Heterogeneous Fenton Catalytic Removal of Organic Pollutant in Aqueous Solution by using Coal Gangue as a Catalyst

2019 ◽  
Vol 12 (4) ◽  
pp. 312-325
Author(s):  
Jiwei Zhang ◽  
Jingjing Xu ◽  
Shuaixia Liu ◽  
Baoxiang Gu ◽  
Feng Chen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Removal Rate ◽  
Organic Pollutant ◽  
Coal Gangue ◽  
Ion Leakage ◽  
Heterogeneous Fenton ◽  
Solution Ph ◽  
X Ray

Background: Coal gangue was used as a catalyst in heterogeneous Fenton process for the degradation of azo dye and phenol. The influencing factors, such as solution pH gangue concentration and hydrogen peroxide dosage were investigated, and the reaction mechanism between coal gangue and hydrogen peroxide was also discussed. Methods: Experimental results showed that coal gangue has the ability to activate hydrogen peroxide to degrade environmental pollutants in aqueous solution. Under optimal conditions, after 60 minutes of treatment, more than 90.57% of reactive red dye was removed, and the removal efficiency of Chemical Oxygen Demand (COD) up to 72.83%. Results: Both hydroxyl radical and superoxide radical anion participated in the degradation of organic pollutant but hydroxyl radical predominated. Stability tests for coal gangue were also carried out via the continuous degradation experiment and ion leakage analysis. After five times continuous degradation, dye removal rate decreased slightly and the leached Fe was still at very low level (2.24-3.02 mg L-1). The results of Scanning Electron Microscope (SEM), energy dispersive X-Ray Spectrometer (EDS) and X-Ray Powder Diffraction (XRD) indicated that coal gangue catalyst is stable after five times continuous reuse. Conclusion: The progress in this research suggested that coal gangue is a potential nature catalyst for the efficient degradation of organic pollutant in water and wastewater via the Fenton reaction.

Preparation of Novel Ag–Si–TiO2 Composite and Research on Its Photocatalytic Degradation of Formaldehyde

2021 ◽  
Vol 13 (3) ◽  
pp. 371-380
Author(s):  
Yongjun Wu ◽  
Nina Xie ◽  
Lu Yu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Formaldehyde Concentration ◽  
Order Kinetic ◽  
Solution Ph ◽  
Visible Absorption ◽  
X Ray ◽  
Co Doped

A novel Ag–Si–TiO2 composite was prepared via sol–gel method for removing residual formaldehyde in shiitake mushroom. The structure of Ag–Si–TiO2 composite was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. Ultraviolet-visible absorption spectroscopy (UV-Vis) and N2 adsorption-desorption tests showed that Ag and Si co-doped decreased the band gap, the Brunauer-Emmett-Teller (BET) specific surface area of the samples increased and the recombination probability of electron-hole pairs (e--h+) reduced. Effect on removal rate of formaldehyde with different Ag-Si co-doped content, formaldehyde concentration and solution pH were investigated, and the results showed that 6.0 wt%Ag-3.0 wt%Si-TiO2 samples had an optimum catalytic performance, and the degradation efficiency reached 96.6% after 40 W 365 nm UV lamp irradiation for 360 min. The kinetics of formaldehyde degradation by Ag–Si–TiO2 composite photocatalyst could be described by Langmuir-Hinshelwood first-order kinetic model.

Comparison of Coal Ash and Activated Carbon for Removal of Humic Acid from Aqueous Solution

2013 ◽  
Vol 864-867 ◽  
pp. 1509-1512
Author(s):  
Xue Mei Zhang ◽  
Yan Zhang ◽  
Di Fan
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Activated Carbons ◽  
Removal Rate ◽  
Coal Ash ◽  
Cost Effective ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Calcium Loading ◽  
Working Solution

This paper presents the adsorption behaviors of humic acid (HA) on coal ashes and powdered activated carbons (PACs). A bituminous coal, with or without calcium-loading, was used as a feedstock for coal ash preparation. The working solution of HA with a concentration of 20 mg/L was used in all adsorption tests. The results showed that calcium-enriched coal ash (CECA) gave rise to the removal rate of HA as high as 84.05%, much higher than those of raw coal ash (RCA) and PACs. The impacts of solution pH and adsorbent dosage on HA adsorption capacity were also investigated. It was found that lower pH facilitated to the removal of HA from aqueous solution by means of CECA, and the optimal CECA dosage was about 1.0g/L at pH 7.00. The data obtained in this study suggested that calcium-enriched coal ash could be useful and cost-effective in the treatment of wastewaters containing HA-like organic macro-molecules.

Effect of pH on Hard Disk Substrate Polishing in Glycine-Hydrogen Peroxide System Abrasive-Free Slurry

2013 ◽  
Vol 562-565 ◽  
pp. 691-696 ◽  
Author(s):  
Si Si Chen ◽  
Hong Lei ◽  
Ru Ling Chen
Keyword(s):  
Hydrogen Peroxide ◽  
Material Removal ◽  
Electrochemical Impedance ◽  
Removal Rate ◽  
Hard Disk ◽  
Reaction Scheme ◽  
Solution Ph ◽  
Effect Of Ph ◽  
Hard Disk Substrate ◽  
Disk Substrate

The effect of pH on the material removal rate (MRR) and surface roughness (Ra) of hard disk substrate in glycine–hydrogen peroxide system abrasive-free slurry was investigated. The results show that, the MRR of hard disk substrate increases when both glycine and H2O2 are used in acidic slurries (pH=3.0) and decreases drastically in alkaline slurries (pH=10.0). The Ra of hard disk substrates is small in acidic slurries and increases drastically in alkaline slurries. Further, the effects of glycine, H2O2, and solution pH on hard disk removal were investigated by auger electron spectroscopy (AES), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. We also develop a reaction scheme describing the surface chemistry of the hard disk in this system.

Biosorption of Zn(II) from Aqueous Solution by Amusium pleuronectes Shell

2016 ◽  
Vol 675-676 ◽  
pp. 7-10
Author(s):  
K. Chantarasunthon ◽  
Kanyakorn Teanchai ◽  
Wichian Siriprom
Keyword(s):  
Aqueous Solution ◽  
Experimental Investigation ◽  
Contact Time ◽  
Physical Adsorption ◽  
Absorption Capacity ◽  
X Ray Diffraction ◽  
Batch Method ◽  
Solution Ph ◽  
X Ray ◽  
High Level

In this study, the experimental investigation and assessment the absorption capacity for Zn ion with Amusium Pleuronectes shell. The investigations were carried out by batch method and variables of the batch experiment include solution pH, Contact time, were determind. The mechanism of bisorption is chemisorption or/and physical adsorption was confirmed by X-ray Diffraction (XRD) and Energy Dispersive X-ray Fluorescence (EDXRF). The results showed that the Amusium Pleuronectes shell has a high level of absorption capacity for Zn (II) ions. Another that result of mechanism of biosorption suggests and confirm with the result of XRD and EDXRF.

Effect of amino acids on X-ray-induced hydrogen peroxide and hydroxyl radical formation in water and 8-oxoguanine in DNA

2008 ◽  
Vol 73 (4) ◽  
pp. 470-478 ◽  
Author(s):  
I. N. Shtarkman ◽  
S. V. Gudkov ◽  
A. V. Chernikov ◽  
V. I. Bruskov
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Radical Formation ◽  
X Ray

scholarly journals Synthesis of Calcium Silicate Hydrate from Coal Gangue for Cr(VI) and Cu(II) Removal from Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6192
Author(s):  
Qing Zhang ◽  
Guijian Liu ◽  
Shuchuan Peng ◽  
Chuncai Zhou
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Variable Temperature ◽  
Coal Gangue ◽  
Molar Ratio ◽  
Solution Temperature ◽  
Solution Ph ◽  
Adsorption Temperature

Both the accumulation of coal gangue and potentially toxic elements in aqueous solution have caused biological damage to the surrounding ecosystem of the Huainan coal mining field. In this study, coal gangue was used to synthesize calcium silicate hydrate (C-S-H) to remove Cr(VI) and Cu(II)from aqueous solutions and aqueous solution. The optimum parameters for C-S-H synthesis were 700 °C for 1 h and a Ca/Si molar ratio of 1.0. Quantitative sorption analysis was done at variable temperature, C-S-H dosages, solution pH, initial concentrations of metals, and reaction time. The solution pH was precisely controlled by a pH meter. The adsorption temperature was controlled by a thermostatic gas bath oscillator. The error of solution temperature was controlled at ± 0.3, compared with the adsorption temperature. For Cr(VI) and Cu(II), the optimum initial concentration, temperature, and reaction time were 200 mg/L, 40 °C and 90 min, pH 2 and 0.1 g C-S-H for Cr(VI), pH 6 and 0.07 g C-S-H for Cu(II), respectively. The maximum adsorption capacities of Cr(VI) and Cu(II) were 68.03 and 70.42 mg·g−1, respectively. Furthermore, the concentrations of Cu(II) and Cr(VI) in aqueous solution could meet the surface water quality standards in China. The adsorption mechanism of Cu(II) and Cr(VI) onto C-S-H were reduction, electrostatic interaction, chelation interaction, and surface complexation. It was found that C-S-H is an environmentally friendly adsorbent for effective removal of metals from aqueous solution through different mechanisms.

scholarly journals Synergistically homogeneous-heterogeneous Fenton catalysis of trace copper ion and g-C3N4 for degradation of organic pollutants

2021 ◽  
Author(s):  
Z. Y. Yao ◽  
G. X. Zhu ◽  
T. L. Lu ◽  
Y. Z. Zhan
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Metal Ions ◽  
Photoelectron Spectroscopy ◽  
Organic Pollutant ◽  
Copper Ion ◽  
Heterogeneous Fenton ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Synergistic Catalysis

Abstract Using the bulk g-C3N4 as a precursor, four g-C3N4 nanosheets were further prepared by ultrasonic, thermal, acid, and alkali exfoliation. The structures of these materials were characterized by various techniques such as X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-Ray spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The synergistical Fenton catalysis of these materials with Cu2+ was evaluated by using rhodamine B as a simulated organic pollutant. The results showed that there existed a significant synergistical Fenton catalysis between Cu2+ and g-C3N4. This synergistic effect can be observed even when the concentration of Cu2+ was as low as 0.064 mg L−1. The properties of g-C3N4 strongly influenced the catalytic activity of the Cu2+/g-C3N4 system. The coexistent of Cu2+ and the alkali exfoliated g-C3N4 showed the most excellent catalytic activity. Hydroxyl radicals as oxidizing species were confirmed in the Cu2+/g-C3N4 system by electron paramagnetic resonance spectrum. The synergistic catalysis may be attributed to the easier reduction of Cu2+ adsorbed on the g-C3N4. This study provided an excellent Fenton catalytic system, and partly solved the rapid deactivation of heterogeneous Fenton catalysts caused by the leaching of metal ions. HIGHTLIGHTS There exists a significant synergistical Fenton catalysis between trace Cu2+ and g-C3N4. The Cu2+ concentration is lower than the maximum acceptable limit in drinking water. This study partly solved the rapid deactivation caused by the leaching of metal ions. This study reminds researchers to pay attention to the possible synergistic catalysis between leached ions and supports.

scholarly journals Removal of crystal violet dye by a novel adsorbent derived from waste active sludge used in wastewater treatment

2019 ◽  
Vol 54 (4) ◽  
pp. 299-308 ◽  
Author(s):  
Deniz Akin Sahbaz ◽  
Sahra Dandil ◽  
Caglayan Acikgoz
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Crystal Violet ◽  
Removal Rate ◽  
Optimum Level ◽  
High Porosity ◽  
Order Kinetic ◽  
Solution Ph ◽  
Active Sludge ◽  
Adsorbent Dosage

Abstract This study dealt with preparation of the activated carbon derived from active sludge as an adsorbent for the adsorption of crystal violet (CV) from aqueous solution. The waste active sludge was activated chemically with KOH and carbonized to get activated carbon with a large surface area and a high porosity. The activated carbon was characterized by Fourier transform infrared (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) instrument, and scanning electron microscopy (SEM). Adsorption of CV from aqueous solution onto the activated carbon was investigated under varying conditions, such as adsorbent dosage (1–6 g/L), solution pH (4–9), contact time period (0–150 min), initial dye concentration (20–100 mg/L), and temperature (25–55 °C). 4.0 g/L of adsorbent dosage was chosen as the optimum level due to having a high removal rate (96.2%) (initial CV concentration 60 mg/L; 150 rpm; pH 6; 25 °C). The adsorption kinetic and adsorption isotherms were well described by the pseudo second order kinetic and the Freundlich isotherm model, respectively. The thermodynamic parameters indicated that the adsorption is a spontaneous process and favored at higher temperatures. The results show that the activated carbon derived from active sludge could be employed as a low-cost material for the removal of CV dye.

Adsorption of 2,4,6-trichlorophenol on bentonite modified with benzyldimethyltetradecylammonium chloride

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Infrared Spectroscopy ◽  
Contact Time ◽  
Removal Rate ◽  
Organic Pollutant ◽  
Freundlich Isotherm ◽  
Solution Concentration ◽  
Isotherm Models ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pseudo Second Order

The objective of this study is to evaluate the performance and capacities of the bentonite of Maghnia, modified with benzyldimethyltetradecylammonium chloride, to remove the organic pollutant 2,4,6-Trichlorophenol (TCP). The modified sample was studied by X-ray diffraction (XRD) technique, infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) methods. The best removal rate (99.52%) was obtained at 19°C, pH 4, solution concentration of 50 mg/L, stirring speed of 180 rpm and contact time of 60 min. The results were well fitted by both Langmuir and Freundlich isotherm models and the pseudo-second-order is the best model to describe the process.

Simultaneous Removal of Heavy-Metal Ions by MnO2 Loaded D301 Resin

2011 ◽  
Vol 255-260 ◽  
pp. 2791-2796 ◽  
Author(s):  
Hong Mei Ma ◽  
Zhi Liang Zhu ◽  
Yong Qian Cheng
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Alkaline Earth ◽  
Removal Rate ◽  
Alkaline Earth Metals ◽  
Simultaneous Removal ◽  
High Concentration ◽  
Solution Ph

MnO2-loaded D301 weak basic anion exchange resin was used as adsorbent to simultaneously remove Co2+, Ni2+, Cd2+, Zn2+ andCu2+ from aqueous solution contained high concentration of alkali and alkaline-earth metals ions. The effects of solution pH and coexistent ions on the adsorption were investigated. The results indicated that Co2+, Ni2+, Cd2+, Zn2+ andCu2+ can be simultaneously removed in the wide pH range of 3 to 8. The coexistence of PO43− decreased the heavy metal ions removal rate, but for other high concentrations coexistence cations and anions such as Na+, K+, Cl−, NO3−, SO42− and HCO3−, there is no significant impact on removal rate of heavy metals. The adsorption isotherm can be well described by Langmuir isotherm. The adsorption processes followed the pseudo first-order kinetics model. High adsorption capacity makes it a good promising candidate material for simultaneous removal of Co2+, Ni2+, Cd2+, Zn2+ andCu2+ from aqueous solution with the co-existence of high concentration of alkali and alkaline-earth metals ions.

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