Treatment of acidic wastewater via fluoride ions removal by SiO2 particles followed by phosphate ions recovery using flow-electrode capacitive deionization

Épshtein, A. E.; Nir, Oded; Monat, Lior; Gendel, Youri

doi:10.1016/j.cej.2020.125892

Cited by 41 publications

(14 citation statements)

References 31 publications

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“…To avoid F(I)-related limitations, fluoride-free solution was used to simulate PIWAA pre-treated for F(I) removal. Previous studies 28 and current industrial practice indicate effective F(I) removal in PIWWA treatment by, for example, adsorption on silicate-bearing materials. Omitting F(I) allowed the use of a standard 0.45 mm spacer rather than the special-grade 1 mm spacer.…”

Section: High-recovery Ed Experimentsmentioning

confidence: 95%

A circular process for phosphoric acid plant wastewater facilitated by selective electrodialysis

Monat

Zhang

Jarošíková

et al. 2022

Preprint

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Phosphoric acid production generates large volumes of industrial wastewater that cannot be treated efficiently by existing processes because of its low pH and high precipitation potential. At present, the wastewater is generally stored in evaporation ponds that are prone to breaches, leakage, and flooding. We developed an alternative three-step process for the treatment of phosphoric acid wastewater including selective electrodialysis, reverse osmosis, and neutralization. Testing the process with synthetic wastewater yielded promising results. An exceptional Na/Ca selectivity (up to 18.3 was observed in low-pH electrodialysis, enabling the separation of concentrated H2SO4 without gypsum scaling. Sulfate removal from the electrodialysis diluate prevented scaling in the subsequent high-recovery (>90%) reverse osmosis step, generating high-quality water. A final reaction between the reverse osmosis concentrate and natural phosphate rock enabled P recovery and neutralization of remaining acidity. The electric-power requirement of the process was estimated to be 4.4 kWh per m3 of wastewater, from which 0.78 m3 of clean water, ~3 kg H2SO4, and ~2.5 kg P were recovered. Overall, lab-scale results indicate that this process would be a sustainable and techno-economically viable solution for the treatment of hazardous wastewater byproducts of the phosphoric acid industry

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Section: High-recovery Ed Experimentsmentioning

confidence: 95%

A circular process for phosphoric acid plant wastewater facilitated by selective electrodialysis

Monat

Zhang

Jarošíková

et al. 2022

Preprint

Self Cite

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“…During the discharging process, this uncharged P tended to be retained in the anode chamber, whereas the quicker release of Cl − back to the spacer chamber was observed within the first 30 min. Epshtein et al 29 reported a similar operation, where highpurity phosphoric acid was successfully separated from other dissociated ionic species present in wastewater by controlling the feed stream pH below 2.1. Note that Faradaic reactions (i.e., oxygen reduction) would also be inevitable in the original anode chamber when reversing the electrode polarity for cell discharging, with these reactions leading to the depletion of H + and inducing an adverse influence on P retention.…”

Section: Methodsmentioning

confidence: 99%

“…These considerations for the selective separation of P overlooked a fundamental aspect that uncharged H 3 PO 4 dominates the strongly acid condition (i.e., pH <2.15) because of protonation, in which the migration of other charged anions hardly changed. 28 Epshtein et al 29 reported recently on the recovery of P from phosphoric acid industry wastewater according to this mechanism. Ninety percent recovery of P was achieved due to the high selectivity of non-ionic H 3 PO 4 from Cl − and SO 4 2− ions under an acidic environment (pH 1.2).…”

Section: Introductionmentioning

confidence: 99%

Selective Recovery of Phosphorus from Synthetic Urine Using Flow-Electrode Capacitive Deionization (FCDI)-Based Technology

Tian

et al. 2020

ACS EST Water

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Extraction of high-purity phosphate (P) from source-separated urine has attracted growing interest, given its potential economic and environmental benefits. In this study, we present an innovative strategy for selectively separating P from synthetic urine containing a high concentration of Cl − , simply by adjusting the charging and discharging processes of a flowelectrode capacitive deionization (FCDI) unit. During the charging process, both P and Cl − will be transported to the anode chamber and be adsorbed by the charged carbon particles. The inevitable Faradaic reactions induced the generation of H + and led to the conversion of charged P ions into uncharged H 3 PO 4 and spontaneous desorption into the electrolyte. When the electrode polarity is reversed, constantly charged species like Cl − would be mostly pushed back into the spacer chamber, whereas neutral H 3 PO 4 was expected to be selectively trapped in the anode chamber due to sluggish pH variations (particularly when using a higher carbon content), forming a P-rich solution. Under the optimal operating conditions (i.e., carbon content of 5 wt %, charging and discharging current densities of 10 and −15 A/m 2 , respectively, and charging and discharging current times of 120 and 30 min, respectively), a stable recovery efficiency (164 mg/L per cycle) and selectivity (ρ > 2, compared to Cl − ) of P were attained at a relatively low level of electric energy consumption. Results demonstrated that FCDI could be a promising technology for efficient P removal and recovery from source-separated urine without the consumption of additional chemicals.

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“…However, phosphorus and nitrogen are also essential nutrients for agricultural production. As such, it would seem advantageous to recover these nutrients from waste streams for later use in agriculture. ,,− Motivated by this concept, many studies have been devoted to selective extraction of nutrients from wastewaters using FCDI technology. Fang et al and Zhang et al investigated ammonia and phosphate removal and preconcentration from synthetic wastewater using an FCDI device. , While more than 80% of the ammonia and phosphate present could be effectively removed, no attention was given to the subsequent recovery of ammonia or phosphorus.…”

Section: Environmental Applications Of Fcdimentioning

confidence: 99%

Flow Electrode Capacitive Deionization (FCDI): Recent Developments, Environmental Applications, and Future Perspectives

Zhang

Lei

et al. 2021

Environ. Sci. Technol.

184

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With the increasing severity of global water scarcity, a myriad of scientific activities is directed toward advancing brackish water desalination and wastewater remediation technologies. Flow-electrode capacitive deionization (FCDI), a newly developed electrochemically driven ion removal approach combining ion-exchange membranes and flowable particle electrodes, has been actively explored over the past seven years, driven by the possibility of energy-efficient, sustainable, and fully continuous production of high-quality fresh water, as well as flexible management of the particle electrodes and concentrate stream. Here, we provide a comprehensive overview of current advances of this interesting technology with particular attention given to FCDI principles, designs (including cell architecture and electrode and separator options), operational modes (including approaches to management of the flowable electrodes), characterizations and modeling, and environmental applications (including water desalination, resource recovery, and contaminant abatement). Furthermore, we introduce the definitions and performance metrics that should be used so that fair assessments and comparisons can be made between different systems and separation conditions. We then highlight the most pressing challenges (i.e., operation and capital cost, scale-up, and commercialization) in the full-scale application of this technology. We conclude this state-of-the-art review by considering the overall outlook of the technology and discussing areas requiring particular attention in the future.

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Treatment of acidic wastewater via fluoride ions removal by SiO2 particles followed by phosphate ions recovery using flow-electrode capacitive deionization

Cited by 41 publications

References 31 publications

A circular process for phosphoric acid plant wastewater facilitated by selective electrodialysis

A circular process for phosphoric acid plant wastewater facilitated by selective electrodialysis

Selective Recovery of Phosphorus from Synthetic Urine Using Flow-Electrode Capacitive Deionization (FCDI)-Based Technology

Flow Electrode Capacitive Deionization (FCDI): Recent Developments, Environmental Applications, and Future Perspectives

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