Pub Date : 2023-02-14DOI: 10.2174/2405520416666230214100228
Q. Zhai, Xiao-dong Li
In order to explore the adsorption effect of tea on heavy metal ions in industrial waste water, Ag+ is used as the research object in this paper. In recent years, heavy metal pollution in water has seriously affected human health and the stability of ecological environment. In order to reduce the harmfulness of heavy metals, various countries have issued a variety of control standards for heavy metals in water, there are still great restrictions in the prevention and control technology and level of heavy metal pollution. Therefore, how to effectively treat the heavy metal pollution in water has become a hot topic in the field of water pollution management. The optimized conditions of the adsorption are obtained. Properties of the thermodynamics, adsorption kinetics, adsorption isotherm are obtained. In order to determine the best adsorption conditions for Ag+, the influence of factors such as pH value, initial concentration of Ag+, tea dosage, contact time and adsorption temperature on the adsorption effect of tea is studied. The thermodynamics, adsorption kinetics, adsorption isotherm are studied. The results showed that when temperature is 25C, the pH of solution was 3.5, the amount of adsorbent was 2.5g/L, the initial concentration of Ag+ was 125μg/Land the contact time was 30min, the adsorption rate was the highest, reaching 98.11%. The thermodynamic study of adsorption showed that at room temperature and above (298.15 - 318.15K), ΔG0 < 0, indicating that the adsorption process can be spontaneous. The value of ΔGo in this study is between -20 and -80 kJ/mol, indicating that this is a physicochemical adsorption process. ΔHo = -80.111 kJ/mol < 0, indicating that the adsorption process of Ag+ is exothermic. ΔSo = -188.977 J/(mol·K)<0, indicating that the adsorption is a process of entropy reduction. The adsorption kinetics study showed that the adsorption equilibrium capacity of different concentration had a large gap with the experimental results, and the correlation coefficient was small by fitting the quasi-first-order kinetic equation and combining with the experimental measurements.When the quasi-second-order kinetic equation was used, the calculated values of the equilibrium adsorption capacity of each concentration were basically close to the experimental measured values, and the correlation coefficient was large, so the kinetics of the adsorption system of Ag+ by tea conformed to the quasi-second-order kinetic equation. The adsorption isotherm of this adsorption process is accorded with Freundlich model and belonged to a heterogeneous adsorption. Tea is a good adsorbent and has a potential for adsorption of Ag+ . No
{"title":"Study on Adsorption of Ag+ by Waste Tea: Adsorption Kinetics, Thermodynamics, Isotherm Properties","authors":"Q. Zhai, Xiao-dong Li","doi":"10.2174/2405520416666230214100228","DOIUrl":"https://doi.org/10.2174/2405520416666230214100228","url":null,"abstract":"\u0000\u0000In order to explore the adsorption effect of tea on heavy metal ions in industrial waste water, Ag+ is used as the research object in this paper.\u0000\u0000\u0000\u0000In recent years, heavy metal pollution in water has seriously affected human health and the stability of ecological environment. In order to reduce the harmfulness of heavy metals, various countries have issued a variety of control standards for heavy metals in water, there are still great restrictions in the prevention and control technology and level of heavy metal pollution. Therefore, how to effectively treat the heavy metal pollution in water has become a hot topic in the field of water pollution management.\u0000\u0000\u0000\u0000The optimized conditions of the adsorption are obtained. Properties of the thermodynamics, adsorption kinetics, adsorption isotherm are obtained.\u0000\u0000\u0000\u0000In order to determine the best adsorption conditions for Ag+, the influence of factors such as pH value, initial concentration of Ag+, tea dosage, contact time and adsorption temperature on the adsorption effect of tea is studied. The thermodynamics, adsorption kinetics, adsorption isotherm are studied.\u0000\u0000\u0000\u0000The results showed that when temperature is 25C, the pH of solution was 3.5, the amount of adsorbent was 2.5g/L, the initial \u0000concentration of Ag+ was 125μg/Land the contact time was 30min, the adsorption rate was the highest, reaching 98.11%. The thermodynamic \u0000study of adsorption showed that at room temperature and above (298.15 - 318.15K), ΔG0 < 0, indicating that the adsorption process can \u0000be spontaneous. The value of ΔGo in this study is between -20 and -80 kJ/mol, indicating that this is a physicochemical adsorption \u0000process. ΔHo = -80.111 kJ/mol < 0, indicating that the adsorption process of Ag+ is exothermic. ΔSo = -188.977 J/(mol·K)<0, \u0000indicating that the adsorption is a process of entropy reduction. The adsorption kinetics study showed that the adsorption equilibrium \u0000capacity of different concentration had a large gap with the experimental results, and the correlation coefficient was small by fitting \u0000the quasi-first-order kinetic equation and combining with the experimental measurements.When the quasi-second-order kinetic equation was \u0000used, the calculated values of the equilibrium adsorption capacity of each concentration were basically close to the experimental measured \u0000values, and the correlation coefficient was large, so the kinetics of the adsorption system of Ag+ by tea conformed to the \u0000quasi-second-order kinetic equation. The adsorption isotherm of this adsorption process is accorded with Freundlich model and belonged to \u0000a heterogeneous adsorption.\u0000\u0000\u0000\u0000Tea is a good adsorbent and has a potential for adsorption of Ag+ .\u0000\u0000\u0000\u0000No\u0000","PeriodicalId":38021,"journal":{"name":"Recent Innovations in Chemical Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45173247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-01DOI: 10.2174/240552041601230505092735
Ying Zhou
{"title":"Meet the Editorial Board Member","authors":"Ying Zhou","doi":"10.2174/240552041601230505092735","DOIUrl":"https://doi.org/10.2174/240552041601230505092735","url":null,"abstract":"","PeriodicalId":38021,"journal":{"name":"Recent Innovations in Chemical Engineering","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135146397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.2174/2405520416666230102113231
E. Zauer, Alexander B. Ershov
The objects of this work are silicon prismanes - new high-energy materials that can be used in various electronic, optoelectronic, thermoelectric, and biological fields and compete with traditional chemical energy carriers. However, only compounds with hexasilacubane and octasilacubane have been synthesized to date. Synthesis of other silapismanes, and even more so polysilaprismanes, has not yet been achieved. Therefore, both the “simplest” and the highest silaprismanes are studied mainly theoretically, including by quantum chemistry methods. to expand information about the enthalpies of formation of "simple" (n=2) and multilayer (n=3–7) silicon prismanes using semi-empirical calculation methods; bond lengths Si-Si and Si-H; compare them with the results of ab initio calculations already available in the literature. The geometry was optimized by semi-empirical methods, the enthalpies of formation, Si-Si and Si-H bond lengths, and the bond angles of the bilayer (m = 3 - 12) and some multilayer (n = 3 - 8 and m = 3 - 9) silaprismanes were determined. Comparison with the enthalpies of formation obtained using ab initio calculations shows that the enthalpies of formation obtained by the MINDO / 3 method (Modified Intermediate Neglect of Differential Overlap, version 3) are closest to the results of ab initio calculations of two-layer silicon prismanes; and for multi-layers - by the AM1 method (Austin Model 1). Large differences in the lengths of Si-H bonds determined ab initio and semi-empirically by both methods are not observed. As for the Si-Si bonds, the results of semi-empirical methods indicate the presence of the so-called auxetic effect in multilayer silaprismanes. We believe that in the future, the calculations carried out in this work and a comparative assessment of the enthalpies of formation obtained by calculation methods will help to overcome the problems associated with the synthesis of silicon prismanes.
{"title":"Silicon Prismanes: Calculation And Comparison Of Heats Of Formation","authors":"E. Zauer, Alexander B. Ershov","doi":"10.2174/2405520416666230102113231","DOIUrl":"https://doi.org/10.2174/2405520416666230102113231","url":null,"abstract":"\u0000\u0000The objects of this work are silicon prismanes - new high-energy materials that can be used in various electronic, optoelectronic, thermoelectric, and biological fields and compete with traditional chemical energy carriers. However, only compounds with hexasilacubane and octasilacubane have been synthesized to date. Synthesis of other silapismanes, and even more so polysilaprismanes, has not yet been achieved. Therefore, both the “simplest” and the highest silaprismanes are studied mainly theoretically, including by quantum chemistry methods.\u0000\u0000\u0000\u0000to expand information about the enthalpies of formation of \"simple\" (n=2) and multilayer (n=3–7) silicon prismanes using semi-empirical calculation methods; bond lengths Si-Si and Si-H; compare them with the results of ab initio calculations already available in the literature.\u0000\u0000\u0000\u0000The geometry was optimized by semi-empirical methods, the enthalpies of formation, Si-Si and Si-H bond lengths, and the bond angles of the bilayer (m = 3 - 12) and some multilayer (n = 3 - 8 and m = 3 - 9) silaprismanes were determined. Comparison with the enthalpies of formation obtained using ab initio calculations shows that the enthalpies of formation obtained by the MINDO / 3 method (Modified Intermediate Neglect of Differential Overlap, version 3) are closest to the results of ab initio calculations of two-layer silicon prismanes; and for multi-layers - by the AM1 method (Austin Model 1). Large differences in the lengths of Si-H bonds determined ab initio and semi-empirically by both methods are not observed. As for the Si-Si bonds, the results of semi-empirical methods indicate the presence of the so-called auxetic effect in multilayer silaprismanes.\u0000\u0000\u0000\u0000We believe that in the future, the calculations carried out in this work and a comparative assessment of the enthalpies of formation obtained by calculation methods will help to overcome the problems associated with the synthesis of silicon prismanes.\u0000","PeriodicalId":38021,"journal":{"name":"Recent Innovations in Chemical Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47522007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.2174/2405520416666230102113211
Mingjun Pang, Shihuan Zhang, Rui Niu
Suspensions can be frequently seen in natural, industrial, and agricultural processes. The addition of dispersed phases (such as solid particles, droplets, and bubbles) greatly affects the rheological properties of matrix liquid. Therefore, it is very important to understand the rheological properties of particle suspensions for optimizing production processes and improving process efficiencies. To explore qualitatively the physical law and internal mechanism of the apparent viscosity of suspensions formed by a Newtonian liquid containing solid particles, droplets, and bubbles, respectively. The apparent viscosity of suspensions was measured and analyzed using a rotary rheometer (MCR302), and the evolution of particles was recorded using a highspeed camera (Revealer 2F01M). When the deformation of deformable particles (such as bubbles or water droplets) is slight (close to a sphere in shape), or the arrangement of rigid particles is disordered, the relative viscosity of suspensions is greater than 1. When the deformation of deformable particles is large (greatly deviating from a sphere in shape) or rigid particles are arranged in order, the apparent viscosity of suspensions decreases and the relative viscosity of suspensions containing deformable particles is less than 1. The apparent viscosity of suspensions is closely related to particle shape, particle arrangement, and volume fraction. The higher volume fraction of particles significantly influences the apparent viscosity of suspensions.
{"title":"Experimental Studies and Comparative Analyses on Apparent\u0000Viscosity of Solid Particle, Droplet, and Bubble Suspensions","authors":"Mingjun Pang, Shihuan Zhang, Rui Niu","doi":"10.2174/2405520416666230102113211","DOIUrl":"https://doi.org/10.2174/2405520416666230102113211","url":null,"abstract":"\u0000\u0000Suspensions can be frequently seen in natural, industrial, and\u0000agricultural processes. The addition of dispersed phases (such as solid particles, droplets, and bubbles) greatly affects the rheological properties of matrix liquid. Therefore, it\u0000is very important to understand the rheological properties of particle suspensions for\u0000optimizing production processes and improving process efficiencies.\u0000\u0000\u0000\u0000To explore qualitatively the physical law and internal mechanism of the apparent viscosity of suspensions formed by a Newtonian liquid containing solid particles,\u0000droplets, and bubbles, respectively.\u0000\u0000\u0000\u0000The apparent viscosity of suspensions was measured and analyzed using a\u0000rotary rheometer (MCR302), and the evolution of particles was recorded using a highspeed camera (Revealer 2F01M).\u0000\u0000\u0000\u0000When the deformation of deformable particles (such as bubbles or water droplets) is slight (close to a sphere in shape), or the arrangement of rigid particles is disordered, the relative viscosity of suspensions is greater than 1. When the deformation of\u0000deformable particles is large (greatly deviating from a sphere in shape) or rigid particles\u0000are arranged in order, the apparent viscosity of suspensions decreases and the relative\u0000viscosity of suspensions containing deformable particles is less than 1.\u0000\u0000\u0000\u0000The apparent viscosity of suspensions is closely related to particle shape,\u0000particle arrangement, and volume fraction. The higher volume fraction of particles significantly influences the apparent viscosity of suspensions.\u0000","PeriodicalId":38021,"journal":{"name":"Recent Innovations in Chemical Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43380150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}