Wyniki wyszukiwania - BazTech

1

Studies on the effect of parameters controlling an adsorption process for anionic dye removal by using commercial activated carbon

Konicki Wojciech, Bojanowska Milena, Bąkowski Michał

Zeszyty Naukowe Politechniki Morskiej w Szczecinie

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2025

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nr 82 (154)

93--104

EN

In the present study, commercial activated carbon (CWZ-14) is tested for the removal of the anionic azodye Direct Red 23 (DR23) from aqueous solutions. The effect of parameters such as initial dye concentration (10‒50 mg/L), pH (3.4‒11.4), and temperature (20‒60 °C) on the adsorption process is studied. The structure and morphology of the commercial activated carbon, as the quality attributes of the adsorbents, are characterized by scanning electron microscope (SEM), N2 adsorption/desorption isotherms (BET), and Fourier transform infrared spectroscope (FTIR). To understand the adsorption behavior of DR23 onto CWZ-14, the experimental kinetic data are analyzed using the pseudo-first-order and pseudo-second-order models. The kinetics of the adsorption of the dye followed the pseudo-second-order kinetics. The isotherms of adsorption data are analyzed via the Langmuir and the Freundlich models. It is observed that the experimental data effectively fits the Langmuir model. The maximum adsorption capacity calculated from the Langmuir isotherm, qm, is 104.2 mg/g. The experimental findings showed that the adsorption is a pH-dependent process, with the maximum adsorption capacity occurring at a pH of 7. Thermodynamic parameters, such as changes in standard free energy (∆G°), enthalpy (∆H°), and entropy (∆S°), are also evaluated. The thermodynamic analysis shows that the adsorption process is endothermic, spontaneous, and a physisorption process.

2

Zastosowanie sztucznej inteligencji do estymacji parametrów fizycznych gazu ziemnego z dodatkiem wodoru

Łaciak Mariusz, Panek Wojciech

Przemysł Chemiczny

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2025

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T. 104, nr 5

560--565

PL

Przedstawiono możliwość wykorzystania wybranych modeli uczenia maszynowego do estymacji parametrów fizycznych gazu ziemnego, opisujących jego jakość, na podstawie której następuje rozliczanie się z odbiorcami. Obecnie często stosowane na szeroką skalę metody wykorzystują w tym celu założony skład gazu ziemnego oraz równania wirialne. Są przez to opatrzone pewną niedokładnością. Prezentowane rozwiązanie może być alternatywą. Metodologia zakładała użycie ograniczonej liczby danych wejściowych, które są zbierane na stacjach redukcyjno-pomiarowych oraz wykorzystywała zmiany temperatury gazu w wyniku efektu Joule'a i Thompsona, zachodzącego podczas redukcji ciśnienia. Modele stworzone na danych syntetycznych pokazują, że estymacja takich parametrów, jak współczynnik ściśliwości Z oraz gęstość gazu może być bardzo dokładna.

EN

The possibility of using selected machine learning models (multiple regression - MLR, random forest - RF, artificial neural network - ANN) to estimate phys. parameters (compressibility coeff. Z, d. of the gas mixt., heat of combustion of the mixt., H2 content in the mixt.) of natural gas describing its qual. was presented. The methodology assumed the use of a limited amt. of input data, which were collected at redn. and measurement stations, and used changes in gas temp. as a result of the Joule-Thompson effect, occurring during pressure redn. Models built on synthetic data show that the estimation of parameters such as the compressibility factor Z and gas d. can be very accurate.

3

Adsorption of resorcinol onto synthetic calcium phosphate compounds: Kinetic, isotherm, and thermodynamic studies

El Bakri Abdellatif, Ferraa Nouhaila, Lachheb Abdelah, Bennani-Ziatini Mounia

Ecological Engineering & Environmental Technology

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2025

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Vol. 26, iss. 1

257--271

EN

Using batch adsorption methods, this work examines the adsorption behavior of resorcinol onto two artificial calcium phosphate compounds, tricalcium phosphate apatite (PTCa) and octocalcium phosphate apatite (OCPa). The study is to assess these materials’ adsorption capacities and investigate the impacts of important parameters like pH, temperature, starting concentration, and adsorbent dosage. When both the Freundlich and Langmuir isotherm models were used, the Langmuir model fit the data better, suggesting monolayer adsorption. PTCa and OCPa were shown to have maximal adsorption capabilities of 13.27 mg/g and 5.05 mg/g, respectively. According to kinetic studies, the adsorption process exhibits pseudo-second-order kinetics, which points to chemisorption. The adsorption is exothermic and spontaneous, driven by physical interactions including van der Waals forces and hydrogen bonds, according to thermodynamic considerations. The study comes to the conclusion that PTCa and OCPa, with their high adsorption capacities and advantageous thermodynamic and kinetic properties, are attractive materials for the elimination of resorcinol from aqueous solutions.

4

Adsorption behaviors of As(III) on bentonite, diatomite, and hematite : implications for scientific remediation of arsenite contamination in soil

Fu Kaibin, Tang Pengcheng, Zhang Wei, Chen Shu, Tao Gang, Liu Junfei

Physicochemical Problems of Mineral Processing

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2024

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Vol. 60, iss. 4

art. no. 192381

EN

Comprehensive understanding of As(III) sorption on natural minerals in contaminated soils is important for scientific decision making in remediation. In this study, the characteristics of As(III) adsorption on three minerals with different crystal structures and chemical compositions (bentonite; diatomite; and hematite) were investigated. The adsorption kinetics and thermodynamics were established. Surface complexation modeling was performed using X-ray diffraction spectroscopy, fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results showed that the pH value had a more significant effect on As(III) adsorption on hematite than on bentonite and diatomite, and As(III) was efficiently adsorbed by hematite at pH 7.0. The pseudo-first-order model provided an excellent fit to the As(III) adsorption on bentonite and hematite; the diffusion of ions or groups played an important role in the adsorption of As(III) on bentonite and hematite. The adsorption of As(III) on diatomite could be fitted with pseudo-first-order and pseudo-second order kinetic equations, as their regression coefficients were equal (R2=0.999). It was inferred that the adsorption of As(III) on diatomite occurred through solution diffusion and surface chemisorption. The As(III) adsorption on bentonite and diatomite was mainly physical and multilayer adsorption, whereas the As(III) adsorption on hematite was mainly chemical and monolayer absorption. The As(III) adsorption on hematite was divided into two stages: fast and slow. At first, the inner monodentate complex (such as ☰Fe-OAs3H-) formed at a high rate, and with the increase in the coverage of As(III) on the surface of iron oxide, the monodentate complex was slowly converted to the bidentate complex. These results verify the possibility of using bentonite, diatomite, and hematite as alternative materials for the remediation of As(III)-contaminated soils, and also indicate that bentonite and diatomite are suitable for the remediation of low As(III)-contaminated soils, while hematite is suitable for the decontamination of high As(III) polluted soil. Selecting suitable remediation materials according to arsenic contamination level is the key to soil scientific remediation.

5

The Removal of Phenol Through Adsorption onto Synthetic Calcium Phosphates – A Study Encompassing Analyses of Kinetics and Thermodynamics

El Bakri Abdellatif, El Boujaady Hicham, Ferraa Nouhaila, Bennani-Ziatni Mounia

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 4

301--315

EN

The characteristics and suitability of hydroxyapatite (HAP), tricalcium apatite phosphate (PTCa), and octocalcium apatite phosphate (OCPa), which possess similar attributes to those of an ideal adsorbent, were investigated to determine their efficacy in phenol removal. The aim of this paper is to assess the adsorption behavior of phenol on phosphates powders synthesized by the co-precipitation method at ambient temperature. Furthermore, the impact of initial phenol quantities and thermal conditions on the adsorption process was explored. X-ray diffraction analysis revealed the formation of HAP, PTCa, and OCPa structures under room temperature conditions. The sample morphologies were subjected to scrutiny utilizing MEB together with X-ray analysis. Additionally, chemical analysis revealed that Ca/P = 1.6, 1.5, and 1.33 for HAP, PTCa, and OCPa, respectively. The synthesized powders exhibited adsorption abilities of 2.86, 2.74, and 2.52 mg/g for HAP, PTCa, and OCPa, respectively, and reached equilibrium in approximately 80 minutes. The study revealed that the experimental data are appropriately represented by the Langmuir and Freundlich adsorption equations for HAP and PTCa, and Langmuir model in the case of OCPa, as well as by the pseudo-first-order and pseudo-second-order adsorption kinetics. Thermodynamic evaluations, including calculations of ΔG°, ΔH°, and ΔS°, were performed. The results indicated that the adsorption mechanisms exhibited physical characteristics, were thermally absorbing in the case of HAP and exothermic for the other two phosphates, PTCa and OCPa, and occurred spontaneously.

6

Influence of thermodynamics on the development of technology and science

Mikielewicz Jarosław, Mikielewicz Dariusz

Archives of Thermodynamics

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2024

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Vol. 45, no. 2

51--61

EN

Understanding thermodynamics can be challenging due to its dealing with abstract concepts such as entropy and energy transfer. This paper outlines six principles of thermodynamics, whose application necessitates a coherent overarching philosophy. The problems studied often entail complex mathematical equations, relying on a strong foundation in physics and mathematics. Moreover, comprehending thermodynamics requires a shift in thinking, focusing on macroscopic properties of matter rather than microscopic interactions, as in other branches of physics. Thermodynamics also introduces a new philosophy in science – the concept of irreversible phenomena, rooted in the heat flow theory, which is currently being extrapolated to other scientific domains. Notably, this involves extending the concept of work to systems performing various types of work beyond volume change.

7

Study on Mn Volatilization Behavior During Vacuum Melting of High-manganese Steel

Lei Jialiu, Fu Yongjun, Xiong Li

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 2

110--116

EN

As an alloying element in steel, manganese can considerably enhance the mechanical properties of structural steel. However, the Mn volatilisation loss in vacuum melting is severe because of the high saturated vapour pressure, resulting in an unstable Mn yield and Mn content fluctuation. Therefore, a systematic study of the volatilisation behaviour of Mn in vacuum melting is required to obtain a suitable Mn control process to achieve precise control of Mn composition, thereby providing a theoretical basis for industrial melting of high-Mn steel. In order to explore the Mn volatilization behavior, the volatilization thermodynamics and volatilisation rate of Mn, as well as the influence factors are discussed in this study. The results shows that Mn is extremely volatilised into the vapour phase under vacuum, the equilibrium partial pressure is closely related to Mn content and temperature. With an increase in the Mn content, a higher C content has a more obvious inhibitory effect on the equilibrium partial pressure of Mn. The maximum theoretical volatilisation rate of Mn shows a linear upward trend with an increase in Mn content. However, a higher C content has a more obvious effect on the reduction of the maximum theoretical volatilisation rate with the increase of Mn content. This study provides an improved understanding of Mn volatilisation behaviour as well as a theoretical foundation for consistent Mn yield control during the vacuum melting process of high-Mn steel.

8

The influence of activity coefficient and equilibrium constant models on the speciation of aqueous solutions of H2SO4–MgSO4–Al2(SO4)3 at 235 and 250 °C

Dickson Okechukwu Vincent, Deleau Thomas, Coquelet Christophe, Espitalier Fabienne, Lombart Julien, Tardy Antoine

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 5

art. no. 167497

EN

Supersaturation occurs in many industrial applications promoting reactive crystallisation between the reactants to form solutes. These solutes accumulate during precipitation, leading to the formation of scales on the inner walls of the reactor and particularly around the stirrer, causing modifications in the hydrodynamics. This encrustation is responsible for process shutdowns in continuous crystallisation processes. Supersaturation control is essential for industrial processes aimed at controlling or inhibiting the formation of these solids. Knowledge of mineral solubility and chemical speciation is required to account for the composition of the complexes in the system in their various solid or aqueous forms. This speciation is obtained by considering the thermodynamic equilibrium constants of the dissociation/complexation reactions involved in the system, the pressure, and the activity coefficients of the chemical species in their molecular or electrolyte form. From these thermodynamic quantities and the state of the system, we can predict the direction of the reaction. This study highlights the risk of the lack of experimental information on equilibrium constants at high temperatures and moderate pressures. Our goal is to evaluate the accuracy of existing models classically used to predict the equilibrium constant in such very hard conditions encountered in hydrometallurgical processes. Furthermore, we demonstrate the influences of equilibrium constants estimation and activity coefficient models on the speciation of H2SO4–Al2(SO4)3–MgSO4 systems, forming hydronium alunite and kieserite in the laterite liquor of hydrometallurgical processes.

9

Studies of Physicochemical Bases and Optimization of Environmentally Safe Technology of Lead Production Waste Recycling

Tileuberdi Ayaulym, Misiuchenka Viktoryia, Tleuov Alibek, Shingisbayeva Zhadra, Anarbayev Abibulla, Ulbekova Mariyam, Khussanov Zhakhongir, Tashenov Yerkebulan, Tleuova Saltanat

Journal of Ecological Engineering

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2023

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Vol. 24, nr 9

293--301

EN

Physicochemical research of peculiarities of technogenic metallurgical wastes and mathematical optimization of ecologically safe technology of their processing are of great practical importance for solving ecological problems of the region. The aim and the main direction of the research are connected with the study of physical and chemical bases of the organization of the technology of waste recycling with separation of valuable metals in the form of their chlorides and simultaneous production of agloporite. Peculiarities of phase and mineralogical composition of raw materials and chloride roasting products were studied by means of modern devices: Q-1500D derivatograph, X-ray diffractometer Panalytical X’PERT, scanning electron microscope JSM-6490LV JOEL. Studies have shown that solid metallurgical waste is characterized by the presence of non-ferrous metals Fe, Ti, Pb, Cu, Zn, and the microstructure is characterized by the presence of silicate, aluminosilicate and ferrite minerals. Using the method of mathematical design with the application of Stuyudent’s criteria and Fisher’s equation, the adequacy of the obtained roasting results was established, providing the degree of extraction up to 86–98%, at the temperature of 1100 °С. The microstructure of the roasted products of the waste mixture with clay binder and calcium chloride is characterized by the predominance of calcium ferrites, silicon ferrites and aluminosilicate minerals. The obtained results of the study of the peculiarities of the physical and chemical bases and the optimization of the safe technology are of practical importance for the solution of the ecological problem of utilization of technogenic wastes with obtaining of valuable products.

10

Removal of Dyes by Adsorption Process Using Date Pits as Material Environmentally Friendly

Adachi Abderrazzak, El Ouadrhiri Faiçal, El Manssouri Ibtissam, Moussaoui Fatima, El Bourachdi Soukaina, Lahkimi Amal

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 8

181--193

EN

This study is based on the use of a natural material in the adsorption process to remove organic pollutants. The objective is to assess its effectiveness in adsorbing the organic pollutant MB from an aqueous solution, while operating in an open system. The DP bioadsorbent was characterized using FTIR and SEM. To determine their effect on adsorption efficiency, a number of variables were examined, including contact time, concentration of pollutant MB, adsorbent mass, pH, temperature, and adsorbent particle size. The effect of these variables on adsorption efficiency shows that a removal rate of 92.66% is achieved under optimum conditions, including a contact time of 35 minutes, a concentration of pollutant MB of 22.5 mg·l-1, an adsorbent mass (mDP) of 1.1 g·l-1 and a solution pH of 5.6. In addition, a progressive decrease in adsorption efficiency is observed with increasing temperature and adsorbent mass. On the other hand, this efficiency increases with increasing a concentration of pollutant MB. Three popular models, the Freundlich, Langmuir, and Dubin-Radushkevich models, have been used to examine the adsorption isotherms of the MB dye on DP. With a correlation factor of 0.98, it was discovered that MB adsorption monitored by the Freundlich isotherm. The Langmuir and Dubinin-Radushkevich models, however, do not adequately describe the data. The kinetic results were studied using the pseudo-first-order and pseudo-second-order equations, and show that MB dye adsorption on DP (adsorbent) follows the pseudo-second-order model. Also estimated were thermodynamic parameters such as (ΔH°), (ΔS°), (ΔG°), enthalpy, entropy, Gibbs free energy respectively to anticipate the character of adsorption. The results indicate that the adsorption process of MB on the bioadsorbent is exothermic. The results derived from the ΔG° values lead to the conclusion that the adsorption of MB occurs spontaneously.

11

Thermodynamics-based measurement of the velocity of high-temperature smoke

Wang Haoyu

Archives of Thermodynamics

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2023

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Vol. 44, no. 1

23--36

EN

In view of the high cost and difficulty of ensuring the accuracy in the measurement of fire smoke velocity, the measurement system developed using platinum resistance temperature detectors and an 8-bit microcontroller, is used to realize the fast measurement of high-temperature fire smoke velocity. The system is based on the thermodynamic method and adopts the Kalman filter algorithm to process the measurement data, so as to eliminate noise and interference, and reduce measurement error. The experimental results show that the Kalman filter algorithm can effectively improve the measurement accuracy of fire smoke velocity. It is also shown that the system has high measurement accuracy, short reaction time, low cost, and is characterized by high performance in the measurement of high-temperature smoke velocity in experiments and practice.

12

Thermodynamic Insight into the Equilibrium Component Prediction in the Al-Ti-Ca-Oxide System

Song Yu-lai, Dou Zhi-he, Zhang Ting-an, Cheng Chu, Fang Hui, Ban Chao-Lei

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 4

1319--1326

EN

The prediction of equilibrium components for chemical reactions is a considerable section in the metallurgical industry. According to the ion and molecule coexistence theory (IMCT), a modified mass action concentration model based on a thermodynamic database is proposed in this paper, which complys with the law of mass conservation and can be applied in the batching process for Al-Ti-Ca-oxide system that originates from SHS (Self-propagating High-temperature Synthesis) metallurgy. The trend for slag and alloy component under different batching conditions are in good agreement with experiment, while the difference between the theoretical calculation and experiment can be attributed to the deviation from the thermodynamic equilibrium. The modified mass action concentration model with melts and slag can be used to predict the composition and content of the system when equilibrium is achieved at a certain temperature under a specific material ratio, which is conducive to reducing the cost of the experiment and predicting the operability of the actual process. Moreover, it is believed that this thermodynamic insight may has certain application prospects in these metallurgical procedure based on the equilibrium process.

13

The behaviour of tannic acid adsorption on fluorite surface: isotherm, kinetic and thermodynamic studies

Tangarfa Mariam, Semlali Aouragh Hassan Naoul

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 1

77--87

EN

Fluorite is an important mineral to produce hydrofluoric acid. As fluorite resources contain calcite as a gangue mineral, the separation between these two calcium containing minerals is difficult. Tannic acid is the most commonly used reagent as a depressant to separate fluorite from calcite by flotation. To enhance this separation, it is so primordial to understand tannic acid physicochemical reactivity via these minerals. Therefore, the aim of this work is to investigate the mechanism of tannic acid adsorption on the fluorite surface by experimental study using isotherm, kinetic and thermodynamic. Adsorption isotherm modelling results showed that the adsorption process is well described by Sips model. On the other hand, the kinetic and thermodynamic require firstly the adsorption study as a function of three main reactional parameters including initial tannic acid concentration, solution pH and temperature. This study showed that acidic pH as well as initial tannic acid concentration increase and temperature decrease promote the studied adsorption. These finding were then exploited to determine the adsorption mechanism by pseudo n order kinetic model adjustment to experimental kinetic data using nonlinear regression method. Obtained high correlation coefficient and low mean absolute error at 95 % confidence level showed good agreement of experimental kinetic data with the tested model. These results revealed that the mechanism of tannic acid adsorption onto fluorite was attributed to a chemical reaction. In addition, the thermodynamic study showed that the studied adsorption process was exothermic.

14

Evaluation of CO2 adsorption capacity with a nano-CaO synthesized by chemical combustion/ball milling

Granados-Correa Francisco, Jiménez-Reyes Melania

Materials Science Poland

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2022

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Vol. 40, No. 2

257--269

EN

The adsorption of CO2 on a nano-calcium oxide (nano-CaO) adsorbent was investigated under different conditions of temperature and supply pressure, considering kinetic, isotherm, and thermodynamic parameters. CaO is a crystalline material with a high surface area and nanosized particles with high porosity, which showed rapid initial CO2 adsorption rates in the moderate temperature range studied. The adsorption was well described by the pseudo-second-order and the intraparticle diffusion kinetic models. The Langmuir isotherm model fitted the experimental data well, indicating a monolayer-type process. The thermodynamic parameters revealed that the CO2/nano-CaO adsorption was endothermic, not spontaneous, and proceeded via physical and chemical processes. The activation energy value confirmed that the mechanism involved is a chemical process. In addition, the nano-CaO adsorbent could be regenerated five times without any significant loss of performance or properties. All the obtained results reveal that this porous nanoadsorbent has huge potential to be applied for CO2-capture technologies on a large scale.

15

Fundamental study of the photocatalytic reduction of CO2: A short review of thermodynamics, kinetics and mechanisms

Gandhi Romil, Moses Aashish, Baral Saroj Sundar

Chemical and Process Engineering

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2022

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Vol. 43, nr 2

223-–228

EN

On the off chance that methods which reduce the global CO2 content are unavailable and inefficient, the increasing CO2 levels will lead to a synchronized rise in temperature across the world. The conversion of this abundant CO2 into hydrocarbons like CH4, CH3OH, CO, HCOOH and hydrogen fuel using different techniques and their use for power could assist with the world’s energy deficiency and solve the CO2 reduction-energy nexus. In this study, photocatalytic CO2 conversion by sunlight will be of primary focus since this bears a resemblance with the regular photosynthesis phenomenon. This work also portrays the writings that have narrated the development of mixtures of two or more carbon ions (C2 ̧) within the photocatalytic reduction of CO2. This paper thus comprises the energy required for CO2 photoreduction, the kinetics mechanisms and thermodynamics requirements. The reaction of CO with water and the hydrogenation of CO2 are covered to understand the gap of Gibb’s free energy between both of the reactions. Likewise, the summary of different metal-based co-catalysts, metal-free co-catalysts and their selectivity towards CO2 reduction by photocatalysis and reduction of CO2 into various hydrocarbons, fuel and materials have also been examined.

16

Thermodynamics and Kinetics Analysis on Carbothermic Reduction of Calcined Magnesite in Vacuum

Tang Qifeng, Ao Jinqing, Peng Biyou, Guo Biao, Yang Tao

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 3

1021--1026

EN

The carbothermic reduction of calcined magnesite in vacuum was studied. By thermodynamic analysis, the starting temperature of reduction reaction dropped from 2173 K to 1523 K when system pressure dropped from 1 atmosphere to 100 Pa. The experiments were carried out at different conditions under 10~100 Pa and the experimental results shown that the reduction extent of MgO improved by increasing the reaction temperature and time, the pellet forming pressure as well as adding fluoride as catalyst. The rate-determining step of carbothermic reduction process was gas diffusion with the apparent activation energy of 241.19~278.56 kJ/mol.

17

The kinetics, thermodynamics and equilibrium study of nickel and lead uptake using corn residues as adsorbent

Tejada-Tovar Candelaria, Villabona-Ortíz Ángel, Gonzalez-Delgado Angel Darío

Journal of Water and Land Development

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2021

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no. 48

197--204

EN

Agricultural residues rich in lignocellulosic biomass are low-cost and sustainable adsorbents widely used in water treatment. In the present research, thermodynamics, kinetics, and equilibrium of nickel(II) and lead(II) ion biosorption were studied using a corncob (Zea mays). The experiments were performed in a batch system evaluating the effect of temperature and dose of adsorbent. Langmuir and Freundlich isotherms were used to study the equilibrium. Thermodynamic and kinetic parameters were determined using kinetic models (pseudo-first order, pseudo-second order, Elovich). Biosorbent characteristics were studied by Fourier-transform infrared spectroscopy, Scanning Electron Microscopy and Energy-dispersive X-ray spectroscopy. It was found that the hydroxyl, carboxyl, and phenolic groups are the major contributors to the removal process. Besides, Pb(II) ions form micro-complexes on the surface of the biomaterial while Ni(II) ions form bonds with active centers. It was found that the highest Ni(II) removal yields were achieved at 0.02 g of adsorbent and 70°C, while the highest Pb(II) removal yields were achieved at 0.003 g and 55°C. A maximum Ni(II) adsorption capacity of 3.52 mg∙g–1 (86%) and 13.32 mg∙g–1 (94.3%) for Pb(II) was obtained in 250 and 330 min, respectively. Pseudo-first order and pseudo-second order models best fit experimental data, and Langmuir and Freundlich models well describe the isotherm of the process. Thermodynamic parameters (ΔH0, ΔG0, ΔS0) suggest that the adsorption process of both cations is exothermic, irreversible, and not spontaneous.

18

Zrównoważone budownictwo; w poszukiwaniu przemiany prometejskiej

Czarnecki Lech, Deja Jan

Inżynieria i Budownictwo

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2021

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R. 77, nr 7

300--308

PL

Przedstawiono krytyczną analizę znaczenia elementów termodynamicznych w kształtowaniu zrównoważonego rozwoju w budownictwie. Przedstawiono współczesne wyzwania stojące przed wykorzystywanymi masowo materiałami, takimi jak beton i cement. Pokazano, jak na przestrzeni lat następuje rozwój betonu: nie przez substytucję, a przez modyfikacje. Na podstawie rzeczywistych danych z polskiego przemysłu cementowego pokazano, jak zmiany technologiczne, ograniczając zapotrzebowanie na energię cieplną w produkcji klinkieru portlandzkiego, próbują przesunąć barierę termodynamiczną całego procesu. Przedstawiono także krytyczne opinie na temat możliwości dokonania takich prometejskich zmian, wskazując jednak, że w wielu publikacjach pojawiają się stwierdzenia, że tylko te zmiany są zdolne wygenerować skokową zmianę w rozwoju ludzkości.

EN

This contribution is a critical analysis of the role of thermodynamic factors in shaping the sustainable development in building engineering. The actual challenges are presented on the example of concrete and cement – the commonly used materials. It has been found that the development of concrete technology occurs by modification, not by substitution. Taking into account the data supplied by Polish cement industry it is possible to reveal that the changes in the field of technology, aimed in the reduction of energy consumption for cement clinker production, replace the thermodynamic barrier of the process as a whole. In this contribution, the critical opinions relating to the possibility of Promethean evolution mentioned above are presented too. However, in many reports there is an idea that only these changes could generate a step change in the development of humanity.

19

Biosorption of Pb(II) by the resistant Enterobacter sp. : Investigated by kinetics, equilibrium and thermodynamics

Liu Lei, Xia Mengya, Hao Jianwen, Xu Haoxi, Song Wencheng

Archives of Environmental Protection

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2021

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Vol. 47, no. 3

28--36

EN

The Pb(II)-resistant bacterium was isolated from heavy metal-contained soils and used as a biosorbent to remove Pb(II). The strain was identified as Enterobacter sp. based on the 16S rRNA sequence analysis. The effect of biosorption properties (pH value, Pb(II) concentration, bacterial concentration and temperature) on Pb(II) was investigated by batch experiments. Results of FTIR and XPS showed that the biosorption process mainly involved some oxygen-containing groups (-OH and -COOH groups). The experimental results and equilibrium data were fitted by pseudo-second-order kinetic model and Langmuir model, respectively. The experimental biosorption isotherms fitted the Langmuir model, and the maximum biosorption capacity was 40.75 mg/g at 298 K. The calculated ΔGо and ΔHо were –4.06 and 14.91(kJ/mol), respectively, which indicated that biosorption process was spontaneous and endothermic. Results show that Enterobacter sp. will be an efficient biosorbent for Pb(II) removal.

20

Jak dobierać parametry obiegu chłodniczego?

Kamecki Piotr

Technika Chłodnicza i Klimatyzacyjna

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2020

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nr 1-2

25--26

PL

Wydaje się, że temat jest banalnie prosty, że użytkownicy mają odpowiednią wiedzę, aby swoje instalacje chłodnicze prowadzić optymalnie z niskim zużyciem energii. Jednak jeśli przyjrzymy się jak naprawdę one pracują to nieraz musimy przyznać, że do optymalnych warunków jest jeszcze bardzo daleko. Autor od kilkunastu lat zajmuje się m. in. działalnością szkoleniową i swoje wnioski wysnuwa także z rozmów z kursantami, którzy stosunkowo często po raz pierwszy słyszą jak dobierać parametry pracy swoich sprężarek. Warto zauważyć, że prawidłowe parametry muszą być określone już na etapie projektowania instalacji.

EN

At the first glance the question is very simple and it seems that the users have enough knowledge to operate their refrigerating plants with a low energy consumption. But in fact the working parameters are very often far from the optimal values. The author presents his conclusions based on his long training activity and questions of the participants. It is worth to notice that correct working parameters of any refrigeration system have to be determined already in the designing process.