Article
Materials Science, Multidisciplinary
Perla Garcia-Guzman, Luis Medina-Torres, Ma. Josefa Bernad-Bernad, Fausto Calderas, Octavio Manero
Summary: In recent years, there has been a growing interest in dietary and pharmacological agents that inhibit cholesterol intestinal absorption. These compounds have various mechanisms to inhibit cholesterol absorption, such as affecting cholesterol solubilization, interfering with cholesterol diffusion, and inhibiting molecular mechanisms responsible for cholesterol absorption. This study investigated the characterization of different clays and their cholesterol adsorption capacity. The results showed that MMT Nanoclay has the highest cation exchange capacity and lowest Z potential, while MMT K10 and K30 have the highest cholesterol adsorption due to their high surface area. Isothermal studies also suggested that MMT allows for multilayer adsorption of cholesterol through hydrophobic sites.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Biotechnology & Applied Microbiology
Sami Guiza, Francois Brouers, Mohamed Bagane
Summary: This study focused on the use of montmorillonite clay for fluoride removal from aqueous solutions through batch process. The maximum removal of fluoride ions occurred at pH 5.0, with temperature reducing mass transfer resistance and reaching equilibrium within 60 minutes. Different adsorption isotherm models and kinetics models were compared, with GBS and BSF being identified as the best models for describing adsorption isotherms and kinetics, respectively.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2021)
Article
Chemistry, Physical
Stephan Kaufhold, Reiner Dohrmann, Jens Groeger-Trampe
Summary: The study investigates the liberation of naturally present fixed cations in pure dioctahedral smectites. The results show that hydrothermal treatment can render at least a part of the fixed cations exchangeable. However, this liberation is accompanied by a decrease in cation exchange capacity, which may be due to smectite dissolution. The fixed cations are strongly bound and can only be liberated if the smectite structure is affected.
APPLIED CLAY SCIENCE
(2023)
Article
Geochemistry & Geophysics
Fernando H. do Nascimento, Jorge C. Masini
Summary: This paper demonstrates that intercalating Na+ homoionic vermiculite with Fe3+ polyhydroxy cations significantly improves the affinity of the clay mineral-based sorbent toward phosphate. Kinetic experiments show fast adsorption, reaching equilibrium within about 200 minutes of contact time, with intraparticle diffusion being the rate-limiting step. Adsorption isotherms fit well with the Freundlich equation and a two-site Langmuir model, indicating heterogeneity of adsorption sites. The separation factor derived from the Langmuir constant reveals favorable and even irreversible adsorption for high-affinity minor adsorption sites. The adsorption capacity is similar to other clay-based phosphate adsorbents and can remove about 71% of available phosphate in reservoir water spiked with 10 mg L-1 P.
Article
Geochemistry & Geophysics
Afonso D. Macheca, Antonio B. Mapossa, Antonio J. Cumbane, Asmina E. Sulemane, Shepherd M. Tichapondwa
Summary: This study investigates the Na2CO3 activation of calcium bentonite clay and evaluates the influence of different conditions on its ion exchange capacity. The results demonstrate that the concentration of Na2CO3, activation temperature, and activation time significantly affect the ion exchange capacity and Na/Ca ratio of the clay. The experimental findings further confirm the structural and property changes of the calcium bentonite clay after activation.
Article
Biotechnology & Applied Microbiology
Mukhethwa P. Mannzhi, Joshua N. Edokpayi
Summary: This study evaluated the effectiveness of modified precipitate derived from Dicerocaryum eriocarpum leaves in removing elevated levels of fluoride. The results showed that the modified precipitate had a high sorption capacity for fluoride and could effectively remove it from aqueous solutions.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2023)
Article
Environmental Sciences
Szende Tonk, Laszlo Elod Aradi, Gabor Kovacs, Alexandru Turza, Eszter Rapo
Summary: The excellent adsorption properties of clay minerals make them a popular choice for removing heavy metals. In this study, ASLAVITAL cosmetic clay powder from Romania was used to remove Cd2+ from water. The morphology and elemental composition of the clay were characterized using various techniques. The Langmuir II model provided the best fit for describing the adsorption process. Physical bonds were observed to form between the clay and Cd2+ during adsorption.
Article
Chemistry, Analytical
Giovanni Del Sordo Filho, Jefferson Koyaishi Torrecilha, Marcos Antonio Scapin, Sonia Maria Barros Oliveira, Paulo Sergio Cardoso da Silva
Summary: The study evaluated the chemical, radiological composition, and cation exchange capacity (CEC) of three commercially available Brazilian raw kaolins, where kaolinite, quartz, and pirophyllite were identified as the main mineral constituents. Results from the adsorption study showed that acid or thermal treatments did not significantly increase the CEC of the three samples. However, the sample with the highest kaolinite content and CEC showed cost-effective benefits for water treatment applications with reduced energy and chemical reagent consumption.
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
(2021)
Article
Chemistry, Physical
Andreia Zacchi Bazzarella, Lucas Destefani Paquini, Ueslei Giori Favero, Ruan de Oliveira Alves, Mario Alberto Simonato Altoe, Demetrius Profeti, Luciene Paula Roberto Profeti
Summary: In this study, the performance of Cu2+-bentonite clay as an alternative adsorbent for ethylenethiourea removal from aqueous solution was evaluated, showing that the adsorption process was spontaneous and exothermic, with a slight dependence on temperature.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Physical
Zuleyha Bingul
Summary: The study investigated the removal of methylene blue dye using natural clay and found that the Langmuir isotherm model was suitable for describing the adsorption process. The highest removal efficiency was achieved with 0.3 g L-1 adsorbent concentration and 20 mg L-1 dye concentration, reaching 94.69%.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Chemistry, Multidisciplinary
C. Arab, R. El Kurdi, D. Patra
Summary: Zn(Cur)O NPs were synthesized and characterized, with adsorption increasing as the nanoparticle amount increases and dye concentration decreases. An acidic medium was found to improve the adsorption process.
MATERIALS TODAY CHEMISTRY
(2022)
Review
Polymer Science
Georgia Michailidou, Ioanna Koumentakou, Efstathios Liakos, Maria Lazaridou, Dimitra A. Lambropoulou, Dimitrios N. Bikiaris, George Z. Kyzas
Summary: Chitin is the second most important and abundant natural biopolymer in the world, mainly sourced from crustaceans. Chitosan, derived from chitin, has high value-added applications in pharmaceutical, biomedical, cosmetics, and food industries. Its potential for adsorption applications due to amino and hydroxyl groups allows for interactions with pollutants such as uranium, mercury, and REEs.
Article
Multidisciplinary Sciences
Ali H. Jawad, Shihab Ezzuldin M. Saber, Ahmed Saud Abdulhameed, Ahlam M. Farhan, Zeid A. ALOthman, Lee D. Wilson
Summary: This research aimed to use natural Iraqi bentonite clay (NIBC) to adsorb the organic dye (methylene blue, MB) from aqueous media. Analytical methods were performed to analyze the physicochemical characteristics of NIBC. The study examined the impacts of adsorbent dosage, pH, and initial concentrations on the removal of MB. Results showed that NIBC had a maximum adsorption capacity of 256 mg/g for MB.
JOURNAL OF KING SAUD UNIVERSITY SCIENCE
(2023)
Article
Metallurgy & Metallurgical Engineering
A. Decher, S. Ramrattan
Summary: A new approach for measuring the active clay content in green sand has been developed, allowing for direct measurement of CEC and calculation of the number of adsorption sites in the molding sand. This new method shows repeatability and accuracy in measuring active clay levels, overcoming systematic errors of traditional tests.
INTERNATIONAL JOURNAL OF METALCASTING
(2021)
Article
Chemistry, Multidisciplinary
Stefania Canana, Cristina Pavan, Chiara Bellomo, Guillermo Escolano-Casado, Giuseppe Chilla, Dominique Lison, Lorenzo Mino, Francesco Turci
Summary: This study reveals the mechanistic data about the interactions between layered silicates (LS) and biomembranes, providing a basis for understanding the interfacial phenomena of LS.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Food Science & Technology
Tebogo Mokgehle, Ntakadzeni Madala, Wilson Gitari, Nikita Tavengwa
Summary: This study investigated the effects of kosmotropic and chaotropic salts on extracting phytochemicals from Solanum retroflexum leaves. Kosmotrope salts were more efficient in extracting polar compounds, while chaotropes were more selective for less polar compounds. The best-performing salts for extracting metabolites were Na2SO4 and NaCl, which could potentially be applied on a commercial scale.
APPLIED BIOLOGICAL CHEMISTRY
(2021)
Article
Environmental Sciences
Elisa Pandelani Munzhelele, Wasiu Babatunde Ayinde, Rabelani Mudzielwana, Wilson Mugera Gitari
Summary: In this study, Fe3+ oxide was incorporated into a pPD polymer matrix through chemical co-polymerization, and the resulting Fe-pPD composite showed a higher affinity towards fluoride uptake compared to arsenite uptake, with some antimicrobial activity against water-borne bacteria. The experimental data for both arsenite and fluoride removal fit the Freundlich isotherm model at different temperatures, showing potential for water purification processes at the community level.
Review
Chemistry, Applied
Tebogo Mphatlalala Mokgehle, Ntakadzeni Madala, Wilson Mugera Gitari, Nikita Tawanda Tavengwa
Summary: Biopolymers are widely known for their sustainable, biodegradable, biocompatible, and antitoxic properties, with applications in cosmetics, food, and wastewater treatment. The latest trend involves the use of polysaccharides and proteins as adsorbents for nutraceutical compounds, as well as in drug delivery systems.
CARBOHYDRATE POLYMERS
(2021)
Article
Geosciences, Multidisciplinary
Segun A. Akinyemi, Bemgba B. Nyakuma, Olajide F. Adebayo, Ayobami T. Kayode, Aliyu Jauro, Olusola A. OlaOlorun, Adeyinka O. Aturamu, Henry Y. Madukwe, Adebanji K. Adegoke, Tuan Amran T. Abdullah, Wilson M. Gitari, Rabelani Mudzielwana, Shahadev Rabha, Binoy K. Saikia, James C. Hower
Summary: This study analyzed coal samples from the Benue Trough Basin in Nigeria using various techniques and found that the coal samples had lower elemental contents and mainly consisted of minerals such as clays and quartz. The coal-forming marsh experienced relatively mild redox conditions and showed evidence of a significant freshwater environment, with differences in thermal reactivity among samples.
JOURNAL OF AFRICAN EARTH SCIENCES
(2021)
Article
Geochemistry & Geophysics
George Oluwole Akintola, Francis Amponsah-Dacosta, Steven Rupprecht, Nithyadharseni Palaniyandy, Sphiwe Emmanuel Mhlongo, Wilson Mugera Gitari, Joshua Nosa Edokpayi
Summary: Carbonaceous shale is gaining more attention due to the presence of methane resources. Techniques such as FTIR, SEM-EDX, and mineralogical analyses are used to assess methane generation potential rapidly and reliably. Core samples from boreholes suggest biogenic methane generation.
Article
Chemistry, Multidisciplinary
Arinao Murei, Karen Pillay, Patrick Govender, Ntevheleni Thovhogi, Wilson M. Gitari, Amidou Samie
Summary: The study demonstrated that silver nanoparticles conjugated with Pyrenacantha grandiflora extracts exhibit strong antibacterial activities against multi-drug resistant bacterial pathogens, showing potential for effective disease management.
Article
Food Science & Technology
Tebogo Mphatlalala Mokgehle, Ntakadzeni Madala, Wilson Mugera Gitari, Nikita Tawanda Tavengwa
Summary: A new, fast and efficient method, MA-ATPE, was used to extract alpha-solanine from Solanum retroflexum using water and ethanol as solvents. Central composite design and response surface modeling were done to determine the optimal extraction conditions. The method showed high extraction efficiency and could be a potential technique for the pharmaceutical industry.
FOOD ANALYTICAL METHODS
(2022)
Article
Chemistry, Physical
Humbelani H. Nekhavhambe, Rabelani Mudzielwana, Mugera W. Gitari, Wasiu B. Ayinde, Oisaemi U. Izevbekhai
Summary: This study found that macadamia nut shells have a good efficiency in the bio-sorption of fluoride and show potential for antimicrobial activity. The adsorption of fluoride by MNS was found to be a spontaneous and endothermic process.
Article
Energy & Fuels
Tebogo Mphatlalala Mokgehle, Ntakadzeni Edwin Madala, Wilson Mugera Gitari, Nikita Tawanda Tavengwa
Summary: The study aimed at optimizing extraction techniques for solasonine and solamargine from Solanum mauritianum biomass. The one-pot microwave-assisted aqueous two-phase extraction (MA-ATPE) method showed the highest yields of both compounds, indicating its potential for efficient extraction of medicinally important metabolites from plant biomass.
BIOMASS CONVERSION AND BIOREFINERY
(2021)
Article
Geosciences, Multidisciplinary
Segun A. Akinyemi, Olajide F. Adebayo, Henry Y. Madukwe, Ayobami T. Kayode, Adeyinka O. Aturamu, Olusola A. OlaOlorun, Bemgba B. Nyakuma, Aliyu Jauro, Wilson M. Gitari, Rabelani Mudzielwana, James C. Hower
Summary: The Benue Trough basin is subdivided into three segments with marine and continental sediments affected by folding movements. Different analytical techniques were used to examine coal samples from the Cretaceous era, providing insights into the depositional environments and conditions.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Polymer Science
Wasiu B. Ayinde, Mugera W. Gitari, James A. Smith, Amidou Samie
Summary: A modified multistructural CNF-AgMgOnHaP composite was successfully synthesized using a hydrothermal bioreduction route, showing improved fluoride sorption performance and antibacterial activity against common bacteria in surface water.
Article
Chemistry, Analytical
Tebogo Mphatlalala Mokgehle, Ntakadzeni Madala, Wilson Mugera Gitari, Nikita Tawanda Tavengwa
JPC-JOURNAL OF PLANAR CHROMATOGRAPHY-MODERN TLC
(2021)
Article
Chemistry, Multidisciplinary
Oisaemi U. Izevbekhai, Wilson M. Gitari, Nikita T. Tavengwa
Summary: This study evaluated the extraction efficiency of silica from diatomaceous earth using response surface methodology, finding that ultrasound-assisted extraction under acidic conditions was the most effective method, providing high yield and purity of silica extraction.
SOUTH AFRICAN JOURNAL OF CHEMISTRY-SUID-AFRIKAANSE TYDSKRIF VIR CHEMIE
(2021)
Article
Water Resources
Olumuyiwa A. Obijole, Gitari Wilson Mugera, Rabelani Mudzielwana, Patrick G. Ndungu, Amidou Samie, Ayinde W. Babatunde
Summary: The study demonstrates that hydrothermally treated aluminosilicate activated clay shows strong potential for fluoride and pathogen removal. The increase in surface area of the adsorbent after treatment, along with improved efficiency in fluoride removal and antimicrobial activity against E. coli strains, highlights the effectiveness of the material in water treatment.
WATER RESOURCES AND INDUSTRY
(2021)
Article
Chemistry, Multidisciplinary
Oisaemi Uduagele Izevbekhai, Wilson Mugera Gitari, Nikita Tawanda Tavengwa, Wasiu Babatunde Ayinde, Rabelani Mudzielwana
Summary: This work synthesized 3-bromo-benzimidazolone using melt condensation and polymerized and functionalized it on silica extracted from diatomaceous earth. The synthesized compound was characterized using FTIR, NMR, SEM-EDS, and TEM, showing the presence of various functional groups. The functionalized silica was effective in treating oily wastewater, with optimized conditions leading to a high adsorption rate, making it applicable for field wastewaters.