CHEMOSPHERE
·
2023
·
IF 8.8
Linsong Cheng,Yuanxiang Mao,Lei Jiang,Rui Ma,Jiangsen Ma,Yiyuan Zhuo,Qiushi Shen,Caocong Liu,Liuwei Zhao,Xiaoyi Xu,Fangying Ji
The high concentration of salt in organic wastewater has a strong inhibitory effect on the removal of pollutants. A method for the efficient removal of trace pollutants in high-salinity organic wastewater was developed. This study investigated the effect of the combination of permanganate [Mn(VII)] and calcium sulfite [S(IV)] on pollutant removal in hypersaline wastewater . The Mn(VII)-CaSO 3 system removed more pollutants from high-salinity organic wastewater than from normal-salinity wastewater. Chloride (increasing from 1 M to 5 M) and low concentration of sulfate (increasing from 0.05 M to 0.5 M) significantly enhanced the system's resistance to pollutants under neutral conditions. Despite the fact that Cl − can combine with the free radicals in the system and reduce their efficiency in removing pollutants, the presence of chloride ions greatly enhances the electron transfer rate in the system, promoting the conversion of Mn(VII) to Mn(III) and significantly increasing the reaction rate of Mn(III) as the primary active species. Therefore, chloride salts can greatly enhance the removal of organic pollutants by Mn(VII)-CaSO 3 . Although sulfate does not react with free radicals, a high concentration of sulfate (1 M) will affect the formation of Mn(III), which greatly weakens the removal effect of the entire system on pollutants. The system can still have a good pollutant removal effect with mixed salt. Altogether, this study demonstrates that the Mn(VII)-CaSO 3 system offers new possibilities for the treatment of organic pollutants in hypersaline wastewater.
研究领域:
环境科学
·
化学工程
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DOI
PubMed
高影响因子
TALANTA
·
2016
·
IF 4.035
Songqing Chen,Xingxiu Qin,Weixi Gu,Xiashi Zhu
Ionic liquids-β-cyclodextrin polymer (ILs-β-CDCP) was attached on Fe 3 O 4 nanoparticles to prepare magnetic solid phase extraction agent (Fe 3 O 4 @ILs-β-CDCP). The properties and morphology of Fe 3 O 4 @ILs-β-CDCP were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction(XRD), size distribution and magnetic analysis. A new method of magnetic solid phase extraction (MSPE) coupled to ICP-OES for the speciation of Mn(II)/Mn(VII) in water samples was established. The results showed that Mn(VII) and total manganese [Mn(II)+Mn(VII)] were quantitatively extracted after adjusting aqueous sample solution to pH 6.0 and 10.0, respectively. Mn(II) was calculated by subtraction of Mn(VII) from total manganese. Fe 3 O 4 @ILs-β-CDCP showed a higher adsorption capacity toward Mn(II) and Mn(VII). Several factors, such as the pH value, extraction temperature and sample volume, were optimized to achieve the best extraction efficiency. Moreover, the adsorption ability of Fe 3 O 4 @ILs-β-CDCP would not be significantly lower after reusing of 10 times. The accuracy of the developed method was confirmed by analyzing certified reference materials (GSB 07-1189-2000), and by spiking spring water, city water and lake water samples.
研究领域:
分析化学
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环境科学
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2022
·
IF 11.357
Honglong Zhang,Zhenyu Shi,Jun Ma,Fuyi Cui,Jing Zhang,Timothy J. Strathmann
In this study, a representative redox mediator, 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), and its para-substituted derivatives (TEMPOs: 4-hydroxyl-TEMPO, 4-acetylamino-TEMPO, and 4-amino-TEMPO) significantly accelerated the abatement of trace organic contaminants (TrOCs, i.e., bisphenol-A (BPA), phenol, amines, and phenylbutazone) by Mn(VII) over a wide pH range of 4.0–9.0. The addition of substituents at para to the > N–O• moiety significantly influenced the degradation kinetics of TrOCs by changing the reduction potentials of TEMPOs and the corresponding oxoammonium cations (TEMPOs+); a linear relationship was observed between the substituents’ para Hammett sigma constants and the reduction potentials of TEMPOs and TEMPOs+. Pseudo-first-order reaction rate constants (kobs, min–1) of TrOC degradation by Mn(VII)/TEMPOs were also affected by the pKa of the TrOCs. Generally, the highest kobs values for individual TrOCs were observed at pH near the pKa even for TEMPOs+ with relatively pH-invariant reduction potentials. Overall, TrOC abatement kinetics were related to a combination of reactive species (Mn(VII), in situ formed MnO2, and TEMPOs+). For BPA, the relative contributions (R) of reactive species ranked as R(TEMPOs+) > R(Mn(VII)) > R(in situ formed MnO2) at pH 4.0–8.0, whereas R(Mn(VII)) > R(TEMPOs+) at pH 9.0 mainly owing to a change in BPA speciation as the pH approached the pKa1 value for BPA. The results of this study are useful for the development of heterogeneous TEMPO-based redox mediators and future applications of TEMPO-mediated oxidation systems for accelerated abatement of TrOCs in water.
研究领域:
环境科学
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化学工程
·
水处理
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2026
·
IF 12.2
Zhou Yang,Feng Yuqing,Wen Rui,Huang Qiping,Guo Qin,Lu Xixin,Han Bin,Xie Haijiao,Ma Jinxing,Jiang Jin,Ma Jun,Gao Yuan
Balancing degradation efficiency with environmental sustainability
remains a critical challenge for permanganate (Mn(VII))-based oxidation
processes in environmental remediation. In this study, we report a
novel system initiated by low-dose Mn(VII) dosage (2 μM) in
combination with peroxymonosulfate (PMS), enabling efficient removal
of emerging contaminants exemplified by bisphenol A (BPA), especially
under alkaline conditions (e.g., pH 10). Notably, distinct from conventional
radical or nonradical activation mechanisms, we identified a previously
unrecognized Mn(VII) regeneration process in the Mn(VII)/PMS system,
as supported by a series of complementary evidence from radical quenching
experiments, stopped-flow spectroscopy, DFT calculations, and kinetic
modeling. The in situ generated Mn(VI) from the reaction of Mn(VII)
and BPA was demonstrated to act as the key intermediate, which was
subsequently reoxidized by PMS via a multihydrogen-bonded complex
back to Mn(VII). This Mn(VI)/Mn(VII) interconversion, reported here
for the first time, not only effectively enhanced contaminant degradation
but also significantly improved Mn(VII) utilization efficiency. These
findings broaden the mechanistic understanding of Mn(VII)-based systems
beyond traditional free radical- and Mn(III)/Mn(V)-driven pathways
and open new insights for developing efficient and environmentally
benign water treatment technologies.
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DOI
PubMed
高影响因子
ACS Omega
·
2022
·
IF 4.132
Qingxiang Wang,Tao Huang,Jing Du,Lulu Zhou
The extraction of uranium (U)-related minerals from raw ore sands via a leaching procedure would produce enormous amounts of tailings, not only causing radioactivity contamination to surroundings but also wasting the potential U utilization. Effective recycling of U from U tailings is propitious to the current issues in U mining industries. In this study, the influence of the composite oxidation of Fe(III) and Mn(VII) intensified by microwave (MW) irradiation on the acid leaching of U from tailings was comprehensively explored in sequential and coupling systems. The U leaching activities from the tailing specimens were explicitly enhanced by MW irradiation. The composite oxidation caused by Fe(III) and Mn(VII) further facilitated the leaching of U ions from the tailing under MW irradiation in two systems. Maximum leaching efficiencies of 84.61, 80.56, and 92.95% for U ions were achieved in the Fe(III)-, Mn(VII)-, and Fe(III)–Mn(VII)-participated coupling systems, respectively. The inappropriateness of the shrinking core model (SCM) demonstrated by the linear fittings and analysis of variance (ANOVA) for the two systems explained a reverse increase of solid cores in the later stage of leaching experiments. The internal migration of oxidant ions into the particle cores enhanced by MW accelerated the dissolution of Al, Fe, and Mn constituents under acidic conditions, which further strengthened U extraction from tailing specimens.
研究领域:
环境科学
·
核工程
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化学工程
·
材料科学
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Lijun Niu,Lili An,Kaiting Zhang,Qian Chen,Xin Yu,Menglu Zhang,Mingbao Feng
The increased release of various emerging organic contaminants into natural waters has posed great threats to ecological safety and public health. The ensuing global water contamination has necessitated the development of highly efficient treatment strategies for water purification . Herein, we presented for the first time that the combined utilization of permanganate (Mn(VII)) and periodate (PI) could synergistically and rapidly accomplish complete destruction of different organic micropollutants (e.g., bisphenol F, methotrexate, and tetracycline) within 2–5 min. Comparatively, the single treatment only eliminated very small amounts of micropollutants. Mechanistic investigations were performed using the trapper-based electron spin resonance , scavenging and probe experiments, UV–vis spectra analysis, determination of iodine species, and multiple validation tests. These data collectively suggested that the highly reactive Mn(V)/Mn(VI) intermediates played the leading role in accelerating contaminant abatement within the Mn(VII)/PI oxidation system. Reactive oxygen/or iodine species ( 1 O 2 , OH, O 2 - , IO 3 , and IO 4 ) and low valence Mn species (Mn(II), Mn(III), and in-situ formed MnO 2 colloids) did not participate in decontamination in this process. Subsequently, the oxidized products of three micropollutants were determined, and the transformation pathways were clarified. Ring-opening, C-C bond cleavage, demethylation, carbonylation , and hydroxylation reactions mainly occurred in the degradation process. Notably, the combined system did not yield any toxic iodinated end products. Finally, the environmental risks of the degradation products were also evaluated based on in silico QSAR-based prediction tools. Overall, this study provides a novel, highly efficient, and green treatment technology, i.e., Mn(VII)/PI system, which could be employed for rapid and sustainable water decontamination.
研究领域:
环境科学
·
水处理
·
化学工程
·
污染控制
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Mingyang Feng,Bo Wei,Hai Kuang,Lushi Lian,Hongyu Dong,Xiaohong Guan
Bisphenols are a class of emerging pollutants frequently detected in drinking water with concentrations ranging from ng/L to μg/L. However, previous studies have typically investigated their degradation at much higher levels (mg/L), limiting the relevance of those findings to the actual scenarios. Given the persistent challenge of effectively removing bisphenols at environmentally relevant concentrations, the development of efficient treatment methods is critical. In this study, we investigated the performance and mechanism of removing 18 trace-level bisphenols from drinking water via a calcium sulfite (CaSO 3 )-coupling permanganate (Mn(VII)/CaSO 3 ) process. Trace-level bisphenols (1.0 μg/L) could be effectively removed by the Mn(VII)/CaSO 3 process at environmentally relevant pH ranges (6.0–8.5). Quantitative structure-activity relationship analysis demonstrated that the degradation rates of bisphenols in this process were strongly positively correlated with their average polarizability. Reactive manganese species were identified to play a dominant role in the degradation of bisphenols. The potential risks of bisphenols could be effectively reduced after degradation by the Mn(VII)/CaSO 3 system. Moreover, the removal of trace-level bisphenols was resistant to interference from the water matrix and efficient in real water samples. Overall, the findings of this study highlight the Mn(VII)/CaSO 3 system as a promising pre-oxidation process for controlling trace-level bisphenols in drinking water.
研究领域:
环境科学
·
水处理技术
·
环境化学
·
污染物降解
·
毒理学
·
分析化学
·
氧化过程
·
饮用水安全
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产品关联
DOI
PubMed
高影响因子
WATER ENVIRONMENT RESEARCH
·
2022
·Vol. 94
·期 9
·e10788
·
IF 3.306
Binbin Shao,Yating Zhu,Jie Chen,Yimin Lin,Xiaohong Guan
During oxidative treatment of iodide (I − )-containing waters, I − is easy to be oxidized into hypoiodous acid (HOI) by various oxidants and the further reaction of HOI with organic compounds can lead to the formation of iodinated disinfection by-products (I-DBPs). Oxidation of HOI to iodate (IO 3 − ) or reduction of HOI to I − has been proposed to reduce the formation of I-DBPs. Because the reaction of HOI with sulfite proceeds rapidly, this study examined the fate of iodine and the formation of I-DBPs in Mn(VII)/sulfite process. Results showed that I − was oxidized to HOI but the further formation of IO 3 − was suppressed due to the fast reduction of HOI to I − by sulfite. The reactions of HOI with SO 3 2− and IO − with SO 3 2− are the major pathways with species-specific second-order rate constants determined to be 1.12 × 10 5 M −1 s −1 and 9.43 × 10 7 M −1 s −1 , respectively. The rapid reaction of HOI with sulfite plays an essential role in minimizing the formation of iodinated products in HOI- and phenol-containing solutions. The toxic risk analysis showed that the toxicity of the generated DBPs from Mn(VII)/sulfite pre-oxidation followed by chlorination only changed slightly. Practitioner Points The decay of I − was negligible in Mn(VII)/sulfite process. The rapid reaction of HOI with SO 3 2− resulted in the negligible generation of IO 3 − . Mn(VII)/sulfite process exerted slight influence on the formation of I-DBPs. Mn(VII)/sulfite process is promising for the pretreatment of I − -containing water.
研究领域:
环境科学
·
水处理工程
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产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Zheng-Yu Dong,Yi-Li Lin,Tian-Yang Zhang,Chen-Yan Hu,Yang Pan,Renjie Pan,Yu-Lin Tang,Bin Xu,Nai-Yun Gao
To improve the performance of the conventional coagulation process, a permanganate (Mn(VII)) pre-oxidation combined with Fe(III)/peroxymonosulfate (PMS) coagulation process (Mn(VII)-Fe(III)/PMS) that can significantly improve the removal of dissolved organic carbon (DOC), turbidity, and micropollutants is proposed in this study. Compared with conventional Fe(III) coagulation, the Mn(VII)-Fe(III)/PMS process can also significantly enhance the removal of iohexol and sulfamethoxazole in raw water. During this process, the primary reduction product, Mn(IV), after Mn(VII) pre-oxidation was adsorbed on the floc surfaces and involved in the Fe(III)/PMS process. The natural organic matter (NOM) in raw water mediated the redox cycle of iron. The synergistic effect of NOM, Fe, and Mn facilitated the redox cycle of Mn(III)/Mn(IV) and Fe(III)/Fe(II) to promote the activation of PMS. The sulfate radical (SO 4 •− ) played an important role in the degradation of micropollutants. The formation potential of the detected volatile disinfection by-product (DBP) during the subsequent chlorination was reduced by 21.9% after the Mn(VII)-Fe(III)/PMS process. This study demonstrated the promising application of the Mn(VII)-Fe(III)/PMS process for coagulation and micropollutant control and illustrated the reaction mechanism. This study provides guidance for improving conventional drinking water treatment processes.
研究领域:
环境科学
·
水处理工程
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产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Dandan Rao,Jie Chen,Hongyu Dong,Junlian Qiao,Baoxue Zhou,Yuankui Sun,Xiaohong Guan
Although permanganate activation by sodium sulfite (Mn(VII)/Na 2 SO 3 ) has shown great potential for rapid abatement of organic contaminants , the limited reactivity under alkaline conditions and undesirable Mn residual may prevent its widespread application. To solve these challenges, calcium sulfite (CaSO 3 ) was employed as a slow-release source of SO 3 2− /HSO 3 − (S(IV)) to activate Mn(VII) in this study. It was found that the application of CaSO 3 solid could extend the effective working pH range of Mn(VII)/S(IV) from ≤7.0 to ≤9.0. Moreover, due to the enhanced precipitation of MnO 2 with the presence of Ca 2+ , very low Mn residual (<0.05 mg/L) was achieved in Mn(VII)/CaSO 3 system. Mn(VII)/CaSO 3 system is a unique two-stage oxidation process in terms of reaction kinetics and reactive oxidants. Specifically, Mn(VII) was rapidly consumed and reactive Mn intermediates (e.g., Mn(VI), Mn(V)), SO 4 •− , and HO • were produced in the first stage. However, the second stage was governed by the interaction between MnO 2 and S(IV), with SO 4 •− and HO • serving as the dominant reactive oxidants. Taking advantage of an automatic titrator, excess S(IV) was found to greatly quench the generated radicals, whereas it did not cause a significant consumption of reactive Mn species. All these results improved our understanding of the Mn(VII)/S(IV) process and could thus facilitate its application.
研究领域:
环境科学
·
化学工程
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DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Shule Duan,Huiyu Dong,Pin Hou,Gangsheng Han,Bochao Zhang,Zhimin Qiang
Permanganate (Mn(VII)) is a widely used oxidant in water treatment , which can oxidize trace organic contaminants (TrOCs) and Mn(II). Interestingly, this study found that presence of Mn(II) could accelerate the abatement of bisphenol A by Mn(VII) only under oxic condition . Herein, the effects of Mn(II) and dissolved oxygen (DO) on the abatement of TrOCs by Mn(VII) oxidation and the related mechanism were investigated. Results indicate that DO was involved in the Mn(VII)/Mn(II) reaction, with the reaction stoichiometry of Δ[Mn(VII)]:Δ[Mn(II)] determined to be 1:2 and 1:1.5 in the presence and absence of DO, respectively. Quenching and electron paramagnetic resonance tests verified that both superoxide radicals (O 2 •− ) and reactive Mn species contributed to the accelerated abatement of TrOCs (bisphenol A, methyl phenyl sulfoxide, and methyl phenyl sulfone) in the Mn(VII)/Mn(II) process. Specifically, O 2 •− was produced through the one-electron reduction of DO and made an important contribution (32.4%–100%) to the abatement of selected TrOCs. This study reveals that Mn(II) could enhance TrOC abatement by Mn(VII) oxidation, and DO played a pivotal role in the Mn(VII)/Mn(II) process.
研究领域:
环境科学
·
水处理工程
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DOI
PubMed
高影响因子
ACS ES&T Engineering
·
2023
·
IF 7.1
Beiping Zhang,Chaoting Guan,Qin Guo,Run Huang,Jin Jiang
Electrochemical technologies and permanganate oxidation are two attractive strategies in water treatment due to their low cost, easy operation, good adaptability, and environmental friendliness. Interestingly, recent studies have demonstrated that the combination of electrolysis and Mn(VII) (E-Mn(VII) process) shows a synergetic effect on organic contaminants degradation. However, the underlying mechanism of the E-Mn(VII) process remains unclear. In this study, the enhanced removal of diclofenac (DCF) by the E-Mn(VII) process was also demonstrated, and the main reactive species were reidentified. It was found that H2O2 was considerably formed via the reduction of O2 on the cathode, and it played a key role in facilitating Mn(VII) transformation into MnO2. Increasing O2 concentration, working potential, and pH value were conducive to H2O2 formation as well as Mn(VII) transformation to MnO2. Higher Mn(VII) dosages did not impact H2O2 formation but also led to faster MnO2 formation. The enhanced formation of MnO2 was favorable for the fast degradation of DCF in the E-Mn(VII) process owing to the catalytic effect of MnO2 on Mn(VII) oxidation. This was confirmed by the observation that (i) the E-Mn(VII) process showed a similar pH-dependent oxidation trend to that of MnO2 catalytic oxidation of Mn(VII) (i.e., the reactivity was much stronger at lower pH); and (ii) the addition of MnO2 prepared ex situ had a significant enhancing effect on DCF oxidation by the E-Mn(VII) process. Moreover, the possible contribution of reactive manganese intermediates such as soluble free Mn(III), Mn(VI), and Mn(V) was ruled out by the results of the probe experiments, UV–visible spectrophotometry, and examining the reactivity of Mn(III) complexes prepared ex situ. Also, the results of radical scavenging experiments indicated the negligible contribution of HO•. Furthermore, for the practical application of the E-Mn(VII) process in water decontamination, suitable operating parameters (e.g., a moderate potential and relatively lower pH) should be determined to avoid the fast loss of Mn(VII) and the electrical energy consumption. Overall, this work brings new insights into the reaction mechanism of the E-Mn(VII) process as well as proposes an efficient, sustainable, and feasible strategy for water and wastewater treatment.
研究领域:
环境科学
·
化学工程
·
水处理
·
电化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）