ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2017
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IF 6.198
Xing Peng,Beidou Xi,Ying Zhao,Qiantao Shi,Xiaoguang Meng,Xuhui Mao,Yonghai Jiang,Zhifei Ma,Wenbing Tan,Hongliang Liu,Bin Gong
Treatment of arsenic by zerovalent iron (ZVI) has been studied extensively. However, the effect of arsenic on the formation of ferric hydroxide precipitates in the ZVI treatment has not been investigated. We discovered that the specific surface area (ca. 187 m2/g) and arsenic content (ca. 67 mg/g) of the suspended solids (As-containing solids) generated in the ZVI treatment of arsenic solutions were much higher than the specific surface area (ca. 37 m2/g) and adsorption capacity (ca.12 mg/g) of the suspended solids (As-free solids) generated in the arsenic-free solutions. Arsenic in the As-containing solids was much more stable than the adsorbed arsenic in As-free solids. XRD, SEM, TEM, and selected area electron diffraction (SAED) analyses showed that the As-containing solids consisted of amorphous nanoparticles, while the As-free solids were composed of micron particles with weak crystallinity. Extended X-ray absorption fine structure (EXAFS) analysis determined that As(V) was adsorbed on the As-containing suspended solids and magnetic solid surfaces through bidentate binuclear complexation; and As(V) formed a mononuclear complex on the As-free suspended solids. The formation of the surface As(V) complexes retarded the bonding of free FeO6 octahedra to the oxygen sites on FeO6 octahedral clusters and prevented the growth of the clusters and their development into 3-dimensional crystalline phases.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ACS ES&T Engineering
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2025
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IF 6.7
Long Su,Lanlan Liu,Jingsai Li,Xiang Chen,Di Fang,Lixiang Zhou
Iron biomineralization driven by chemoautotrophic iron-oxidizing bacteria (e.g., Acidithiobacillus ferrooxidans) facilitates acid mine water remediation but faces considerable technical challenges such as slow Fe(II) oxidation and Fe(III) precipitation. To address these challenges, we used the widely present acid-resistant algae (e.g., Parachlorella kessleri) as a green booster for Fe biomineralization. The assistance of P. kessleri in biomineralization with A. ferrooxidans improved the production of ferric hydroxysulfate minerals (66.2% schwertmannite and 33.8% goethite) in mine water (pH 2.7) with 1.6 and 1.4 times faster rates of Fe(II) oxidation and total soluble Fe precipitation. Mechanistically, algae-secreted extracellular organic matter (EOM), especially CHONS-containing high-molecular-weight (400–650 Da) compounds with low double-bond equivalent (DBE ≤ 10, O/C < 0.2) and high carbon atom (C ≥ 15) (e.g., proteins), acted as electron shuttles with electron accepting and electron donating capacities of 0.9 and 0.7 mmol e–/g C, respectively, that accelerate electron transfer between Fe(II) and A. ferrooxidan to generate more reactive oxygen species (H2O2 and ·OH) for Fe(II) oxidation. Algal EOM could also bond readily with Fe(II) at low pH to form EOM-bound Fe(II). Compared with free Fe(II), EOM-bound Fe(II) was more easily oxidized in the acidic mine water due to its relatively lower Gibbs free energy, higher current intensity, and smaller charge transfer resistance. In Fe(III) precipitation, single spherical algal cells could serve as seed crystals that initiate the heterogeneous nucleation of ferric hydroxysulfate minerals and accelerate their crystallization in mine water by reducing the supersaturation demand. These findings provide new insights into the highly efficient bioremediation of metal-rich acid mine waters with algal-bacterial synergy.
研究领域:
环境生物学
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微生物学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Yuhao Zuo,Shao-dong Zhou,Yuchen He,Ke-Jun Wu
The use of Fe 3+ salts for leaching spent LiFePO 4 (LFP) batteries is gaining attention due to its mild, eco-friendly conditions. However, efficient Fe/Li separation remains challenging, as precipitation causes Li loss or impurity introduction, and conventional solvent extraction offers low Li efficiency (∼80 %) and complex processes. This study employed data mining and theoretical analysis to rapidly identify a synergistic P204/N235 extraction system. A closed-loop process coupling H 3 PO 4 stripping and FePO 4 precipitation was developed, achieving 99.45 % Fe removal and only 1.25 % Li loss in a single extraction stage. The Fe/Li separation factor reached 14,243. During stripping, Fe recovery reached 95 % in one stage. The aqueous phase over 10 stripping cycles was reused for FePO 4 preparation, and the raffinate was retained for Li recovery. This integrated approach enables efficient Fe/Li separation and high-value resource utilization from LFP leachates.
研究领域:
冶金学
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材料科学
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化学工程
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环境科学
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电池回收
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
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IF 15.1
Lulu Chen,Xiaona Dong,Ruonan Feng,Wanying Li,Dahu Ding,Tianming Cai,Canlan Jiang
Triclosan (TCS) is a compound in pharmaceutical and personal care products (PPCPs) that preferentially accumulates in soil and may threaten human health. Iron-based persulfate activation processes (Fe-PAPs) are a promising technique in soil remediation but are limited by their narrow pH application range and resultant iron precipitation. In this study, oxalic acid (OA) was specifically introduced to improve the efficiency of Fe 2+ -activated persulfate (PS) processes for TCS degradation in soil. The complexation of OA and Fe 2+ improved the total iron concentration in the Fe 2+ /OA/PS system and prevented iron precipitation. Fe-minerals in soil were also dissolved by OA, which participated in PS activation. The most appropriate proportion of Fe 2+ /OA/PS is 1:1:1, and approximately 85% of the TCS was degraded within 240 min compared with 45% in the Fe 2+ /PS system. SO 4 • - and 1 O 2 played important roles on TCS oxidation, while O 2 • - and CO 2 • - mainly participated in the iron cycle. The weak stretch of Fe-O in OA containing treatments in ATR-FTIR measurements provided evidence that OA dissolved the Fe-minerals. The introduction of OA in the Fe 2+ /PS system in four different soils reduced the negative effect of soil organic matter on TCS degradation. Three types of intermediates including hydroxylation, cleavage of ether bonds and cyclization products, were identified by LC-Q-TOF-MS. Column experiments were used to study the feasibility of in situ chemical oxidation (ISCO) remediation of TCS in the Fe 2+ /OA/PS system. Our findings indicated the ability of OA to be used as a cheating agent in Fe-PAPs for TCS soil remediation.
研究领域:
环境科学
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土壤化学
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污染物降解
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修复技术
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产品关联
DOI
高影响因子
Environmental Science-Nano
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2022
·Vol. 9
·期 8
·2906-2921
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IF 9.473
Jiachen Huang,Jianquan Luo,Xiangrong Chen,Shichao Feng,Yinhua Wan
Nanofiltration (NF) membranes have been widely applied in wastewater treatment. However, their wider applications and further popularization are still hindered owing to severe membrane fouling and decreasing cleaning efficiency. In this study, Fenton/Fenton-like agents with a strong foulant degradation ability are prepared and selected, and their influence on the physicochemical properties of polyamide (PA) NF membranes and cleaning efficiency are systematically investigated. It is found that the secondary fouling caused by ferric hydroxide precipitates makes the conventional Fenton agent unsuitable for membrane cleaning. Then, a Fenton-like agent with magnetic Fe3O4 nanoparticles modified by γ-poly-glutamic acid (γ-PGA) and L-histidine (L-His) is prepared for membrane cleaning with a low concentration of hydrogen peroxide (<1 mM). Therein, the γ-PGA coating significantly inhibits the agglomeration of nanoparticles by improving their hydrophilicity/dispersibility and reduces their adsorption on the membrane as well as metal ion leaching. More importantly, the imidazole functional groups of L-histidine endow Fe3O4 nanoparticles with a higher affinity for hydrogen peroxide, thus ameliorating their catalytic activity for foulant degradation. Combining alkaline cleaning and Fenton-like catalysis cleaning, the stubborn pore fouling can be almost fully removed (100% and 95% for dead-end and cross-flow filtrations, respectively) because the alkali-induced pore swelling effect would enlarge the membrane pores and enhance the mass transfer of free radicals (˙O2− and ˙OH) into the pores and the release of oxidated foulants. Such a magnetic cleaning agent can be easily recovered and reused for green and sustainable membrane cleaning.
研究领域:
环境科学
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化学工程
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材料科学
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水处理
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DOI
高影响因子
危险品化学品经营许可证（带存储）