The results presented in this study highlight the level of total phenolic content (TPC), total fl... more The results presented in this study highlight the level of total phenolic content (TPC), total flavonoid content (TFC) and protein-precipitating capacity (PPC) correlated with the antioxidant capacity of new cider varieties enriched with valuable bio compounds by the addition of blueberry and black carrot extracts. The cider variants were treated with ultrasound (constant frequency of 20 kHz) at 20%, 30% and 40% amplitude (A) for two, five or seven minutes. TPC determination was performed by Folin–Ciocâlteu method and TFC was determined by an aluminum chloride colorimetric method. The antioxidant capacity was determined by ferric-reducing antioxidant power assay (FRAP), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assay and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity. The results showed that the antioxidant performance indicators (FRAP, ABTS and DPPH) were positively correlated with the TPC and TFC of the ultrasound-treated cider variants, sugge...
Drinking water supply is essential for public health, quality of life, sustainable development of... more Drinking water supply is essential for public health, quality of life, sustainable development of economic activity, and environmental protection. In this context, it is important to ensure continuous improvement of all stages of processes to guarantee water quality and safety [1]. The main objectives of the study are: -development of an integrated method and probable risk analysis for a drinking water supply system; -risk assessment of contamination of raw water with nitrate [2].
The Black Sea is one of the world�s most polluted seas. Chemicals such as oil, fertilizers, insec... more The Black Sea is one of the world�s most polluted seas. Chemicals such as oil, fertilizers, insecticides and herbicides which do not decompose in the ground, enter the Black Sea, which becomes a huge repository for these collections mixed fertilizers and poisons. Domestic wastewater significantly contributes to pollution with organic matter and nutrients, and may be responsible for the spreading of diseases. A major component of the synergistic strategies for the environmental protection of the Black Sea consists the proper wastewater treatment. It is necessary to limit the amounts of nutrients such as ammonia, which may be discharged in treated effluents, to prevent excessive growths of algae and aquatic plants that can cause serious harm or even destroy the aesthetic value of water. In the frame of a case study, on the base of Bardenpho process, the simulation of remediation the increasing of ammonia concentration in municipal wastewater effluents was done using the SuperPro Desig...
Modeling, simulation, and optimization play today a crucial role in achieving a full exploitation... more Modeling, simulation, and optimization play today a crucial role in achieving a full exploitation of the bioprocesses potential. SUPERPRO DESIGNER is the most useful and used simulator 1 for technological processes of fine chemical and biochemical products. The main advantages of this simulator consist in a large data base of specific chemical compounds and unit operations, and the evaluation of
Two ways for treatment of waste water resulted from production of sulfur dyes have been investiga... more Two ways for treatment of waste water resulted from production of sulfur dyes have been investigated. Due to the difficulties of theoretical modeling, the processes were simulated by the use of neural networks. In order to identify an optimal solution, on the base of these simulations several non-linear programming problems were solved.
ABSTRACT In this work, the time-optimal control of startup distillation columns by iterative prog... more ABSTRACT In this work, the time-optimal control of startup distillation columns by iterative programming proposed by Woinaroschy [ Ind. Eng. Chem. Res. 2008, 47, 4158.] is extended to the case of nonideal mixtures. The minimization of distillation startup time is performed by iterative dynamic programming employing randomly chosen candidates for admissible control. The control variables are the reflux ratio and/or the reboiler heat duty. The dynamic distillation model proposed by the author in the mentioned work is applied with a preliminary computation of suitable correlation relations for equilibrium constants. An illustrative application for separation of a propene−propane mixture at plant scale is presented. Because of the small relative volatility of this mixture and respective high reflux ratio, the decrease of the reboiler heat consumption corresponding to the minimization of the startup time is significant.
... USED AS COMPOSITE SUPPORT FOR HEAT LOSS CONTROL Tănase Dobre, Marta Stroescu, Oana Cristina P... more ... USED AS COMPOSITE SUPPORT FOR HEAT LOSS CONTROL Tănase Dobre, Marta Stroescu, Oana Cristina Pârvulescu, Anicuţa Stoica, Mihaela Mihalcea "Politehnica" University of Bucharest, Faculty of Applied Chemistry and Material Science, Bucharest, Romania ...
Abstract The washing method for uranium contaminated soils using three different reagents wa s in... more Abstract The washing method for uranium contaminated soils using three different reagents wa s investigated. Experimental data have been obtained for four types of soils, which have been characteri zed in terms of particle size distribution, as well as structu re and chemical composition. Thus, the decontamination degree for each type of soil and reagent respectively has been measured. Subsequently, the decontamination process ha s been simulated using an artificial neural network. Based on this neural network, within the frame of a sensitivity analysis study, and after more than 1,000,000 Monte Carlo simulations it has been established that the most significant parameter (with a contribution to variance of 83.7%) is the soil granulometry. Clay concentration has a significant non-negligible negative influence on the fractional d econtamination degree. This means that higher values of clay concentration correspond to a decreasing of the fractional decontamination degree. A si milar e...
UPB Scientific Bulletin, Series B: Chemistry and Materials Science
A remediation method is presented in order to limit the pollution degree due to mining activities... more A remediation method is presented in order to limit the pollution degree due to mining activities of soils with radioactive uranium. The washing method of polluted soils was investigated.For remediation of radioactive soils the following systems were used : a) water, b) 0.1M sulfuric acid, and c) sodium chloride solution (100 g/L sodium chloride + 10 g /L sodium carbonate). The washing conditions in a system with mechanical agitation werw: mass ratio solid/liquid 1:2, contact time 2 hours, temperature 20 ± 2ºC.Experimental investigations were performed on four types of soils, which have been characterized in terms of particle size distribution, texture and chemical composition.It was established the remediation degree for each type of soil and reagent.
The paper deals with multi-objective cost-environment optimization of bioprocesses. Citric acid i... more The paper deals with multi-objective cost-environment optimization of bioprocesses. Citric acid is one of the most important organic acids produced by microbiological methods. Due to the fact that market is very competitive, the process economics is of paramount importance for survival. The optimization strategy can play an important role in reduction of production costs. The optimization approach consists in coupling a process simulator (i.e. SuperPro Designer) with a high-level numerical computing language (i.e. Matlab) in an optimization loop. The high-level language expands the simulator functionality by offering access to its optimization tools and the possibility of creating complex scripts (e.g. scripts for ecological evaluation of a bioprocess, mathematical models for unitary procedures etc.) which can be linked to the simulator. The aim of this strategy is to realize a complete multi-objective optimization by linking a dynamic model of the bioreactor elaborated in Matlab wi...
The paper presents the dynamic evolution of a divided wall distillation column (DWC) during the s... more The paper presents the dynamic evolution of a divided wall distillation column (DWC) during the startup period and the response to some step signals of main operating parameters: reflux ratio, feed composition and flowrate, side-draw flowrate, and reboiler duty. The investigation is made using a rigorous dynamic model of the DWC and is based on a column design obtained by a trial and error method in the frame of HYSYS process simulator. The main results of the study consist in the fact that the dynamic response of a fully thermally integrated distillation column is not affected by the internal recycle streams, and is similar to the dynamic response of classical columns.
The results presented in this study highlight the level of total phenolic content (TPC), total fl... more The results presented in this study highlight the level of total phenolic content (TPC), total flavonoid content (TFC) and protein-precipitating capacity (PPC) correlated with the antioxidant capacity of new cider varieties enriched with valuable bio compounds by the addition of blueberry and black carrot extracts. The cider variants were treated with ultrasound (constant frequency of 20 kHz) at 20%, 30% and 40% amplitude (A) for two, five or seven minutes. TPC determination was performed by Folin–Ciocâlteu method and TFC was determined by an aluminum chloride colorimetric method. The antioxidant capacity was determined by ferric-reducing antioxidant power assay (FRAP), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assay and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity. The results showed that the antioxidant performance indicators (FRAP, ABTS and DPPH) were positively correlated with the TPC and TFC of the ultrasound-treated cider variants, sugge...
Drinking water supply is essential for public health, quality of life, sustainable development of... more Drinking water supply is essential for public health, quality of life, sustainable development of economic activity, and environmental protection. In this context, it is important to ensure continuous improvement of all stages of processes to guarantee water quality and safety [1]. The main objectives of the study are: -development of an integrated method and probable risk analysis for a drinking water supply system; -risk assessment of contamination of raw water with nitrate [2].
The Black Sea is one of the world�s most polluted seas. Chemicals such as oil, fertilizers, insec... more The Black Sea is one of the world�s most polluted seas. Chemicals such as oil, fertilizers, insecticides and herbicides which do not decompose in the ground, enter the Black Sea, which becomes a huge repository for these collections mixed fertilizers and poisons. Domestic wastewater significantly contributes to pollution with organic matter and nutrients, and may be responsible for the spreading of diseases. A major component of the synergistic strategies for the environmental protection of the Black Sea consists the proper wastewater treatment. It is necessary to limit the amounts of nutrients such as ammonia, which may be discharged in treated effluents, to prevent excessive growths of algae and aquatic plants that can cause serious harm or even destroy the aesthetic value of water. In the frame of a case study, on the base of Bardenpho process, the simulation of remediation the increasing of ammonia concentration in municipal wastewater effluents was done using the SuperPro Desig...
Modeling, simulation, and optimization play today a crucial role in achieving a full exploitation... more Modeling, simulation, and optimization play today a crucial role in achieving a full exploitation of the bioprocesses potential. SUPERPRO DESIGNER is the most useful and used simulator 1 for technological processes of fine chemical and biochemical products. The main advantages of this simulator consist in a large data base of specific chemical compounds and unit operations, and the evaluation of
Two ways for treatment of waste water resulted from production of sulfur dyes have been investiga... more Two ways for treatment of waste water resulted from production of sulfur dyes have been investigated. Due to the difficulties of theoretical modeling, the processes were simulated by the use of neural networks. In order to identify an optimal solution, on the base of these simulations several non-linear programming problems were solved.
ABSTRACT In this work, the time-optimal control of startup distillation columns by iterative prog... more ABSTRACT In this work, the time-optimal control of startup distillation columns by iterative programming proposed by Woinaroschy [ Ind. Eng. Chem. Res. 2008, 47, 4158.] is extended to the case of nonideal mixtures. The minimization of distillation startup time is performed by iterative dynamic programming employing randomly chosen candidates for admissible control. The control variables are the reflux ratio and/or the reboiler heat duty. The dynamic distillation model proposed by the author in the mentioned work is applied with a preliminary computation of suitable correlation relations for equilibrium constants. An illustrative application for separation of a propene−propane mixture at plant scale is presented. Because of the small relative volatility of this mixture and respective high reflux ratio, the decrease of the reboiler heat consumption corresponding to the minimization of the startup time is significant.
... USED AS COMPOSITE SUPPORT FOR HEAT LOSS CONTROL Tănase Dobre, Marta Stroescu, Oana Cristina P... more ... USED AS COMPOSITE SUPPORT FOR HEAT LOSS CONTROL Tănase Dobre, Marta Stroescu, Oana Cristina Pârvulescu, Anicuţa Stoica, Mihaela Mihalcea "Politehnica" University of Bucharest, Faculty of Applied Chemistry and Material Science, Bucharest, Romania ...
Abstract The washing method for uranium contaminated soils using three different reagents wa s in... more Abstract The washing method for uranium contaminated soils using three different reagents wa s investigated. Experimental data have been obtained for four types of soils, which have been characteri zed in terms of particle size distribution, as well as structu re and chemical composition. Thus, the decontamination degree for each type of soil and reagent respectively has been measured. Subsequently, the decontamination process ha s been simulated using an artificial neural network. Based on this neural network, within the frame of a sensitivity analysis study, and after more than 1,000,000 Monte Carlo simulations it has been established that the most significant parameter (with a contribution to variance of 83.7%) is the soil granulometry. Clay concentration has a significant non-negligible negative influence on the fractional d econtamination degree. This means that higher values of clay concentration correspond to a decreasing of the fractional decontamination degree. A si milar e...
UPB Scientific Bulletin, Series B: Chemistry and Materials Science
A remediation method is presented in order to limit the pollution degree due to mining activities... more A remediation method is presented in order to limit the pollution degree due to mining activities of soils with radioactive uranium. The washing method of polluted soils was investigated.For remediation of radioactive soils the following systems were used : a) water, b) 0.1M sulfuric acid, and c) sodium chloride solution (100 g/L sodium chloride + 10 g /L sodium carbonate). The washing conditions in a system with mechanical agitation werw: mass ratio solid/liquid 1:2, contact time 2 hours, temperature 20 ± 2ºC.Experimental investigations were performed on four types of soils, which have been characterized in terms of particle size distribution, texture and chemical composition.It was established the remediation degree for each type of soil and reagent.
The paper deals with multi-objective cost-environment optimization of bioprocesses. Citric acid i... more The paper deals with multi-objective cost-environment optimization of bioprocesses. Citric acid is one of the most important organic acids produced by microbiological methods. Due to the fact that market is very competitive, the process economics is of paramount importance for survival. The optimization strategy can play an important role in reduction of production costs. The optimization approach consists in coupling a process simulator (i.e. SuperPro Designer) with a high-level numerical computing language (i.e. Matlab) in an optimization loop. The high-level language expands the simulator functionality by offering access to its optimization tools and the possibility of creating complex scripts (e.g. scripts for ecological evaluation of a bioprocess, mathematical models for unitary procedures etc.) which can be linked to the simulator. The aim of this strategy is to realize a complete multi-objective optimization by linking a dynamic model of the bioreactor elaborated in Matlab wi...
The paper presents the dynamic evolution of a divided wall distillation column (DWC) during the s... more The paper presents the dynamic evolution of a divided wall distillation column (DWC) during the startup period and the response to some step signals of main operating parameters: reflux ratio, feed composition and flowrate, side-draw flowrate, and reboiler duty. The investigation is made using a rigorous dynamic model of the DWC and is based on a column design obtained by a trial and error method in the frame of HYSYS process simulator. The main results of the study consist in the fact that the dynamic response of a fully thermally integrated distillation column is not affected by the internal recycle streams, and is similar to the dynamic response of classical columns.
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Papers by Alexandru Woinaroschy