Maria Harja

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Verified

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• Professor
• Head of Department at Gheorghe Asachi Technical University of Iași

This article presents an in-depth exploration of diverse methodologies for the separation and removal of various classes of antibiotics from water and aqueous solutions. Focusing on recent advancements, the study offers a comprehensive overview of active substances and novel combinations employed in the removal processes. Notably, the role of adsor...

Currently, the large amount of waste produced is a significant problem for the environment and for the people who live near the deposits of by-products obtained from technological processes. Limited storage capacity, as well as the uncontrolled disposal of waste or industrial by-products from landfills, are growing concerns for environmental protec...

Environmental pollution is a major issue that we are dealing with at the moment. The reuse of industrial waste, which is used as raw materials in other industries such as the construction materials industry, is a beneficial way to reduce pollution. This is possible due to the physical, chemical, and mineralogical properties of industrial waste. Exa...

Due to rising customer demand, the manufacturing of electrical and electronic equipment has expanded dramatically in recent years; nevertheless, because technology is advancing so quickly, the equipment's lifespan has decreased. Consequently, an enormous volume of electronic waste (also known as "e-waste") is produced each day. The majority of thes...

In the cement industry, the actual challenges are the preservation of the raw materials and energy resources, as well as reduction of pollutant emissions. In this context, the cement producers demand studies to reduce of the production costs and atmospheric emissions. One way to achieve these objectives, is to use alternative fuels or by-product ra...

The present study aimed to use geopolymer materials synthesized from different fly ashes, which are promising for the adsorption of copper ions from aqueous solutions. The characterization of fly ashes and prepared adsorbents was performed by energy-dispersive X-ray spectroscopy (EDS) analysis, Brunauer–Emmett–Teller (BET) surface area analysis, an...

Fiberglass is a waste generated in the construction materials industry, which is not dangerous for the environment, but long-term and very long-term storage is expensive. Finding a method of reuse as in creating a useful composite material led to the research work in this study. The impact of waste fiberglass and furnace slag on the characteristics...

Cement production at the global level has grown at a dizzying pace in recent decades, and with it the consumption of thermal and electrical energy of the producing factories. As a result, the negative effects on the environment also increased, effects also blamed on cement producers. The classic sources of obtaining the necessary thermal energy are...

Traditional building materials have a major contribution to carbon emissions, consumption of natural resources, all these affecting environmental. To avoid the disadvantages that come from the cement industry, one strategy could be to use alternative materials as substitutes for cement-based materials. In plus these materials can be obtaining from...

This study aims to investigate the influence of the treatment temperature on the mechanical properties of recycled and crushed glass (RCG) and to develop new materials in the civil field (interiors, art objects, constructions, etc.). Crushed glass (RCG) was thermally treated through a crystallization process in stages (T1, T2, T3, etc.). This metho...

The decreasing amount of the world's water supply is a significant issue nowadays. Global warming is one of the key factors contributing to the increasing loss of water supplies, but wasteful water usage for domestic and industrial use is also a major factor. The water consumption reduction by using proper additives is a technique to reduce high wa...

Reducing the carbon footprint is a strategic objective established for environmental protection the European Union. It is proposed that Europe be climate neutral until 2050. This objective can also be achieved in Romania, if the large energy-consuming industries, that produce inorganic binders (cement, lime, plaster), implement the best available t...

The production of electrical and electronic equipment has increased significantly in recent years because of an increase in consumer demand, yet their life expectancies have shortened as a result of the rapid advancement of technology. As a result, a significant amount of electronic waste (or "e-waste") is generated every day. Most of these wastes...

Glass is a substance that is present in most houses since glass-based items are made and consumed in relatively high quantities. This has led to the buildup of glass in concerning quantities all over the world, which is a problem for the environment. It is well known that glass has several advantageous physiochemical features that qualify it as an...

Advanced strategies have recently been investigated in order to decrease the environmental pollution, the danger of depleting raw material stocks, and increasing pollution following the release of significant volumes of CO2, resulted by the manufacturing of ordinary cement. The total or partial substitution of cement with a variety of wastes or by-...

Researches in material oxides offers solutions in a variety of fields including environment, energy production and storage, biotechnology, medicine and healthcare, electronics, etc. Nanomaterials have concerned attention in recent decades due to their different enhanced properties, such as a large surface, particle size, optical or magnetic propert...

The co-incineration of tires waste is inexpensive; the questions are referring to the influence over clinker quality and gaseous emissions. The use of tires waste as a waste-derived fuel imposes more researches to establish influence over process parameters, technological availability, costs, kiln design for processing different type of fuels, qual...

The fly ash wastes (materials rich in silica, aluminum, and iron) could be advanced valorized by using as pozzolanic materials in the formulation of mortar and concrete. The partial hydrolysis of its, during alkali activation process, gel formation, and polycondensation produce the compulsory properties. The study had as objective to determine the...

Increasing the safety of use of water and land resources, improving the quality of life of the population and reducing the risk of diseases are urgent scientific challenges for modern society. Zeolites are cost-effective natural sorbents suggested to solve environmental problems. The paper presented data on the sorption activity of analcime-bearing...

We carried out experimental studies of the dependence of the sorption of phosphate ion with ilmenite-leucoxene ore (non-magnetic fraction of the gravitational concentrate, Pizhemskoe deposit, Middle Timan, Russia) on the concentration of sodium phosphate solution and pH of the medium. Phosphorus sorbed mainly in the form of HPO42– and H2PO4– ions o...

This study aimed to analyse the bioaccumulation of heavy metal ions in plants of spontaneous flora. An urban area was established from which soil samples were taken and analyses were performed on the content of heavy metal ions. The soil samples were collected from Iasi's urban area to determine the heavy metal concentrations, obtain maps of sensit...

CeO2/ZnO-based photocatalytic materials were synthesized by the sol-gel method in order to establish heterojunctions that increase the degradation efficiency of some types of antibiotics by preventing the recombination of electron–hole pairs. The synthesized materials were analysed by XRD, SEM, EDAX, FTIR, and UV-Vis. After several tests, the optim...

The title story of our article entitled '' Studies on the Removal of Congo Red Dye by an Adsorbent Based on Fly-Ash@Fe3O4 Mixture'' has been highlighted on the homepage of Magnetochemistry (https://www.mdpi.com/journal/magnetochemistry) as the attached screenshot shows.

Heterogeneous photocatalysis has been increasingly investigated during the past years and has been recognized as a promising technique for clean and safe water purification. The current study exploits the advantage of this technique demonstrating that the removal of a biorefractory water pollutant named clofibric acid can be really improved by phot...

In this work, a brief assessment of using microalgae (Arthrospira platensis PCC 8005) for lowering carbon emissions during biotrickling filtration of volatile organic compounds (VOCs) from air is performed. In this regard, the removal efficiency of acetic acid vapors (used as model VOC in this study) and carbon dioxide production from this process...

The effectiveness of a Fe3O4-loaded fly ash composite for the adsorption of Congo red dye was assessed in this work. The structure and properties of the magnetic adsorbent were established by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffractometer (XRD), vibrating sample magnetometer (VSM), and dynamic light s...

According to Eurostat in 2018, Romania occupies the penultimate place in waste recycling. Packaging waste, generated in the European Union, was 174 kg per capita, but these quantities varied between Croatia - 67.8 kg per capita and Germany - 227.5 kg per capita. In the first place are waste paper and cardboard - 41%, plastic - 19%, glass - 18%, woo...

The cooperation between phase change materials (PCMs) and geopolymer (GP) is energy-efficient way for improving the thermal performance of construction materials. This study discusses the effect of PCM combination with GP matrix on obtained concretes' mechanical and thermal properties. Attapulgite/lauric-capric acid eutectic mixture (ATP/LCEM) comp...

Biomass fly ash (BFA) from a biomass cogeneration plant was encapsulated into calcium alginate microspheres (ALG/Ca) and characterized. An FTIR analysis indicated that BFA loading weakened molecular interactions between ALG/Ca constituents (mainly hydrogen bonding and electrostatic interactions), thus changing the crosslinking density. SEM and AFM...

TiO2 nanoparticles synthesized by the sol-gel method and doped with Ag were characterized by SEM, EDAX, FTIR, BET, XRD and TEM, then tested in the photocatalytic degradation of methylene blue (MB) under UV irradiation. The experimental results indicate that the average size of the raw particles was 10 nm, and their size was increased by calcination...

Modified fly ash materials are currently on an upward trend internationally. The recovery of waste such as ash resulting in obtaining new products has an economic advantage but also has a significant impact on the environment because of reducing pollution due to storage. At present, there are many methods to synthesize new materials from wastes, th...

Two types of biosorbents, based on Saccharomyces pastorianus immobilized in calcium alginate, were studied for the removal of pharmaceuticals from aqueous solutions. Synthetized biocomposite materials were characterized chemically and morphologically, both before and after simulated biosorption. Ethacridine lactate (EL) was chosen as a target molec...

In this study, ethacridine lactate removal from aqueous solution using a biosorbent material based on residual microbial biomass and natural polymers in fixed-bed continuous column was investigated. Composite beads of Saccharomyces pastorianus residual biomass and calcium alginate were obtained by immobilization technique. The prepared biosorbent w...

The use of finite resources for obtaining syngas and the accumulation of large amounts of liquid wastes give place to discussions and researches about new technologies and approaches to waste capitalization. Gasification is gaining attention as an efficient process for the conversion of waste. This paper highlights the advantages of using liquid wa...

The experimental study investigates the feasibility of using two extensively waste (wastewater treatment sludge and oak wood ash) as raw materials in the manufacture of clay-free bricks. The wastes were characterized by particle-size distribution, chemical composition (EDX), X-ray diffraction (XRD), thermal analysis, and scanning electron microscop...

The Congo Red dye was removed from a simulated textile wastewater solution using fly ash from a local power plant. The characterisation of fly ash was studied in detail by SEM, EDX, XRD, FTIR, BET surface area and TGA techniques. The influence of four parameters (contact time, initial concentration, adsorbent dose, and temperature) was analysed, th...

\mathrm{TiO}_2$_Pd prepared by the incipient wet impregnation (IWI) method was successfully used as a photocatalyst for the degradation of an emerging water pollutant, clofibric acid (CA). It exhibits an improved photoactivity in comparison with different commercial titania in the degradation of CA (25 ppm). The irradiation intensity, photocatalyst...

Fly ash wastes (silica, aluminum and iron-rich materials) could be smartly valorized by their incorporation in concrete formulation, partly replacing the cement. The necessary binding properties can be accomplished by a simple procedure: an alkali activation process, involving partial hydrolysis, followed by gel formation and polycondensation. The...

Pharmaceuticals are recognized as emerging water microcontaminants that have been reported in several aquatic environments worldwide; therefore, the elimination of these pollutants is a global challenge. This study aimed to develop a biosorbent based on Saccharomyces pastorianus residual biomass encapsulated in a calcium alginate matrix and to eval...

Fly ash/magnetite material was used for the adsorption of copper ions from synthetic wastewater. The obtained material was characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) surface area, and vibrating...

This study investigated the adsorption capacity of one material based on the treatment of fly ash with sodium hydroxide as a novel adsorbent for toxic Cu2+ ion removal from aqueous media. The adsorbent was obtained through direct activation of fly ash with 2M NaOH at 90 °C and 6 h of contact time. The adsorbent was characterized by recognized techn...

Cephalexin (CPX) is recognized as a water pollutant, and it has been listed in a number of countries with a risk factor greater than one. Herein, the present work focused on the synthesis, characterization and biosorption capacity evaluation of Saccharomyces cerevisiae immobilized in calcium alginate as a biosorbent to remove CPX from aqueous solut...

This work focused on the use of cellulose acetate polymer for the preparation of porous asymmetric membranes using a phase inversion process. These membranes were characterised by scanning electron microscopy, a bubble-point method and sorption measurements. The preparation method used induced membrane anisotropy. The capacity of the membranes in t...

Novel bricks have been produced by firing mixes of water treatment sludge (WTS) and fired clay brick waste (BW). The capitalization of sludge in the construction industry is the most economically sound option. In this study, a series of different proportioning ratios of water treatment sludge and fired clay brick waste were studied. The WTS rations...

In the last years, various experimental works investigated the efficiency of different type of promoters over CO2 absorption. The absorption process is recommended for removal of acidic contaminants from flue gases and for obtaining new products. The absorption with chemical reaction (chemisorption) can be done in: potassium carbonate solution prom...

The industry generates large quantities of waste, which must be capitalized and transformed in compounds with high added value. The objective of the present study is to obtain white waterborne paint using calcium carbonate as filler, a waste results from Romanian plant fertilizer manufacturing. The paints are used for protection of surfaces, with t...

In the last years, various experimental works investigated the efficiency of different type of promoters over CO2 absorption. The absorption process is recommended for removal of acidic contaminants from flue gases and for obtaining new products. The absorption with chemical reaction (chemisorption) can be done in: potassium carbonate solution prom...

The industry generates large quantities of waste, which must be capitalized and transformed in compounds with high added value. The objective of the present study is to obtain white waterborne paint using calcium carbonate as filler, a waste results from Romanian plant fertilizer manufacturing. The paints are used for protection of surfaces, with t...

This work highlights the performance of TiO 2 _W material as adsorbent and photocatalyst. The titanium dioxide was synthesized by sol-gel method from titanium (IV) butoxide (TIBT) in presence of cetyl-trimethyl-ammonium bromide (CTAB). The TiO 2 _W composite was obtained by doping the titanium dioxide using Na 2 WO 4 as precursor. The UV-DR and BET...

The fly ash generated from a Romanian power plant was used as a starting material in this study. The aim of the study was to obtain a low cost material based on the treatment of fly ash with Fe 3 O 4 for utilization as an adsorbent for cadmium ion removal. The adsorbent that was synthesized was characterized using different techniques. The adsorpti...

Five adsorbents based on fly ash treated with NaOH for the adsorption of cadmium ion from aqueous solutions were investigated. The materials were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and the Brunauer-Emmett-Teller (BET) surface area methods. The results demonstrated that the specific...

The aim of this study is to gain a better understanding of ash properties that makes it suitable for obtaining geopolymeric/zeolitic materials, as well as to demonstrate that thermal analysis can be used as an innovative procedure to compare different activation methods. Establishing a relationship between the physical and chemical characteristics...

The aim of this study is to gain a better understanding of ash properties that makes it suitable for obtaining geopolymeric/zeolitic materials, as well as to demonstrate that thermal analysis can be used as an innovative procedure to compare different activation methods. Establishing a relationship between the physical and chemical characteristics...

The initial characteristics of Romanian fly ash from the CET II Holboca power plant show the feasibility of its application for the production of a new material with applicability in environmental decontamination. The material obtained was characterized using standard techniques: scanning electron microscopy (SEM), energy dispersive X-ray analysis...

Novel hybrid inorganic CoFe2O4/carboxymethyl cellulose (CMC) polymeric framework nanobeads-type adsorbents with tailored magnetic properties were synthesized by a combination of coprecipitation and flash-cooling technology. Precise self-assembly engineering of their shape and composition combined with deep testing for cadmium removal from wastewate...

This work highlights new insights into the performance of TiO2 doped with noble metal catalysts for the photocatalytic degradation of organic water pollutants. Different samples of titanium dioxide doped with noble metals (Au and Pd) were successfully synthesized via incipient wet impregnation (IWI) and ultrasound-assisted impregnation (US) methods...

In the present paper, aspects concerning the obtained and characterization of additive systems used for maximizing filler retention, and the effects on paper properties, were investigated. The effects of retention additives over properties of paper, containing fibers from in-situ loading (IS-CCP), were analyzed against the effects of additives over...

The rational use of water and soil resources and their effective purification are actual scientific problems for modern society. Inexpensive and effective natural sorbents, zeolites, are widely used to solve environmental problems and improve the safety of the use of water and soil resources. This article presents results of our study of the sorpti...

Mixed oxides containing zinc and lanthanum were prepared by coprecipitation in alkaline medium, followed by calcination at 400 • C. The initial precipitation product and the calcined form were characterized by Brunauer-Emmett-Teller (BET) method adsorption of nitrogen at −196 • C, Scanning Electron Microscopy/Electron-Probe Microanalysis (SEM/EPM),...

Congo red (CR), an anionic azo dye, is investigated due to negative impacts on human health. Various materials have been used to adsorb CR through adsorption process: NiO/graphene nano sheets; MWCNTs/LDHs; NiMgAl-LDOs; α-Fe2O3 nanorods; Bentonite/Zeolite-NaP; Ca-Al LDH; Al(OH)3/CuMnAl-LDH nanocomposite; NiFeLDH nanosheet/carbon fiber nanocomposite....

Major changes of the environment are caused by the presence of pollutants in air, soil, and wastewaters. From these, a major attention is accorded to the industrial wastewaters, because can contain simultaneous different types of pollutants such as heavy metals, anions, dyes, phenols, pesticides, drugs, etc. For wastewater treatment, consecrated me...

"The objective of this paper is presenting the experimental results of the viscosity measuring for the aqueous solutions of potassium carbonate with new amines as promoters. In this work, ethylenediamine (EDA) and triethylenetetramine (TETA) were chosen as rate promoter candidates. The viscosity of the ternary aqueous solutions (K2CO3-Amine-H2O) ha...

REVISTA DE CHIMIE Cite as: Rev. Chim. https://doi.org/10.37358/Rev.Chim.1949 OSIM Nr. R102355 ISSN Print 0034-7752 ISSN Online 2668-8212 Journal Metrics * Impact Factor 2019: 1.755 * 5-Year IF: 1.351 * CiteScore: 2.2 * H index: 28 (InCites Journal Citation Reports) Revista de Chimie REVISTA DE CHIMIE Revista de Chimie is internationally rec...

Bed insulation provided with an air purification system, designed to prevent and combat a microbial / viral infectation of a patient, composed of a metal frame made of removable aluminum profile, with four legs of corner type profile joined together by profiles flat at the top and with flat or corner profiles at the bottom, using some screws, a tra...

Wastes are the sustainable sources of raw materials for the synthesis of new adsorbent materials. This study has as objectives the advanced capitalization of fly ash, by sulphuric acid activation methods, and testing of synthesized materials for heavy metals removal. Based on the previous studies, the synthesis parameters were 1/3 s/L ratio, 80 °C...

The photocatalytic performance of a commercial TiO2 doped by incipient wet impregnation with palladium (sample named TiO2-Pd), was evaluated in the heterogeneous degradation process using as test molecule the clofibric acid (CA), a metabolism product of a drug used as blood lipid regulator. The catalyst was characterised by XRD, SEM and UV-VIS refl...

In the current work, the preparation of a complex wastewater coagulant based on polymeric sulfates of aluminum/iron from fly ash is presented. The performance of the coagulation�flocculation process is mostly influenced by the coagulant type, which enhances the aggregation of particles and leads to formation of fast-settling flocs by charge neutral...

The aim of this study is modeling of the process of Ni(II) removal onto new materials synthesized by a facile coprecipitation method. The literature presents different surfactants intercalated on MgAl-LDH with applicability for nickel ions removal, but the researches on the use of this material ��as cast�� as adsorbent for Ni(II) ions are limited,...

Apart of new equipment’s development such as absorption columns with higher efficiency, for chemical industry, there is a strong need for greenhouse gases reduction in order to assure the environmental protection and, consequently, many studies regarding the purification methods of exhausted gases have been performed. There are several types of rea...

Nanomaterials have attracted a great interest among the researchers due to their special proprieties and wide applicability in different fields, with special emphasis on wastewater treatment processes. Heterogeneous photocatalysis is a process in which a semiconductor material is irradiated and generate hydroxyl radical, which are able to degrade a...

This study aims to present the possibility to obtain bismuth-doped nanohydroxyapatite coatings on the surface of the titanium implants by using a solution-derived process according to an established biomimetic methodology. The bioactivity of the titanium surface was increased by an alkali-thermal treatment. Then, under biomimetic conditions, the ti...

Abstract. Among the variety of the ecotoxicants the petroleum products are the most environmentally dangerous, since the intensive migration of pollutants from them can occur because of the solubility of ionic components. Zeolites have high adsorption and cation exchange capacity and can be used as adsorbents for hydrocarbons polluting water bodies...

It is generally acknowledged that a real challenge nowadays is the development of new materials for environmental applications. In fact, the problem of environmental pollution is one of the most critical issues, determining global warming, extreme weather phenomena, decay of health till loss of human lives etc. This highly innovative and promising...

Abstract TiO2-assisted photocatalysis is used in numerous environmental applications and for the manufacturing of different products. Ag-doped TiO2 nanoparticles were synthesized by impregnation using silver nitrate solution on TiO2 obtained by sol-gel method and on commercial Degusa P25 (Evonik). Silver is widely studied as a dopant for semicondu...

We present a comparative evaluation of efficiency of titanium dioxide polymorphs as an active photocatalyst (commercially available DegussaP25, anatase (Sigma Aldrich), natural leucoxene concentrate (Pizhemskoe deposit, Russia) and titanium dioxide nanotubes based on it). The materials obtained on the basis of relatively inexpensive and affordable...

TiO2-assisted photocatalysis is used in numerous environmental applications and for the manufacturing of different products. Ag-doped TiO2 nanoparticles were synthesized by impregnation using silver nitrate solution on TiO2 obtained by sol-gel method and on commercial Degusa P25 (Evonik). Silver is widely studied as a dopant for semiconductor mater...

In this study is present the advantages and disadvantages of the use of different type of coagulants and flocculants for industrial wastewater treatment. This paper details how to survey and select appropriate reagents permit resolve of many problems appear in wastewater treatment. It is designed to be used as a study to learn about the operation o...

The increase of CO2 concentration in the atmosphere is in strong relation with the human-induced warming up due to industrial processes, transportation, etc. In order to reduce the CO2 content, end of pipe post-combustion methods can be used in addition to other methods and techniques. The CO2 capture by absorption in potassium carbonate–bicarbonat...

This work presents data on the mineral and chemical composition of zeolite-containing and clay rocks considered as carriers for oil-oxidizing microorganisms, as well as their textural characteristics. The authors proved the use of mineral sorbents based on clay and zeolitecontaining rocks for design of a biogeosorption material of destructive type....

This study presents an alternative coating method based on biomimetic approach to grow the hydroxyapatite layers on the titanium surface. In order to increase the bioactivity of the titanium surface the anodization and alkali ÷ thermal oxidation pre-treatments have been applied. Titanium implants were then coated with a hydroxyapatite layer under b...