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.

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.

Speciation and Removal of Arsenic in column packed with chitosan

2006 ◽  
Vol 1 (4) ◽  
Author(s):  
Martha Benavente ◽  
Marcos Arévalo ◽  
Joaquín Martínez
Keyword(s):  
Arsenic Removal ◽  
Arsenic Speciation ◽  
Packed Column ◽  
Arsenic Concentration ◽  
Breakthrough Curves ◽  
Arsenic Adsorption ◽  
Major Species ◽  
Standard Solution ◽  
Ph Range ◽  
Removal Of Arsenic

The arsenic speciation and arsenic removal in chitosan packed column were studied. Arsenic removal experiments were carried out with an arsenic standard solution (1.0 mg/l) and drilled well water samples from Limon Mine Community at different pH, water flowrate, and volume of adsorbent material. The simulation of arsenic speciation was carried out at a pH range from 0 to 12, a temperature of 25ºC, a pE equal to 4, and a total arsenic concentration of 1.34 x 10-5 mol kg-1. According to speciation calculations arsenic is found mainly in oxidized form in the conditions of Limon Mine’s drilled well waters, dihydrogen arsenate ion (H2AsO4-), and hydrogen arsenate ion (HAsO42-) being the major species. The experiments showed that arsenic adsorption depends mainly on the pH as well as the activity of functional groups that compose the chitosan structure. At pH 3 and volume of adsorbent material of 337.8 cm3 an adsorption of 94% was obtained from arsenic standard solution, and the arsenic present in the Limon Community’s water was almost totally removed at pH 3 and 7. The use of the results for designing purposes demands the breakthrough curves for chitosan to be determined.

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.

Arsenic removal by ferric-chloride coagulation – effect of phosphate, bicarbonate and silicate

2011 ◽  
Vol 64 (5) ◽  
pp. 1046-1055 ◽  
Author(s):  
Dóra Laky ◽  
István Licskó
Keyword(s):  
Adverse Effect ◽  
Arsenic Removal ◽  
Linear Regression Analysis ◽  
Arsenic Concentration ◽  
Ferric Hydroxide ◽  
Multiple Linear Regression Analysis ◽  
Ph Values ◽  
Robust Model ◽  
Coagulant Dosage ◽  
Negative Effect

Jar tests with synthetic water were carried out in order to investigate the effect of phosphate, bicarbonate and silicate on arsenic removal efficiency by in-situ formed ferric hydroxide. Above 12 mg C/L inorganic carbon concentration, the adverse effect of bicarbonate was definite, and resulted in higher remaining arsenic concentration. At all pH values (7.5–7.8) and coagulant dosages (0.84–3.00 mg/L Fe) tested, the negative effect of phosphate on arsenic removal was also evident. In the presence of silicate small ferric-hydroxide colloids were formed, which were able to go through the 0.45 μm pore-size membrane. Compared to silicate-free systems, 2.5–3.5 times higher coagulant dose was needed to achieve the target arsenic concentration in the presence of 14–23 mg/L Si. At higher pH values the adverse effect of silicate was even more significant. All data were merged and multiple linear regression analysis was carried out in order to build up a robust model to predict the residual arsenic concentration if the raw water contains 50–60 μg/L initial arsenic concentration. The estimation was based on the following variables: PO4-P concentration, final pH, Si concentration, Fe(III) dose. The most important influencing factors proved to be the silicate concentration and applied coagulant dosage.

Removal of Arsenic from Groundwater Using Nano-Metal Oxide Adsorbents

2017 ◽  
Vol 751 ◽  
pp. 766-772 ◽  
Author(s):  
Phitchaya Muensri ◽  
Supamas Danwittayakul
Keyword(s):  
Particle Size ◽  
Arsenic Removal ◽  
Average Particle Size ◽  
Sample Volume ◽  
Adsorptive Capacity ◽  
Hydroxyl Groups ◽  
Average Particle ◽  
Human Beings ◽  
Arsenic Adsorption ◽  
Removal Of Arsenic

Arsenic can be found in groundwater that is harmful to human beings. In this research, we present the potential uses of ZnO microparticles, ZnO and TiO2 nanoparticles to removal arsenic in groundwater. The experiments of %arsenic removal upon using ZnO microparticles ZnO and TiO2 nanoparticles were conducted in 25 mL of sample volume with 0.05 g of nanoadorpbents at pH 6. We found that the efficiency of arsenic adsorption increased with a reduction of particle size of theadsorbents. Upon using nanoadsorbents to remove arsenic from the solutions with the concentrations of 200-2000 ppb, we found that the %removal of arsenic decreased from 100% to 84% for ZnO nanoparticles and 100% to 97% for TiO2 nanoparticles. Adsorption capacities upon using ZnO and TiO2 nanoparticles were 0.85 and 0.99 mg of arsenic/g of sorbents, respectively. TiO2 nanoparticles exhibited a better adsorption ability to arsenic than that ZnO because TiO2 nanoparticles had a smaller average particle size and larger surface area allowed the adsorption of hydroxyl groups on the surface that could bond with in coming HAsO42- via hydrogen bonding resulting in a better arsenic adsorptive capacity.

Preparation of an Iron Oxide Modified Montmorillonite for Removal of Arsenic in Waters

2010 ◽  
Vol 156-157 ◽  
pp. 849-853 ◽  
Author(s):  
Hai Fei Liu ◽  
De Ren Miao ◽  
Fei Liu
Keyword(s):  
Iron Oxide ◽  
Arsenic Removal ◽  
Polluted Water ◽  
X Ray Diffraction ◽  
Characteristic Analysis ◽  
Experimental Conditions ◽  
Thermal Gravimetry ◽  
Modified Montmorillonite ◽  
Removal Of Arsenic ◽  
Better Than

Most concerns have focused on the arsenic (As) contamination in wastewater. Montmorillonite (MMT) has been proved to be a good adsorbent for removal heavy metals existing as cation in ground water while it is invalid for anions. However, arsenic usually exists as anions in aqueous. Accordingly, suitable modifications on MMT need to be done before using. This paper presents the results that a kind of commercial MMT has been modified by iron oxides under normal and inverse titration conditions. The x-ray diffraction (XRD), Thermal Gravimetry Analysis and Differential Thermal Analysis (TGA-DTA) and SBET analysis have been employed to elucidate the modification mechanisms. Modification characteristic analysis illustrated that the iron oxide associated with MMT by coated style as polymerization of hydroxyl-Fe (Fe (OH) 3) under inverse titration condition. Under normal titration condition, on the other hand, the iron oxide associated with MMT predominant by intercalation as goethite (FeOOH). The arsenic removal efficiencies of different modified products for polluted water have also been verified by batch experiments. Results proved that Iron oxide modified MMT on the removal efficiency of arsenic significantly increased and the normal titration is better than inverse titration as indicated by the arsenic removal ratios under the same experimental conditions. Based on these results, the iron oxide modified MMT by normal titration procedure is a promising material for removal arsenic in wastewaters.

Study on Mn-Fe-LDH Material for Remediation of Arsenic Contaminated Water

2017 ◽  
Vol 730 ◽  
pp. 200-205 ◽  
Author(s):  
Wei Zhuo Wang ◽  
Jian Min Bian
Keyword(s):  
Layered Double Hydroxides ◽  
Arsenic Removal ◽  
Adsorption Property ◽  
Toxic Substances ◽  
Arsenic Adsorption ◽  
Exchange Method ◽  
Main Method ◽  
Series Of Experiments ◽  
Removal Of Arsenic ◽  
Double Hydroxides

Arsenical water pollution refers to the toxicity of arsenic. The form of trivalent arsenic has been seen as more toxic substances, which will be great improved by the manmade pollution. Compared with other technologies, adsorption is the main method of removal of arsenic pollution, for its higher efficiency and lower cost. Based on the adsorption theory and ion exchange method, the layered double hydroxides material containing ferric iron and manganese (Mn-Fe-LDH) was prepared to remove arsenic in this paper. We have designed some experiments for synthesis of this material. The reaction process and elemental compositions has been studied and the adsorption property of arsenic adsorption onto layered double hydroxides was verified through a series of experiments. Study shows that the Mn-Fe-LDH material can be used as a good adsorbent material for its high removal efficiency. The adsorption capacity of the Mn-Fe-LDH material is not affected by the interference of pH and Cl-/SO42- ion strength. It was a broad prospect for the development and application of arsenic removal materials.

Arsenic Removal via Cellulose-Based Organic/Inorganic Hybrid Materials from Drinking Water

2012 ◽  
Vol 730-732 ◽  
pp. 563-568
Author(s):  
Catarina Martins ◽  
Rui F. Duarte ◽  
Maria C.F. Magalhães ◽  
Dmitry Evtuguin
Keyword(s):  
Aqueous Solutions ◽  
Hybrid Materials ◽  
Arsenic Removal ◽  
Sol Gel ◽  
Arsenic Concentration ◽  
Cellulose Fiber ◽  
Silica Network ◽  
Bleached Pulp ◽  
Removal Of Arsenic

Cellulose/silica derived hybrids materials (CSH), functionalized with aluminium, calcium, and propylammonium ions, were tested for their possible use in the removal of arsenic from aqueous solutions with controlled compositions to levels lower than 10 μg As/L. CSH were synthesized by sol-gel method using bleached pulp, as source of cellulose fiber, and tetraethoxysilane (TEOS) as main silica precursor. The silica network, made in situ, contained various anchored cations such as propylammonium (CSH-PA), aluminium (CSH-Al) and, calcium (CSH-Ca). Thin films or mesoparticles of silica were deposited on cellulose fibers as shown by SEM and XRD. These hybrid materials were immersed in controlled ionic strength aqueous solutions with arsenic concentrations lower than 0.2 mg As/L. The best performance was shown by CSH-PA that was able to remove a maximum of 20 % of the total arsenic concentration.

scholarly journals Dynamic desorption of arsenic from polymer-supported hydrated iron(III) oxide in a wastewater treatment plant

2017 ◽  
Vol 76 (9) ◽  
pp. 2380-2388 ◽  
Author(s):  
Jian-Long Hu ◽  
Xiao-Song Yang ◽  
Ting Liu ◽  
Li-Nan Shao ◽  
Wang Zhang
Keyword(s):  
Wastewater Treatment ◽  
Adsorption Capacity ◽  
Wastewater Treatment Plant ◽  
Arsenic Removal ◽  
Treatment Plant ◽  
Arsenic Adsorption ◽  
Wastewater Treatment Process ◽  
Long Time ◽  
Naoh Solution ◽  
Polymer Supported

Abstract Polymer-supported hydrated iron(III) oxide (PHIO) was successfully applied as adsorbent for arsenic removal in a wastewater treatment plant in Nandan, China. The practical PHIO adsorbent samples (PHIO-P) were collected from the adsorption column of the wastewater treatment plant, and desorption experiments of the adsorbent were carried out. Our results showed that the formation of precipitates on the surface of PHIO-P might block the porous channel of the adsorbent and decrease its arsenic adsorption capacity. In the dynamic arsenic desorption experiment, the arsenic desorption equilibrium was achieved more quickly at decreasing desorption velocity, and higher arsenic desorption efficiency was obtained at increasing NaOH concentration in regenerant. It was found that the PHIO-P adsorbent could be well regenerated at 1.0 M NaOH solution and desorption velocity of 5 BV h−1. Comparing with the raw adsorbent, the maximum arsenic adsorption capacity of PHIO-P decreased by 41.1% after practical running for 26 months. Additionally, the frequently used waste PHIO adsorbent could be treated as non-hazardous material in the arsenic-containing wastewater treatment process after long-time use.

scholarly journals Development of ion-imprinted cryogels for selective removal of arsenic from environmental waters

2019 ◽  
Vol 9 (4) ◽  
pp. 4119-4125
Keyword(s):  
Adsorption Capacity ◽  
Arsenic Removal ◽  
Removal Rate ◽  
Anthropogenic Activities ◽  
Arsenic Concentration ◽  
Environmental Water ◽  
Maximum Adsorption Capacity ◽  
Environmental Waters ◽  
Ion Imprinted ◽  
Removal Of Arsenic

Arsenic present by nature as metalloid, having transportability in the environment via diverse sources. Because of both natural processes and anthropogenic activities, arsenic is found in environmental water sources. The aim of this study is to design ion-imprinting-based cryogel adsorbents for the removal of arsenic species from environmental waters. Since trivalent arsenic exhibit a high afgfinity for sulfhydryl groups, cysteine-based functional monomer, i.e. MAC, was synthesized and MAC–As(III) complex was prepared. Ionimprinted polymeric adsorbents were fabricated via cryopolymerization. Elemental analysis studies have shown that the cryogel monolith contains 192.8 μmol/g mol MAC/g polymer. The maximum adsorption capacity of ion-imprinted cryogels at an initial arsenic concentration of 10 ppm was found to be 372.5 μg/g at pH 8.0. Arsenic removal rate of the imprinted cryogels from environmental water sample was determined as 94.8% In the studies carried out for the removal of arsenic from the environmental waters, 94.8% removal efficiency was achieved. Reusability assays of ion-imprinted cryogels were performed and there was no significant decrease in adsorption capacity.

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