Journal of Environmental Chemical Engineering
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2021
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IF 5.909
Ruoming Tong,Pengshuang Zhang,Yaoqi Yang,Ruiyuan Zhang,Xuhui Sun,Xingmao Ma,Virender K. Sharma
This paper presents a new process to synthesize ferrate(VI) (Fe VI O 4 −2 ) continuously through the oxidation of ferric ion (Fe 3+) by hypochlorite (OCl - ) under alkaline condition. Synthesis was performed under different experimental conditions ([OH - ] = 5.0 – 16.0 M, and T = 20 – 45 °C) to obtain optimum yield of ferrate(VI). Under the most favorable condition (i.e., ([Fe 3+ ] = 0.10 M, [OCl - ]: [Fe 3+ ] = 10.0, [OH - ] = 10.0 M, and T = 40 °C), the yield of ferrate(VI) in the newly designed reactor increased by about 11% in 60 min compared to conventional reactor (or increased in [FeO 4 2- ] from 4.0 × 10 −2 M to 4.5 × 10 −2 M). The rapid mixing under flow condition in the closed coil of the new reactor improved the reaction efficiency and yield. When [Fe 3+ ] was varied in the range from 0.10 to 0.20 M in the reactor under the same condition, the optimum concentration of Fe 3+ was at 0.16 M, which increased the concentration of FeO 4 2- to 6.8 × 10 −2 M. Applying ultrasound power density (5.0–25.0 W/L) in the reaction process further increased the yield by about 12% (or increased [FeO 4 2- ] from 6.8 × 10 −2 M without ultrasound to 7.6 × 10 −2 M at 15.0 W/L). Overall, operating the newly designed reactor under ultrasound could increase the concentration of synthesized ferrate(VI) from 4.0 × 10 −2 M to 7.6 × 10 −2 M. At pH 7.0, the prepared ferrate(VI) completely removed atrazine (ATZ), sulfachloropyridazine (SCP), ibuprofen (IBP), and naproxen (NAP)) in water.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Ruobing Pi,Huanyu Liu,Xuhui Sun,Ruiyuan Zhang,Jiaxin Zhang,Virender K. Sharma
A strategy of periodic reverse current (PRC) electrolysis in the electrochemical synthesis of ferrate(VI) (Fe VI O 4 2- ) was developed to alleviate the problem of anode passivation to increase the yield. The use of a cyclic reverse controller in the PRC electrolysis improved the space–time yield of ferrate(VI), demonstrated by carrying out experiments under different polarity switching frequencies (23.1 – 163.6 times per hour), electrolyte flow rates (20–60 rad), and electrolyte concentrations (8–16 mol/L NaOH). At a switching frequency of 112.5 times per hour in 12 mol/L NaOH at an electrolyte flow rate of 60 rad, the available current density increased from 56.6 mA/cm 2 (DC electrolysis alone) to 73.2 mA/cm 2 (cyclic reverse current electrolysis), and the concentration of ferrate(VI) increased from 0.16 mol/L to 0.28 mol/L. The formation rate of ferrate(VI) under the non-passivated state of the electrode was established. The comparison of the experimentally obtained ferrate(VI) concentrations with the expected levels from the rate equation allows the estimation of the degree of passivation of the electrode which aids in minimizing passivation of the anode in the long-term production of high yield ferrate(VI). The prepared ferrate(VI) successfully removed sulfachloropyridazine (SCP), a sulfonamide antibiotic, in water.
研究领域:
环境科学
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电化学
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水处理技术
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DOI
高影响因子
WATER RESEARCH
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2024
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IF 11.4
Xiaoxiang Cheng,Dongshun Sai,Xinsheng Luo,Haiqing Chang,Peijie Li,Jingtao Xu,Daoji Wu,Heng Liang
Ultrafiltration (UF) is increasingly used in the pretreatment of shale gas produced water (SGPW), whereas severe membrane fouling hampers its actual operation. In this work, ferrate(VI)-based oxidation was proposed for membrane fouling alleviation in SGPW pretreatment, and the activation strategies of calcium peroxide (CaO 2 ) and ultraviolet (UV) were selected for comparison. The findings indicated that UV/Fe(VI) was more effective in removing fluorescent components, and the concentration of dissolved organic carbon was reduced by 24.1 %. With pretreatments of CaO 2 /Fe(VI) and UV/Fe(VI), the terminal specific membrane flux was elevated from 0.196 to 0.385 and 0.512, and the total fouling resistance diminished by 52.7 % and 76.2 %, respectively. Interfacial free energy analysis indicated that the repulsive interactions between pollutants and membrane were notably enhanced by Fe(VI)-based oxidation, thereby delaying the deposition of cake layers on the membrane surface. Quenching and probe experiments revealed that high-valent iron intermediates (Fe(IV)/Fe(V)) played significant roles in both CaO 2 /Fe(VI) and UV/Fe(VI) processes. Besides, hydroxyl radicals ( • OH) were also important reactive species in the UV/Fe(VI) treatment, and the synergistic effect of Fe(IV)/Fe(V) and • OH showed a positive influence on SGPW fouling mitigation. In general, these findings establish a theoretical underpinning for the application of Fe(VI)-based oxidation for UF membrane fouling mitigation in SGPW pretreatment.
研究领域:
环境工程
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水处理
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膜技术
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化学工程
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2023
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IF 11.4
Binbin Shao,Jing Deng,Hongyu Dong,Shuchang Wang,Enchao Li,Xiaohong Guan
Recent research has primarily focused on the utilization of reductants as activators for Fe(VI) to generate high-valent iron species (Fe(IV)/Fe(V)) for the degradation of emerging organic contaminants (EOCs). However, a significant drawback of this approach arises from the reaction between reductants and ferrates, leading to a decrease in oxidation capacity. This study introduces a novel discovery that highlights the potential of the iron(III)-(1,10-phenanthroline) (Fe(III)-Phen) complex as an activator, effectively enhancing the degradation of EOCs by Fe(VI) and augmenting the overall oxidation capacity of Fe(VI). The degradation of EOCs in the Fe(VI)/Fe(III)-Phen system is facilitated through two mechanisms: a direct electron transfer (DET) process and electron shuttle action. The DET process involves the formation of a Phen-Fe(III)–Fe(VI)* complex, which exhibits a stronger oxidation ability than Fe(VI) alone and can accept electrons directly from EOCs. On the other hand, the electron shuttle process utilizes Fe(III)-Phen as a redox mediator to transfer electrons from EOCs to Fe(VI) through the Fe(IV)/Fe(III) or Fe(IV)/Fe(II)/Fe(III) cycle. Moreover, the Fe(III)-Phen complex can improve the utilization efficiency of Fe(V) by preventing its self-decay. This study’s findings may present a viable option for utilizing an effective catalyst to enhance the oxidation of EOCs by Fe(VI) and Fe(V).
研究领域:
环境化学
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水处理
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高级氧化过程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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