Fixed bed adsorption of As(III) on iron-oxide-coated natural rock (IOCNR) and application to real arsenic-bearing groundwater

Maji, Sanjoy Kumar; Kao, Ying-Jer; Wang, Chin-Jen; Lu, Guang-Sin; Wu, Jia-Jing; Liu, Chen‐Wuing

doi:10.1016/j.cej.2012.07.033

Cited by 55 publications

(19 citation statements)

References 38 publications

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“…Recently, As (III) breakthrough curves in a fixed bed with iron oxide-coated natural rock were well simulated using PHREEQC with the WATEQ4F database (Maji et al 2012). On the other hand, the As transport process in an iron oxidecontaining soil column could not be predicted using batch equilibrium adsorption parameters due to kinetic limitations (Williams et al 2003).…”

Section: Field Column Resultsmentioning

confidence: 99%

Groundwater arsenic removal using granular TiO2: integrated laboratory and field study

Cui

et al. 2014

Environ Sci Pollut Res

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High concentrations of arsenic (As) in groundwater pose a great threat to human health. The motivation of this study was to provide a practical solution for As-safe water in As geogenic areas using granular TiO 2 (GTiO 2 ). The kinetics results indicated that the As (III/V) adsorption on GTiO 2 conformed to the Weber-Morris (WM) intraparticle diffusion model. The Langmuir isotherm results suggested that the adsorption capacities for As (III) and As (V) were 106.4 and 38.3 mg/g, respectively. Ion effect study showed that cationic Ca and Mg substantially enhanced As (V) adsorption, whereas no significant impact was observed on As (III). Silicate substantially decreased As (V) adsorption by 57 % and As (III) by 50 %. HCO 3 − remarkably inhibited As (V) adsorption by 52 %, whereas it slightly reduced As (III) adsorption by 8 %. Field column results demonstrated that ∼700 μg/L As was removed at an empty bed contact time (EBCT) of 1.08 min for 968 bed volumes before effluent As concentration exceeded 10 μg/L, corresponding to 0.96 mg As/g GTiO 2 . Two household filters loaded with 110 g GTiO 2 in the on-off operational mode can provide 6-L/day As-safe drinking water up to 288 and 600 days from the groundwater containing ∼700 μg/L As and ∼217 μg/L As, respectively. Integration of batch experiments and column tests with systematic variation of EBCTs was successfully achieved using PHREEQC incorporating a charge distribution multisite complexation (CD-MUSIC) model and one-dimensional reactive transport block.

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Section: Field Column Resultsmentioning

confidence: 99%

Groundwater arsenic removal using granular TiO2: integrated laboratory and field study

Cui

et al. 2014

Environ Sci Pollut Res

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“…When using this fine-tuning approach, the parameters obtained from batch adsorption must be modified to satisfactorily approximate the column data. Kinetic limitations were initially thought to be the critical contributor in predicting the As transport process in the TiO 2 columns using parameters obtained with batch experiments (Hu et al, 2015a;Maji et al, 2012); however, after excluding their influence, the effect of coexisting ions on As adsorption was recognized as the main challenge. Herein, while simultaneously considering the adsorptions of As, Ca 2+ , Si(OH) 4 , and HCO 3 − , and the formation of Ca-As-TiO 2 ternary surface complexes, the breakthrough curves of As, Ca 2+ , Si(OH) 4 , and HCO 3 − in the TiO 2 filters were well-simulated with the PHREEQC Table 2 -Summary of As removal from geogenic groundwater and wastewater using column filtration.…”

Section: Phreeqc Coupled With Cd-music To Simulate As Transport In Thmentioning

confidence: 99%

Recent progress of arsenic adsorption on TiO 2 in the presence of coexisting ions: A review

Jing

2016

Journal of Environmental Sciences

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“…6,7 On the other hand, even without the kinetics block, the adsorptive filtration of As(III) in synthetic water matrices through iron-oxide-coated rock can be successfully modeled. 8 This success may be attributed to instantaneous uptake of As by most metal oxides. However, a real difficulty surfaces when predicting the groundwater As breakthrough curves in field columns, even with the kinetics block and additional As adsorption reactions.…”

Section: ■ Introductionmentioning

confidence: 99%

“…However, a real difficulty surfaces when predicting the groundwater As breakthrough curves in field columns, even with the kinetics block and additional As adsorption reactions. 8,9 The compound effects of groundwater matrices on As adsorption cannot be overstated.Groundwater As adsorption on metal oxides can be suppressed or enhanced in the presence of coexisting ions. Previous studies demonstrated that some anions such as phosphate and silicate could strongly compete with As adsorption, 10 whereas others including sulfate, nitrate, and chloride only have negligible effects.…”

mentioning

confidence: 99%

Groundwater Arsenic Adsorption on Granular TiO₂: Integrating Atomic Structure, Filtration, and Health Impact

Shi

Jing

2015

Environ. Sci. Technol.

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A pressing challenge in arsenic (As) adsorptive filtration is to decipher how the As atomic surface structure obtained in the laboratory can be used to accurately predict the field filtration cycle. The motivation of this study was therefore to integrate molecular level As adsorption mechanisms and capacities to predict effluent As from granular TiO 2 columns in the field as well as its health impacts. Approximately 2,955 bed volumes of groundwater with an average of 542 μg/L As were filtered before the effluent As concentration exceeded 10 μg/L, corresponding to an adsorption capacity of 1.53 mg As/g TiO 2 .After regeneration, the TiO 2 column could treat 2,563 bed volumes of groundwater, resulting in an As load of 1.36 mg/g TiO 2 . Column filtration and EXAFS results showed that among coexisting ions present in groundwater, only Ca 2+ , Si(OH) 4 , and HCO 3 − would interfere with As adsorption. The compound effects of coexisting ions and molecular level structural information were incorporated in the PHREEQC program to satisfactorily predict the As breakthrough curves. The total urinary As concentration from four volunteers of local residences, ranging from 972 to 2,080 μg/L before groundwater treatment, decreased to the range 31.7−73.3 μg/L at the end of the experimental cycle (15− 33 days). ■ INTRODUCTIONAdsorptive filtration is one of the most cost-effective and userfriendly techniques to provide arsenic (As) safe drinking water in geogenic As contaminated areas.1,2 Integration of mounting molecular-level evidence over the past decade has shown that the mechanism of As adsorption mainly involves the formation of bidentate binuclear inner sphere surface complexes. 3−5Although substantial progress has improved our understanding of batch and field filtration experiments, a pressing challenge is to decipher how the molecular-level mechanism obtained in the laboratory can be used to accurately predict the field filtration cycle.Rethinking the failure in prediction of field filtration breakthrough curves using parameters obtained with batch experiments, we realized that the adsorption kinetics might not be the critical contributor, as initially thought. The difference in reaction kinetics between batch complete-mixed and column flow-through conditions has long been recognized and solved by incorporating a nonequilibrium kinetics block in simulation code such as PHREEQC. 6,7 On the other hand, even without the kinetics block, the adsorptive filtration of As(III) in synthetic water matrices through iron-oxide-coated rock can be successfully modeled. 8 This success may be attributed to instantaneous uptake of As by most metal oxides. However, a real difficulty surfaces when predicting the groundwater As breakthrough curves in field columns, even with the kinetics block and additional As adsorption reactions. 8,9 The compound effects of groundwater matrices on As adsorption cannot be overstated.Groundwater As adsorption on metal oxides can be suppressed or enhanced in the presence of coexisting ions. Previo...

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Fixed bed adsorption of As(III) on iron-oxide-coated natural rock (IOCNR) and application to real arsenic-bearing groundwater

Cited by 55 publications

References 38 publications

Groundwater arsenic removal using granular TiO2: integrated laboratory and field study

Groundwater arsenic removal using granular TiO2: integrated laboratory and field study

Recent progress of arsenic adsorption on TiO 2 in the presence of coexisting ions: A review

Groundwater Arsenic Adsorption on Granular TiO₂: Integrating Atomic Structure, Filtration, and Health Impact

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Fixed bed adsorption of As(III) on iron-oxide-coated natural rock (IOCNR) and application to real arsenic-bearing groundwater

Cited by 55 publications

References 38 publications

Groundwater arsenic removal using granular TiO2: integrated laboratory and field study

Groundwater arsenic removal using granular TiO2: integrated laboratory and field study

Recent progress of arsenic adsorption on TiO 2 in the presence of coexisting ions: A review

Groundwater Arsenic Adsorption on Granular TiO2: Integrating Atomic Structure, Filtration, and Health Impact

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Groundwater Arsenic Adsorption on Granular TiO₂: Integrating Atomic Structure, Filtration, and Health Impact