Removal of copper ions from aqueous solution by tree

Abstract Tree fern, an agricultural by-product, was used for the sorptive removal of copper ions from aqueous solution. The experimental data was analysed by Langmuir, Freundlich and Redlich-Peterson isotherms. The equilibrium sorption capacity of copper ions was determined from the Langmuir equation and found to be 11.7 mg/g. A batch sorption model, based on the assumption of the pseudo-second-order mechanism, was developed to predict the rate constant of sorption, the equilibrium sorption capacity and the initial sorption rate with the effect of initial copper ion concentration and the tree fern dose. Various thermodynamic parameters, such as DG 0 , DH 0 and DS 0 , have been calculated. The thermodynamics of copper ion/tree fern system indicates spontaneous and endothermic nature of the process.

Top-cited articles in chemical engineering in Science Citation Index Expanded: A bibliometric analysis

Abstract This study aimed to identify and to analyze characteristics of top-cited articles published in the Web of Science chemical engineering subject category from 1899 to 2011. Articles that have been cited more than 100 times were assessed regarding publication outputs, and distribution of outputs in journals. Five bibliometric indicators were used to evaluate source countries, institution and authors. A new indicator, Y-index, was created to assess quantity and quality of contribution to articles. Results showed that 3828 articles, published between 1931 and 2010, had been cited at least 100 times. Among them 54% published before 1991, and 49% top-cited articles originated from US. The top eight productive institutions were all located in US. The top journals were Journal of Catalysis, AIChE Journal, Chemical Engineering Science and Journal of Membrane Science. Y-index was successfully applied to evaluate publication character of authors, institution, and countries

Top-cited articles in chemical engineering in Science Citation Index Expanded: A bibliometric analysis

Abstract This study aimed to identify and to analyze characteristics of top-cited articles published in the Web of Science chemical engineering subject category from 1899 to 2011. Articles that have been cited more than 100 times were assessed regarding publication outputs, and distribution of outputs in journals. Five bibliometric indicators were used to evaluate source countries, institution and authors. A new indicator, Y-index, was created to assess quantity and quality of contribution to articles. Results showed that 3828 articles, published between 1931 and 2010, had been cited at least 100 times. Among them 54% published before 1991, and 49% top-cited articles originated from US. The top eight productive institutions were all located in US. The top journals were Journal of Catalysis, AIChE Journal, Chemical Engineering Science and Journal of Membrane Science. Y-index was successfully applied to evaluate publication character of authors, institutions, and countries/regions

Absorption of heavy metals from waste streams by peat

Adsorption of heavy metal ions (e.g. copper, nickel and lead) onto sphagnum moss peat was investigated. The influence of pH, concentration, temperature, nature of solute, number of solutes simultaneously present, peat dose and reaction time on batch adsorption equilibria and kinetics tests were examined. Batch adsorption of 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 of metal removal. The use of peat in removal of lead from aqueous solution was studied in batch experiments. Investigations included the effect of pH and temperature of adsorption. The adsorption equilibria data followed Langmuir and Freundlich models. Efficiency of 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 of 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 diffusion is not the only rate determining step in peat metal adsorption. A rate equation is described for the study of the kinetics of adsorption of aqueous divalent metal ions onto sphagnum moss peat for a range of conditions. An empirical model was devised for predicting percentage metal ion adsorbed. The model showed a high coefficient of correlation, indicating its reasonableness. The last section describes the results of an examination into the simultaneous adsorption by peat of 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 of competitive adsorption in batch systems for copper and nickel system was also studied in various ratios of metal concentration. A mathematical model was used successfully and shown to be predictive for various ratio of metal ions concentration in competitive adsorption. The dose effect on the uptake of 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 of nickel was unusual. The results also showed that the kinetics of adsorption were best described by a second-order expression rather than a first-order model. For metal ions which are of different size but are divalent metal ions, we used lead(II) and copper(II) as well as lead(II) and nickel(II) systems. The effects of 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 of any single metal such as copper, lead and nickel was hindered by the presence of 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% of that of 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

Pseudo-isotherms using a second order kinetic expression constant

Abstract. The kinetics of four sorption systems, Cu/tree fern, Pb/tree fern, AB9/activated clay and BR18/activated clay have been studied based on the assumption of a pseudo-second order rate law. Pseudo-isotherms using the pseudo-second order kinetic expression constant have been developed to describe the four liquid-solid sorption systems. The experimental results have been analyzed using a pseudo-Langmuir and a pseudo-Redlich-Peterson isotherm. Both isotherms were found to represent the measured sorption data well. According to the evaluation using the pseudo-Langmuir equation, the monolayer sorption capacities were obtained to be 13.9, 46.6, 124 and 105 mg g −1 for copper, lead, AB9 and BR18 respectively

A bibliometric analysis of global research on genome sequencing from 1991 to 2010 Yidan

This study was carried out to evaluate the global scientific production of genome sequencing research to assess the characteristics of the research performances and the research tendencies. Data were obtained from Science Citation Index Expanded database during 1991-2010. Conventional methods including document types, journals, categories, countries and institutions were used to analyze publication output to reveal the global performance. The development of genome sequencing research during last 20 years was described by synthetically analyzing the distribution of words in article title, author keywords, and KeyWords Plus in different periods. The results show that disease and protein related researches were the leading research focuses, and comparative genomics and evolution related research had strong potential in the near future.Key words: Genome sequencing, research trend, scientometrics, science citation index expanded (SCI-Expanded), word cluster analysis, keywords

A Comprehensive Study of Groundbreaking Machine Learning Research: Analyzing Highly Cited and Impactful Publications across Six Decades

Machine learning (ML) has emerged as a prominent field of research in computer science and other related fields, thereby driving advancements in other domains of interest. As the field continues to evolve, it is crucial to understand the landscape of highly cited publications to identify key trends, influential authors, and significant contributions made thus far. In this paper, we present a comprehensive bibliometric analysis of highly cited ML publications. We collected a dataset consisting of the top-cited papers from reputable ML conferences and journals, covering a period of several years from 1959 to 2022. We employed various bibliometric techniques to analyze the data, including citation analysis, co-authorship analysis, keyword analysis, and publication trends. Our findings reveal the most influential papers, highly cited authors, and collaborative networks within the machine learning community. We identify popular research themes and uncover emerging topics that have recently gained significant attention. Furthermore, we examine the geographical distribution of highly cited publications, highlighting the dominance of certain countries in ML research. By shedding light on the landscape of highly cited ML publications, our study provides valuable insights for researchers, policymakers, and practitioners seeking to understand the key developments and trends in this rapidly evolving field