For that purpose, two solid materials (SiO2 and Al2O3) presenting catalytic activity were used for the removal of eight micropollutants from natural potabl...
Cover Page
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Proper tuning of hydroxyl excess offers multiple options for the implementation of monodisperse magnetically responsive nanoparticles in drinking water technology. Results concerning Cr(VI) uptake indicate that a small increase in hydroxyl excess features synthesized nanoparticles with an uptake capacity of 2.5 mg/g owing to the decrease in particl...
Article
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The removal of contaminants of emerging concern (CECs) occurring in wastewater effluents, such as pharmaceutically active substances (PhACs) and personal care products, pose a big research challenge since they can be a major source of pollution for water bodies and a danger to public health. The objective of this work was to perform a comprehensive...
Article
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The impact of hydroxyl excess as defined by the Fe(II)/hydroxide ratio during the synthesis of Fe3O4 nanoparticles by oxidative precipitation of FeSO4 was examined as a critical parameter determining the potential for Cr(VI) uptake from polluted water. Various samples were prepared by varying the OH− excess in the range of −0.10 up to +0.03 M and c...
Article
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Iron oxyhydroxides (FeOOHs) appear to be the optimal group of materials among inorganic adsorbents for the removal of phosphates from water, providing significant adsorption capacities. This research work presents a thermodynamic study of phosphate adsorption by examining five different FeOOHs sorbent nanomaterials. The otablebtained results indica...
Article
The present study evaluates the separation performance of a commercially available polymeric membrane, when employed for the upgrade of biogas to enrich CH4 from a simulated binary gas mixture. For this purpose, a laboratory-scale membrane set-up device has been designed and assembled, aiming to achieve the production of high purity biomethane (>95...
Article
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The present study focuses on the refractory upgrade and reuse of the mining wastes/byproducts of the magnesite mine “Grecian Magnesite SA” (Chalkidiki, N. Greece), by the addition of hematite (α-Fe2O3) nanomaterial. These by-products were also examined after the application of thermal pre-treatment, i.e., treated at 850 οC for 30 min, prior to sint...
Article
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The 12th International Conference on “Instrumental Methods of Analysis” www.ima2021.gr (accessed on 8 November 2021)), was organized by the Aristotle University of Thessaloniki and National Technical University of Athens, during 20–23 September 2021 as a virtual event, providing the opportunity for high-level analytical scientists from all around t...
Article
Uranium (U) pollution in groundwater has become a serious problem worldwide. Even in low concentrations, U has both radiological and toxicological impacts on human health. In this study an integrated hydrogeological approach was applied to conceptualize an aquifer system, and determine the origin of U detected in the aquifer of the eastern Halkidik...
Article
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This study examines the removal of p-CBA via the application of heterogeneous catalytic ozonation in the presence of 13 minerals. The solids were used as raw materials or after hydrophilic/hydrophobic modification. The optimal minerals were zeolite, calcite, dolomite, and thermally treated talc. The kinetic study showed that the decomposition of oz...
Article
The addition of alumina (Al2O3), chromite concentrate (CC) and ore (CO) and maghemite (Fe2O3) in the magnesite minerals enrichment wastes investigated, aiming to upgrade the refractory properties of products after thermal treatment at 1300◦ C. Firing shrinkage, water absorption, apparent porosity and bulk density, considered as the main relevant pa...
Article
The aim of this study is to evaluate the role of PZC and wettability of the catalysts in heterogeneous catalytic ozonation process. For that purpose, 18 solid materials examined as potential catalysts for heterogeneous catalytic ozonation, regarding the degradation of small amounts (4 μΜ) of p-chlorobenzoic acid (p-CBA - typical micropollutant) at...
Article
Full-text available
The aim of this study is to elucidate the mechanism of micropollutants’ removal in drinking water by the application of catalytic ozonation, using transition metals as appropriate catalysts. For that purpose, the degradation of 500 μg/L of p-chlorobenzoic acid (p-CBA) and benzotriazole with the addition of 2 mg/L of ozone in the presence of 1 mg/L...
Conference Paper
Full-text available
The aim of this work was the study of chemical and mineralogical characteristics of serpentinized peridotites, produced in the magnesite mines of Gerakini (Chalkidiki, Greece), and the impact evaluation of magnetic separation and of thermal treatment with the addition of oxides in specimens of solid wastes left after the mineral enrichment processe...
Article
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Catalytic ozonation was applied for the removal of small concentrations (4 μM) of micropollutants benzotriazole, carbamazepine, p-CBA from aqueous solutions at pH 7. These compounds present different physicochemical characteristics and different kinetic rate constants, when reacting with ozone or hydroxyl radicals in range of <0.15–3 × 105, 5.2 × 1...
Article
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A promising solution for membrane fouling reduction in membrane bioreactors (MBRs) could be the adjustment of operating parameters of the MBR, such as hydraulic retention time (HRT), food/microorganisms (F/M) loading and dissolved oxygen (DO) concentration, aiming to modify the sludge morphology to the direction of improvement of the membrane filtr...
Article
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This is the first study that examines the effect of operating conditions on fouling of Membrane Bio-Reactors (MBRs), which treat municipal wastewater in field conditions, with specific regard to the controlled development of filamentous microorganisms (or filaments). The novelty of the present work is extended to minimize the dissolved oxygen (DO)...
Conference Paper
Full-text available
The optimum dose of MgO, in mining wastes/by-products of magnesite mine "Grecian Magnesite SA" (Chalkidiki, N. Greece), containing mainly serpentine ores, was calculated in order to maximize the formation of desirable olivine (forsterite) after thermal treatment at 1300 o C, aiming to upgrade their refractory properties and find alternative uses un...
Article
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Elevated concentrations of heavy metals in drinking water resources and industrial or urban wastewater pose a serious threat to human health and the equilibrium of ecosystems [...]
Article
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The research on selenium presence in water resources has revealed the need to determine the respective aquatic species. As selenium oxyanions SeO32− (SeIV) and SeO42− (SeVI) predominate in natural waters, their determination is essential, mainly due to different ecotoxicity properties, as well as to different removal options from relevant-polluted...
Article
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Catalytic membrane ozonation is a hybrid process that combines membrane filtration and catalytic ozonation. The membrane deposited with an appropriate solid material acts as catalyst. As a consequence, the catalytic membrane contactor can act simultaneously as contactor (i.e., improving the transfer/dissolution of gaseous ozone into the liquid phas...
Article
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Triclocarban (TCC) is an antibacterial agent found in pharmaceuticals and personal care products (PPCP). It is potentially bioaccumulative and an endocrine disruptor, being classified as a contaminant of emerging concern (CEC). In normal uses, approximately 96% of the used TCC can be washed down the drain going into the sewer system and eventually...
Article
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In order to enhance the efficiency of heterogeneous catalytic ozonation, the effect of thermal treatment on three commonly used and inexpensive minerals, i.e., zeolite, talc and kaolin (clay), which present different physicochemical properties as potential catalysts, has been examined for the removal of para-chlorobenzoic acid (p-CBA). p-CBA is con...
Article
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Groundwater quality deterioration and overexploitation constitute two critical environmental issues worldwide. In this study, with the aim to achieve a groundwater sustainability purpose, a preliminary hydrogeochemical survey is conducted in the Flamouria basin, Pella prefecture, Northern Greece using available and collected data. For this purpose,...
Article
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This study examines the development of a nanocomposite consisting of iron oxy-hydroxides (FeOOH) embedded on magnetite (Fe 3 O 4) nanocarriers, towards its application for the simultaneous uptake of As(V) and Sb(V) ionic forms at concentrations below drinking water regulation and its magnetically-assisted recovery at the end of the process. Conside...
Article
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Using moderate populations of filaments in the biomass of Membrane Bio-Reactors (MBRs) is a biological anti-fouling method which has been increasingly applied over the last few years. This study aims to quantify the effect of COD to TN ratio, Dissolved Oxygen (DO) concentration and temperature on filaments’ population and Trans-Membrane Pressure (T...
Article
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Membrane fouling still remains a drawback for membrane bioreactors; there is nevertheless a natural promising solution which is the growth of filamentous microorganisms in moderate concentrations. In this project, an innovative 25 L membrane bioreactor is used, consisting of two aerated tanks and a membrane tank. The first tank is supplied with hig...
Article
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Catalytic ozonation is an Advanced Oxidation Process (AOPs) based on the production of hydroxyl radicals, which are very reactive oxidative species. The aim of this study is to evaluate the catalytic activity of calcite on the ozonation of four different typical micropollutants (atrazine, benzotriazole, carbamazepine, and p-CBA) at pH 7 and for low...
Article
Full-text available
The present study evaluates micropollutant degradation from water by catalytic ozonation in a pilot scale unit comprising of a hydrophobic membrane for ozone dilution and a column filled with granules of the catalyst. The catalysts examined are alumina, calcite, dolomite, goethite, pearlite, polyethylene terephthalate (PET) and zeolite. Experimenta...
Article
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The present study aims at comparing the two most promising water treatment technologies for selenium removal. A techno‐economical comparison of Se(IV) uptake between the laboratory synthesized iron oxy hydroxide (FeOOH/2.5) with the highest positive surface density of 3.25 mmol [OH−]/g and adsorption capacity 4.3 μg Se(IV)/mg FeOOH/2.5 at pH 7, and...
Article
The aims of this work were to investigate the ozone mass transfer in a continuous flow pilot unit in dependence on operating conditions and to study the effect of dead-end function of hollow fiber membranes on the ozonation performance. Dead-end operation of membranes maximizes their performance, providing maximum ozone exploitation, which in turn...
Article
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Membrane fouling investigations in membrane bioreactors (MBRs) are a top research issue. The aim of this work is to study the combined effect of colloids and soluble microbial products (SMPs) on membrane fouling. Two lab-pilot MBRs were investigated for treating two types of wastewater (wwt), synthetic and domestic. Transmembrane pressure (TMP), SM...
Article
This study provides a realistic estimation of uptake efficiency and operational cost for Se(IV) removal by the two most promising processes: coagulation/precipitation with iron salts and adsorption onto iron oxy-hydroxides granules. Removal efficiency at pH 7 and temperature 20 °C, corresponding to residual Se(IV) concentrations below the drinking...
Article
The qualitative and quantitative characterization of several mining by-product samples, were collected from the magnesite mine of "Grecian Magnesite SA" company (Gerakini, Chalkidiki, North Greece), was aiming to evaluate the possibility of upgrading their refractory properties by applying thermal treatment. The concentration range of main componen...
Article
Full-text available
The surface configuration of tetravalent manganese feroxyhyte (TMFx) was appropriately modified to achieve higher negative surface charge density and, hence, to improve its efficiency for the removal of dissolved Cd and Pb mostly cationic species from water at pH values commonly found in surface or ground waters. This was succeeded by the favorable...
Article
Nitrate pollution of surface and groundwater resources is a major worldwide environmental problem. In this study nitrogen isotopes of water, soil, fertilizer and manure were analyzed to determine the pollution sources of nitrate in the groundwater and surface waters of Anthemountas basin. The SIAR model and multivariate statistical analysis were us...
Article
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This study investigates the effect of different additives, such as coagulants/flocculants, adsorption agents (powdered activated carbon, PAC), and bio-film carriers, on the fouling propensity of a lab-scale membrane bio-reactor (MBR) treating synthetic municipal wastewater. The coagulation agents FO 4350 SSH, Adifloc KD 451, and PAC1 A9-M at concen...
Article
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Research on selenium pollution in natural waters is continuous and discouraging. In this study, coagulation/precipitation was applied with the use of Fe(II), Fe(III), and poly-aluminum chloride (PACl) salts for Se(IV) removal at concentration range 10–100 μg Se(IV)/L that is commonly found in drinking waters. Prehydrolyzed Fe(III)-FeCl3 delivered t...
Cover Page
Full-text available
Elevated concentrations of heavy metals in drinking water resources and industrial or urban wastewater pose a serious threat to human health and the equilibrium of ecosystems. During the last few decades, authorities have tended to set more strict regulations on acceptable limits challenging the improvement of conventional treatment technologies or...
Article
Full-text available
Continuous processes are always preferred over batch ones when reproducible and scalable industrial procedures are needed. This work illustrates the production of magnetite nanoparticles by oxidative precipitation in aqueous media, following a continuous approach that offers additional advantages. Particularly, the developed reaction setup succeeds...
Article
In this study, stabilization/solidification of electric arc furnace dust and Pb-refining dust was investigated. Stabilization of both wastes was performed by mixing each raw waste with MgO, Portland cement, MgO with MgCl2 (magnesium oxychloride cement), and MgO with phosphate salts (magnesium phosphate cement), at ratios between 5 and 25 wt%. Stabi...
Article
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Despite significant risks to human health due to elevated Cr(VI) concentrations in drinking water, a selective adsorbent capable of purifying water before consumption is still not commercially available. This work introduces an integrated household water filtration setup, for point-of-use applications, loaded with a tin-based Cr(VI)-oriented adsorb...
Conference Paper
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Water pollution is a critical environmental issue nowadays. One major problem is the pollution of freshwaters by pollutants of low concentrations (ng/L–μg/L), known as micropollutants. The most promising techniques for micropollutants degradation are Advanced Oxidation Processes (AOPs). Heterogeneous catalytic ozonation is among them, and recent st...
Conference Paper
Full-text available
In magnesite-producing mines, the initial extraction of the ore is followed by a series of processes for the separation of magnesite from the host ultramafic rock, with the latter considered the by-product of the separation processes. Due to the serpentinization of the ultramafic rocks and the consequent alteration of the primary minerals olivine a...
Article
The homogeneous catalytic ozonation, through the addition of dissolved metal ions, acting as catalysts, was applied for the removal/degradation of small concentrations of p-CBA, used as model micropollutant, from aqueous solutions. For this purpose five different transition metal ions, i.e. Co(II), Fe(II), Mn(II), Ni(II) and Zn(II), were studied at...
Article
Batch and continuous mode experiments were used to determine the influence of physic-chemical characteristics of iron oxy-hydroxides (FeOOHs) on selenium adsorption. Batch experiments and continuous flow rapid small-scale column tests (RSSCTs) at pH 7 and NSF (National Sanitation Foundation) water matrix, showed that the adsorption capacity of FeOO...
Conference Paper
Full-text available
Qualitative and quantitative characterization of seven samples (W 1-W 7), which were collected from various grades from "Rachoni" magnesite mine of "Grecian Magnesite SA" company in Gerakini, Chalkidiki, Greece, was performed in this study. The characterization was aiming to their evaluation regarding the possibility of upgrading their properties u...
Conference Paper
Full-text available
In the present study, mineralogical and chemical characterization of ten samples (X1-X10) was made for chromite ore-hosting ultramafic rock samples collected from the Xerolivado mine of Vourinos. Their characterization is aiming to their evaluation regarding the possibility of upgrading their physicochemical properties using various treatment metho...
Article
Fluoride, an anionic pollutant, is possibly to be found in excessive concentrations especially in groundwaters and can show detrimental effects on human health, in concentrations higher than the commonly applied legislation limit of 1.5 mg/L The most commonly applied method for water de-fluoridation is performed by Al-based coagulants, which howeve...
Article
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The presence of antimony in water remains a major problem for drinking water technology, defined by the difficulty of available adsorbents to comply with the very low regulation limit of 5 μg/L for the dominant Sb(V) form. This study attempts to develop a new class of water adsorbents based on the combination of amorphous iron oxy-hydroxide with Fe...
Article
Electrocatalysis for energy‐efficient chemical transformations is a central concept behind sustainable technologies. Numerous efforts focus on synthesizing hydrogen peroxide, a major industrial chemical and potential fuel, using simple and green methods. Electrochemical synthesis of peroxide is a promising route. Herein it is demonstrated that the...
Article
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The implementation of nanotechnology in drinking water treatment is a very promising field for applied research. A major part of this effort focuses on the reduction of the dimensionality of the conventional cost-effective adsorbents that have been successfully used for decades. The development of engineered nanoparticles has the potential to provi...
Patent
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Η παρούσα εφεύρεση αναφέρεται στη μέθοδο σύνθεσης νανοσωματιδίων γεωμετρίας πυρήνα-φλοιού που αποτελούνται από μια εσωτερική μαγνητική φάση και επικάλυψη από μια ενδιάμεση στρώση υδροξυ-οξειδίου του σιδήρου και ενός πολυστρωματικού διπλού υδροξειδίου δισθενούς-τρισθενούς μετάλλου με υποκατάσταση ανθρακικών ιόντων από θειικά και μοριακό τύπο Μ2+1-xM...