The main objectives of this present paper were to indicate the immobilization of nano zerovalent ... more The main objectives of this present paper were to indicate the immobilization of nano zerovalent iron (nZVI) onto a polymeric material (Purolite A400) and the synthesis of the polymeric material (A400-nZVI) through sodium borohydride (NaBH4) reduction. The obtained polymeric material (A400-nZVI) was used for the nitrate ions removal from a simulated groundwater at different conditions. The polymeric materials, without and with nano zerovalent iron (A400 and A400-nZVI), were characterized trough the FTIR, SEM-EDAX, XRD, and TGA analysis. The analysis confirmed the presence of nano zerovalent iron (nZVI) onto the polymeric material (A400). The adsorption capacity of A400-nZVI, used as polymeric adsorbent, was evaluated by kinetic and thermodynamic studies. The obtained experimental results indicated that the nitrate ions reduction was fitted well by models: pseudo-second-order kinetic and Freundlich isotherm. According to the kinetic model results, a reaction mechanism could exist in ...
This paper reviews the advantages and disadvantages of the use of fertilizers obtained from leath... more This paper reviews the advantages and disadvantages of the use of fertilizers obtained from leather waste, to ameliorate the agricultural soil quality. The use of leather waste (hides and skins) as raw materials to obtain biopolymer-based fertilizers is an excellent example of a circular economy. This allows the recovery of a large quantity of the tanning agent in the case of tanned wastes, as well as the valorization of significant quantities of waste that would be otherwise disposed of by landfilling. The composition of organic biopolymers obtained from leather waste is a rich source of macronutrients (nitrogen, calcium, magnesium, sodium, potassium), and micronutrients (boron, chloride, copper, iron, manganese, molybdenum, nickel and zinc), necessary to improve the composition of agricultural soils, and to remediate the degraded soils. This enhances plant growth ensuring better crops. The nutrient release tests have demonstrated that, by using the biofertilizers with collagen or ...
steps. The presence of oxalic acid into sorbent composition favors the formation by calcinations ... more steps. The presence of oxalic acid into sorbent composition favors the formation by calcinations at 700 o C of zinc titanate stable forms, type Zn 2 TiO 4 , ZnTiO 3 and Zn 6 Al 2 O 9 . This sorbents could be used in high temperatures gas desulfurization processes due to their higher specific surface
This work aims to attain an efficient removal of the organic compounds from residual effluents de... more This work aims to attain an efficient removal of the organic compounds from residual effluents derived from the manufacture of Ranitidine and Loperamide, evaluating the possibilities of removing them by means of photo-assisted techniques. The experimental plan was developed taking in consideration a number of influencing factors: reaction time, catalyst concentration, pH, structure and concentration of the initial chemical compound, type of process applied. The experimental data allowed to comparatively evaluate the degradation of the pharmaceutical effluents and to determine the efficiency of their degradation by means of photo-assisted techniques. The optimal operating conditions were established. The presence of many organic contaminants in wastewaters, surface waters and ground waters may result from contaminated soil, agricultural runoff, industrial wastewaters and leakage of hazardous compounds storage. The presence of these organic compounds in water poses a serious threat to...
CRISTINA ORBECI1, MIRCEA STEFAN2*, ANNETTE MADELENE DANCILA1, MIHAI SILVIU TUDOSIE3,4 1 Universit... more CRISTINA ORBECI1, MIRCEA STEFAN2*, ANNETTE MADELENE DANCILA1, MIHAI SILVIU TUDOSIE3,4 1 University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Gh. Polizu Str., 011061, Bucharest, Romania 2. University Titu Maiorescu, Pharmacy Faculty, Bucharest, 22 Dâmbovnicului Str., 040441, Bucharest, Romania 3 University of Medicine and Pharmacy Carol Davila Bucharest, 8 Eroii Sanitari Blvd., 050474, Bucharest, Romania, 4 Army Center for Medical Research, Bucharest, Romania
The sorbents based on ZnO have good retaining properties for H2S from residual gases. The aim of ... more The sorbents based on ZnO have good retaining properties for H2S from residual gases. The aim of this article is the improvment of sorbent properties through the structural, morfological and textural changes produced on zinc titanate sorbents for desulfurisation at hot temperatures adding graphite. The sorbents containing ZnO-TiO2+ghaphite were obtained through mecanical half-wet mixing of zinc oxide, titane dioxide and graphite method, drying the intermediate product and finally calcination at 700oC. The samples were characterized from compozitional, structural and morphologycal point of view. The introduction of graphite during sorbent preparation favorized only the formation of zinc titanate type Zn2TiO4 which is most stable and most reactive H2S adsorbent in relation to other forms of zinc titanate: ZnTiO3, Zn2Ti3O8.
The main goal of the present paper was to synthesize the polyvinyl alcohol-SiO2 nanoparticles pol... more The main goal of the present paper was to synthesize the polyvinyl alcohol-SiO2 nanoparticles polymeric membrane by wet-phase inversion method. The efficiency of prepared membranes (without and with SiO2) was investigated using a versatile laboratory electrodialysis system filled with simulated wastewaters that contain zinc ions. All experiments were performed at following conditions: the applied voltage at electrodes of 5, 10 and 15 V, a concentration of zinc ions solution of 2 g L−1, time for each test of 1 h and at room temperature. The demineralization rate, extraction percentage of zinc ions, current efficiency and energy consumption were determined. The polymeric membranes were characterized by Fourier Transforms Infrared Spectroscopy-Attenuated Total Reflection (FTIR-ATR), Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS). The higher value of percentage removal of zinc ions (over 65%) was obtained for the polymeric membrane with SiO2 nanopart...
This work is devoted to examine the effectiveness of the different commercial liquid additives fo... more This work is devoted to examine the effectiveness of the different commercial liquid additives for fish (sweet corn and molasses) on corrosion of mild steel in natural water by different methods (gravimetric and potentiostatic polarization) at room temperature. The corrosion tests were employed to evaluate corrosion rate (CR) and inhibition efficiency (IE %). The maximum inhibition efficiency was obtained for the inhibitor type molasses of 90.00% by gravimetric method for a period of 3 hours and over 31 % by potentiostatic polarization method. It was found that the commercial liquid additives acted as a good inhibitors for the tested environment. Furthermore, the corroded metal was observed by metallographic microscope.
The main objectives of this present paper were to indicate the immobilization of nano zerovalent ... more The main objectives of this present paper were to indicate the immobilization of nano zerovalent iron (nZVI) onto a polymeric material (Purolite A400) and the synthesis of the polymeric material (A400-nZVI) through sodium borohydride (NaBH4) reduction. The obtained polymeric material (A400-nZVI) was used for the nitrate ions removal from a simulated groundwater at different conditions. The polymeric materials, without and with nano zerovalent iron (A400 and A400-nZVI), were characterized trough the FTIR, SEM-EDAX, XRD, and TGA analysis. The analysis confirmed the presence of nano zerovalent iron (nZVI) onto the polymeric material (A400). The adsorption capacity of A400-nZVI, used as polymeric adsorbent, was evaluated by kinetic and thermodynamic studies. The obtained experimental results indicated that the nitrate ions reduction was fitted well by models: pseudo-second-order kinetic and Freundlich isotherm. According to the kinetic model results, a reaction mechanism could exist in ...
This paper reviews the advantages and disadvantages of the use of fertilizers obtained from leath... more This paper reviews the advantages and disadvantages of the use of fertilizers obtained from leather waste, to ameliorate the agricultural soil quality. The use of leather waste (hides and skins) as raw materials to obtain biopolymer-based fertilizers is an excellent example of a circular economy. This allows the recovery of a large quantity of the tanning agent in the case of tanned wastes, as well as the valorization of significant quantities of waste that would be otherwise disposed of by landfilling. The composition of organic biopolymers obtained from leather waste is a rich source of macronutrients (nitrogen, calcium, magnesium, sodium, potassium), and micronutrients (boron, chloride, copper, iron, manganese, molybdenum, nickel and zinc), necessary to improve the composition of agricultural soils, and to remediate the degraded soils. This enhances plant growth ensuring better crops. The nutrient release tests have demonstrated that, by using the biofertilizers with collagen or ...
steps. The presence of oxalic acid into sorbent composition favors the formation by calcinations ... more steps. The presence of oxalic acid into sorbent composition favors the formation by calcinations at 700 o C of zinc titanate stable forms, type Zn 2 TiO 4 , ZnTiO 3 and Zn 6 Al 2 O 9 . This sorbents could be used in high temperatures gas desulfurization processes due to their higher specific surface
This work aims to attain an efficient removal of the organic compounds from residual effluents de... more This work aims to attain an efficient removal of the organic compounds from residual effluents derived from the manufacture of Ranitidine and Loperamide, evaluating the possibilities of removing them by means of photo-assisted techniques. The experimental plan was developed taking in consideration a number of influencing factors: reaction time, catalyst concentration, pH, structure and concentration of the initial chemical compound, type of process applied. The experimental data allowed to comparatively evaluate the degradation of the pharmaceutical effluents and to determine the efficiency of their degradation by means of photo-assisted techniques. The optimal operating conditions were established. The presence of many organic contaminants in wastewaters, surface waters and ground waters may result from contaminated soil, agricultural runoff, industrial wastewaters and leakage of hazardous compounds storage. The presence of these organic compounds in water poses a serious threat to...
CRISTINA ORBECI1, MIRCEA STEFAN2*, ANNETTE MADELENE DANCILA1, MIHAI SILVIU TUDOSIE3,4 1 Universit... more CRISTINA ORBECI1, MIRCEA STEFAN2*, ANNETTE MADELENE DANCILA1, MIHAI SILVIU TUDOSIE3,4 1 University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Gh. Polizu Str., 011061, Bucharest, Romania 2. University Titu Maiorescu, Pharmacy Faculty, Bucharest, 22 Dâmbovnicului Str., 040441, Bucharest, Romania 3 University of Medicine and Pharmacy Carol Davila Bucharest, 8 Eroii Sanitari Blvd., 050474, Bucharest, Romania, 4 Army Center for Medical Research, Bucharest, Romania
The sorbents based on ZnO have good retaining properties for H2S from residual gases. The aim of ... more The sorbents based on ZnO have good retaining properties for H2S from residual gases. The aim of this article is the improvment of sorbent properties through the structural, morfological and textural changes produced on zinc titanate sorbents for desulfurisation at hot temperatures adding graphite. The sorbents containing ZnO-TiO2+ghaphite were obtained through mecanical half-wet mixing of zinc oxide, titane dioxide and graphite method, drying the intermediate product and finally calcination at 700oC. The samples were characterized from compozitional, structural and morphologycal point of view. The introduction of graphite during sorbent preparation favorized only the formation of zinc titanate type Zn2TiO4 which is most stable and most reactive H2S adsorbent in relation to other forms of zinc titanate: ZnTiO3, Zn2Ti3O8.
The main goal of the present paper was to synthesize the polyvinyl alcohol-SiO2 nanoparticles pol... more The main goal of the present paper was to synthesize the polyvinyl alcohol-SiO2 nanoparticles polymeric membrane by wet-phase inversion method. The efficiency of prepared membranes (without and with SiO2) was investigated using a versatile laboratory electrodialysis system filled with simulated wastewaters that contain zinc ions. All experiments were performed at following conditions: the applied voltage at electrodes of 5, 10 and 15 V, a concentration of zinc ions solution of 2 g L−1, time for each test of 1 h and at room temperature. The demineralization rate, extraction percentage of zinc ions, current efficiency and energy consumption were determined. The polymeric membranes were characterized by Fourier Transforms Infrared Spectroscopy-Attenuated Total Reflection (FTIR-ATR), Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS). The higher value of percentage removal of zinc ions (over 65%) was obtained for the polymeric membrane with SiO2 nanopart...
This work is devoted to examine the effectiveness of the different commercial liquid additives fo... more This work is devoted to examine the effectiveness of the different commercial liquid additives for fish (sweet corn and molasses) on corrosion of mild steel in natural water by different methods (gravimetric and potentiostatic polarization) at room temperature. The corrosion tests were employed to evaluate corrosion rate (CR) and inhibition efficiency (IE %). The maximum inhibition efficiency was obtained for the inhibitor type molasses of 90.00% by gravimetric method for a period of 3 hours and over 31 % by potentiostatic polarization method. It was found that the commercial liquid additives acted as a good inhibitors for the tested environment. Furthermore, the corroded metal was observed by metallographic microscope.
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