Interfacial microstructures and adsorption mechanisms of benzohydroxamic acid on Pb2+-activated cassiterite (1 1 0) surface

Sulfuration flotation is the most widely used technology in malachite beneficiation. However, the inhomogeneity of malachite surfaces usually results in a non-uniform sulfuration surface. The motivation of this work is attempt to adopt different functional combination collectors to enhance the sulfuration flotation of malachite. Accordingly, the flotation behaviors and adsorption mechanisms of benzohydroxamic acid (BHA) and sodium butyl-xanthate (SBX) on the surface of malachite were systematically investigated using flotation tests, zeta-potential measurements, Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and first-principle calculations. The test results of vulcanization flotation showed that the combined collectors of SBX with BHA possessed a higher recovery than only using SBH by 20%, indicating that there may be a synergistic effect between BHA and SBX. The IR and Raman spectroscopy demonstrated that both BHA and SBX could chemically adsorb onto the malachite surface. The density functional theory (DFT) calculation results further indicated that the combined adsorption energy of BHA and SBX was much lower than that of only BHA or SBX, which confirmed the synergistic effects of BHA and SBX on the malachite surface. This work may shed new light on the design and development of more efficient combined flotation reagents.

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Comparison of the fixation of several metal ions onto a low-cost biopolymer

Water Science & Technology Water Supply ◽

10.2166/ws.2002.0172 ◽

2002 ◽

Vol 2 (5-6) ◽

pp. 217-224 ◽

Cited By ~ 6

Author(s):

Z. Reddad ◽

C. Gérente ◽

Y. Andrès ◽

P. Le Cloirec

Keyword(s):

Aqueous Solutions ◽

Metal Ions ◽

Low Cost ◽

Operating Conditions ◽

Order Kinetic ◽

Adsorption Mechanisms ◽

Equilibrium Data ◽

Order Kinetic Model ◽

Beet Pulp ◽

Removal Of Metal Ions

In the present work, sugar beet pulp, a common waste from the sugar refining industry, was studied in the removal of metal ions from aqueous solutions. The ability of this cheap biopolymer to sorb several metals namely Pb2+, Cu2+, Zn2+, Cd2+ and Ni2+ in aqueous solutions was investigated. The metal fixation capacities of the sorbent were determined according to operating conditions and the fixation mechanisms were identified. The biopolymer has shown high elimination rates and interesting metal fixation capacities. A pseudo-second-order kinetic model was tested to investigate the adsorption mechanisms. The kinetic parameters of the model were calculated and discussed. For 8 × 10-4 M initial metal concentration, the initial sorption rates (v0) ranged from 0.063 mmol.g-1.min-1 for Pb2+ to 0.275 mmol.g-1.min-1 for Ni2+ ions, with the order: Ni2+ > Cd2+ > Zn2+ > Cu2+ > Pb2+. The equilibrium data fitted well with the Langmuir model and showed the following affinity order of the material: Pb2+ > Cu2+ > Zn2+ > Cd2+ > Ni2+. Then, the kinetic and equilibrium parameters calculated qm and v0 were tentatively correlated to the properties of the metals. Finally, equilibrium experiments in multimetallic systems were performed to study the competition of the fixation of Pb2+, Zn2+ and Ni2+ cations. In all cases, the metal fixation onto the biopolymer was found to be favourable in multicomponent systems. Based on these results, it is demonstrated that this biosorbent represents a low-cost solution for the treatment of metal-polluted wastewaters.

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Integrated structural and chemical analyses for HCl-supported hydrochar and their adsorption mechanisms for aqueous sulfachloropyridazine removal

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2021.126009 ◽

2021 ◽

pp. 126009

Author(s):

Lin Liu ◽

Siong Fong Sim ◽

Sen Lin ◽

Jiang Wan ◽

Wei Zhang ◽

...

Keyword(s):

Chemical Analyses ◽

Adsorption Mechanisms

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Stormwater Runoff Treatment Using Pervious Concrete Modified with Various Nanomaterials: A Comprehensive Review

Sustainability ◽

10.3390/su13158552 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8552

Author(s):

Vahid Alimohammadi ◽

Mehdi Maghfouri ◽

Delaram Nourmohammadi ◽

Pejman Azarsa ◽

Rishi Gupta ◽

...

Keyword(s):

Heavy Metals ◽

Compressive Strength ◽

Adsorption Capacity ◽

Removal Rate ◽

Stormwater Runoff ◽

Infiltration Rate ◽

Stormwater Treatment ◽

Adsorption Mechanisms ◽

Wide Range ◽

Adsorption Processes

Clean water is a vital need for all living creatures during their lifespan. However, contaminated stormwater is a major issue around the globe. A wide range of contaminants, including heavy metals, organic and inorganic impurities, has been discovered in stormwater. Some commonly utilized methods, such as biological, physical and chemical procedures, have been considered to overcome these issues. However, these current approaches result in moderate to low contaminant removal efficiencies for certain classes of contaminants. Of late, filtration and adsorption processes have become more featured in permeable concretes (PCs) for the treatment of stormwater. As nanoparticles have vast potential and unique characterizations, such as a higher surface area to cure polluted stormwater, employing them to improve permeable concretes’ capabilities in stormwater treatment systems is an effective way to increase filtration and adsorption mechanisms. The present study reviews the removal rate of different stormwater contaminants such as heavy metals, organic and other pollutants using nanoparticle-improved PC. The application of different kinds of nanomaterials in PC as porous media to investigate their influences on the properties of PC, including the permeability rate, compressive strength, adsorption capacity and mix design of such concrete, was also studied. The findings of this review show that different types of nanomaterials improve the removal efficiency, compressive strength and adsorption capacity and decrease the infiltration rate of PC during the stormwater treatment process. With regard to the lack of comprehensive investigation concerning the use of nanomaterials in PC to treat polluted stormwater runoff, this study reviews 242 published articles on the removal rate of different stormwater contaminants by using PC improved with nanoparticles.

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Adsorption mechanism of NH3, NO, and O2 molecules over FexOy/AC catalyst surface: a DFT-D3 study

New Journal of Chemistry ◽

10.1039/d0nj05628f ◽

2021 ◽

Author(s):

Chaoyue Xie ◽

Yunlan Sun ◽

Baozhong Zhu ◽

Weiyi Song ◽

Minggao Xu

Keyword(s):

Activated Carbon ◽

Adsorption Mechanism ◽

Catalyst Surface ◽

Specific Adsorption ◽

Adsorption Mechanisms ◽

Iron Based ◽

Iron Based Catalysts ◽

Supported Iron ◽

Denox Efficiency

Activated carbon-supported iron-based catalysts (FexOy/AC) show excellent deNOx efficiency. However, the specific adsorption mechanisms of NH3, NO, and O2 molecules on their surfaces are still unknown. In this study, the...

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Effects of Hydration on the Adsorption of Benzohydroxamic Acid on the Lead-Ion-Activated Cassiterite Surface: A DFT Study

Langmuir ◽

10.1021/acs.langmuir.0c03575 ◽

2021 ◽

Vol 37 (6) ◽

pp. 2205-2212

Author(s):

Jianyong He ◽

Hongliang Zhang ◽

Tong Yue ◽

Wei Sun ◽

Yuehua Hu ◽

...

Keyword(s):

Dft Study ◽

Lead Ion ◽

Benzohydroxamic Acid

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Mechanisms and adsorption capacities of biochar for the removal of organic and inorganic pollutants from industrial wastewater

International Journal of Environmental Science and Technology ◽

10.1007/s13762-020-03060-w ◽

2020 ◽

Author(s):

T. G. Ambaye ◽

M. Vaccari ◽

E. D. van Hullebusch ◽

A. Amrane ◽

S. Rtimi

Keyword(s):

Organic Contaminants ◽

Pyrolysis Temperature ◽

Low Cost ◽

Industrial Effluents ◽

Economic Benefits ◽

Inorganic Pollutants ◽

Solution Ph ◽

Adsorption Mechanisms ◽

Adsorption Capacities ◽

Temperature Solution

AbstractCurrently, due to the rapid growth of urbanization and industrialization in developing countries, a large volume of wastewater is produced from industries that contain chemicals generating high environmental risks affecting human health and the economy if not treated properly. Consequently, the development of a sustainable low-cost wastewater treatment approach has attracted more attention of policymakers and scientists. The present review highlights the recent applications of biochar in removing organic and inorganic pollutants present in industrial effluents. The recent modes of preparation, physicochemical properties and adsorption mechanisms of biochar in removing organic and inorganic industrial pollutants are also reviewed comprehensively. Biochar showed high adsorption of industrial dyes up to 80%. It also discusses the recent application and mechanism of biochar-supported photocatalytic materials for the degradation of organic contaminants in wastewater. We reviewed also the possible optimizations (such as the pyrolysis temperature, solution pH) allowing the increase of the adsorption capabilities of biochar leading to organic contaminants removal. Besides, increasing the pyrolysis temperature of the biochar was seen to lead to an increase in its surface area, while it decreases their amount of oxygen-containing functional groups, consequently leading to a decrease in the adsorption of metal (loid) ions present in the medium. Finally, the review suggests that more research should be carried out to optimize the main parameters involved in biochar production and its regeneration methods. Future efforts should be also carried out towards process engineering to improve its adsorption capacity to increase the economic benefits of its implementation.

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Sustainable Chromium (VI) Removal from Contaminated Groundwater Using Nano-Magnetite-Modified Biochar via Rapid Microwave Synthesis

Molecules ◽

10.3390/molecules26010103 ◽

2020 ◽

Vol 26 (1) ◽

pp. 103

Author(s):

Xiaoming Song ◽

Yuewen Zhang ◽

Nan Cao ◽

Dong Sun ◽

Zhipeng Zhang ◽

...

Keyword(s):

Synthesis Method ◽

Microwave Treatment ◽

Contaminated Groundwater ◽

Maximum Adsorption Capacity ◽

Intraparticle Diffusion Model ◽

Adsorption Mechanisms ◽

Chromium Vi ◽

Modified Biochar ◽

Pseudo Second Order ◽

Nano Fe3o4

This study developed a nano-magnetite-modified biochar material (m-biochar) using a simple and rapid in situ synthesis method via microwave treatment, and systematically investigated the removal capability and mechanism of chromium (VI) by this m-biochar from contaminated groundwater. The m-biochar was fabricated from reed residues and magnetically modified by nano-Fe3O4. The results from scanning electron microscopy (SEM) and X-ray diffraction (XRD) characterisations confirmed the successful doping of nano-Fe3O4 on the biochar with an improved porous structure. The synthesised m-biochar exhibited significantly higher maximum adsorption capacity of 9.92 mg/g compared with that (8.03 mg/g) of the pristine biochar. The adsorption kinetics followed the pseudo-second-order model and the intraparticle diffusion model, which indicated that the overall adsorption rate of Cr(VI) was governed by the processes of chemical adsorption, liquid film diffusion and intramolecular diffusion. The increasing of the pH from 3 to 11 significantly affected the Cr(VI) adsorption, where the capabilities decreased from 9.92 mg/g to 0.435 mg/g and 8.03 mg/g to 0.095 mg/g for the m-biochar and pristine biochar, respectively. Moreover, the adsorption mechanisms of Cr(VI) by m-biochar were evaluated and confirmed to include the pathways of electrostatic adsorption, reduction and complexation. This study highlighted an effective synthesis method to prepare a superior Cr(VI) adsorbent, which could contribute to the effective remediation of heavy metal contaminations in the groundwater.

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