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.

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.

scholarly journals Rapid Degradation of Carbon Tetrachloride by Microscale Ag/Fe Bimetallic Particles

2021 ◽  
Vol 18 (4) ◽  
pp. 2124
Author(s):  
Xueqiang Zhu ◽  
Lai Zhou ◽  
Yuncong Li ◽  
Baoping Han ◽  
Qiyan Feng
Keyword(s):  
Humic Acid ◽  
Catalytic Reduction ◽  
Direct Reduction ◽  
Cost Effective ◽  
Degradation Efficiency ◽  
Pseudo First Order Reaction ◽  
Solution Ph ◽  
Reaction Stage ◽  
Bimetallic Particles ◽  
Slow Reaction

Cost-effective zero valent iron (ZVI)-based bimetallic particles are a novel and promising technology for contaminant removal. The objective of this study was to evaluate the effectiveness of CCl4 removal from aqueous solution using microscale Ag/Fe bimetallic particles which were prepared by depositing Ag on millimeter-scale sponge ZVI particles. Kinetics of CCl4 degradation, the effect of Ag loading, the Ag/Fe dosage, initial solution pH, and humic acid on degradation efficiency were investigated. Ag deposited on ZVI promoted the CCl4 degradation efficiency and rate. The CCl4 degradation resulted from the indirect catalytic reduction of absorbed atomic hydrogen and the direct reduction on the ZVI surface. The CCl4 degradation by Ag/Fe particles was divided into slow reaction stage and accelerated reaction stage, and both stages were in accordance with the pseudo-first-order reaction kinetics. The degradation rate of CCl4 in the accelerated reaction stage was 2.29–5.57-fold faster than that in the slow reaction stage. The maximum degradation efficiency was obtained for 0.2 wt.% Ag loading. The degradation efficiency increased with increasing Ag/Fe dosage. The optimal pH for CCl4 degradation by Ag/Fe was about 6. The presence of humic acid had an adverse effect on CCl4 removal.

Removal of Methylene Blue from Aqueous Solution by Powdered Expanded Graphite: Adsorption Isotherms and Thermodynamics

2012 ◽  
Vol 424-425 ◽  
pp. 1313-1317 ◽  
Author(s):  
Shui Cheng Tan ◽  
Peng Hui Shi ◽  
Rui Jing Su ◽  
Min Cong Zhu
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Adsorption Isotherms ◽  
Dye Adsorption ◽  
Expanded Graphite ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Different Temperatures ◽  
Isotherms And Thermodynamics ◽  
Langmuir And Freundlich Equations

The powdered expanded graphite (EG) was used as a porous adsorbent for the removal of the cationic dye, methylene blue (MB), from aqueous solution. The dye adsorption experiments were carried out with the bath procedure. Adsorption isotherms at different temperatures were determined and modeled with Langmuir and Freundlich equations. Thermodynamic parameters were calculated and correlated with the adsorption behaviors. The effects of solution pH on the adsorption were also studied.

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.

Interaction Influence of Contact Time and pH on Cobalt Retention by Carbon Nanotubes Bearing Various Loads of TiO2 and Fe3O4

2021 ◽  
Vol 17 ◽  
Author(s):  
Ismail Fasfous ◽  
Amjad El-Sheikh ◽  
Anas Awad ◽  
Yahya El-Degs ◽  
Jamal Dawoud
Keyword(s):  
Carbon Nanotubes ◽  
Removal Rate ◽  
Cost Effective ◽  
Research Area ◽  
Second Order ◽  
Nano Materials ◽  
Solution Ph ◽  
Retention Capacity ◽  
Pseudo Second Order ◽  
Kinetics Of

Background: Nano-materials have facilitated remarkable advances in the remediation of many environmental problems. A few studies have tackled the removal of Co(II) from aqueous solutions using nano-materials. Herein, we recently studied the retention kinetics of cobalt species on carbon nanotubes (CNT) bearing different amounts of TiO2 and Fe3O4 nano-materials individually. c Method: CNT and their TiO2/Fe3O4-modified nano-material forms were well characterized. Cobalt retention by these adsorbents was investigated at different influencing factors: Co(II) content, solution pH, and time. The kinetic data were fitted with pseudo-first-order, pseudo-second-order rate models and intra-particle diffusion models for better elucidation of the mechanism of Co retention. Results: XRD evidenced the formation of TiO2 and Fe3O4. High loads of both oxides were needed for higher and faster Co retention by CNT. Co retention capacity increased with increasing the solution pH. The pseudo-second-order model presented the kinetics of Co retention at 30 oC, and 48% of available capacity was attained within the first hour of interaction by CNT-TiO2 and with a moderate S/L ratio of 0.5 g/L. Co retention was increased with the amount of oxide to reach a maximum value of 16. 40 mg/g (90.2% TiO2) and 13.60 mg/g (48.2% Fe3O4). The Jovanović equilibrium model predicted the maximum retention values as the nearest to the experimental ones. Conclusion: The potential of CNT-Fe3O4 /TiO2 nano-materials has been successfully demonstrated for the removal of cobalt, which makes them highly attractive and cost-effective adsorbents for wastewater treatment. The reported retention and removal rate values were relatively better than those seen in the literature. Loading different active oxides by CNT is an interesting research area as selective adsorbents can be fabricated with affordable experimental costs.

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.

The adsorption of Sb(III) in aqueous solution by Fe2O3-modified carbon nanotubes

2013 ◽  
Vol 68 (3) ◽  
pp. 658-664 ◽  
Author(s):  
Tingchao Yu ◽  
Chao Zeng ◽  
Miaomiao Ye ◽  
Yu Shao
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Ph Value ◽  
Removal Rate ◽  
Nitrogen Adsorption ◽  
Solution Ph ◽  
Freundlich Adsorption Isotherm ◽  
Modified Carbon Nanotubes ◽  
Adsorption Desorption

A novel kind of iron oxide supported on carbon nanotubes (CNTs) was prepared for adsorption of antimony (Sb)(III) in aqueous solution. The iron (III) oxide (Fe2O3)-modified CNTs were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption–desorption and Fourier transform infrared spectrometer. Parameters affecting the adsorption efficiencies, including solution pH value, initial Sb(III) concentration, adsorbent dosage, adsorption time and temperature, were investigated. The results indicate that the removal rate of Sb(III) by Fe2O3-modified CNTs is 99.97% under the initial Sb(III) concentration of 1.5 mg/L, adsorbents dosage of 0.5 g/L, temperature of 25 oC and pH value of 7.00, which is 29.81% higher than that of the raw CNTs. The adsorption capacity increased correspondingly from 3.01 to 6.23 mg/g. The equilibrium adsorption data can be fitted to the Freundlich adsorption isotherm. In addition, it has been found that the solution pH values and adsorption temperatures have no significant influence on Sb(III) removal.

scholarly journals Removal of phosphate from aqueous solution by sewage sludge-based activated carbon loaded with pyrolusite

2017 ◽  
Vol 8 (2) ◽  
pp. 192-201 ◽  
Author(s):  
Sicong Yao ◽  
Meicheng Wang ◽  
Jilong Liu ◽  
Shuxiong Tang ◽  
Hengli Chen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Sewage Sludge ◽  
Activated Carbons ◽  
Removal Rate ◽  
Chemical Activation ◽  
Phosphate Removal ◽  
Bet Surface Area ◽  
Phosphate Adsorption ◽  
Order Kinetic

Abstract Activated carbons were prepared from sewage sludge by chemical activation with pyrolusite (PAC) to develop an efficient adsorbent for phosphate removal from aqueous solution. One percent (wt.) pyrolusite addition was proved to have an important effect on pore formation of the produced carbon. PAC showed 17.06% larger Brunauer–Emmett–Teller (BET) surface area than the sewage sludge-based activated carbon without modification (SAC). The adsorption results showed that the phosphate removal by PAC was 13% higher than SAC's. The adsorption experiments also showed that PAC had very good performance with high phosphate removal rate (ca. 90%) in a wide pH range (pH = 4–8), and could be stable after 30 min reaction. Adsorption isotherm and kinetics studies demonstrated that phosphate adsorption onto the modified adsorbent was well fitted by the Langmuir isotherm and could be described by the pseudo-second-order kinetic model. The modified sewage sludge-based activated carbons were effective and alternative adsorbents for the removal of phosphorus from aqueous solution due to their considerable adsorptive capacities and the low-cost renewable sources.

Enhancement of Antimicrobial Triclocarban Ultrasonic-Degradation by Fenton-Like

2014 ◽  
Vol 1030-1032 ◽  
pp. 382-386
Author(s):  
Wen Qiang Jiang ◽  
Cheng Cheng Jiang ◽  
Xia Meng
Keyword(s):  
Aqueous Solution ◽  
Removal Rate ◽  
Treatment Method ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Ultrasonic Degradation ◽  
New Treatment

Ultrasonic-degradation of the antimicrobial triclocarban (TCC) in aqueous solution with Fenton-like enhancement as a new treatment method was investigated. The effects of several important factors on TCC degradation were researched, including H2O2 concentration, solution pH. The results showed that US/Fenton-like system can effectively remove the TCC in aqueous solution. The removal rate of TCC can reach more than 94% at optimal conditions ( [H2O2]=2.0 mmol/L, pH=3.0).

Adsorption Behaviors of Chlortetracycline on Granular Activated Carbons

2012 ◽  
Vol 610-613 ◽  
pp. 1701-1704
Author(s):  
Man Cheng Zhang ◽  
Wei Wang ◽  
Cong Jian Huang ◽  
Ai Min Li
Keyword(s):  
Pore Structure ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Activated Carbons ◽  
Adsorption Behavior ◽  
Bet Surface Area ◽  
Pore Width ◽  
Solution Ph ◽  
Average Pore ◽  
Adsorption Behaviors

The adsorption behaviors of chlortetracycline on two kinds of granular activated carbons with different BET surface area and average pore width have been studied. The results show that larger BET surface area is beneficial for the adsorption capacity, and wider pore structure can enhance the adsorption rate. Initial solution pH has great effect on the adsorption behavior, and the suitable pH for the effective adsorption is from 4 to 8.

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