Article
Engineering, Environmental
Matome Mothetha, Kefeni Kebede, Vhahangwele Masindi, Titus Msagati
Summary: The efficacy of Ca2+-rich MgO nanoparticles in treating acid mine drainage (AMD) was evaluated using various techniques including FTIR, HR-FIB/SEM, EDS, XRF, and XRD. Optimum conditions for treatment were determined to be 45-60 min of mixing time, a dosage of >=10,000 mg/dm3 of feedstock (Ca2+-rich MgO nanoparticles), and ambient temperature and pH levels. The removal efficiency of embedded metals (Fe3+, Mn2+, Cr2+, Cu2+, Ni2+, Pb2+, Al3+, and Zn2+) reached 99%, while sulfate levels were reduced by at least 40%. The use of Ca2+-rich MgO nanoparticles proved to be effective in the treatment of AMD, although further polishing techniques are required to remove residual sulfates.
ENVIRONMENT PROTECTION ENGINEERING
(2023)
Article
Multidisciplinary Sciences
Zhang Ming, Hu Dongke, Pan Shaoyu, Chen Guozhou
Summary: Permeability tests using a flexible wall permeameter were conducted to investigate the impact of bentonite-HDTMA on the permeability of Loess, a potential lining material for solid waste landfills. The results revealed that compacted Loess from the middle and lower reaches of the Yellow River in China did not meet the required impermeability standards for landfill liners. However, the permeability of Loess mixed with more than 10% bentonite ratio was significantly lower than the acceptable limit. The addition of a small amount of HDTMA slightly increased the permeability of Loess, but a certain ratio of bentonite-HDTMA still ensured impermeability.
SCIENTIFIC REPORTS
(2023)
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
Elahe Abedi, Mohammad Javad Amiri, Mehran Sayadi
Summary: This research investigates the sorption behavior of heavy metals and pigments onto activated bentonite clay in soybean oil under different bleaching methods, finding that the adsorption is most effective under ultrasonic bleaching method. The sorption thermodynamics is endothermic and the process is spontaneous within a certain temperature range.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Review
Environmental Sciences
Varney Kromah, Soehoe-Panhyonon Benedict Powoe, Charles Asumana
Summary: Fluoride contamination of groundwater is a significant issue, and the use of composite oxyhydroxide mineral ores for adsorption has been proven to be a feasible environmental remediation technique. Research results indicate that some raw mineral assemblage adsorbents and their pretreated versions are better than or practically similar to current commercial fluoride filters.
Article
Chemistry, Physical
Wondwosen Sime Geleta, Esayas Alemayehu, Bernd Lennartz
Summary: The study demonstrates that coating pumice with zirconium can enhance defluoridation capacity, making it suitable for purifying excess fluoride from groundwater. Further investigations on the influences of competing ions and other factors are advisable for explicit conclusions.
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)
Review
Environmental Sciences
Anushka Rathnayake, Oshadi Hettithanthri, Sandun Sandanayake, Kushani Mahatantila, Anushka Upamali Rajapaksha, Meththika Vithanage
Summary: This review assesses the physicochemical characteristics and fluoride removal performances of hydroxyapatite (HAP) and HAP-based composites. Novel HAP tailored composites demonstrate high fluoride removal capabilities, especially at neutral and near-neutral pH. Multiple mechanisms including physical surface adsorption, ion-exchange, and electrostatic interactions are involved in defluoridation. Further research should focus on scaling up HAP-based composites for commercial defluoridation.
ENVIRONMENTAL POLLUTION
(2022)
Article
Engineering, Environmental
Carl Francis Zulueta Lacson, Ming-Chun Lu, Yao-Hui Huang
Summary: Fluoride removal was studied through ballasted precipitation, with calcium remaining the most feasible precipitant and CaCO3 demonstrating the highest defluoridation efficiency among the discarded and recovered materials.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Engineering, Chemical
Raissa Antonelli, Geoffroy Roger Pointer Malpass, Meuris Gurgel Carlos da Silva, Melissa Gurgel Adeodato Vieira
Summary: This study investigated the adsorption behavior of antibiotic ciprofloxacin in a calcined Verdelodo clay-packed fixed-bed system. The experimental results showed a breakthrough adsorption capacity of 0.038 mmol g(-1) and a mass transfer zone of 4.29 cm. Comparison with ofloxacin adsorption performance and density functional theory computations were also conducted.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Chemistry, Physical
S. A. Martin, I Perez, A. Rivera
Summary: Bentonite shows potential as a drug delivery system in the pharmaceutical industry due to its high drug loading capacity and controlled drug release properties. It efficiently adsorbs and releases vancomycin, achieving a higher load when in its monovalent cationic form. In vitro assays demonstrate that the vancomycin release profiles meet pharmaceutical standards, suggesting the potential use of Bentonite as a vancomycin carrier.
APPLIED CLAY SCIENCE
(2021)
Article
Biochemistry & Molecular Biology
Adane Woldemedhin Kalsido, Beteley Tekola Meshesha, Beshah M. Behailu, Esayas Alemayehu
Summary: In this study, column adsorption studies on acid-treated Bentonite for fluoride removal indicated an optimized operating condition with 100% removal rate, adsorptive capacity of 2.46 mg/g, and desirability of 1.0. The relationship between experimental and expected response values was analyzed, and variance analysis determined the importance of independent variables and their interactions, ultimately proving the success of acid activation for field application of Bentonite adsorbent.
Article
Electrochemistry
Hao Wang, Wenwen Jiang, Pengfei Nie, Bin Hu, Yongsheng Hu, Manhong Huang, Jianyun Liu
Summary: In this study, a new method for defluoridation was developed by synthesizing lanthanum-doped hydroxyapatite-modified three-dimensional reduced graphene oxide. The resulting electrode showed excellent selectivity and high cycle stability for fluoride removal in a capacitive deionization system, achieving a fluoride removal rate of 90.5% with an effluent concentration below the permissible limit of the World Health Organization.
ELECTROCHIMICA ACTA
(2022)
Article
Materials Science, Multidisciplinary
Rajangam Vinodh, Yesudass Sasikumar, Muthiahpillai Palanichamy, Raji Atchudan, Tansir Ahamad
Summary: In this study, a composite of bentonite clay and APTES was prepared for CO2 adsorption using a simple extrudation procedure. The maximum CO2 adsorption of 16% was achieved for the 5% Bentonite/APTES composite, which retained 88.75% of its initial adsorption capacity over 15 cycles. (C) 2021 Elsevier B.V. All rights reserved.
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
Engineering, Environmental
Hai Nguyen Tran, Fatma Tomul, Nguyen Thi Hoang Ha, Dong Thanh Nguyen, Eder C. Lima, Giang Truong Le, Chang-Tang Chang, Vhahangwele Masindi, Seung Han Woo
JOURNAL OF HAZARDOUS MATERIALS
(2020)
Article
Geochemistry & Geophysics
Beauclair Nguegang, Vhahangwele Masindi, Titus Alfred Makudali Msagati, Memory Tekere
Summary: The study demonstrates that a vertically flowing wetland combined with Vetiveria zizanioides plants and soil substrate can effectively treat acid mine drainage by removing metals and sulfate chemicals. The substrate plays a significant role in metal removal, while plants and external factors also contribute to the reduction of chemical species. Prolonged assessment is needed to understand its long-term performance.
Article
Engineering, Environmental
K. L. Muedi, H. G. Brink, V Masindi, J. P. Maree
Summary: This study successfully synthesized Fe/AlO(OH) from acid mine drainage and examined its arsenate removal capabilities. Optimized conditions were found to be 150 ppm of As(V), a solid:liquid ratio of 1 g: 250 mL, a contact time of 60 min, ambient temperature, and pH.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Geochemistry & Geophysics
Rhulani Shingwenyana, Ayanda N. Shabalala, Ryneth Mbhele, Vhahangwele Masindi
Summary: The concept of circular economy in wastewater treatment has gained significant attention recently, driven by the interest in reducing the ecological footprints of mining activities and metallurgical processes. Countries such as South Africa, China, Australia, and the United States are facing water pollution issues due to acid mine drainage. Through approaches like wastewater treatment, beneficiation, and valorisation, clean water and valuable minerals can be reclaimed from AMD.
Article
Chemistry, Multidisciplinary
Khathutshelo Lilith Muedi, Vhahangwele Masindi, Johannes Philippus Maree, Nils Haneklaus, Hendrik Gideon Brink
Summary: This study presents the first known exploration of using a nanocomposite synthesized from recovered Fe(III) and Al(III) to adsorb Congo red dye. The results showed that the adsorbent had high removal efficiency for the dye and could be regenerated for multiple uses.
Article
Geochemistry & Geophysics
Khathutshelo Lilith Muedi, Vhahangwele Masindi, Johannes Philippus Maree, Hendrik Gideon Brink
Summary: This study evaluated the effectiveness of PDFe/Al adsorbent recovered from real acid mine drainage in removing Cr(VI) from water. Under optimal conditions, a removal rate of over 95% was achieved, along with a high adsorption capacity. Over 90% of the adsorbed Cr(VI) could be recovered after multiple adsorption-desorption cycles. The study proposed a reaction mechanism involving rapid adsorption, in situ Cr(VI) reduction, and adsorption-induced surface strain. This research provides a rapid, effective, and economical solution for treating Cr(VI)-contaminated wastewater using recovered PDFe/Al.
Review
Green & Sustainable Science & Technology
K. Nkele, L. Mpenyana-Monyatsi, V. Masindi
Summary: This review extensively discusses the sources of manganese in wastewater, its ecological toxicological concerns, treatment options, and the potential for manganese recovery from wastewater streams. It highlights the challenges of practicing circular economy in manganese recovery and emphasizes the importance of adopting circular economy and waste beneficiation concepts for ecological sustainability.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Environmental Sciences
V. Masindi, A. Shabalala, S. Foteinis
Summary: The study found that using wastewater treatment methods can effectively process different types of wastewater, such as co-treating wastewater from a phosphorus recovery system with acid mine drainage, to reduce the levels of metals and sulphate contaminants in the wastewater.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Environmental Sciences
Muyahavho Enemiah Mugwili, Frans Boudewijn Waanders, Vhahangwele Masindi, Elvis Fosso-Kankeu
Summary: The ever-growing contamination of surface water due to various catchment activities poses threats and stress to downstream water treatment entities. Specifically, the presence of ammonia, microbial contaminants, organic matter, and heavy metals has been an issue of paramount concern to water treatment entities since stringent regulatory frameworks require these pollutants to be removed prior to water consumption. Herein, a hybrid approach that integrates struvite crystallization (precipitation) and breakpoint chlorination (stripping) for the removal of ammonia from aqueous solution was evaluated. Overall, synergistic and complementary effects of integrating struvite synthesis and breakpoint chlorination hold great promise for the removal of ammonia from aqueous solutions thus confirming that this technology could potentially be used to curtail the effects of ammonia in the receiving environments and drinking water.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Engineering, Environmental
Collen Nepfumbada, Nikita Tawanda Tavengwa, Vhahangwele Masindi, Spyros Foteinis, Efthalia Chatzisymeon
Summary: This study proposes a co-management method for municipal wastewater (MWW) and acid mine drainage (AMD), in which low-value phosphorus recovered from MWW is used to treat AMD. MWW was treated with calcium hydroxide (Ca(OH)2) to greatly reduce ammonia content (89%) and practically eliminate phosphates (>99%). The recovered low-value phosphorus material, in the form of calcium phosphate (Ca3(PO4)2), was then used to treat AMD from coal mining. The treatment effectively depleted metals in AMD (>99% removal) and greatly reduced sulphate (SO4) content (90.6%), under optimal conditions of 90 min contact time, 10 g L-1 Ca3(PO4)2 dosage, and room temperature and ambient pH. The method shows promise for sustainable management of wastewater matrices and can contribute to advancing the UN's sustainable development goals.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Article
Environmental Sciences
Ntsako Dellas Baloyi, Memory Tekere, Khumbudzo Walter Maphangwa, Vhahangwele Masindi
Summary: This study assessed the temporal dynamics and ecotoxicological risk of phthalic acid esters (PAEs) in aquatic ecosystems. Water samples were collected from seven selected sites over six consecutive months to evaluate seasonal variabilities. The results showed that DBP was the most abundant PAE homologue, and DBP and DiDP posed high risk to aquatic organisms. The findings are important for guiding regulators, custodians, and catchment management forums in understanding the status and potential effects of PAEs in the environment.
Article
Environmental Sciences
Vhahangwele Masindi, Ryneth Mbhele, Spyros Foteinis
Summary: In this study, the alkaline supernatant from struvite recovery system was successfully co-treated with acid mine drainage (AMD) from municipal wastewater. Different ratios of AMD to struvite supernatant were examined, and the quality of the co-treated effluent and generated sludge were analyzed. The results showed that the optimal ratio was 1:9, which effectively removed metals and sulphate from AMD and suggested opportunities for mineral recovery. The final effluent pH was regulated to acceptable levels, and the reduction in electrical conductivity indicated the attenuation of contaminants. This passive co-treatment approach offers potential for scaling up and introducing circular economy and zero liquid discharge in wastewater treatment and management.
Article
Green & Sustainable Science & Technology
Vhahangwele Masindi, Spyros Foteinis
Summary: In rural and peri-urban areas of developing countries, groundwater used for drinking water is polluted due to onsite wastewater management systems, which poses a significant threat to public health. High levels of faecal contamination and other pollutants were found in groundwater samples, indicating the need for treatment before consumption. A simple classification model was developed to assess water quality, identify pollution sources, and prioritize water infrastructure investments in developing regions.
CLEANER ENGINEERING AND TECHNOLOGY
(2021)
Article
Multidisciplinary Sciences
Vhahangwele Masindi
Article
Engineering, Environmental
A. Mavhungu, V Masindi, S. Foteinis, R. Mbaya, M. Tekere, I Kortidis, E. Chatzisymeon
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2020)
