scholarly journals Activated carbon from bamboo waste modified with iron and its application in the study of the adsorption of arsenite and arsenate

2013 ◽  
Vol 11 (2) ◽  
pp. 160-170 ◽  
Author(s):  
Juan Moreno-Piraján ◽  
Liliana Giraldo

AbstractActivated carbon obtained from bamboo waste was synthesised and modified with iron (BAC-Fe) and used for the removal of arsenic from aqueous solutions. Two different adsorption models were used for analysing the data. The adsorption capacities were determined for BAC-arsenite, BAC-Fe-arsenite, BAC-arsenate and BAC-Fe-arsenate, with a qmax (µg g−1) of 14.89, 19.19, 22.32 and 27.32 respectively. Adsorption capacity varied as a function of pH and modifications to the sorbent. Adsorption isotherms from an aqueous solution of arsenite and arsenates on activated carbons were determined. These adsorption isotherms were consistent with the Langmuir and Freundlich adsorption models. Adsorption kinetics followed a pseudo-first order rate equation, as did the kinetics for BAC-Fe-arsenite and BAC-Fe-arsenate adsorption.

2012 ◽  
Vol 14 (4) ◽  
pp. 88-94 ◽  
Author(s):  
R.P. Suresh Jeyakumar ◽  
V. Chandrasekaran

Abstract In this work, the efficiency of Ulva fasciata sp. activated carbons (CCUC, SCUC and SSUC) and commercially activated carbon (CAC) were studied for the removal of Cu (II) ions from synthetic wastewater. Batch adsorption experiments were carried out as a function of pH, contact time, initial copper concentration and adsorbent dose. The percentage adsorption of copper by CCUC, SSUC, SCUC and CAC are 88.47%, 97.53%, 95.78% and 77.42% respectively. Adsorption data were fitted with the Langmuir, Freundlich and Temkin models. Two kinetic models pseudo first order and the pseudo second order were selected to interpret the adsorption data.


2018 ◽  
Vol 5 (8) ◽  
pp. 171667 ◽  
Author(s):  
Xiong Liu ◽  
Longqi Xu ◽  
Yaqing Liu ◽  
Wenqi Zhou

Types of resins anchored on citric acid were synthesized and identified. The citric acid-modified resins PS-CA, PS-O-CA and PS-N-CA were synthesized by anchoring citric acid on PS-Cl, PS-OH and PS-NH 2 , respectively. The PS-CA, PS-O-CA and PS-N-CA were used to adsorb Fe 3+ , Al 3+ , Cu 2+ , Pb 2+ , Cd 2+ and Hg 2+ . The influences of pH, adsorption time and metal ion concentration on the adsorption capacities of the resins were investigated. After optimization, PS-CA was a good adsorbent to Fe 3+ , Cu 2+ , Pb 2+ and Cd 2+ with q m values of 143.9 mg g −1 , 77.4 mg g −1 , 18.9 mg g −1 and 119.9 mg g −1 , respectively. PS-N-CA was a good adsorbent to Al 3+ and Hg 2+ with q m values of 176.6 mg g −1 and 114.9 mg g −1 , respectively. The adsorption kinetics and adsorption isotherm experiments indicated that the pseudo-first-order rate equation was more appropriate for characterizing the kinetic data and the Langmuir model was more suitable for fitting the equilibrium data. The reusability of the citric acid-modified resins was also evaluated and these resins exhibited considerable reusability.


2015 ◽  
Vol 72 (12) ◽  
pp. 2229-2235 ◽  
Author(s):  
Xiaohong Liu ◽  
Fang Wang ◽  
Song Bai

An original activated carbon prepared from walnut peel, which was activated by zinc chloride, was modified with ammonium hydroxide or sodium hydroxide in order to contrast the adsorption property of the three different activated carbons. The experiment used a static adsorption test for p-nitrophenol. The effects of parameters such as initial concentration, contact time and pH value on amount adsorbed and removal are discussed in depth. The thermodynamic data of adsorption were analyzed by Freundlich and Langmuir models. The kinetic data of adsorption were measured by the pseudo-first-order kinetics and the pseudo-second-order kinetics models. The results indicated that the alkalized carbon samples derived from walnut peel had a better performance than the original activated carbon treated with zinc chloride. It was found that adsorption equilibrium time was 6 h. The maximum removal rate of activated carbon treated with zinc chloride for p-nitrophenol was 87.3% at pH 3,whereas the maximum removal rate of the two modified activated carbon materials was found to be 90.8% (alkalized with ammonium hydroxide) and 92.0% (alkalized with sodium hydroxide) at the same pH. The adsorption data of the zinc chloride activated carbon were fitted to the Langmuir isotherm model. The two alkalized activated carbon samples were fitted well to the Freundlich model. The pseudo-second-order dynamics equation provided better explanation of the adsorption dynamics data of the three activated carbons than the pseudo-first-order dynamics equation.


2017 ◽  
Vol 57 (2) ◽  
pp. 131 ◽  
Author(s):  
Alice Vagenknechtová ◽  
Karel Ciahotný ◽  
Veronika Vrbová

SiO<sub>2</sub> deposits which cause technical problems on combustion equipment are built by combustion of biogas containing siloxanes. Therefore, in these cases, the siloxanes must be removed from the biogas. For siloxane removal from biogas, its adsorption on activated carbon is often used. After saturation, the saturated adsorbent must be replaced. The adsorbent cost constitutes the main part of the operational costs of the purification equipment. Therefore it is necessary to find an adsorbent having high adsorption capacity for siloxane at a possible low price. Using laboratory apparatus and biogas produced from waste-water treatment sludge at the wastewater treatment plant Prague Bubenec various activated carbons were tested for siloxane removal and their adsorption capacities for siloxanes were estimated, and the adsorbent cost relative to 1 kg of siloxanes removed from biogas were calculated. The lowest price for the removal of 1 kg of siloxanes was determined by Chezacarb, Sil Extra 40 AP and 4–60 adsorbents. Another important information obtained from the test is that the weakly adsorbed siloxane (OMCTS) is displaced by the larger molecule of DMCPCS during adsorption.


2019 ◽  
Vol 19 (2) ◽  
pp. 50-54
Author(s):  
W. K. Buah ◽  
J. Darmey ◽  
F. Osei

AbstractCoconut shells are used as precursors for preparation of activated carbons. The shells could vary in terms of their maturity. The influence of the maturity of the shells on gold adsorption efficiencies of derived activated carbons (ACs) from gold di-cyanide solution was investigated. The shells were pyrolysed at 900 ºC and the resulting chars were activated in steam at the same temperature for different durations. Assessment of the properties of the derived ACs revealed that; the hardness, gold adsorption capacities and rates of gold adsorption of the ACs depended on the maturity of the shells. The more matured the shells the harder the AC. The relative hardness and gold adsorption rates of the mature coconut shells activated carbons, HMand RM, respectively and those of the less mature shells, HLand RL, respectively were in the order of HM >HL and RM >RL. The relative hardness of the ACs derived from the more mature and less mature shells after 3 hrs activation were 99.3% and 94.0%, respectively and the gold adsorption rates were 5.78 mg Au/hr/gand 4.95 mg Au/hr/g, respectively. The adsorption rates and relative hardness depended on the duration of activation, where longer activation times resulted in increase in the adsorption rates and a decrease in relative hardness of the derived ACs. Keywords: Adsorption, Activated Carbon, Coconut Shells, Maturity, Relative Hardness


2012 ◽  
Vol 9 (2) ◽  
pp. 938-948 ◽  
Author(s):  
Liliana Giraldo ◽  
Juan Carlos Moreno-Piraján

We obtain activated carbons with high portion of meso pores using coffee residues as precursor for the application of adsorption of large adsorbates. Because of its natural properties, the coffee residue exhibited a large pore size. In this work, the coffee residue were impregnated with ZnCl2and KOH, and then carbonized under the nitrogen conditions and activated with CO2respectively. Obtained activated carbons are used in the adsorption of ions Hg(II) and Zn(II). These adsorbents are efficacious to remove these ions from aqueous solution, with monocomponent equilibrium adsorption capacities ranging from from 0.002 to 0.380 mmol∙g-1for Hg on ACK3 and from 0.002 to 0.330 mmol∙g-1for ACZ3. For Zn(II) on ACK2 from 0.002 to 0.300 mmol∙g-1, and from 0.001 to 0.274 mmol∙g-1for ACZ2.


RSC Advances ◽  
2016 ◽  
Vol 6 (47) ◽  
pp. 40818-40827 ◽  
Author(s):  
Zizhang Guo ◽  
Jian Zhang ◽  
Hai Liu

This study shows that oxalic acid (OA) and succinic acid (SA) were employed to modify Phragmites australis (PA)-based activated carbons (ACs) during phosphoric acid activation to improve Rhodamine B (RhB) removal from aqueous solutions.


2012 ◽  
Vol 610-613 ◽  
pp. 259-263 ◽  
Author(s):  
Fei Shang ◽  
Xiao Lv Zhou ◽  
Zhen Xing Zhou ◽  
Chen Yan Hu ◽  
Jing Zhang ◽  
...  

In this paper,granular activated carbon GAC was used to investigate the adsorption capacity and adsorption rate of a typical nitrogen-containing organic compounds L-phenylalanine. GAC shows a high adsorption capacity for the L-phenylalanine and the adsorption isotherms conform to with Langmuir model.The pseudo-first-order equation shows the best fitting for adsorption kinetics in L-phenylalanine adsorption by GAC. Besides the factors such as the temperature, adsorption time and activated carbon quantity were studied.


2020 ◽  
Vol 14 (4) ◽  
pp. 553-562
Author(s):  
Abhijit Jadhav ◽  
◽  
Govindaraj Mohanraj ◽  
Suseeladevi Mayadevi ◽  
Ashok Gokarn ◽  
...  

In this paper activated carbon is prepared from coconut leaves by chemical activation during slow pyrolysis at 673 K in an inert atmosphere. Activated carbon is prepared in the stiochiometric ratio of 1:1 (CL1), 2:1 (CL2) and 3:1 (CL3). Optimized 3:1 ratio is preferable for further study. BET surface area of CL3 activated carbon was found 1060.57 m2/g. It is greater than those of CL1 and CL2. The batch sorption study experiments were conducted with respect to solute concentration of 2.5–122.8 mg/l and solution temperature of 313–343 K. The Langmuir, Freundlich and Temkin isotherm studies were conducted. The experimental data fitted very well for the pseudo-first order and pseudo-second-order. The results have established good potentiality for the CL3 activated carbon to be used as a sorbent for the removal of lead from wastewater.


Author(s):  
Renganathan Sahadevan ◽  
Ajit Balaji Kannavadi Devaraj ◽  
Dharmendira Kumar Mahendradas ◽  
Baskar Gurunathan ◽  
Manickam Velan

Biosorption of lignin compounds by the Eichhornia crassipes was investigated in batch studies. Batch experiments were conducted to study the effect of initial sorbent dosage, solution pH and lignin compounds concentration. Langmuir and Freundlich adsorption isotherm models were used to represent the equilibrium data. The Freundlich isotherm model was found to be fitted very well with the experimental data when compared to Langmuir isotherm model. The results showed that the equilibrium uptake capacity was found to be increased with decrease in biomass dosage. The lignin compound removal was influenced by the initial lignin compounds concentration. The sorption results were analysed for pseudo first order and pseudo second order kinetic model. It was observed that the kinetic data fitted very well with the pseudo second order rate equation when compared to the pseudo first order rate equation. Sorption results were analyzed for the intra particle diffusion model.


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