Collnet Journal of Scientometrics and Information Management, Jul 2, 2020
This study aimed to analyze the characteristics of artificial intelligence-related publications i... more This study aimed to analyze the characteristics of artificial intelligence-related publications in Science Citation Index Expanded (SCIEXPANDED) from 1991 to 2018. The analyzed aspects covered distribution of annual publications, citations per publication, journals, Web of Science categories, countries, institutions, as well as research foci and their trends. A total of 13,251 artificial intelligence-related articles were found. Articles were published in a wide range of journals and Web of Science categories. The United States took the lead position in total, single country, international collaboration, and first, corresponding, and single author articles as well as citations per publication among 119 countries. Chinese Academy of Sciences in China, Islamic Azad University in Iran, and Massachusetts Institute of Technology (MIT) in USA were the three most productive institutions. MIT had higher citations per publication. An international collaborative article by authors from Canada, the United States, and Switzerland was the most frequently cited article with the most total citations from Web of Science Core Collection since publication through the end of 2018. Results from word cluster analysis showed that models, neural networks, learning, and prediction were the most popular topics and features, classification, and optimization might be focus in artificial intelligence research.
The main object of this study is to investigate the research trend in removal of dyes from waste ... more The main object of this study is to investigate the research trend in removal of dyes from waste water by using adsorption technology for the past 16 years. Data are based on the online version of Science Citation Index (SCI), Web of Science from 1993 to 2008 that covers all the articles published for the past 16 years in SCI journals. Articles referring to dye adsorption were assessed by many aspects including model fitting the trend of publication outputs during 1993-2008, distribution of author keywords and keyword plus analysis. Distribution of articles based on subject categories and journals along with the country wise publications were also studied. From the analysis of words appeared in the title and keywords, it can be concluded that "activated carbon," "biosorption," "kinetics," "Methylene blue," and "isotherms" could be more popular words and the new words like "photocatalytic degradation," "photocatalysis," "titanium dioxide," and "oxidation" appeared to be the new advanced techniques that are going to be adopted more in future studies. This method of bibliometric analysis can help the relevant researchers to realize the panorama of globalized way of dye removal from wastewater and establish the further research direction.
COLLNET Journal of Scientometrics and Information Management
This study aimed to evaluate the tendency of insomnia articles in SCI-EXPANDED database. Data was... more This study aimed to evaluate the tendency of insomnia articles in SCI-EXPANDED database. Data was obtained from the online version of Science Citation Index Expanded (SCI-EXPANDED) database in the Web of Science Core Collection of Clarivate Analytics within the publication year from 1991 to 2018. The publications were assessed regarding their document types, languages, and journals. We used three citation indicators such as C 2018, TC 2018, and CPP 2018 to determine the citation received by publications. We used the Y-index method formulated by Ho. The study found 16,478 insomnia documents within 15 document types indexed in the Web of Science, and articles type was used most constituting 66% (10,801) of the documents. Ninety-five percent of the articles were published in English. The journal of Sleep published most of the insomnia article then followed by Sleep Medicine. The 30% of 10,801 articles were published in the top category of clinical neurology. The G7 countries published most of the insomnia articles. The most productive country and institution was United States and Harvard University respectively. The article entitled “A new method for measuring daytime sleepiness: The Epworth sleepiness scale” published by Johns in 1991was the most cited article with TC 2018 of 7,191 and C 2018 of 661 citations. The most industrious and had more potential to published insomnia articles was M.M. Ohayon. Moreover, the study showed that most of the insomnia articles were related to depression, anxiety, cancer, and schizophrenia. Insomnia is a serious problem with synergistic effects for normal body health. Bibliometric method can help researchers to have comprehensive knowledge on insomnia and initiate an orientation for further research so as to solve a problem. Furthermore, it may also help researchers to determine the impact of insomnia publications as well as to identify relevant research groups in the field of insomnia.
COLLNET Journal of Scientometrics and Information Management, 2020
A bibliometric analysis was conducted to evaluate the global scientific output of KSHV/HHV8 resea... more A bibliometric analysis was conducted to evaluate the global scientific output of KSHV/HHV8 research in the Science Citation Index Expanded from 1991 to 2016. The publications were analysed in terms of document type, language of publication, trends in publication, journals, Web of Science categories, and publications of countries, institutions, and authors. The results showed that Journal of Virology led 610 journals. The researchers focused on the category of virology. The USA took the lead position among 92 countries with 58% of all the KSHV/HHV8 articles. Top ten productive institutions were all from the USA. National Cancer Institute, University of California, San Francisco, and Harvard University from the USA led top three the institutions. A comprehensive analysis of keywords revealed that HIV, lymphoma, and EBV were recent foci. The proportion of number of single institution articles : number of nationally collaborative articles : number of internationally collaborative articles (S : N : I) was used to compare performance of institutions. Y-index was also applied to evaluate authors’ publication performance. Chang’s group published the first in KSHV/HHV8 research field.
To gain insight into the trend of bacterial nanocellulose research, a bibliometric analysis was p... more To gain insight into the trend of bacterial nanocellulose research, a bibliometric analysis was performed using the Science Citation Index Expanded database from 2005 to 2020. The study concentrated on the publication’s performance in terms of annual outputs and citations, mainstream journals, categories of the Web of Sciences, leading countries, prominent institutions, and trends in research. Current research priorities and future trends were analyzed after summarizing the most commonly used keywords extracted from words in the paper title analysis, authors’ keyword analysis, and KeyWords Plus. The findings revealed that the annual output in the form of scholarly articles on bacterial nanocellulose research steadily increased during the first quartile of the study period, followed by a very rapid increase in the last five-years of the study. Increasing mechanical strength would remain the main future focus of bacterial nanocellulose research to create its scope in different field o...
Malaysian Journal of Library & Information Science
Editorial materials express the opinions of the scientific community and guides the publication f... more Editorial materials express the opinions of the scientific community and guides the publication foci; thus, providing insight into the dynamics of the knowledge ecosystem in a scenario that impacts innovation and public policies. The purpose of this bibliometric analysis was to identify the main characteristics of the editorial materials published at the beginning stage of the COVID-19 pandemic, published between 2019 and April 30, 2020 and indexed in the Web of Science Core Collection. A total of 537 editorial materials were written by 1,455 authors, primarily in English, and in the general and internal medicine category. The majority of these editorial materials were published in the British Medical Journal and Lancet. The United States, China, and United Kingdom had the most editorial materials, with Harvard Medical School, Imperial College, and Oxford University were the leading universities. Richard Horton was the most prolific author and the editorial material by Hui et al. (2...
Introduction: The purpose of this study is to analyze the multiple sclerosis research in Science ... more Introduction: The purpose of this study is to analyze the multiple sclerosis research in Science Citation Index-Expanded from 1992 to 2019 in order to determine the top features, trends, and topics. Methods: In this scientometric study, research population was all articles related to multiple sclerosis in the Web of Science from 1992 to 2019. These articles were retrieved from the Science Citation Index-Expanded and analyzed based on various indicators and characteristics. Results: There was a significant increase in the number of articles from 408 in 1992 to 2756 in 2019. A sum of 42,112 articles related to multiple sclerosis has been published in 3,032 journals, which were classified among the 131 Web of Science categories. The top two categories were clinical neurology and neurosciences. Multiple Sclerosis Journal published the most articles. Articles published in the Neurology Journal also had the highest citation per publication. Most of the articles were in English, while 23 o...
The batch adsorption of Ni(II) onto sphagnum moss peat has been studied. The reaction was pH depe... more The batch adsorption of Ni(II) onto sphagnum moss peat has been studied. The reaction was pH dependent, the optimum range being 4.0-7.0. Langmuir and Freundlich isotherms, established for various initial nickel concentrations and for a range ofpH values, were used to obtain a single relationship between initial metal concentration, metal removal, and initial pH. The latter was found to control efficiency of nickel removal. Kinetic data suggested involvement of a chemical rate-limiting step, and a predictive relationship was derived relating nickel removal to peat dose. !n comparison with other metals, nickel removal is poor, and possible reasons are discussed.
Adsorption o f heavy metal ions (e.g. copper, nickel and lead) onto sphagnum moss peat was invest... more Adsorption o f heavy metal ions (e.g. copper, nickel and lead) onto sphagnum moss peat was investigated. The influence o f pH, concentration, temperature, nature o f solute, number o f solutes simultaneously present, peat dose and reaction time on batch adsorption equilibria and kinetics tests were examined. Batch adsorption o f copper and nickel onto peat was pH dependent, the optimum range being 4.0 to 5.0 for copper and 4.0 to 7.0 for nickel. Langmuir and Freundlich isotherms showed a single relationship between initial metal concentration, metal removal, and initial pH. The latter was found to control efficiency o f metal removal. The use o f peat in removal o f lead from aqueous solution was studied in batch experiments. Investigations included the effect o f pH and temperature o f adsorption. The adsorption equilibria data followed Langmuir and Freundlich models. Efficiency o f lead removal depended very little on the reaction temperatures (12 to 37°C) and initial pH values (4.0 to 6.0). The results suggested that the adsorption process is endothermic for lead-peat adsorption. Kinetic data suggested involvement o f a chemical rate-limiting step, and a predictive relationship was derived relating metal removal to peat dose. In comparison with other metals, nickel removal is poor, and possible reasons are discussed. Kinetic results also indicated that pore diffiision is not the only rate determining step in peat metal adsorption. A rate equation is described for the study o f the kinetics o f adsorption o f aqueous divalent metal ions onto sphagnum moss peat for a range o f conditions. An empirical model was devised for predicting percentage metal ion adsorbed. The model showed a high coefficient o f correlation, indicating its reasonableness. The last section describes the results o f an examination into the simultaneous adsorption by peat o f several metals. Initially copper and nickel from both single-and bi solute systems were tested. In general, pore diffusion appeared to be the rate-controlling step. The effects o f competitive adsorption in batch systems for copper and nickel system was also studied in various ratios o f metal concentration. A mathematical model was used successfully and shown to be predictive for various ratio o f metal ions concentration in competitive adsorption. The dose effect on the uptake o f metals on moss peat was also studied for bi-solute adsorption systems. The best interpretation which could be placed on the data was that the behaviour o f nickel was unusual. The results also showed that the kinetics o f adsorption were best described by a second-order expression rather than a first-order model. For metal ions which are o f different size but are divalent metal ions, w e used lead(II) and copper(II) as well as lead(II) and nickel(II) systems. The effects o f competitive adsorption in batch systems indicated that copper had a greater effect on lead adsorption than did nickel. However, lead had a greater effect on nickel than copper. A copper, lead and nickel triple-solute system was also tested. The adsorption o f any single metal such as copper, lead and nickel was hindered by the presence o f the other metals. The competitive effect appears to have affected the three ions in the order nickel > lead > copper with nickel affected most; the adsorption capacity for each solute from the mixed solution was 15.9, 57.4 and 71.5% o f that o f a single-solute system for copper, lead and nickel, respectively. The kinetic results showed that the heavy metals are adsorbed fairly rapidly, and that there is a relatively good fit between experimental data and the second order model for copper, lead and nickel. CoiTection list 4.2. Pseudo Second-Order Reaction Model Original in the thesis Corrected d(P), dt 2A-[(p)"-(P),f r f (P) , dt = a:((p)o-(p),]= 4 h p),
ÐA pseudo-second order rate equation describing the kinetics of sorption of divalent metal ions o... more ÐA pseudo-second order rate equation describing the kinetics of sorption of divalent metal ions onto sphagnum moss peat at dierent initial metal ion concentrations and peat doses has been developed. The kinetics of sorption were followed based on the amounts of metal sorbed at various time intervals. Results show that sorption (chemical bonding) might be rate-limiting in the sorption of divalent metal ions onto peat during agitated batch contact time experiments. The rate constant, the equilibrium sorption capacity and the initial sorption rate were calculated. From these parameters, an empirical model for predicting the sorption capacity of metal ions sorbed was derived.
Novel biosorbent 'maize bran' has been successfully utilized for the removal of Cr(VI) from aqueo... more Novel biosorbent 'maize bran' has been successfully utilized for the removal of Cr(VI) from aqueous solution. The effect of different parameters such as contact time, sorbate concentration, pH of the medium and temperature were investigated and maximum uptake of Cr(VI) was 312.52 (mg g −1) at pH 2.0, initial Cr(VI) concentration of 200 mg L −1 and temperature of 40 • C. Effect of pH showed that maize bran was not only removing Cr(VI) from aqueous solution but also reducing toxic Cr(VI) into less toxic Cr(III). The sorption kinetics was tested with first order reversible, pseudo-first order and pseudo-second order reaction and it was found that Cr(VI) uptake process followed the pseudo-second order rate expression. Mass transfer of Cr(VI) from bulk to the solid phase (maize bran) was studied at different temperatures. Different thermodynamic parameters, viz., G • , H • and S • have also been evaluated and it has been found that the sorption was feasible, spontaneous and endothermic in nature. The Langmuir and Freundlich equations for describing sorption equilibrium were applied and it was found that the process was well described by Langmuir isotherm. Desorption studies was also carried out and found that complete desorption of Cr(VI) took place at pH of 9.5.
T he sorption of lead ions onto peat has been studied. Equilibriu m isotherms have been measured ... more T he sorption of lead ions onto peat has been studied. Equilibriu m isotherms have been measured and modelled. Kinetic studies have been carried out in a batch adsorber to study the effect of initial concentration, agitatio n and temperature. A pseudo-second order kinetic model has been proposed to correlate the experimental data.
ABSTRACf: The sorption of lead ions on to peat in an agitated batch adsorber has been studied. A ... more ABSTRACf: The sorption of lead ions on to peat in an agitated batch adsorber has been studied. A model has been developed for the design of a two-stage batch adsorber based on pseudo second-order sorption kinetics. The model has been optimised with respect to contact time in order to minimise total contact time to achieve a fixed percentage of metal ion removal.
The sorption of three divalent metal ions — copper, nickel and lead — from aqueous solution onto ... more The sorption of three divalent metal ions — copper, nickel and lead — from aqueous solution onto peat in single component systems has been studied and the equilibrium isotherms determined. The experimental data have been analysed using the Langmuir, Freundlich, Redlich-Peterson, Toth, Temkin, Dubinin-Radushkevich and Sips isotherm models. In order to determine the best fit isotherm for each system, six
The use of peat for removal of copper(II) from aqueous solution has been investigated at various ... more The use of peat for removal of copper(II) from aqueous solution has been investigated at various initial copper ion concentrations and masses of peat. The equilibrium sorption study can be described by the Langmuir equation and defined in terms of the operating lines for each batch contacting system. The mechanisms of the rate of sorption of copper(II) were analysed using the Elovich equation and a pseudo-second-order model. Both rate mechanisms provided a very high degree of correlation of the experimental sorption rate data suggesting either model could be used in design applications.
Collnet Journal of Scientometrics and Information Management, Jul 2, 2020
This study aimed to analyze the characteristics of artificial intelligence-related publications i... more This study aimed to analyze the characteristics of artificial intelligence-related publications in Science Citation Index Expanded (SCIEXPANDED) from 1991 to 2018. The analyzed aspects covered distribution of annual publications, citations per publication, journals, Web of Science categories, countries, institutions, as well as research foci and their trends. A total of 13,251 artificial intelligence-related articles were found. Articles were published in a wide range of journals and Web of Science categories. The United States took the lead position in total, single country, international collaboration, and first, corresponding, and single author articles as well as citations per publication among 119 countries. Chinese Academy of Sciences in China, Islamic Azad University in Iran, and Massachusetts Institute of Technology (MIT) in USA were the three most productive institutions. MIT had higher citations per publication. An international collaborative article by authors from Canada, the United States, and Switzerland was the most frequently cited article with the most total citations from Web of Science Core Collection since publication through the end of 2018. Results from word cluster analysis showed that models, neural networks, learning, and prediction were the most popular topics and features, classification, and optimization might be focus in artificial intelligence research.
The main object of this study is to investigate the research trend in removal of dyes from waste ... more The main object of this study is to investigate the research trend in removal of dyes from waste water by using adsorption technology for the past 16 years. Data are based on the online version of Science Citation Index (SCI), Web of Science from 1993 to 2008 that covers all the articles published for the past 16 years in SCI journals. Articles referring to dye adsorption were assessed by many aspects including model fitting the trend of publication outputs during 1993-2008, distribution of author keywords and keyword plus analysis. Distribution of articles based on subject categories and journals along with the country wise publications were also studied. From the analysis of words appeared in the title and keywords, it can be concluded that "activated carbon," "biosorption," "kinetics," "Methylene blue," and "isotherms" could be more popular words and the new words like "photocatalytic degradation," "photocatalysis," "titanium dioxide," and "oxidation" appeared to be the new advanced techniques that are going to be adopted more in future studies. This method of bibliometric analysis can help the relevant researchers to realize the panorama of globalized way of dye removal from wastewater and establish the further research direction.
COLLNET Journal of Scientometrics and Information Management
This study aimed to evaluate the tendency of insomnia articles in SCI-EXPANDED database. Data was... more This study aimed to evaluate the tendency of insomnia articles in SCI-EXPANDED database. Data was obtained from the online version of Science Citation Index Expanded (SCI-EXPANDED) database in the Web of Science Core Collection of Clarivate Analytics within the publication year from 1991 to 2018. The publications were assessed regarding their document types, languages, and journals. We used three citation indicators such as C 2018, TC 2018, and CPP 2018 to determine the citation received by publications. We used the Y-index method formulated by Ho. The study found 16,478 insomnia documents within 15 document types indexed in the Web of Science, and articles type was used most constituting 66% (10,801) of the documents. Ninety-five percent of the articles were published in English. The journal of Sleep published most of the insomnia article then followed by Sleep Medicine. The 30% of 10,801 articles were published in the top category of clinical neurology. The G7 countries published most of the insomnia articles. The most productive country and institution was United States and Harvard University respectively. The article entitled “A new method for measuring daytime sleepiness: The Epworth sleepiness scale” published by Johns in 1991was the most cited article with TC 2018 of 7,191 and C 2018 of 661 citations. The most industrious and had more potential to published insomnia articles was M.M. Ohayon. Moreover, the study showed that most of the insomnia articles were related to depression, anxiety, cancer, and schizophrenia. Insomnia is a serious problem with synergistic effects for normal body health. Bibliometric method can help researchers to have comprehensive knowledge on insomnia and initiate an orientation for further research so as to solve a problem. Furthermore, it may also help researchers to determine the impact of insomnia publications as well as to identify relevant research groups in the field of insomnia.
COLLNET Journal of Scientometrics and Information Management, 2020
A bibliometric analysis was conducted to evaluate the global scientific output of KSHV/HHV8 resea... more A bibliometric analysis was conducted to evaluate the global scientific output of KSHV/HHV8 research in the Science Citation Index Expanded from 1991 to 2016. The publications were analysed in terms of document type, language of publication, trends in publication, journals, Web of Science categories, and publications of countries, institutions, and authors. The results showed that Journal of Virology led 610 journals. The researchers focused on the category of virology. The USA took the lead position among 92 countries with 58% of all the KSHV/HHV8 articles. Top ten productive institutions were all from the USA. National Cancer Institute, University of California, San Francisco, and Harvard University from the USA led top three the institutions. A comprehensive analysis of keywords revealed that HIV, lymphoma, and EBV were recent foci. The proportion of number of single institution articles : number of nationally collaborative articles : number of internationally collaborative articles (S : N : I) was used to compare performance of institutions. Y-index was also applied to evaluate authors’ publication performance. Chang’s group published the first in KSHV/HHV8 research field.
To gain insight into the trend of bacterial nanocellulose research, a bibliometric analysis was p... more To gain insight into the trend of bacterial nanocellulose research, a bibliometric analysis was performed using the Science Citation Index Expanded database from 2005 to 2020. The study concentrated on the publication’s performance in terms of annual outputs and citations, mainstream journals, categories of the Web of Sciences, leading countries, prominent institutions, and trends in research. Current research priorities and future trends were analyzed after summarizing the most commonly used keywords extracted from words in the paper title analysis, authors’ keyword analysis, and KeyWords Plus. The findings revealed that the annual output in the form of scholarly articles on bacterial nanocellulose research steadily increased during the first quartile of the study period, followed by a very rapid increase in the last five-years of the study. Increasing mechanical strength would remain the main future focus of bacterial nanocellulose research to create its scope in different field o...
Malaysian Journal of Library & Information Science
Editorial materials express the opinions of the scientific community and guides the publication f... more Editorial materials express the opinions of the scientific community and guides the publication foci; thus, providing insight into the dynamics of the knowledge ecosystem in a scenario that impacts innovation and public policies. The purpose of this bibliometric analysis was to identify the main characteristics of the editorial materials published at the beginning stage of the COVID-19 pandemic, published between 2019 and April 30, 2020 and indexed in the Web of Science Core Collection. A total of 537 editorial materials were written by 1,455 authors, primarily in English, and in the general and internal medicine category. The majority of these editorial materials were published in the British Medical Journal and Lancet. The United States, China, and United Kingdom had the most editorial materials, with Harvard Medical School, Imperial College, and Oxford University were the leading universities. Richard Horton was the most prolific author and the editorial material by Hui et al. (2...
Introduction: The purpose of this study is to analyze the multiple sclerosis research in Science ... more Introduction: The purpose of this study is to analyze the multiple sclerosis research in Science Citation Index-Expanded from 1992 to 2019 in order to determine the top features, trends, and topics. Methods: In this scientometric study, research population was all articles related to multiple sclerosis in the Web of Science from 1992 to 2019. These articles were retrieved from the Science Citation Index-Expanded and analyzed based on various indicators and characteristics. Results: There was a significant increase in the number of articles from 408 in 1992 to 2756 in 2019. A sum of 42,112 articles related to multiple sclerosis has been published in 3,032 journals, which were classified among the 131 Web of Science categories. The top two categories were clinical neurology and neurosciences. Multiple Sclerosis Journal published the most articles. Articles published in the Neurology Journal also had the highest citation per publication. Most of the articles were in English, while 23 o...
The batch adsorption of Ni(II) onto sphagnum moss peat has been studied. The reaction was pH depe... more The batch adsorption of Ni(II) onto sphagnum moss peat has been studied. The reaction was pH dependent, the optimum range being 4.0-7.0. Langmuir and Freundlich isotherms, established for various initial nickel concentrations and for a range ofpH values, were used to obtain a single relationship between initial metal concentration, metal removal, and initial pH. The latter was found to control efficiency of nickel removal. Kinetic data suggested involvement of a chemical rate-limiting step, and a predictive relationship was derived relating nickel removal to peat dose. !n comparison with other metals, nickel removal is poor, and possible reasons are discussed.
Adsorption o f heavy metal ions (e.g. copper, nickel and lead) onto sphagnum moss peat was invest... more Adsorption o f heavy metal ions (e.g. copper, nickel and lead) onto sphagnum moss peat was investigated. The influence o f pH, concentration, temperature, nature o f solute, number o f solutes simultaneously present, peat dose and reaction time on batch adsorption equilibria and kinetics tests were examined. Batch adsorption o f copper and nickel onto peat was pH dependent, the optimum range being 4.0 to 5.0 for copper and 4.0 to 7.0 for nickel. Langmuir and Freundlich isotherms showed a single relationship between initial metal concentration, metal removal, and initial pH. The latter was found to control efficiency o f metal removal. The use o f peat in removal o f lead from aqueous solution was studied in batch experiments. Investigations included the effect o f pH and temperature o f adsorption. The adsorption equilibria data followed Langmuir and Freundlich models. Efficiency o f lead removal depended very little on the reaction temperatures (12 to 37°C) and initial pH values (4.0 to 6.0). The results suggested that the adsorption process is endothermic for lead-peat adsorption. Kinetic data suggested involvement o f a chemical rate-limiting step, and a predictive relationship was derived relating metal removal to peat dose. In comparison with other metals, nickel removal is poor, and possible reasons are discussed. Kinetic results also indicated that pore diffiision is not the only rate determining step in peat metal adsorption. A rate equation is described for the study o f the kinetics o f adsorption o f aqueous divalent metal ions onto sphagnum moss peat for a range o f conditions. An empirical model was devised for predicting percentage metal ion adsorbed. The model showed a high coefficient o f correlation, indicating its reasonableness. The last section describes the results o f an examination into the simultaneous adsorption by peat o f several metals. Initially copper and nickel from both single-and bi solute systems were tested. In general, pore diffusion appeared to be the rate-controlling step. The effects o f competitive adsorption in batch systems for copper and nickel system was also studied in various ratios o f metal concentration. A mathematical model was used successfully and shown to be predictive for various ratio o f metal ions concentration in competitive adsorption. The dose effect on the uptake o f metals on moss peat was also studied for bi-solute adsorption systems. The best interpretation which could be placed on the data was that the behaviour o f nickel was unusual. The results also showed that the kinetics o f adsorption were best described by a second-order expression rather than a first-order model. For metal ions which are o f different size but are divalent metal ions, w e used lead(II) and copper(II) as well as lead(II) and nickel(II) systems. The effects o f competitive adsorption in batch systems indicated that copper had a greater effect on lead adsorption than did nickel. However, lead had a greater effect on nickel than copper. A copper, lead and nickel triple-solute system was also tested. The adsorption o f any single metal such as copper, lead and nickel was hindered by the presence o f the other metals. The competitive effect appears to have affected the three ions in the order nickel > lead > copper with nickel affected most; the adsorption capacity for each solute from the mixed solution was 15.9, 57.4 and 71.5% o f that o f a single-solute system for copper, lead and nickel, respectively. The kinetic results showed that the heavy metals are adsorbed fairly rapidly, and that there is a relatively good fit between experimental data and the second order model for copper, lead and nickel. CoiTection list 4.2. Pseudo Second-Order Reaction Model Original in the thesis Corrected d(P), dt 2A-[(p)"-(P),f r f (P) , dt = a:((p)o-(p),]= 4 h p),
ÐA pseudo-second order rate equation describing the kinetics of sorption of divalent metal ions o... more ÐA pseudo-second order rate equation describing the kinetics of sorption of divalent metal ions onto sphagnum moss peat at dierent initial metal ion concentrations and peat doses has been developed. The kinetics of sorption were followed based on the amounts of metal sorbed at various time intervals. Results show that sorption (chemical bonding) might be rate-limiting in the sorption of divalent metal ions onto peat during agitated batch contact time experiments. The rate constant, the equilibrium sorption capacity and the initial sorption rate were calculated. From these parameters, an empirical model for predicting the sorption capacity of metal ions sorbed was derived.
Novel biosorbent 'maize bran' has been successfully utilized for the removal of Cr(VI) from aqueo... more Novel biosorbent 'maize bran' has been successfully utilized for the removal of Cr(VI) from aqueous solution. The effect of different parameters such as contact time, sorbate concentration, pH of the medium and temperature were investigated and maximum uptake of Cr(VI) was 312.52 (mg g −1) at pH 2.0, initial Cr(VI) concentration of 200 mg L −1 and temperature of 40 • C. Effect of pH showed that maize bran was not only removing Cr(VI) from aqueous solution but also reducing toxic Cr(VI) into less toxic Cr(III). The sorption kinetics was tested with first order reversible, pseudo-first order and pseudo-second order reaction and it was found that Cr(VI) uptake process followed the pseudo-second order rate expression. Mass transfer of Cr(VI) from bulk to the solid phase (maize bran) was studied at different temperatures. Different thermodynamic parameters, viz., G • , H • and S • have also been evaluated and it has been found that the sorption was feasible, spontaneous and endothermic in nature. The Langmuir and Freundlich equations for describing sorption equilibrium were applied and it was found that the process was well described by Langmuir isotherm. Desorption studies was also carried out and found that complete desorption of Cr(VI) took place at pH of 9.5.
T he sorption of lead ions onto peat has been studied. Equilibriu m isotherms have been measured ... more T he sorption of lead ions onto peat has been studied. Equilibriu m isotherms have been measured and modelled. Kinetic studies have been carried out in a batch adsorber to study the effect of initial concentration, agitatio n and temperature. A pseudo-second order kinetic model has been proposed to correlate the experimental data.
ABSTRACf: The sorption of lead ions on to peat in an agitated batch adsorber has been studied. A ... more ABSTRACf: The sorption of lead ions on to peat in an agitated batch adsorber has been studied. A model has been developed for the design of a two-stage batch adsorber based on pseudo second-order sorption kinetics. The model has been optimised with respect to contact time in order to minimise total contact time to achieve a fixed percentage of metal ion removal.
The sorption of three divalent metal ions — copper, nickel and lead — from aqueous solution onto ... more The sorption of three divalent metal ions — copper, nickel and lead — from aqueous solution onto peat in single component systems has been studied and the equilibrium isotherms determined. The experimental data have been analysed using the Langmuir, Freundlich, Redlich-Peterson, Toth, Temkin, Dubinin-Radushkevich and Sips isotherm models. In order to determine the best fit isotherm for each system, six
The use of peat for removal of copper(II) from aqueous solution has been investigated at various ... more The use of peat for removal of copper(II) from aqueous solution has been investigated at various initial copper ion concentrations and masses of peat. The equilibrium sorption study can be described by the Langmuir equation and defined in terms of the operating lines for each batch contacting system. The mechanisms of the rate of sorption of copper(II) were analysed using the Elovich equation and a pseudo-second-order model. Both rate mechanisms provided a very high degree of correlation of the experimental sorption rate data suggesting either model could be used in design applications.
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