Article
Biochemistry & Molecular Biology
Huimei Shan, Chunya Zeng, Chaoran Zhao, Hongbin Zhan
Summary: This study evaluates the effects of Iron oxides (FeOx) species and their decoration on GO/CS composites for Cr(VI) removal, finding that Fe(III) is a better decoration material. The Fe2O3-GO/CS composite shows high removal efficiency (94.3%) and adsorption capacity (83.8 mg/g) under optimal conditions. Cr(VI) adsorption is spontaneous, endothermic, and best fitted with the Sips model.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2021)
Article
Environmental Sciences
Dibya Ranjan Rout, Hara Mohan Jena
Summary: This study successfully synthesized a novel ternary composite that serves as an innovative and excellent adsorbent for wastewater treatment. The composite exhibited excellent Cr(VI) removal performance, with adsorption mechanisms involving electrostatic attraction, pi-pi interaction, ion exchange, and metal ion complexion.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Chemistry, Physical
Yunquan Liu, Huimei Shan, Chunya Zeng, Hongbin Zhan, Yanyue Pang
Summary: In this study, alpha-FeO(OH)/GOCS microspheres were prepared and used for the removal of Cr(VI) from aqueous solutions. The effects of various factors on the adsorption process were investigated, and it was found that pH, mass and volume ratio, coexisting ions, time, temperature, and initial concentration of Cr(VI) all influenced the removal efficiency. The equilibrium adsorption capacity of Cr(VI) was found to be 24.16 mg/g, and the removal rate was 97.69% under specific experimental conditions. The adsorption process followed a pseudo-second-order kinetic model and was spontaneous and endothermic. No secondary pollution of Fe was observed during the Cr(VI) adsorption process.
Article
Environmental Sciences
Simranjeet Singh, T. S. Sunil Kumar Naik, Amith G. Anil, Sutripto Khasnabis, Bidisha Nath, U. Basavaraju, Vineet Kumar, V. K. Garg, S. Subramanian, Joginder Singh, Praveen C. Ramamurthy
Summary: A novel green nanocomposite has been prepared by immobilizing CaO nanoparticles on the surface of graphene oxide, which shows promising adsorption capacity for Cr(VI) removal and serves as an excellent sensor for Cr(VI) sensing.
Article
Environmental Sciences
Lingling Wang, Dionysios D. Dionysiou, Jianming Lin, Yuxian Huang, Xiaolan Xie
Summary: The research found that humic acid and Cr(VI) displayed synergy in their removal process by ZnO-30N-zeolite, accelerating the removal of humic acid significantly while not affecting the removal capacity of Cr(VI). This study proposed a kinetic mechanism for the synergistic removal of humic acid and Cr(VI) by ZnO-30N-zeolite in a binary pollutant system.
Article
Environmental Sciences
Jianlei Gao, Mengyuan Feng, Yixin Yan, Zixu Zhao, Yingchun Wang
Summary: In this research, a new composite adsorbent (SC@ZVI@CS-AA) was designed and synthesized for the removal of Cr(VI) in groundwater. The adsorption process was dominated by chemisorption and the removal efficiency of Cr(VI) reached 95%. SC@ZVI@CS-AA had good cyclic adsorption performance, showing great potential in the remediation of Cr(VI)-contaminated groundwater.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Materials Science, Paper & Wood
M. R. El-Aassar, F. M. Mohamed, Ibrahim Hotan Alsohaimi, R. E. Khalifa
Summary: This study verified the adsorption of hexavalent chromium from synthetic aqueous solution using a new low-cost adsorbent prepared from H2O2-modified olive seed residue solid waste/Anthracite/Chitosan composite. The Langmuir model best described the adsorption process, indicating it is endothermic and a non-spontaneous reaction.
Article
Chemistry, Applied
Mojtaba Safaviyan, Mehdi Faramarzi, Seyed Aboutaleb Mousavi Parsa, Hajir Karimi
Summary: In this study, a novel Cr(VI) adsorbent, TEPA-enriched MGO, was developed and characterized. The optimal parameters for Cr(VI) sorption, including Cr(VI)/MGOT ratio, temperature, and pH, were determined through Box-Behnken Design. The maximum adsorption capacity was found to be 287.15 mg/g. The Lagergren kinetic and Langmuir isotherm models accurately represented the adsorption process on MGOT. Based on the obtained results, MGOT was identified as an excellent reusable adsorbent for selective Cr(VI) sorption and magnetic separation from wastewater.
REACTIVE & FUNCTIONAL POLYMERS
(2022)
Article
Chemistry, Physical
Yashvi Sheth, Swapnil Dharaskar, Mohammad Khalid, Rashmi Walvekar
Summary: A novel composite adsorptive film was prepared in this study by modifying chitosan with 1butyl-3-methylimidazolium acetate (Chitosan-[BMIM][OAc]). The film demonstrated excellent removal efficiency and fast kinetics for Cr(VI) removal from contaminated water.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Engineering, Chemical
Yanlin Liu, Xiaohuan Tang, Limin Zhou, Zhirong Liu, Jinbo Ouyang, Yiming Dai, Zhanggao Le, Adesoji A. Adesina
Summary: In this study, chitosan/graphene oxide (CS/GO) nano-electrodes were fabricated for the efficient electrosorption of U(VI) from uranium-containing effluents. The CS/GO-4 electrode showed the best electrosorption performance for U(VI) due to its well-balanced meso-/micro-porous structure and superior conductivity. The isotherms and kinetics were fitted by Langmuir model. The maximum removal capacity for U(VI) reached 271.2 mg/g at 0.9 V, which was almost double compared to 0.0 V. The electrosorption-desorption cycles further demonstrated the potential application of CS/GO electrode materials for the removal of U(VI) from radioactive wastewater.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Yunquan Liu, Huimei Shan, Yanyue Pang, Hongbin Zhan, Chunya Zeng
Summary: Iron modified chitosan/coconut shell activated carbon (Fe/CSCC) composite bead was synthesized and characterized for the removal of Cr(VI). The results showed that the adsorption capacity of Cr(VI) increased with the increase of iron loading, contact time, initial concentration, and temperature, but decreased with the increase of pH, mass and volume ratio. The Fe/CSCC exhibited a high removal efficiency of 97.25% at specific conditions. The presence of coexisting ions led to a decrease in adsorption capacity, and Fe/CSCC showed a pseudo-second-order kinetic with a maximum adsorption capacity of 64.49 mg/g. Characterization analysis revealed that electrostatic attraction and complexation played a major role in the adsorption process.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Chemistry, Multidisciplinary
Feng Gao, Lei Zhang, Libin Yang, Xuefei Zhou, Yalei Zhang
Summary: Three types of graphene oxides (GOs) were prepared and used for the removal of Cr(VI). The adsorption performance of GOs was affected by initial concentration, pH, adsorbent dosage, contact time, and temperature. The adsorption mechanisms involved redox reaction, electrostatic attraction, pore filling, ion exchange, and complexation. The adsorption processes were mainly monolayer chemisorption and equilibrium could be reached in 30 min. The saturation adsorption capacities of GO-M1, GO-M2, and GO-M3 for Cr(VI) were estimated to be 3.5412 mg.g(-1), 2.3631 mg.g(-1), and 7.0358 mg.g(-1), respectively. The adsorption processes of Cr(VI) by GOs were endothermic, entropy-driven, and thermodynamically spontaneous and feasible. These findings provide important insights into the mechanism and application of Cr(VI) removal by GOs.
Article
Materials Science, Multidisciplinary
Julide Hizal, Nergiz Kanmaz, Mesut Yilmazoglu
Summary: This study investigated the retention of uranyl ions using a novel, natural and cost-effective adsorbent, humic acid (HA) embedded chitosan/polyvinyl alcohol (Ch/PVA-HA) bio composite. The Ch/PVA-HA achieved the highest adsorption capacity reported in literature in a column system. The batch tests showed that the adsorption isotherm of uranyl ions changed from Freundlich to Langmuir when the surface of Ch/PVA copolymer was covered with HA. The presence of HA enhanced the distribution ratio of uranyl ions between the adsorbent phase and aqueous solution.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Physical
Delong Kong, Lijuan He, Hansheng Li, Fan Zhang, Zenghong Song
Summary: In this study, a new 3-glycidoxypropyltrimethoxysilane cross-linked graphene oxide/chitosan composite aerogel was successfully synthesized, with a stable porous structure and high adsorption performance. The composite aerogel showed good reusability and high adsorption capacity for Cr(VI) and other ions, following Langmuir monolayer adsorption and pseudo-second-order kinetic model.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Materials Science, Multidisciplinary
Sanjiwani Korde, Swati Tandekar, Christine Jeyaseelan, D. Saravanan, Ravin Jugade
Summary: A magnetic chitosan-zirconia-iron oxide nanocomposite was synthesized and used for adsorption of Cr(VI) ions, showing good adsorption capacity and easy separation using an external magnet. Characterization of the synthesized adsorbent was conducted using various analytical methods, revealing specific adsorption models and kinetics with high adsorption capacity.
