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Removal Of Metal Ions

Tianli Yang, Ren He, Guihua Nie, Wenlei Wang, Gui Zhang, Yunchu Hu, Lichao Wu
In this work, carbon quantum dots were first prepared through one-pot hydrothermal route of the propyl aldehyde and sodium hydroxide via an aldol condensation reaction, and a novel solid-phase extraction adsorbent of hollow calcite single crystals was prepared via the precipitation of metal nitrates by the CO2 diffusion method in the presence of CQDs and further applied for excessive Cd(II) ions removal from water. The spectra and morphologies of the etched calcite were investigated by X-ray diffraction, Fourier transform infrared spectrometry, Scanning electron microscope, and Transmission electron microscopy...
December 4, 2018: Scientific Reports
Baharak Sajjadi, James William Broome, Wei Yin Chen, Daniell L Mattern, Nosa O Egiebor, Nathan Hammer, Cameron L Smith
The main objective of a series of our researches is to develop a novel acoustic-based method for activation of biochar. This study investigates the capability of biochar in adsorbing Ni(II) as a hazardous contaminant and aims at enhancing its adsorption capacity by the addition of extra nitrogen and most probably phosphorous and oxygen containing sites using an ultrasono-chemical modification mechanism. To reach this objective, biochar physically modified by low-frequency ultrasound waves (USB) was chemically treated by phosphoric acid (H3 PO4 ) and then functionalized by urea (CO(NH2 )2 )...
March 2019: Ultrasonics Sonochemistry
Ying Li, Gaoling Wei, Caihua Zhang, Xiaoliang Liang, Wei Chu, Hongping He, Joseph W Stucki, Lingya Ma, Xiaoju Lin, Jianxi Zhu
The interaction between magnetite and aqueous Fe(II) profoundly impacts the mineral recrystallization, trace-metal sequestration, and contaminant reduction. The iron ions in natural magnetite are extensively substituted by other cations. It is still unclear whether the substitution with thermodynamically favorable redox repairs (e.g., Co2+ /Co3+ ) plays a vital role in the reducing capability of the coupled system. Herein, a series of Co-substituted magnetite samples (Fe3-x Cox O4 , 0.00 ≤ x ≤ 1...
November 24, 2018: Science of the Total Environment
Azile Nqombolo, Anele Mpupa, Aphiwe S Gugushe, Richard M Moutloali, Philiswa N Nomngongo
In this work, cobalt-methylimidazolate framework has been used as an adsorbent in the removal of Pb(II) from acid mine drainage in adsorption batch system. X-ray diffraction, Fourier-transform infrared spectroscopy, Brunauer-Emmet-Teller and transmission electron microscope were used for structural, morphological, and surface characteristics of cobalt-methylimidazolate framework. The concentration of heavy metal ions in water samples was measured by inductively coupled plasma optical emission spectrometry. Different experimental factors/variables (such as contact time, dosage, and pH) affecting the adsorption of Pb(II) from acid mine drainage were optimized by response surface methodology based on central composite design...
December 3, 2018: Environmental Science and Pollution Research International
Jesus Cantu, Diego F Gonzalez, Yvette Cantu, Tom Eubanks, J G Parsons
In the present study, pyrrhotite (Fe7 S8 ) was investigated for the removal of Pb2+ and Cu2+ ions from aqueous solution. The Fe7 S8 material was prepared through a solvothermal method and was characterized using XRD. The average particle size for the nanomaterial was determined to be 29.86 ± 0.87 nm using XRD analysis and Scherrer's equation. Batch studies were performed to investigate the effects of pH, time, temperature, interfering ions, and the binding capacity of Pb2+ and Cu2+ ions to the Fe7 S8 nanomaterial...
July 2018: Microchemical Journal, Devoted to the Application of Microtechniques in All Branches of Science
Yonghai Gan, Xiaomeng Wang, Li Zhang, Bingdang Wu, Guoyang Zhang, Shujuan Zhang
Fluoride (F- ) pollution is a worldwide issue. Coagulation with aluminum (Al) salts is an efficient and economical method for the removal of F- . However, due to the strong complexation between Al3+ and F- , the residual F- and Al after coagulation usually exceed the limits. Zirconium (Zr) coagulants have drawn increasing attention due to their excellent flocculation ability for organic matter. In this work, the performance and mechanism of ZrCl4 coagulation for F- removal were investigated with the widely used Al2 (SO4 )3 as a reference...
November 28, 2018: Chemosphere
M I A Abdel Maksoud, Gharieb S El-Sayyad, A H Ashour, Ahmed I El-Batal, Mohamed A Elsayed, Mohamed Gobara, Ahmed M El-Khawaga, E K Abdel-Khalek, M M El-Okr
This study reports the photocatalytic degradation of Methylene Blue (MB) dye (a class of dyestuffs that are resistant to biodegradation) under the influence of UV-light irradiation. Antibacterial and antibiofilm activities of ferrite nanoparticles (FO NPs) were examined against some pathogenic bacteria isolated from the medical operating room surfaces. In the same context, metals-substituted spinel cobalt ferrite nanoparticles with nominal composition [Mx Co1-x Fe2 O4 NPs; (M = Zn, Cu, Mn; x = 0.0, 0...
November 28, 2018: Microbial Pathogenesis
Pingfeng Fu, Zihao Chen, Tianwen Yang
The porous metallic iron/carbon (Fe0 /C) ceramsites, with virtues of low cost and 'green' fabrication, were prepared by direct reduction roasting of magnetite, coal, and paper mill sludge. The X-ray diffraction data revealed that Fe0 was generated in situ by reducing the magnetite at 1,200 °C. Scanning electron microscopy with energy-dispersive X-ray spectroscopy indicated that Fe0 particles, with a size of <10 μm, were highly dispersed on carbon particles to form an integrated anode (Fe0 ) and cathode (C) structure of microelectrolysis filters...
November 2018: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Francielle Almeida Cordeiro, Bárbara Marques Coutinho, Gisele Adriano Wiezel, Karla de Castro Figueiredo Bordon, Cristiane Bregge-Silva, Nathalia Gonsales Rosa-Garzon, Hamilton Cabral, Beatrix Ueberheide, Eliane Candiani Arantes
Background: Lachesis muta rhombeata (Lmr) is the largest venomous snake in Latin America and its venom contains mainly enzymatic components, such as serine and metalloproteases, L-amino acid oxidase and phospholipases A2 . Metalloproteases comprise a large group of zinc-dependent proteases that cleave basement membrane components such as fibronectin, laminin and collagen type IV. These enzymes are responsible for local and systemic changes, including haemorrhage, myonecrosis and inflammation...
2018: Journal of Venomous Animals and Toxins Including Tropical Diseases
C Lavanya, R Geetha Balakrishna, Khantong Soontarapa, Mahesh S Padaki
This study investigates the removal of heavy metal ions and humic acid using Cellulose acetate (CA) and Poly (methyl vinyl ether-alt-maleic acid) (PMVEMA) blend membranes. Antifouling properties of blend membranes were also investigated. Flat sheet membranes were prepared by phase inversion technique using different concentrations of CA and PMVEMA. The prepared membranes were characterized and their performance was evaluated by measuring pure water flux, water uptake capacity and humic acid removal. Rejection of humic acid (HA) was observed to be around 97% for all the blend membranes because of electrostatic interactions between the functional groups of HA and blends...
November 26, 2018: Journal of Environmental Management
Zonglin Gu, Wei Song, Zaixing Yang, Ruhong Zhou
Heavy metal ions from water and wastewater are non-biodegradable and tend to accumulate in the soil and living organisms, polluting the environment and causing serious health hazards in humans. Therefore, effective treatment of heavy metal ions in aqueous media is critical for public health and environmental sustainability. In this paper, we employ molecular dynamics simulations to investigate the removal efficiency of heavy metal cations (Cd2+, Hg2+, and Pb2+) by a zirconium phosphonate based metal-organic framework (MOF) filter and also to explore its underlying molecular mechanism...
November 29, 2018: Physical Chemistry Chemical Physics: PCCP
Hitesh Saravaia, Hariom Gupta, Pooja Popat, Parthrajsinh Sodha, Vaibhav Kulshrestha
Magnesium doped lithium manganese oxide nanosorbent is prepared by a single step solid state method and characterized with appropriate analytical techniques, adsorption kinetic model and isotherms. Competitive and non-competitive adsorption studies are performed for a range of heavy metal ions. Prepared nanosorbent has shown explicit selectivity for various heavy metal ions and no remarkable influence of coexisting common interfering ions (Na+, K+, Mg2+ and Ca2+) which are generally coexist with all natural sources of water, contaminated water and industrial waste...
November 29, 2018: ACS Applied Materials & Interfaces
Ward van der Stam, Indy du Fossé, Gianluca Grimaldi, Julius O V Monchen, Nicholas Kirkwood, Arjan J Houtepen
The photoluminescence (PL) quantum yield of semiconductor nanocrystals (NCs) is hampered by in-gap trap states due to dangling orbitals on the surface of the nanocrystals. While crucial for the rational design of nanocrystals, the understanding of the exact origin of trap states remains limited. Here, we treat CdTe nanocrystal films with different metal chloride salts and we study the effect on their optical properties with in situ spectroelectrochemistry, recording both changes in absorption and photoluminescence...
November 13, 2018: Chemistry of Materials: a Publication of the American Chemical Society
Saraswati Saini, Jatinder Kaur Katnoria, Inderpreet Kaur
  The present study pertains to evaluate the efficiency of Dendrocalamus strictus charcoal powder as an adsorbent to adsorb copper ions from aqueous solution under different conditions of pH, initial metal ion concentration, adsorbent dose, contact time, and temperature. Physical characterization of Dendrocalamus strictus charcoal powder was performed using different techniques such as scanning electron microscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, Brunauer Emmett and Teller surface analysis and X-ray diffraction...
November 1, 2018: Water Environment Research: a Research Publication of the Water Environment Federation
Shishu Zhu, Xiaojie Li, Jian Kang, Xiaoguang Duan, Shaobin Wang
Minerals and transitional metal oxides of earth-abundant elements are desirable catalysts for in situ chemical oxidation in environmental remediation. However, catalytic activation of peroxydisulfate (PDS) by manganese oxides was barely investigated. In this study, one-dimension manganese dioxides (α- and β-MnO2) were discovered as effective PDS activators among the diverse manganese oxides for selective degradation of organic contaminants. Compared with other chemical states and crystallographic structures of manganese oxide, β-MnO2 nanorods exhibited the highest phenol degradation rate (0...
November 27, 2018: Environmental Science & Technology
Yiyi Deng, Shuang Huang, David A Laird, Xiugui Wang, Zhuowen Meng
Adsorption mechanisms and competition between Cd2+ and Ni2+ for adsorption by rice straw biochars prepared at 400 °C (RB400) and 700 °C (RB700) were investigated in this study. Based on the Langmuir model, the maximum adsorption capacities (mg g-1 ) of Cd2+ and Ni2+ on RB400 and RB700 were in the order of Cd2+ (37.24 and 65.40) > Ni2+ (27.31 and 54.60) in the single-metal adsorption isotherms and Ni2+ (25.20 and 32.28) > Cd2+ (24.22 and 26.78) in the binary-metal adsorption isotherms. Cd2+ competed with Ni2+ for binding sites at initial metal concentrations >10 mg L-1 for RB400 and > 20 mg L-1 for RB700...
November 15, 2018: Chemosphere
Monika Nehra, Neeraj Dilbaghi, Nitin Kumar Singhal, Ashraf Aly Hassan, Ki-Hyun Kim, Sandeep Kumar
The excessive discharge of phosphate in water bodies is one of the primary factors causing eutrophication. Therefore, its removal is of significant research interest. The present study deals with the development and performance of highly effective phosphate-adsorbent. Here, we have synthesized MIL-100(Fe) metal-organic frameworks as a facile strategy to effectively remove phosphate from eutropic water samples. The adsorbent was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and wavelength dispersive X-ray fluorescence (WDXRF)...
November 14, 2018: Environmental Research
Belisa A Marinho, Raquel O Cristóvão, Rui A R Boaventura, Vítor J P Vilar
Water pollution by human activities is a global environmental problem that requires innovative solutions. Arsenic and chromium oxyanions are toxic compounds, introduced in the environment by both natural and anthropogenic activities. In this review, the speciation diagrams of arsenic and chromium oxyanions in aqueous solutions and the analytical methods used for their detection and quantification are presented. Current and potential treatment methods for As and Cr removal, such as adsorption, coagulation/flocculation, electrochemical, ion exchange, membrane separation, phyto- and bioremediation, biosorption, biofiltration, and oxidative/reductive processes, are presented with discussion of their advantages, drawbacks, and the main recent achievements...
November 24, 2018: Environmental Science and Pollution Research International
Qiang Li, Lizhou Tang, Jiang Hu, Ming Jiang, Xiaodong Shi, Tianxi Zhang, Yuan Li, Xuejun Pan
Biochars were produced from long-root Eichhornia crassipes at four temperatures: 200, 300, 400 and 500°C, referred to as LEC200, LEC300, LEC400 and LEC500, respectively. The sorption ability of lead, zinc, copper and cadmium from aqueous solutions by four kinds of biochars was investigated. All the biochars had lower values of CEC and higher values of pH. LEC500 was the best one to bind toxic metals which can be reflected in the results of SEM, BET and elemental analyser. It was also found that alkyl, carboxyl, phosphate and cyano groups in the biochars can play a role in binding metals...
October 2018: Royal Society Open Science
Mohammad Rezaul Karim, Mohammed Omer Aijaz, Nabeel H Alharth, Hamad F Alharbi, Fahad S Al-Mubaddel, Md Rabiul Awual
The nanofibers membranes were fabricated by poly(vinyl alcohol)/chitosan (PVA/Chi) using an electro-spun technique for selective and high adsorption of lead (Pb(II)) and cadmium (Cd(II)) ions based on the solution acidity. The PVA/Chi NFs membranes were characterized systematically using several instrumentations. In addition, several experimental parameters such as initial metal ions concentration, interaction time, adsorbent dosage, solution pH and the effects of competing ions on Pb(II) and Cd(II) adsorption were evaluated...
November 22, 2018: Ecotoxicology and Environmental Safety
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