CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Yuefei Ji,Yuanyuan Shi,Lu Wang,Junhe Lu
Nitrobenzene (NB) is a recalcitrant organic compound caused great environmental concerns. Sulfate radical-based advanced oxidation processes (SR-AOPs) are promising environmental remediation and wastewater treatment technologies. In this contribution, we observed that degradation of NB by thermally activated persulfate oxidation process resulted in the formation of a suite of intermediates including 2-nitrophenol (2-NP), 3-nitrophenol (3-NP), 4-nitrophenol (4-NP), 2,4-dinitrophenol (2,4-DNP), 2,6-dinitrophenol (2,6-DNP), and 2,4,6-trinitrophenol (2,4,6-TNP) as well as coupling products. The formation of the nitrophenols was suggested to follow the sequence of mononitrophenols → dinitrophenols → trinitrophenol. Time-dependent evolutions of mononitrophenols and dinitrophenols were illustrated and their formation mechanisms were proposed. The evolution patterns of mononitrophenols were fitted by sequential reaction kinetic model. The formation of polynitrated phenolic compounds suggests that both denitration and nitration processes occurred during SO 4 − -based oxidation of NB. Nitration agent (i.e., NO 2 ) arising from the conversion of nitro group upon SO 4 − /HO attack is proposed to play an important role in the formation of polynitrated compounds. TOC measurement revealed that mineralization was less efficient as compared with NB degradation. The presence of NO 2 − was found to inhibit the degradation of NB but promote the formation of 2,4-DNP. Temperature played an important role in both the degradation of NB and the distribution of products. Since polynitrated aromatics are more persistent and mutagenic, the results of this contribution suggest that particular attention should be paid to their formation during SO 4 − -based oxidation processes.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2021
·
IF 6.789
Tao Huang,Shu-wen Zhang,Lulu Zhou,Hui Tao,Aiyin Li
Ultrasonication has been mechanically applied widely in the recycling of spent lithium-ion (SLI) batteries while its influence on chemical pathways has barely been reported. In this study, ultrasonication and sulfate radicals were used in a coupling system to obtain efficient recoveries of Co and Li from SLI batteries. The synergistic effect of ultrasonication and sulfate radicals on recycling was quantitatively analysed by significance analysis and surface responses in a central composite design . The employment of persulfate significantly affected the whole recycling process during the sonication . Factors including acoustic time, operating powers, and temperature all had a significant effect on the recoveries of Co and Li. The maximum recovery efficiencies of Co and Li of 97.33% and 99.25%, respectively, and the minimum loss rate of Al of 4.13% were simultaneously obtained by the fitting predictor. The optimal combination of factors for the sonication system included an acoustic time (min) of 5.5, an operating power (W) of 168, a temperature (°C) of 86, and a ratio of cathode foil to S-solution (mg/mL) of 1:60. A moiety of cathode active material was directly separated from the aluminium collector by sulfate radical-related reactions. Co and Li cations dissolved from LiCoO 2 by carbon dioxide radicals were reprecipitated by excess oxalate. The research demonstrated the positively synergistic influence caused by ultrasonication and sulfate radicals on achieving efficient recoveries of Co and Li from SLI batteries, explicitly expanding the technical choices for the recycling procedure.
研究领域:
环境科学
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化学工程
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2020
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IF 9.038
Xuerui Yang,Xue Cao,Li Zhang,Yanlin Wu,Lei Zhou,Guangli Xiu,Corinne Ferronato,Jean-Marc Chovelon
The widespread utilization of pesticides has attracted increasing attention to their environmental impacts and effective removal strategies. In the present study, the degradation of herbicides picloram (PCLO) and aminopyralid (AMP) with similar structures were investigated systematically by thermo activated persulfate. Overweight SO 4 •− was determined to be the predominant oxidizing species by quenching experiment. Obtained by laser-flash photolysis (LFP), reaction rate constants of SO 4 •− towards AMP and PCLO were determined at 1.56 × 10 9 M −1 s −1 and 1.21 × 10 9 M −1 s −1 , respectively. Product analysis revealed that both substances underwent similar oxidation paths, namely, successive oxidation on pyridine ring and formation of coupling-products as well as further hydroxylation and decarboxylation . Amino group on the pyridine ring was identified as the main reactive site, which was further confirmed by DFT calculation. It was susceptible attacked by SO 4 •− to form deamination, nitration , and self-coupling products. These couples could be further oxidatively dehydrated to form azo and a series of azo derivatives . EOCSAR program predicted significant hazards on aquatic species during the formation of these couplings and azo derivatives. Our work emphasized the potential ability and toxicity of contaminates to produce azo substances in the presence of amino groups on the pyridine ring.
研究领域:
环境科学
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化学工程
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PubMed
高影响因子
Catalysts
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2022
·Vol. 12
·期 10
·1232
·
IF 4.501
Yunhe Li,Weibao Liu,Lezhuo Li,Siyuan Jiang,Xiuwen Cheng
In this study, a nickel ferrite (NiFe2O4) system was constructed to purify a phenol solution in water. During the process, the influences of several critical operating parameters including the NiFe2O4amount, PS dosage, MW power, initial pH value, and different natural water anions were systematically studied. The results indicated that the constructed system performed excellently regarding the removal efficiency (97.74%) of phenol within 30 min. Meanwhile, the influence of co-existing anions such as Cl−, NO3−, H2PO4−, and HCO3−was also studied, which displayed an inhibiting action on phenol degradation, while HA facilitated it. To explore the reaction mechanism of this system, major free radical quenching experiments were conducted, and it was confirmed that both SO4•−and HO• were primary radicals. Moreover, stability experiments confirmed the apt stability of the NiFe2O4system. Besides, the mineralization and toxicity analysis performed during phenol degradation also confirmed the superiority of the as-constructed system. Furthermore, the possible degradation mechanism of phenol was proposed. Hence, this system could be applied in advanced wastewater treatment.Keywords:persulfate;microwave;sulfate radicals;phenol;nickel ferrite
研究领域:
环境科学
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化学工程
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高影响因子
Desalination and Water Treatment
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2016
·
IF 1.272
Yongsheng Lu,Xingxing Yang,Lu Xu,Zhan Wang,Yunfeng Xu,Guangren Qian
The Fe3+/persulfate system for Rhodamine B (RhB) oxidative degradation has been investigated. The catalytic mechanism in the Fe3+/persulfate system was proposed as follows: Fe3+ was restored to Fe2+ by the generated intermediate products during the degradation process. The influence parameters were examined in batch experiments, including Fe3+ and persulfate concentration and initial pH. The results indicated that the Fe3+/persulfate system exhibited good performance for RhB degradation and followed first-order kinetics. 95.91% of the RhB was removed within 30 min under the following conditions: [Fe3+]0 = 1 mM, [persulfate]0 = 1 mM and pH 3.0. The RhB degradation efficiencies increased as the Fe3+ and persulfate concentrations increased. In addition, the RhB degradation was inhibited in the presence of inorganic anions, which was primarily due to a complex reaction between Fe3+ and various anions except for .
研究领域:
环境科学
·
化学
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DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Jiayue Dong,Peizeng Yang,Deyang Kong,Yiqiang Song,Junhe Lu
Polycyclic aromatic hydrocarbons (PAHs) have become a global environmental concern due to their potential hazardous implication for human health. In this study, we found that sulfate radical (SO 4 •− ) could effectively degrade naphthalene (NAP), a representative PAH in groundwaters, generating 1-naphthol. This intermediate underwent further degradation, yielding ring-opening products including phthalic acid and salicylic acid. However, the presence of nitrite (NO 2 − ), a prevalent ion in subsurface environments, was observed to compete with NAP for SO 4 •− , thus slowing down the NAP degradation. The reaction between NO 2 − and SO 4 •− generated a nitrogen dioxide radical (NO 2 • ). Concurrently, in-situ formed 1-naphthol underwent further oxidization to the 1-naphthoxyl radical by SO 4 •− . The coupling of 1-naphthoxyl radicals with NO 2 • gave rise to a series of nitrated NAP, namely 2-nitro-1-naphthol, 4-nitro-1-naphthol, and 2,4-dinitro-1-naphthol. In addition, the in-situ formed phthalic acid and salicylic acid also underwent nitration , generating nitrophenolic products, although this pathway appeared less prominent than the nitration of 1-naphthol. When 10 μΜ NAP was subjected to heat activated peroxydisulfate oxidation in the presence of 10 μΜ NO 2 − , the total yield of nitrated products reached 0.730 μΜ in 120 min. Overall, the presence of NO 2 − dramatically altered the behavior of NAP degradation by SO 4 •− oxidation and contributed to the formation of toxic nitrated products. These findings raise awareness of the potential environmental risks associated with the application of SO 4 •− -based oxidation processes for the remediation of PAHs-polluted sites in presence of NO 2 − .
研究领域:
环境科学
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化学
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PubMed
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Peizeng Yang,Hailing Chu,Jiating Liu,Teng Zhang,Junhe Lu
Sulfate radical (SO 4 •− ) advanced oxidation processes (SR-AOPs) are efficient for degrading a broad spectrum of contaminants. This study demonstrates that the existence of environmentally relevant concentrations of nitrite (NO 2 − ) can lead to the formation of N -nitrosodimethylamine (NDMA), a probable human carcinogen, when heat activated peroxydisulfate (heat/PDS) is applied to address contaminants with dimethylamine moieties, such as tetracyclines. NO 2 − effectively competes with tetracyclines for SO 4 •− at a high second-order reaction rate constant of 8.8 × 10 8 M −1 s −1 , thus suppressing the degradation. Simultaneously, SO 4 •− reacts with NO 2 − to form the nitrogen dioxide radical (NO 2 • ) which rapidly dimerizes to a potent nitrosating agent named dinitrogen tetroxide (N 2 O 4 ). N 2 O 4 , in turn, attacks the dimethylamine moiety in tetracyclines via nucleophilic substitution, contributing to the degradation of parent compounds and generating an active intermediate that quickly decomposes to NDMA, along with the release of R + and NO 3 − . The released R + can be further oxidized by SO 4 •− to form phenolic intermediates which combine with NO 2 • to generate nitrated products. When 5 μM oxytetracycline (OTC) was treated with 0.5 mM PDS in the presence of 20 μM NO 2 − at 60 °C, the highest formation of NDMA was 0.045 μM in 1 h. NDMA formation was also observed for other compounds with dimethylamine moieties, such as methylene blue, phenylurea herbicides, etc., with the molar yield ranging from 0.07 to 3.53 %, negatively related to the R-N bond dissociation energy of the precursors. These findings suggest that NDMA can be commonly generated when SO 4 •− is applied to the degradation of dimethylamine pollutants in wastewater treatment or groundwater remediation where NO 2 − ubiquitously exists, which may pose a serious threat to the aquatic environment.
研究领域:
环境科学
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毒理学
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Qun Wang,Han Zeng,Youheng Liang,Ye Cao,Yang Xiao,Jun Ma
The heterogeneous catalyst Mackinawite (FeS) was applied to activate periodate (IO 4 − ) to degrade endocrine disruptors bisphenol AF (BPAF). This study investigated the influence of FeS dosage, periodate dosage, BPAF concentration, initial pH value and inorganic ions on BPAF degradation by FeS/IO 4 − system. The results showed that the BPAF was effectively degraded by FeS/IO 4 − system. The acidic pH exhibited higher efficiency in BPAF degradation compared with alkaline and neutral conditions. Furthermore, the BPAF degradation was dramatically promoted in the presence of Cl − and SO 4 2− , whereas CO 3 2− inhibited BPAF degradation. The radical scavenging tests and EPR indicated that singlet oxygen ( 1 O 2 ), superoxide radicals (O 2 − ) and SO 4 − were committed to the degradation of BPAF, among which O 2 − , 1 O 2 were predominant radicals. The separate experiments showed that Fe(Ⅱ) participated in the activation of periodate. Furthermore, the effects of sulfur species (including the S 2− , SO 3 2− ) on BPAF degradation by FeS/IO 4 − system were studied. The radical quenching tests suggested that S 2− and SO 3 2− were responsible for producing SO 4 − . The findings of this study elucidated an approach for the removal of micro-pollutants in the water environment through heterogeneous activation of periodate by FeS.
研究领域:
环境科学
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化学
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高影响因子
International Journal of Environmental Science and Technology
·
2020
·Vol. 17
·期 8
·3761-3770
·
IF 2.54
Song Q.,Zhang D.,Niu X.,Li Y.,Ma J.,Fan Y.,Zhou S.
The frequent occurrence of cyanobacteria blooms has gained worldwide concern. The conventional pre-oxidation methods are not only less effective in removing Microcystis aeruginosa cells, but also tend to trigger secondary pollution with an inevitable release of intracellular organic matter. In this study, Fe 2+ /persulfate process was applied to generate sulfate radicals and simultaneously form in situ Fe (III) for integrated oxidation–coagulation, leading to a notable enhancement in M. aeruginosa removal without cell breakage and better control of microcystins. Results showed that the Fe 2+ /persulfate mass ratio of 1:1 and the FeSO 4 dosage of 0.1 mmol/L were efficient in M. aeruginosa removal. With the optimal FeSO 4 dosage, up to 90.1% of M. aeruginosa were removed intact with the cell zeta potential of − 0.814. After settling down of M. aeruginosa within 30 min, the chlorophyll-a removal efficiency reached 98.9% and microcystins decreased remarkably. Furthermore, the degradation of algal organic matters was significantly enhanced with a relatively lower residual Fe. Protein-like substances and dissolved microbial metabolites were preferentially oxidized. The cell lysis only occurred to a small number of M. aeruginosa during the Fe 2+ /persulfate process, preventing from the environmental risk posed. This work demonstrates that an appropriate Fe 2+ /persulfate ratio and FeSO 4 addition is a feasible and promising method for removing M. aeruginosa in an environmental-friendly and cost-effective way.
研究领域:
环境科学
·
水处理工程
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Jie Ye,Yue Lai,Chao Wang,Raymond Jianxiong Zeng,Changgeng Liu,Hao Lin,Shungui Zhou,Zhen He
Sulfate radical ( SO 4 · - )-based advanced oxidation processes (SR-AOPs) are promising for sludge dewatering. In this work, an electrochemically driven Fe 0 -activated sulfite system (E/Fe/sulfite) was developed and demonstrated for sustainably releasing Fe 2+ to activate sulfite for dewatering waste activated sludge. Under the optimal conditions (sulfite dosage = 40 mg/g dry solids, current density = 30 mA/cm 2 , pH = 6, and time = 60 min), the reduction of capillary suction time and water content of sludge cake were 87.9 ± 2.8 % and 73.1 ± 0.8 %, respectively. The improved dewatering performance was attributed to the degradation of tightly-bound extracellular polymeric substances, along with the decreased live/dead cell ratio and the increased permeability of sludge flocs. The thermal effect (∼21–59 °C) in the E/Fe/sulfite system accelerated the release of intracellular proteins, which could be effectively degraded by the strong oxidizing SO 4 · - . The results also suggested that electrochemical oxidation and thermal effect in the E/Fe/sulfite system had a synergistic impact on improving sludge dewaterability. According to the density functional theory calculation, the hydrophobic amino acids produced from protein degradation were favorable for forming the drainage channels and enhancing sludge dewaterability. This study provides new insights for understanding the SR-AOPs and their applications to sludge treatment.
研究领域:
环境科学
·
污水处理
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高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Jingquan Wang,Min Zheng,Yang Deng,Min Liu,Ying Chen,Naiyun Gao,Erdeng Du,Wenhai Chu,Hongguang Guo
The international campaign to ban bisphenol A (BPA) has resulted in increasing application of BPA substitutes. However, investigations have mainly been confined to the removal of single contaminant from the water, resulting in an inefficient burden. Furthermore, systematic study and synthetical discussion of bisphenol analogues (BPs) kinetics and transformation pathways were largely underemphasized. Chemical oxidation of BPA and four typical alternatives (i.e., bisphenol AF, bisphenol E, bisphenol F and bisphenol S) in a UV-activated persulfate system was examined in this study. The effects of persulfate (PS) dosage, pH and water matrix constituents (i.e., bicarbonate, chloride and natural organic matter) were comprehensively examined using a combination of laboratory experiments and mathematical modeling. According to our findings, the removal characteristics of different BPs employing SO 4 • − -induced removal technology, including degradation mechanisms and influencing trends by water matrix, revealed similarly. The second order-rate constants of SO 4 • – reacting with BPs served as the main variables mediating the variation in degradation kinetics. Frontier molecular orbital theory and density functional theory suggested BPs molecules possessed the same susceptible positions to free radicals. In the UV-activated PS process, transformation pathways included hydroxylation, electron-transfer, substitution, and rearrangement triggered by ortho-cleavage, with certain intermediates exhibiting higher toxicity than the parent chemicals. The findings of this study provided valuable information to estimate potential environmental risks of using BPA alternatives.
研究领域:
环境科学
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化学
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PubMed
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Selvendiran Periyasamy,Xiaochang Lin,Soliu O. Ganiyu,Sathish-Kumar Kamaraj,Abdoulaye Thiam,Dezhao Liu
Antibiotics in the environment provoke serious consequences on living beings and can be effectively remediated by prominent advanced oxidation process . In this study, electrochemical advanced oxidation treatment in a lab-scale reactor for the degradation of florfenicol (FLO) was studied with the aid of boron-doped diamond anode (BDD). The results exhibited that the FLO degradation follows pseudo-first-order kinetics. As the current intensity rose from 60 mA to 250 mA, the FLO removal efficiency increased and the corresponding reaction rate constant increased from 0.0213 to 0.0343 min −1 , which was likely due to the more efficient participation of free hydroxyl radical ( • OH) generated at the BDD anode. Faster degradation and higher mineralization of electrolyzed FLO solution were achieved at higher current intensity as well as in higher SO 4 2− concentration medium, as a consequence of catalytic participation of oxidants (free • OH as well as sulfate radical (SO 4 •− ) and persulfate (S 2 O 8 2− )). The increase in FLO concentration from 30 to 50 mg L −1 resulted in a reaction rate constant decrease (from 0.0235 to 0.0178 min −1 ). Eight transformation by-products ( m/z = 372.99, 359.8, 338.0, 324.04, 199.00, 185.02, 168.99 and 78.989) and three inorganic ions (NO 3 − , Cl − and F − ) were analyzed by UPLC‒Q‒TOF‒MS/MS and Ion‒chromatography, respectively. The Vibrio fischeri bioluminescence inhibition revealed an increase of toxicity during the electrochemical oxidation that could be attributed mostly to the generated organic chlorinated by-products ( m / z = 372.99, 359.8) and inorganic species (ClO 2 − and ClO 3 − ).
研究领域:
环境科学
·
电化学工程
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毒理学
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PubMed
高影响因子
危险品化学品经营许可证（带存储）