JOURNAL OF HAZARDOUS MATERIALS
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2020
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IF 9.038
Xiaoxiao Zhang,Zhonglin Chen,Jing Kang,Shengxin Zhao,Binyuan Wang,Pengwei Yan,Fengxia Deng,Jimin Shen,Wei Chu
In this study, kinetics, influencing factors and potential mechanisms involved in the degradation of chloral hydrate (CH) by UV/peroxymonosulfate (PMS) process were demonstrated. The degradation rate of CH could reach 89.6% by UV 254 /PMS process, significantly exceeding UV 300 /PMS (0.7%), UV 350 /PMS (6.3%), UV 254 direct photolysis (9.0%) and PMS alone (0.0%) processes. CH degradation in UV 254 /PMS system followed pseudo first-order degradation kinetics with an apparent rate constant of 0.186 min −1 , which was suppressed by Cl − and HCO 3 − . The optimal pH for CH degradation was around 5.0. Direct mineralization accounted for the CH degradation in UV/PMS system. Interestingly, the addition of PMS at the neutral condition before UV irradiation transferred CH into trichloroacetic acid (TCAA). The transformation efficiency of CH into TCAA at 10 min was enhanced from 2.17%–40.38% with the elevation of initial pH from 7.0–8.0. The subsequent exposure of UV lamps ceased the transformation of CH into TCAA and facilitated the direct mineralization of CH, but it did not work in the refractory TCAA degradation. Finally, it was revealed that HO predominantly participated CH degradation in UV/PMS process, while O 2 − was responsible for the transformation of CH into TCAA by addition of PMS before UV irradiation.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
Journal of Water Process Engineering
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2020
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IF 3.465
Zhuang Lin,Wenlei Qin,Lei Sun,Xiangjuan Yuan,Dongsheng Xia
The degradation of Bisphenol A (BPA) in the vacuum ultraviolet/ ultraviolet/ peroxymonosulfate (VUV/UV/PMS) process based on a mini-fluidic VUV/UV photoreaction system has been comprehensively investigated focusing on the degradation performances and kinetics in this study. With 20 min reaction at pH 7.0 in VUV/UV/PMS process, the removal efficiency and the apparent degradation rate constant ( k app ) of BPA were > 95.2 % and 0.145 min −1 (R 2 = 0.9935). In addition, the impacts of operational parameters and co-existing constituents on BPA degradation are systematically evaluated. Importantly, the effective degradation of BPA (> 96.1 % at least) achieved at the test pH conditions (5–11) after 30 min reaction and achieved the highest BPA removal rate at pH = 11 (0.243 min −1 , R 2 = 0.9952). The electron paramagnetic resonance and radical scavenger experiments confirmed that both hydroxyl radical ( OH) and sulfate radical (SO 4 − ) are the predominant reactive radicals in VUV/UV/PMS process. The second-order reaction rate constants of BPA with OH and SO 4 − under different pH conditions were determined to be 0.74–1.86 × 10 10 M −1 s −1 and 2.92–5.01 × 10 9 M −1 s −1 via the competition kinetics. Meanwhile, the relative contribution rate of OH decreased from 97.2 %–33.1 % with the increasement of pH from 5.0 to 11.0, while the relative contribution rate of SO 4 − rose from 1.7 % to 48.9 %. The present study demonstrated that the VUV/UV/PMS process, as a new advanced oxidation process, has potential applications for micropollutants removal in water.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Feng Jiang,Bin Qiu,Dezhi Sun
Biological treatment is not completely effective for the removal of all refractory organics, including fulvic-like and humic-like substances, in fresh leachate from municipal solid waste (MSW) incineration. In this study, a UV/peroxymonosulfate (PMS) process was used to degrade the refractory pollutants that remained in the bio-treatment effluent. The reaction conditions were optimal when 10 g/L of PMS was used at a pH of 8.96. 70.6% of COD was degraded within 60 min with optimal reaction conditions. The refractory organics were degraded by the UV/PMS process, which generated intermediates with low molecular weight. The mechanisms involved in this advanced degradation process were uncovered by detecting the generation and conversion of radicals during the oxidation reaction.
研究领域:
环境科学
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污水处理
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DOI
高影响因子
RSC Advances
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2020
·Vol. 10
·期 30
·17627-17634
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IF 3.119
Shoufeng Tang,Jiachen Tang,Deling Yuan,Zetao Wang,Yating Zhang,Yandi Rao
Humic substances are polyelectrolytic macromolecules; their presence in water leads to many environmental problems without effective treatment. In this work, the elimination of humic acid (HA), a typical humic substance, has been examined through ultraviolet (UV) activation systems in the presence of peroxydisulfate (PDS) and peroxymonosulfate (PMS), respectively. The results indicated that 92.9% and 97.1% of HA were eliminated with rate constants of 0.0328 ± 0.0006 and 0.0436 ± 0.0011 min−1 with 180 and 60 min treatment times at pH 6 and 3 when adding 3 and 1 mmol L−1 oxidant during UV/PDS and UV/PMS, respectively; the corresponding electric energies per order were 0.0287 and 0.0131 kW h m−3. The HA removal was systematically investigated by varying different reaction parameters, including radical scavengers, persulphate dose, solution pH, and initial HA concentration, and by addition of various common ions. Moreover, the decomposition details were identified through the changes in the dissolved organic carbon, unique UV absorbances, and UV spectroscopic ratios. Furthermore, the destruction mechanism was verified by fluorescence spectroscopy, demonstrating that the HA structure was decomposed to small molecular fractions in the two UV/persulphate systems. In addition, the purification of HA by the two UV/persulphate processes was assessed in actual water matrices.
研究领域:
环境科学
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水处理技术
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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
Ye Du,Wen-Long Wang,Zhi-Wei Wang,Chang-Jie Yuan,Ming-Qi Ye,Qian-Yuan Wu
Byproduct formation (chlorate, bromate, organic halogen, etc.) during sulfate radical (SO4•–)-based processes like ultraviolet/peroxymonosulfate (UV/PMS) has aroused widespread concern. However, hypohalous acid (HOCl and HOBr) can form via two-electron transfer directly from PMS, thus leading to the formation of organic halogenated byproducts as well. This study found both PMS alone and UV/PMS can increase the toxicity to mammalian cells of wastewater, while the UV/H2O2 decreased the toxicity. Cytotoxicity of two wastewater samples increased from 5.6–8.3 to 15.7–29.9 mg-phenol/L, and genotoxicity increased from 2.8–3.1 to 5.8–12.8 μg 4-NQO/L after PMS treatment because of organic halogen formation. Organic halogen formation from bromide rather than chloride was found to dominate the toxicity increase. The SO4•–-based process UV/PMS led to the formation of both organic halogen and inorganic bromate and chlorate. However, because of the very low concentration (<20 μg/L) and relatively low toxicity of bromate and chlorate, contributions of inorganic byproducts to toxicity increase were negligible. PMS would not form chlorate and bromate, but it generated a higher concentration of total organic halogen, thus leading to a more toxic treated wastewater than UV/PMS. UV/PMS formed less organic halogen and toxicity because of the destruction of byproducts by UV irradiation and the removal of byproduct precursors. Currently, many studies focused on the byproducts bromate and chlorate during SO4•–-based oxidation processes. This work revealed that the oxidant PMS even needs more attention because it caused higher toxicity due to more organic halogen formation.
研究领域:
环境科学
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毒理学
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水处理
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化学工程
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Chen Ling,Chaolin Li,Aiping Liang,Wenhui Wang
Microplastics (MPs) pose a severe threat to the environment and human health, and effective treatment techniques are urgently desired to prevent the global spread of MPs pollution. However, efficient degradation of MPs remains difficult. Herein, vacuum ultraviolet (VUV) activated peroxymonosulfate (PMS) was firstly proposed as a promising technique for the degradation of polyethylene MPs. The weight loss of MPs reaches as high as 51.5% under mild conditions ([PMS] = 32 mmol/L, initial pH = 7, [MPs] = 1 g/L, [Time] = 48 h), which is the record performance achieved at room temperature and ambient pressure for MPs degradation. The excellent degradation performance is uncovered to originate from the synergistic effect of VUV and activated PMS. Direct photolysis of VUV can rapidly oxidize the surface of MPs to reduce its hydrophobicity and thus enhance the adsorption of reactive oxidation species (i.e., SO 4 ⋅− and HO ⋅ ) rooted from the VUV activated PMS, which was further confirmed by DFT calculations. The degradation of MPs repeatedly undergoes the process of VUV photolysis oxidation of the surface, degradation via VUV/UV/PMS-derived reactive oxidation species, shedding, and re-exposure of the new surface via VUV photolysis oxidation. This study highlights the unique role of the VUV photolysis in MPs degradation, paving a new route for designing practical MPs pollution remediation techniques.
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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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Ruijie Xie,Jian Ji,Kaiheng Guo,Dongxue Lei,Qingjuan Fan,Dennis Y.C. Leung,Haibao Huang
In this study, wet scrubber coupled with UV/peroxymonosulfate (PMS) was used as a semi-batch process for removing gaseous VOCs. Both ethyl acetate and toluene could be removed efficiently using this coupled process due to the generation of SO 4 − and HO . The mass-transfer coefficients in this coupled process were larger than in wet scrubbing only process. The roles of SO 4 − and HO were investigated, in which SO 4 − acted as the predominant radical for toluene degradation while HO was major for ethyl acetate. This could be further confirmed by simultaneous degradation of ethyl and toluene. Moreover, the reaction solution reused at least four times still showed excellent performance for VOCs removal via re-adding PMS. A possible mechanism on toluene degradation was proposed based on the evolutions of intermediates during the process. This study clarified the roles of non-selective radical (i.e. HO ) and selective radical (i.e. SO 4 − and Cl ) in the removal of a continuous-flow gaseous VOCs by this coupled process.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
Water
·
2023
·Vol. 15
·期 10
·1920
·
IF 3.4
Yishu Cai,Fan Chen,Lingfang Yang,Lin Deng,Zhou Shi
Nanoplastics have gradually become a concern due to the wide use of plastics. Nanoplastics in aqueous phase can be exposed to users through water supply networks and cannot be efficiently removed by conventional water treatment processes. This work studied the degradation of polystyrene nanoplastics (PS-NP) by two commonly used advanced oxidation systems: UV/NaClO and UV/peroxymonosulfate (PMS). Results showed that almost no turbidity was detected in the PS-NP solution (5.00 mg/L) after treated by both UV/NaClO and UV/PMS for 360 min, suggesting the excellent turbidity removal ability. Yet, scanning electron microscope (SEM) and total organic carbon (TOC) removal tests demonstrated that PS-NP could not be completely degraded by UV/NaClO. The mineralization rate using UV/NaClO was only 7.00% even when the NaClO concentration increased to 5.00 mM, and many PS-NP particles could still be observed in SEM images. By contrast, the mineralization rate reached 63.90% in the UV/PMS system under the identical experimental conditions, and no spherical particles appeared in the SEM results. Density functional theory (DFT) calculations revealed that the different reaction sites and energy barriers of SO4•−and•Cl on PS-NP resulted in the differences in mineralization rates and degradation intermediates. The degradation pathway of PS-NP by UV/NaClO and UV/PMS was proposed accordingly. Additionally, the intermediates toxicity evaluation by a luminescent bacteria test showed that the inhibition rate in the UV/NaClO system (2.97%) was not markedly different from that in the control group without any treatment (1.98%); while that in UV/PMS system increased sharply to 98.19%. This work demonstrated that UV/PMS was more effective in PS-NP degradation than UV/NaClO, and the chemical risks of degradation intermediates were non-negligible.Keywords:nanoplastics;polystyrene degradation;mechanisms;DFT calculation;toxicity assessment
研究领域:
环境科学
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化学工程
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毒理学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 26
·12844-12855
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IF 3.925
Ning Yang,Lixi Xiao,Yuwei Deng,Zhiyu Wu,Hang Yin,Yang Liu,Mengru Li,Yuxuan Ye,Dandan Wang,Qiang Li,Fei Pan,Dongsheng Xia
In this study, a novel catalyst was prepared by loading OMS-2 onto activated carbon fiber (ACF) via a one-step hydrothermal method, which was further adopted for carbamazepine treatment. SEM, TEM and XRD analyses indicate that OMS-2 was successfully loaded on ACF. In the OMS-2@ACF/UV/PMS system, the degradation rate of CBZ (20 mg L−1) was 98.1% and the mineralization rate was 53.3%, which were higher than those of the traditional UV/PMS process. The enhanced performance in the presence of OMS-2@ACF was attributed to the redox cycle between Mn2+/Mn3+/Mn4+, which then accelerated PMS activation to generate more active species. The primary reactive species, including SO4˙−, ˙OH, O2˙− and 1O2, were confirmed through EPR and radical capture experiments. Additionally, the material exhibited excellent reusability even after 5 cycles, and remarkable performance for CBZ degradation was found in real water samples.
研究领域:
环境科学
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催化材料
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DOI
高影响因子
危险品化学品经营许可证（带存储）