scholarly journals MODIFICATION OF OXIDIZED ACTIVATED CARBON SURFACE BY Fe AND Mn FOR ARSENIC REMOVAL FROM AQUEROUS SOLUTION

2018 ◽  
Vol 56 (2C) ◽  
pp. 80-87
Author(s):  
Pham Thi Hai Thinh
Keyword(s):  
Activated Carbon ◽  
Arsenic Removal ◽  
Arsenic Concentration ◽  
Carbon Surface ◽  
Batch Adsorption ◽  
Arsenic Adsorption ◽  
Removal Capacity ◽  
Adsorption Capacities ◽  
Oxidation Efficiency ◽  
Oxidized Activated Carbon

Carboxylate groups on oxidized activated carbon surface were transformed to the forms of Mn2+ and Fe3+ (signed as OAC-Mn and OAC-Fe respectively) through multi-step procedure. This modified activated carbon then was used as an adsorption material for arsenic removing from aqueous solution. Synthetic water containing As(III) and As(V) was used for study of arsenic adsorption capacities of OAC-Fe and OAC-Mn. The similar study had also been done with original granular activated carbon for comparison. The effects of modified metals onto oxidized activated carbon, metals doses and initial arsenic concentration on the removal of As(III), As(V) have been surveyed and discussed. Batch adsorption experiments were carried out with arsenic concentration in the range of 1 – 50 mg/l. Langmuir models were used for the adsorption isotherm screening. The results showed that both of OAC-Fe and OAC-Mn have good adsorption capacities for As(III) but OAC-Fe has a greater removal capacity for As(V) than OAC-Mn. OAC-Mn was identified as a good material for the of As(III) removal, because of its oxidation efficiency of As(III) to As(V) during adsorption process.

Evaluation of the Adsorption Potential of Synthesized Anatase Nanoparticles for Arsenic Removal

2011 ◽  
Vol 1317 ◽  
Author(s):  
Z. Özlem Kocabaş ◽  
Yuda Yürüm
Keyword(s):  
Arsenic Removal ◽  
Sol Gel ◽  
Arsenic Concentration ◽  
Equilibrium Concentration ◽  
Arsenic Species ◽  
Batch Adsorption ◽  
Adsorption Models ◽  
Removal Capacity ◽  
Anatase Nanoparticles ◽  
Langmuir And Freundlich Models

ABSTRACTTitanium dioxide has been extensively tested in environmental applications, especially in separation technologies. In the present study, anatase nanoparticles were synthesized by using a sol-gel method, and batch adsorption experiments were carried out to analyze arsenic removal capacity of the anatase nanoparticles from water. The maximum arsenic removal percentages were found ~ 84 % for As(III) at pH 8 and ~98% for As(V) at pH 3, respectively, when 5 g/l anatase nanoparticles were used at an initial arsenic concentration of 1 mg/l. The results of the sorption experiments, which take into consideration the effects of equilibrium concentration on adsorption capacity, were analyzed with two popular adsorption models, Langmuir and Freundlich models. From the comparison of R2 values, the adsorption isotherm for As(III) was fitted satisfactorily well to the Langmuir equation (R2 > 0.996) while the adsorption behavior of As(V) on anatase nanoparticles was described better with Freundlich equation (R2 > 0.991). This study proposes the potential adsorbent material for water which is contaminated with arsenic species.

Four years of development and field-testing of IHE arsenic removal family filter in rural Bangladesh

2008 ◽  
Vol 58 (1) ◽  
pp. 53-58 ◽  
Author(s):  
B. Petrusevski ◽  
S. Sharma ◽  
W. G. van der Meer ◽  
F. Kruis ◽  
M. Khan ◽  
...  
Keyword(s):  
Arsenic Removal ◽  
Local Population ◽  
Iron Concentration ◽  
Arsenic Concentration ◽  
Field Testing ◽  
Arsenic Adsorption ◽  
Arsenic Level ◽  
Rural Bangladesh ◽  
Removal Capacity ◽  
Guideline Value

UNESCO-IHE has been developing an arsenic removal family filter with a capacity of 100 L/day based on arsenic adsorption onto iron oxide coated sand, a by-product of iron removal plants. The longer term and field conditions performance of the third generation of eleven family filters prototypes were tested in rural Bangladesh for 30 months. All filters achieved initially highly effective arsenic removal irrespective of arsenic concentration and groundwater composition. Arsenic level in filtrate reached 10 μg/l after 50 days of operation at one testing site and after 18 months of continuous operation at other 3 testing sites. Arsenic level at other 7 sites remained below the WHO guideline value till the end of study. Positive correlation was found between arsenic removal capacity of the filter and iron concentration in groundwater. In addition to arsenic, iron present in groundwater at all testing sites was also removed highly effectively. Manganese removal with IHE family filter was effective only when treating groundwater with low ammonia. A simple polishing sand filter, after IHE family filter, resulted in consistent and effective removal of manganese. IHE family filters were easy to operate and were well accepted by the local population.

As(III) Removal by Dynamic Adsorption onto Amberlite XAD7 Functionalized with Crown Ether and Doped with Fe(III) Ions

2019 ◽  
Vol 70 (7) ◽  
pp. 2330-2334
Author(s):  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Narcis Duteanu ◽  
Corneliu Mircea Davidescu ◽  
Iosif Hulka ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Arsenic Removal ◽  
Arsenic Concentration ◽  
Fixed Bed ◽  
World Health ◽  
Arsenic Content ◽  
Arsenic Adsorption ◽  
Stage Of Development ◽  
Wide Range ◽  
Health Organization

Arsenic content in groundwater�s present a wide range of concentration, ranging from hundreds of micrograms to thousands of micrograms of arsenic per litter, while the maximum permitted arsenic concentration established by World Health Organization (WHO) is 10 mg L-1. According to the WHO all people, regardless of their stage of development and their social economic condition, have the right to have access to adequate drinking water. The most efficient and economic technique used for arsenic removal is represented by adsorption. In order to make this remediation technique more affordable and environmentally friendly is important to new materials with advance adsorbent properties. Novelty of present paper is represented by the usage of a new adsorbent material obtained by physical - chemical modification of Amberlite XAD polymers using crown ethers followed by iron doping, due to well-known affinity of arsenic for iron ions. Present paper aims to test the obtained modified Amberlite polymer for arsenic removal from real groundwater by using adsorption in a fixed bed column, establishing in this way a mechanism for the adsorption process. During experimental work was studied the influence of competing ions from real water into the arsenic adsorption process.

scholarly journals Evaluation of Fe-Mg Binary Oxide for As (III) Adsorption—Synthesis, Characterization and Kinetic Modelling

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 805
Author(s):  
Saif Ullah Khan ◽  
Rumman Zaidi ◽  
Feroz Shaik ◽  
Izharul Haq Farooqi ◽  
Ameer Azam ◽  
...  
Keyword(s):  
Arsenic Removal ◽  
Kinetic Modelling ◽  
Arsenic Concentration ◽  
Experimental Studies ◽  
Precipitation Method ◽  
Arsenic Adsorption ◽  
Adsorbent Dosage ◽  
X Ray ◽  
Co Precipitation ◽  
Contaminated Waters

Nanotechnology has received much attention in treating contaminated waters. In the present study, a facile co-precipitation method was employed to synthesize a novel iron and magnesium based binary metal oxide using a stoichiometrically fixed amount of FeNO3.9H2O and MgNO3.6H2O in a proportion of molar concentration 1:1 and was later evaluated in removing As (III) from contaminated waters. Characterization of the prepared nanomaterial was done using X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-Ray Analysis (EDAX) and ultraviolet–visible spectrophotometry (UV-VIS). Experimental studies on batch scale were carried out, examining the effect of varying initial concentrations of metal, adsorbent dosage, application time and initial pH on removal efficiency. Arsenic removal increased on increasing adsorbent dosage (0.1–1 g/L) but trend reversed on increasing initial arsenic concentration attaining qmax of 263.20 mg/g. Adsorption was quite efficient in pH range 4–8. Freundlich fitted better for adsorption isotherm along with following Pseudo-2nd order kinetics. The reusability and effect of co-existing ions on arsenic adsorption, namely SO42−, CO32− and PO43− were also explored with reusability in 1st and 2nd cycles attained adsorptive removal up to 77% and 64% respectively. The prepared nano-adsorbent showed promising results in terms of high arsenic uptake (qmax of 263.20 mg/g) along with facile and cost-effective synthesis. Thus, the co-precipitation technique used in this work is a simple one step procedure without any use of any precursor as compared to most of the other procedures used for synthesis.

scholarly journals Adsorption of arsenic and phosphate from groundwater onto a calcined laterite as fixed bed in column experiments

2020 ◽  
Vol 8 (2) ◽  
pp. 227-243
Author(s):  
Yacouba Sanou ◽  
Raymond Kabore ◽  
Samuel Pare
Keyword(s):  
Arsenic Removal ◽  
Arsenic Concentration ◽  
Fixed Bed ◽  
Column Experiments ◽  
Arsenic Adsorption ◽  
Experimental Conditions ◽  
Ph Values ◽  
Naoh Solution ◽  
Removal Of Arsenic ◽  
Maximum Removal

This work was focused on laterite soil as adsorbent for the removal of arsenic and phosphate from groundwater using column experiments. Results revealed a decrease of arsenic removal efficiency from 100 to 79% with flow rate increasing. Maximum removal of 100% for arsenic and 85% for phosphates was obtained for pH values between 3.5 and 6. The increase of initial arsenic concentration and phosphate amount caused an increase of arsenic adsorption up to 24 µg/g while 58.5 µg/g for phosphate. NaOH solution could desorb 86.8% of arsenic and the reuse of regenerated laterite indicated its efficiency in same experimental conditions.

scholarly journals The interaction of metallic ions onto activated carbon surface using computational chemistry software

2020 ◽  
Vol 38 (5-6) ◽  
pp. 191-204
Author(s):  
AL Paredes-Doig ◽  
A Pinedo-Flores ◽  
J Aylas-Orejón ◽  
D Obregón-Valencia ◽  
MR Sun Kou
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Electron Density ◽  
Activated Carbons ◽  
Surface Acidity ◽  
Chemical Activation ◽  
Carbon Surface ◽  
Maximum Adsorption Capacity ◽  
Metallic Ions ◽  
Oxidized Activated Carbon

Activated carbon was prepared from the seeds of aguaje palm ( Mauritia flexuosa L.f.) by a chemical activation with phosphoric acid. This activated carbon was used for adsorbing metal ions: Pb(II), Cd(II), and Cr(III). To understand the mechanism of adsorption of these heavy metals (Cr, Cd, and Pb), the activated carbon surface was oxidized with nitric acid (1 M) increasing the oxygenated surface groups showing an increasing in their adsorption capacities of these metals. The oxidized activated carbon slightly increased the maximum adsorption capacity to 5–7%. The order of adsorption for unoxidized and oxidized activated carbons was Pb> Cd> Cr. This experimental information was corroborated by molecular modeling program Hyperchem 8 based adsorption mainly on two factors: the electron density and orbitals—highest occupied molecular orbital and lowest unoccupied molecular orbital.Activated carbons were characterized by adsorption/desorption of N2, obtaining an increase of microporous surface area for oxidized activated carbon. An increase of surface acidity and a reduction of isoelectric points were observed in oxidized activated carbon. According to these results, the adsorption of metal ions is favored in contact with an oxidized activated carbon, which has more amount of phenolic and carboxylic functional groups. Similarly, decreasing the isoelectric point indicates that the surface has a higher negative charge. The surface information was corroborated by Hyperchem, which indicates that the surface of the oxidized activated carbon has a higher electron density, indicating a larger amount of electrons on its surface, which means the surface of oxidized activated carbon charges negatively and thereby attracts metal ions.

Arsenic removal by iron and manganese coated sand

2007 ◽  
Vol 56 (7) ◽  
pp. 161-169 ◽  
Author(s):  
J.K. Yang ◽  
K.H. Song ◽  
B.K. Kim ◽  
S.C. Hong ◽  
D.E. Cho ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Arsenic Removal ◽  
Arsenic Concentration ◽  
Solution Ph ◽  
Adsorption Sites ◽  
Column System ◽  
Diffuse Layer Model ◽  
Oxidation Efficiency ◽  
Coated Sand ◽  
Background Ions

In this study, as a promising technique for the treatment of both As(III) and As(V) at the same time in a single reactor, a column reactor containing both manganese-coated sand (MCS) and iron-coated sand (ICS), at different configuration of MCS and ICS, was used to treat wastewater contaminated with As(III). Prior to column experiments, batch experiments for the adsorption of As(V) by ICS were performed with variation of solution pH, ionic strength and types of background ions to investigate the effect of these parameters on the As(V) adsorption behaviour. As(V) adsorption onto ICS was quite similar with the variation of ionic strength by using NaNO3 as a background ion as well as in the presence of different types of background ions except phosphate. The adsorption curves shifted to the lower pH region with the increase of the initial arsenic concentration due to the finite number of adsorption sites on the ICS. For model prediction on the adsorption of As(V) onto ICS, the MINEQL program employing an inner-sphere complexation and a diffuse layer model was used. Model predictions generally agreed well with experimental results. From the column test, column system packed with equal ratio of MCS and ICS was identified as the best system due to a promising oxidation efficiency of As(III) to As(V) by MCS and adsorption of As(V) by both MCS and ICS.

scholarly journals Arsenic Removal from Water by Adsorption onto Iron Oxide/Nano-Porous Carbon Magnetic Composite

2019 ◽  
Vol 9 (18) ◽  
pp. 3732 ◽  
Author(s):  
Sahira Joshi ◽  
Manobin Sharma ◽  
Anshu Kumari ◽  
Surendra Shrestha ◽  
Bhanu Shrestha
Keyword(s):  
Activated Carbon ◽  
Aqueous Solutions ◽  
Sugarcane Bagasse ◽  
Contact Time ◽  
Arsenic Removal ◽  
Chemical Activation ◽  
Batch Adsorption ◽  
Magnetic Composite ◽  
One Pot ◽  
Magnetic Fe3o4

This study aimed to develop magnetic Fe3O4/sugarcane bagasse activated carbon composite for the adsorption of arsenic (III) from aqueous solutions. Activated carbon (AC) was prepared from sugarcane bagasse by chemical activation using H3PO4 as an activating agent at 400 °C. To enhance adsorption capacity for arsenic, the resultant AC was composited with Fe3O4 particles by facile one-pot hydrothermal treatment. This method involves mixing the AC with aqueous solution of iron (II) chloride tetrahydrate, polyvinyl pyrrolidone (PVP), and ethanol. Batch adsorption experiments were conducted for the adsorption of As (III) onto the composite. The effects of pH, adsorbent dosage, and contact time on the arsenic adsorption were studied. The result showed that the composite could remove the arsenic from the water far more effectively than the plain AC. The highest percentage of arsenic removal was found at pH at 8, adsorbent dose of 1.8 g/L, and contact time of 60 min. Langmuir and Freundlich adsorption isotherm was used to analyze the equilibrium experimental data. Langmuir model showed the best fit compared to the Freundlich model with a maximal capacity of 6.69 mg/g. These findings indicated that magnetic Fe3O4/sugarcane bagasse AC composite could be potentially applied for adsorptive removal of arsenic (III) from aqueous solutions.

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