Coprecipitation of arsenate with iron(III) in aqueous sulfate media: Effect of time, lime as base and co-ions on arsenic retention

Jia, Yongfeng; Demopoulos, George P.

doi:10.1016/j.watres.2007.08.017

Cited by 143 publications

(53 citation statements)

References 21 publications

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“…Higher levels of arsenic tend to be found in ground water sources than in surface water sources (i.e., lakes and rivers) of drinking water. The demand on ground water from municipal systems and private drinking water wells may cause water levels to drop and release arsenic from rock formations and exacerbate the arsenic levels in ground water [1][2][3]. Arsenic exposure can result in carcinogenic and noncarcinogenic responses in humans.…”

Section: Introductionmentioning

confidence: 99%

Retention Studies on Arsenic From Aqueous Solutions by Lime Treated Semi Arid Soils

Moghal

Reddy²,

Mohammed³

et al. 2017

geomate

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ABSTRACT:In this study, locally available semi-arid soils (Al-Ghat and Al-Qatif) having different chemical and mineralogical characteristics are considered as barrier materials, and their response to arsenic adsorption at varying initial concentrations, pH conditions, temperature and dilution ratios is studied. Empirical models (Langmuir and Freundlich) are applied to ascertain monolayer or heterogeneous adsorption. Lime is added to these soils in order to enhance their geotechnical properties. Kinetic models are employed to validate the type and nature of arsenic sorption onto these soils (whether pseudo first-order or second-order). Also Elovich and intraparticle diffusion models revealed that along with surface adsorption, chemisorptions and diffusion are the other processes occurring concurrently in the system, but it was not able to identify the dominant phenomenon among these models. It was concluded that both Al-Ghat and Al-Qatif soils when amended with lime can attenuate arsenic, and the experimental results correlate well with selected empirical models.

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Section: Introductionmentioning

confidence: 99%

Retention Studies on Arsenic From Aqueous Solutions by Lime Treated Semi Arid Soils

Moghal

Reddy²,

Mohammed³

et al. 2017

geomate

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“…The pH of the arsenate solution was adjusted with 6 N HCl to ∼1 before mixing with the Fe I I I solution. The arsenate-Fe I II coprecipitates were synthesized by neutralizing the acidic As V -Fe III chloride or sulfate solutions to pH ∼7 using CaO (Jia and Demopoulos 2008). In detail, As V -Fe III solutions were prepared by mixing 33 mL of the arsenate stock solution with 267 mL of an Fe III stock solution, resulting in an Fe/As molar ratio of 16.…”

Section: Methodsmentioning

confidence: 99%

The effect of microbial sulfidogenesis on the stability of As–Fe coprecipitate with low Fe/As molar ratio under anaerobic conditions

Wang

Pan

et al. 2015

Environ Sci Pollut Res

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The effect of microbial sulfidogenesis on As transformation and mobilization in solid phase with low Fe/As ratio is still not well known. In this study, microbial transformation and mobilization of As in the As-Fe coprecipitate with different sulfate levels were investigated using chemical extraction and K-edge XANES of As and S. Results showed that approximately 2.7, 24.4, and 83.7 % of total As were released into the aqueous phase in the low-, mid-, and high-sulfate treatments, respectively, indicating that the presence of large amounts of sulfate could enhance microbial arsenic mobilization in the As-Fe coprecipitate. In the low-sulfate treatment, As mobilization was primarily attributed to the reductive dissolution of the Fe (oxy)hydroxides and the As reduction and desorption. In the mid- and high-sulfate treatments, the reduction of arsenate and ferric iron was significantly enhanced. Complete ferric iron reduction was observed in the solid phase, implying that Fe (oxy)hydroxide was transformed to secondary minerals and may be the one of the primary causes for the enhanced As mobilization. Thermodynamic calculations predicted the formation of thioarsenite species after 35 days of incubation based on the concentration of dissolved As(III) and S(-II). Since thioarsenic species is more mobile, its formation may be one of the most important factors enhancing the As release in the high-sulfate system. The result of this study is of significance to completely predict the environmental behavior of As associated with Fe (hydr)oxides in the presence of microbial sulfidogenesis under anoxic conditions.

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“…The result is shown in Table 2. 0.27 g/l As(III) was in the residual solution, for As(III) is not absorbed the surface of FeO(OH) [9,26,27].…”

Section: Mongolian Journal Of Chemistry 17 (43) 2016 18-22mentioning

confidence: 99%

Arsenic removal from waste water by ozone oxidation combined with ferric precipitation

Zhang

Yang

2017

Mong. J. Chem.

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Abstract:The oxidation of As(III) to As(V) followed by precipitation and adsorption is thought to be the most effective process for removal of arsenic in industrial wastewater. In this work, the oxidation of As(III) to As(V) with ozone was carried out in an acidic solution. After oxidation, arsenic was removed by precipitation in an iron (III) sulfate system under ambient pressure at 90°C in acid. Batch experimental results show that ozone is quite effective in oxidizing As(III) at low pH. And more than 90% of 5g/l As(III) was removed from the acidic solution by precipitation with Fe 2 (SO 4 ) 3 in 7-8 hours. Key words: Arsenate, Arsenite, Ozone, Oxidation, Precipitation INTRODUCTIONRecently, the toxic behavior of arsenic is receiving increased attention as the arsenic pollution has been reported worldwide. Arsenic is a common element which is widely distributed throughout the rock, soil, natural water and marine environments and associated with some base and precious metals in the sulfide ores [1][2][3]. Hereupon, the mining and metallurgical industries have expended considerable research efforts to develop environmentally acceptable methodologies for the arsenic removal from waste water. Under natural conditions As is mostly found in inorganic forms as trivalent arsenite (As(III)) or as oxyanions of pentavalent arsenate (As(V)). In comparison with As(V), As(III) is high mobile and more difficult to be removed from the aqueous solution. All of the arsenic precipitation work carried out involved both ferric iron and pentavalent arsenic in solution, based on the substantially correct premise [2,4]. It is necessary to oxidize the trivalent arsenic to its pentavalent state before the arsenic removal. A lot of researchers focused on the methods for oxidation of As(III) to As(V) using different oxidants [5][6][7]8]. In several studies, ozone applications have been reported for treatment of wastewater and water, but very few studies are for oxidation of As [6][7][8][9][10]. The most characteristic chemical properties of ozone are its strong oxidizing and high standard redox potential according to the reaction conditions. It is strong oxidizing nature and its tendency to transfer an O atom with coproduction of O 2 [4]. The standard redox potentials in acid (1) and in alkaline (2) solutions are the following reactions.

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Coprecipitation of arsenate with iron(III) in aqueous sulfate media: Effect of time, lime as base and co-ions on arsenic retention

Cited by 143 publications

References 21 publications

Retention Studies on Arsenic From Aqueous Solutions by Lime Treated Semi Arid Soils

Retention Studies on Arsenic From Aqueous Solutions by Lime Treated Semi Arid Soils

The effect of microbial sulfidogenesis on the stability of As–Fe coprecipitate with low Fe/As molar ratio under anaerobic conditions

Arsenic removal from waste water by ozone oxidation combined with ferric precipitation

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