Activation effect of lead ions on scheelite flotation: Adsorption mechanism, AFM imaging and adsorption model

2019 ◽  
Vol 209 ◽  
pp. 955-963 ◽  
Author(s):  
Liuyang Dong ◽  
Fen Jiao ◽  
Wenqing Qin ◽  
Hailing Zhu ◽  
Wenhao Jia
Keyword(s):  
Adsorption Mechanism ◽  
Lead Ions ◽  
Adsorption Model ◽  
Activation Effect ◽  
Afm Imaging

scholarly journals Microwave-assisted preparation of manganese dioxide modified activated carbon for adsorption of lead ions

2020 ◽  
Author(s):  
Heng Yan ◽  
Wenhai Hu ◽  
Song Cheng ◽  
Hongying Xia ◽  
Quan Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Manganese Dioxide ◽  
Microwave Heating ◽  
Metal Ion ◽  
Adsorption Mechanism ◽  
Lead Ions ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Fast Heating

Abstract In this study, manganese dioxide was evenly distributed on the surface of activated carbon (AC), and the porous structure of AC and the surface functional groups of manganese dioxide were used to adsorb the heavy metal ion Pb(II). The advantages of microwave heating are fast heating and high selectivity. The mole ratio control of the AC and MnO2 in 1:0.1, microwave heating to 800 °C, heat preservation for 30 min. The maximum adsorption capacity of the MnO2-AC prepared by this method on Pb(II) can reach 664 mg/L at pH = 6. It can be observed by SEM that manganese dioxide particles are dispersed evenly on the surface and pore diameter of AC, and there is almost no agglomeration. The specific surface area was 752.8 m2/g, and the micropore area was 483.9 m2/g. The adsorption mechanism was explored through adsorption isotherm, adsorption kinetics, FTIR, XRD, XPS. It is speculated that the adsorption mechanism includes electrostatic interaction and specific adsorption, indicating that lead ions enter into the void of manganese dioxide and form spherical complexes. The results showed that the adsorption behavior of Pb(II) by MnO2-AC was consistent with the Langmuir adsorption model, the quasi-second-order kinetic model, and the particle internal diffusion model.

Preparation of xanthated bentonite and its removal behavior for Pb(II) ions

2010 ◽  
Vol 61 (5) ◽  
pp. 1235-1243 ◽  
Author(s):  
Y. F. He ◽  
F. R. Li ◽  
R. M. Wang ◽  
F. Y. Li ◽  
Y. Wang ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Particle Size Analysis ◽  
Lead Ions ◽  
Size Analysis ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Xanthate was successfully grafted onto bentonite by a relatively simple solution reaction. The obtained xanthated bentonite (XBent) was characterized by FT-IR spectrophotometer, thermogravimetric analysis (TG), particle size analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). XBent acting as a type of environmentally friendly adsorbent was applied to remove lead ions from aqueous solutions. The optimum conditions were as follows: [Pb2 + ] = 500 mg L−1, [XBent] = 2 g L−1, pH = 5.0; oscillating 60 min under 200 rpm at 25°C. The removal rate of lead was up to 99.9%. It was found that the lead(II) ions—XBent adsorption isotherm model fitted well to the Freundlich isotherm. The adsorption mechanism was also investigated by SEM and XRD, which concluded that lead ions were complexed or chelated with XBent. XBent appears to have potential to be used later in water treatment as a type of inorganic polymer reagent.

Fabrication of composites with ultra-low chitosan loadings and the adsorption mechanism for lead ions

2020 ◽  
Vol 27 (30) ◽  
pp. 37927-37937
Author(s):  
Shuo Ai ◽  
Yongchun Huang ◽  
Tenghui Xie ◽  
Xiangyu Zhang ◽  
Chengdu Huang
Keyword(s):  
Adsorption Mechanism ◽  
Lead Ions

scholarly journals Activation Mechanism of Lead(II) to Ilmenite Flotation Using Salicylhydroxamic Acid as Collector

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 567
Author(s):  
Hang Liu ◽  
Wenqing Zhao ◽  
Jihua Zhai ◽  
Xiaolong Lu ◽  
Pan Chen ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Adsorption Mechanism ◽  
Lead Ions ◽  
Activation Mechanism ◽  
Salicylhydroxamic Acid ◽  
Benzohydroxamic Acid ◽  
Adsorption Analysis ◽  
Potential Shifts ◽  
Lead Species

In this study, salicylhydroxamic acid (SHA), which exhibits superior flotation performance to conventional collector benzohydroxamic acid (BHA), was first introduced in ilmenite flotation. The addition of lead(II) can significantly increase the recovery of ilmenite using SHA as collector. Thus, the adsorption mechanism of SHA on lead(II)-activated ilmenite surface was systematically studied using micro-flotation tests, adsorption analysis, zeta potential measurements, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Micro-flotation results revealed that SHA had stronger collecting ability than BHA, and ilmenite floatability could be activated by lead ions with either SHA or BHA as collector. Ilmenite showed good floatability at pH 6–8 (over 90% recovery) in the presence of Pb2+ and SHA. In such conditions, the main lead species of Pb(OH)+ and Pb2+ acted as active sites and caused positive surface potential shifts, thereby increasing the adsorbed amounts of negatively charged SHA on the surface of the mineral. FTIR and XPS analyses suggested that the lead species was chemically adsorbed on the surface of ilmenite to form active sites chelated by SHA. Moreover, the free lead ions in solution might form the Pb–SHA complexes to adsorb on the mineral surface, thereby increasing the floatability of ilmenite.

Study of equilibrium isotherms of biosorption of lead ions onto Posidonica oceanica biomass: estimation of steric and energetic parameters using a statistical mechanics approach

2014 ◽  
Vol 92 (10) ◽  
pp. 1185-1195 ◽  
Author(s):  
Mohamed Khalfaoui ◽  
Asma Nakhli ◽  
Chadlia Aguir ◽  
Aref Omri ◽  
Mohamed Farouk M’henni ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Adsorbed Layer ◽  
Canonical Formalism ◽  
Receptor Site ◽  
Lead Ions ◽  
Biomass Estimation ◽  
Adsorption Model ◽  
Experimental Conditions ◽  
Adsorption Enthalpy ◽  
Site Density

Experimental adsorption isotherms of metal ions, such as Pb2+, from an aqueous solution onto raw and modified Posidonia materials with various contents of succinyl groups (from 29.8% to 39.2%) have been analyzed using a multilayer adsorption model. For such a purpose, a double layer model was selected to describe the adsorption process. The establishment of the model expression is based on a statistical physics treatment, and especially on the grand canonical formalism. We mainly introduce four parameters affecting the adsorption process, namely, the fraction or the number of adsorbed ions per site, the receptor site density, and the energetic parameters related to each adsorbed layer. The study of the anchorage number allows us to follow the evolution of the lead adsorption when varying the experimental conditions. The evolution of the effectively occupied receptor site density shows that the van der Waals and hydrogen bonds are involved during the adsorption process. The magnitudes of the adsorption energies indicate that lead ions are physisorbed onto Posidonia. Furthermore, the disorder during the adsorption process was followed via the investigation of the entropy. The adsorption process was spontaneous as it is indicated by the free adsorption enthalpy.

Adsorption mechanism of lead ions on porous ceramsite prepared by co-combustion ash of sewage sludge and biomass

2020 ◽  
Vol 702 ◽  
pp. 135017 ◽  
Author(s):  
Yuchi Chen ◽  
Jingwen Shi ◽  
Hao Rong ◽  
Xian Zhou ◽  
Fangyuan Chen ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Adsorption Mechanism ◽  
Lead Ions

scholarly journals Preparation of sustainable non-combustion filler substrate from waterworks sludge/aluminum slag/gypsum/silica/maifan stone for phosphorus immobilization in constructed wetlands

2019 ◽  
Vol 80 (1) ◽  
pp. 153-163 ◽  
Author(s):  
Guanghui Wang ◽  
Jingqing Gao ◽  
Rongxue Yang ◽  
Jingshen Zhang ◽  
Han Guo ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Phosphorus Removal ◽  
Adsorption Mechanism ◽  
High Efficiency ◽  
Removal Rate ◽  
Combustion Process ◽  
Speciation Analysis ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Phosphorus Adsorption

Abstract In this study, an artificial wetland filler matrix capable of effectively fixing phosphorus was prepared using a non-combustion process to save energy. To evaluate the adsorption performance of this filler, adsorption experiments were performed and the phosphorus adsorption mechanism characterization was studied. An alkaline environment was found to be conducive to the increase of adsorption capacity, but excessive alkalinity was not conducive to adsorption. Static adsorption experiments showed that the phosphorus removal rate could reach 95% in the simulated phosphorus-containing wastewater after adsorption completion. The adsorption process is closely simulated by the pseudo-second-kinetic adsorption model. The isothermal adsorption experiment data were consistent with the Langmuir and the Freundlich adsorption isotherms. The characterization results showed a large number of micropores and adsorption binding sites inside and on the surface of the filler. Speciation analysis on the adsorbed phosphorus revealed that chemisorption by calcium in this filler was the dominant adsorption mechanism. The research results of this study provide the basis and reference for the development of high-efficiency phosphorus removal filler in constructed wetlands.

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