JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Zijin Liu,Xianbo Sun,Jie Fu,Wen Liu,Zhengqing Cai
Polycyclic aromatic hydrocarbons (PAHs) are frequently released in aqueous phase by oil spill or from other sources, and photochemical oxidation is one of their major weathering processes. In this study, the photochemical behavior of phenanthrene (PHE, as a representative PAH) were studied and the effects of nitrogenous compounds were evaluated. The results showed that nitrate was an effective photosensitizer for improving the photodegradation of PHE, but the promoting effect was less effective in seawater due to the presence of halogen ions; the ammonia played a negligible role on PHE degradation. The photochemical ionization was a key process for PHE degradation, it can be retarded due to the quenching of triplet excited state by dissolved oxygen, and the inhibition was most prominent in fresh water. The presence of nitrate increased the steady state concentration of •OH from 2.08 × 10 −15 M to 1.04 × 10 −14 M in fresh water, and from 1.5 × 10 −16 M to 2.08 × 10 −15 M in seawater. The secondary-order reaction rate constant between PHE and •OH ( k • OH , PHE ) was determined as 5.70 × 10 9 M −1 s −1 . Similar trend was observed for 1 O 2 . The contribution of •OH to PHE removal was more prominent in fresh water than in seawater due to the quenching effects of halogen, and the increasing of nitrate enlarged the contribution of •OH. Two possible PHE degradation pathways were proposed based on GC-MS analysis and DFT calculation. The Quantitative Structure-activity Relationship (QSAR) evaluation showed that some degradation intermediates were more toxic than PHE, but the total environmental risk was still diminished due to the low percentage of toxic intermediates. This study provided theoretical and experimental insights into the influence of nitrogenous compounds on the photodegradation of PHAs in water environment.
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高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Junwen Ding,Jinlong Wang,Xinsheng Luo,Daliang Xu,Yatao Liu,Peijie Li,Shirong Li,Rui Wu,Xinlei Gao,Heng Liang
Membrane-based technology has been confirmed as an effective way to treat emulsified oily wastewater, however, membrane fouling is still one of practical challenges in long-term operation. Herein, a novel passive-active combined strategy was proposed to control membrane fouling in continuous oily wastewater purification, where the δ-MnO 2 decoration layer helped to reduce the total fouling ratio (passive strategy for fouling mitigation) and the catalytic cleaning effectively removed the irreversible oil fouling (active strategy for fouling removal). The functional membrane was prepared via in-situ modification, referred to as δ-MnO 2 @TA-PES. The morphology, crystalline phase, chemical structure and surface properties of the membranes were systematically characterized. Compared with PES, the δ-MnO 2 @TA-PES possessed superhydrophilicity, enhanced electronegativity and narrowed pore size. The δ-MnO 2 @TA-PES achieved high water permeation flux of 723.9 L· m − 2 · h − 1 ·bar −1 , excellent oil rejection with separation efficiency above 98.5% for various emulsions, and durable anti-oil-fouling performance with FRR b of 98.0%. Notably, the oil cake layer fouling on δ-MnO 2 @TA-PES was greatly alleviated owing to its enhanced surface properties. In addition, δ-MnO 2 @TA-PES showed high cleaning efficiency in the peroxymonosulfate (PMS) cleaning process, where the radical and nonradical pathways occurred simultaneously. And the active substances generated in the nonradical process (especially 1 O 2 ) were considered as the main contributor to the reduction of irreversible fouling. Overall, the novel strategy of fouling control ensured the efficient operation of ultrafiltration membranes for the continuous oily wastewater purification.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 30
·期 7
·17854-17864
·
IF 5.19
Li Yi,Xie Shiwei,Yao Jiaxiong
The decay of free radicals involved in side reactions is one of the challenges faced by electrochemical degradation of organic pollutants. To this end, a non-radical oxidation system was constructed by a natural air diffusion cathode (ADC) and a Ti-based dimensional stable anode coated by RuO 2 (RuO 2 -Ti anode) for cathodic hydrogen peroxide activation by anodic chlorine evolution. The ADC fabricated by the carbon black of BP2000 produced a stable concentration of hydrogen peroxide of 339.94 mg L −1 (current efficiency of 73.4%) without aeration, which was superior to the cathode made by the XC72 carbon black. The flow-by ADC-RuO 2 system consisted of an ADC and a RuO 2 -Ti anode showed high selectivity to aniline (AN) compared to benzoate (BA) in a NaCl electrolyte, whose degradation efficiencies were 97.72% and 1.3%, respectively. Rapid degradations of a mixture of emerging pollutants and AN were also observed in the ADC-RuO 2 system, with pseudo-first-order kinetic constants of 0.51, 1.29, 0.89, and 0.99 min −1 for Bisphenol A (BPA), tetracycline (TC), sulfamethoxazole (SMX) and AN, respectively. Quenching experiments revealed the main reactive oxygen species for the pollutant degradation was singlet oxygen ( 1 O 2 ), which was also identified by the electron spin resonance (ESR) analysis. Finally, the steady-stable content of 1 O 2 was quantitatively determined to be 6.25 × 10 −11 M by the method of furfuryl alcohol (FFA) probe. Our findings provide a fast, low energy consumption and well controlled electrochemical oxidation method for selective degradation of organic pollutants. Graphical abstract H 2 O 2 generated on an air diffusion cathode by naturally diffused O 2 , reacts with ClO − produced from chloride oxidation on the RuO 2 -Ti anode to form singlet oxygen ( 1 O 2 ). The electrochemical system shows an efficient oxidation to electron-rich emerging pollutants including bisphenol A, tetracycline, sulfamethoxazole and aniline, but a poor performance on the electron-deficient compounds (e.g., benzoate).
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高影响因子
ENVIRONMENTAL POLLUTION
·
2022
·
IF 9.988
Liuyang He,Shangding Yang,Lie Yang,Shitai Shen,Yulong Li,Dejin Kong,Zhuqi Chen,Shengmao Yang,Jia Wang,Li Wu,Zulin Zhang
The non-radical pathway of periodate (PI) activation for the removal of persistent organic contaminants has received increasing attention due to its higher stability and oxidative advantages. In this study, the degradation of sulfamethoxazole (SMX) by ball mill treated magnetic sludge biochar (BM-MSBC) through activation of PI by electron transfer mechanism was reported. Experimental and characterization results showed that the ball milling treatment resulted in a better pore and defect structure, which also significantly enhanced the electron transfer capacity of the sludge biochar. The BM-MSBC/PI system exhibited notable dependence of activator concentration and initial pH, while the effect of PI concentration was not significant. The coexisting substances (common anions and natural organic matters) hardly affect the degradation of SMX in the BM-MSBC/PI system. The phytotoxicity experiments suggested that the treatment of BM-MSBC/PI system could significantly reduce the biological toxicity of SMX solution. This study provides a novel, economical, and facile modification method for the application of sludge biochar in advanced oxidation processes .
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ENVIRONMENTAL TECHNOLOGY
·
2022
·
IF 3.475
Sheng Sheng,Jingjing Fu,Siyuan Song,Yuxuan He,Jin Qian,Ziyang Yi
The increasing use of fluoroquinolone antibiotics, which are found in various environmental media, is a constant threat to ecological safety and human health. In this paper, SrFeO3@MoS2 heterogeneous catalyst was prepared to activate peroxymonosulfate (PMS) for the degradation of levofloxacin (LVO). The characteristics of SrFeO3@MoS2 samples were studied and the optimum conditions for the removal of LVO by SrFeO3@MoS2/PMS system were investigated. The removal of LVO by the SrFeO3@MoS2-0.3/PMS system could reach 96.06% within 20 min of reaction. The effect of inorganic anions (SO42−, Cl−, NO3− and H2PO4−) commonly found in actual water bodies on catalytic reaction was explored. The reusability investigation revealed that the catalyst could still remove 88.06% of LVO within 20 min after four cycles. Moreover, SO4•−, •OH and 1O2 were identified by Electron Paramagnetic Resonance (EPR) tests and scavenger experiments, where the SO4•− and •OH were dominant reactive species. Combining with the XPS characterisation, the activation mechanism of SrFeO3@MoS2-0.3/PMS was proposed, and the oxygen vacancies and transition metals on the sample surface were active sites of PMS activation. Furthermore, the possible degradation pathways of LVO were well-established based on the detected intermediates.
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高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Wenxiao Zheng,Yingkai Chen,Hengyi Fu,Zhang Yan,Zhenchao Lei,Weijian Duan,Chunhua Feng
The generation of chlorinated byproducts during the electrochemical oxidation (EO) of Cl − -laden wastewater is a significant concern. We aim to propose a concept of converting reactive species (e.g., reactive chlorines and HO • resulting from electrolysis) into 1 O 2 via the addition of H 2 O 2 , which substantially alleviates chlorinated organic formation. When phenol was used as a model organic compound, the results showed that the H 2 O 2 -involving EO system outperformed the H 2 O 2 -absent system in terms of higher rate constants (5.95 × 10 −2 min −1 vs. 2.97 × 10 −2 min −1 ) and a much lower accumulation of total organic chlorinated products (1.42 mg L −1 vs. 8.18 mg L −1 ) during a 60 min operation. The rate constants of disappearance of a variety of phenolic compounds were positively correlated with the Hammett constants ( σ ), suggesting that the reactive species preferred oxidizing phenols with electron-rich groups. After the identification of 1 O 2 that was abundant in the bulk solution with the use of electron paramagnetic resonance and computational kinetic simulation, the routes of 1 O 2 generation were revealed. Despite the consensus as to the contribution of reaction between H 2 O 2 and ClO − to 1 O 2 formation, we conclude that the predominant pathway is through H 2 O 2 reaction with electrogenerated HO • or chlorine radicals (Cl • and Cl 2 • − ) to produce O 2 • − , followed by self-combination. Density functional theory calculations theoretically showed the difficulty in forming chlorinated byproducts for the 1 O 2 -initiated phenol oxidation in the presence of Cl − , which, by contrast, easily occurred for the Cl • -or HO • -initiated phenol reaction. The experiments run with real coking wastewater containing high-concentration phenols further demonstrated the superiority of the H 2 O 2 -involving EO system. The findings imply that this unique method for treating Cl − -laden organic wastewater is expected to be widely adopted for generalizing EO technology for environmental applications.
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高影响因子
FUEL
·
2022
·
IF 8.035
Wenran Gao,Yiling Wan,Shanhui Zhao,Muhammad Asif Akhtar,Kuan Ding,Bin Li,Yinlong Wu,Shoujun Zhang,Shu Zhang
Ketonization of biomass-derived oxygenates is promising for sustainable production of platform chemicals, but the catalyst activity will be severely inhibited by furanic compounds. To investigate the mechanism of the inhibition effect, furanic compounds with different side functional groups were chosen for co-ketonization with propanoic acid over CeO 2 . Results from 12 h continuous reaction showed that conversion of propanoic acid changed slightly when furan was co-fed with propanoic acid, while decreased significantly from 100 % for sole propanoic acid feeding to <55 % when co-feeding with furfural and furfuralcohol. Therefore, the inhibition ability followed the order of furfural ≈ furfuralcohol ≫ furan, which agreed well with the coke yield on the spent catalysts (51 %, 47 %, and 22 %, respectively). DFT calculation indicated that furfural and furfuralcohol, with the adsorption energy of 17–19 kJ·mol −1 , were much easier to adsorb on the catalyst than furan (11 kJ·mol −1 ). However, the lack of α-H of these furanic compounds led to their conversion into aromatic coke components. It is evidenced that the oxygenated side groups, rather than the furan ring, are responsible for the inhibition effect. Successive ketonization-combustion-ketonization tests revealed that simple air calcination can hardly recover the activity of the spent CeO 2 . This investigation gives new insights into the inhibitory impact of furans on the ketonization activity.
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高影响因子
FUEL
·
2022
·
IF 8.035
Wansi Lin,Yuan Cheng,Huai Liu,Junhua Zhang,Lincai Peng
The design of high-efficiency heterogeneous catalyst plays a central role for catalytic transfer hydrogenation (CTH) of biomass-derived furfural (FAL) into furfuryl alcohol (FOL). Herein, a novel zirconium doped polyacrylonitrile (PAN) nanofiber (Zr@PAN) was assembled via electrospinning technology. Systematic characterizations revealed that the high catalytic activity for CTH of FAL into FOL was provided by the cooperative effect between Lewis acid and Lewis base sites due to the chelation effect between zirconium ions and cyano-groups on PAN. Besides, a kinetic model specifying this reaction has been set up and showed a good correlation (R 2 > 0.94) between the measured and predicted data, which can effectively monitor the process and tailor the reaction conditions to attain the desired product. Although the activity of Zr-20@PAN decreased after three cycles of recovery, the introduction of bridging agent, such as lignin and tea polyphenol, can solve the recovery defect well due to their abundant hydroxyl group or carboxyl group.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Chengyun Zhou,Yuntao Liang,Wu Xia,Eydhah Almatrafi,Biao Song,Ziwei Wang,Yuxi Zeng,Yang Yang,Yanan Shang,Chaohai Wang,Guangming Zeng
Highly efficient single atom catalysts are critical to substantially promote for peroxymonosulfate (PMS) activation to organic pollutant degradation , but it remains a challenge at present. Herein, single atom Mn anchored on N-doped porous carbon (SA-Mn-NSC) was synthesized by ball milling of Mn-doped carbon nitride and spirulina biochar to dominantly activate PMS . The precursor of carbon nitride and spirulina possessed a strong coordinating capability for Mn(II), facilitating the formation of highly dispersed nitrogen-coordinated Mn sites (Mn-N 4 ). The SA-Mn-NSC catalyst exhibited high activity and stability in the heterogeneous activation of PMS to degrade a wide range of pollutants within 10 min, showing an outstanding degradation rate constant of 0.31 min −1 in enrofloxacin (ENR) degradation. The high surface density of Mn-N 4 sites and abundant interconnected meso–macro pores were highly favorable for activating PMS to produce 1 O 2 and high-valent manganese (Mn(IV)) for pollutant degradation. This work offers a new pathway of using a low-cost and easily accessible single-atom catalysts (SACs) and could inspire more catalytic oxidation strategies.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yuyang Qin,Hongjing Li,Jun Ma
The effect of chloride ion (Cl − ) on the degradation of organic contaminants (OCs) by thermally activated peroxymonosulfate (TAP) was assessed in this study. P -aminobenzoic acid (PABA), sulfadiazine (SDZ), bisphenol A (BPA), and chloramphenicol (CAP) were employed as model OCs with different structure. The degradation efficiencies of PABA, SDZ, BPA, and CAP were respectively 76.4 %, 90.8 %, 10.1 %, and 14.5 % by TAP (70 °C) after 60 min treatment, further raised to 97.6 %, 97.4 %, 55.2 %, and 30.5 % in the presence of Cl − (1 mM). When Cl − concentration increased to 10 mM, PABA and SDZ were completely degraded respectively after 7 min and 10 min, 97.1 % of BPA and 59.5 % of CAP were removed within 60 min. In TAP system, PABA and SDZ were primarily degraded by direct peroxymonosulfate (PMS) oxidation , while BPA and CAP were mostly removed by hydroxyl radical and sulfate radical oxidation. In Cl − /TAP mixtures, the degradation of PABA and BPA was mainly attributed to hypochlorous acid oxidation, SDZ was chiefly removed via direct PMS oxidation, and CAP was principally oxidized by radicals. Furthermore, the intermediate products of OCs degradation during Cl − /TAP oxidation were identified, and primary degradation pathways were proposed. The removal efficiencies of total organic carbon were markedly improved from 19.3 % to 25.3 % by TAP to 52.6 %–69.0 % in Cl/TAP system. The concentrations of typical chlorinated by-products after OCs oxidation were 17.2 μg/L–86.3 μg/L in Cl − /TAP system. Considering the complexity of actual wastewater, 51.3 %–100 % removal efficiencies of OCs by TAP oxidation were achieved in Cl − -containing secondary effluent. Understanding the role of Cl − in OCs degradation is essential for the practical application of Cl − /TAP oxidation in advanced wastewater treatment.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Peng He,Chunyao Gu,Binlin Tang,Yihao Zhou,Min Gan,Jianyu Zhu
With excellent photoelectric properties and catalytic stability, carbon nitride and its derivatives are drawing increasing interest in persulfate activation for treating emerging pollutants in wastewater. In the present work, the synthesized cobalt-doped C 3 N 5 (C 3 N 5 -Co) has well-defined surface properties and excellent performance in SMX degradation by activating peroxymonosulfate (PMS) with the assistance of visible light, and the removal rate can reach 99.57 % within 20 min. Moreover, the system shows superior operability over a wide pH range with promising catalytic stability and environmental suitability. Quenching experiments and EPR spectroscopic indicated that high-valent cobalt oxide (Co(IV)) species, SO 4 •- , •OH, O 2 •- , and 1 O 2 work in C 3 N 5 -Co 0.59 /PMS/SMX-vis combined system. The conversion of the oxidation product phenyl methyl sulfoxide (PMSO 2 ) > 98 % using phenyl methyl sulfoxide (PMSO) as a probe agent demonstrated that high-valent cobalt oxide (Co(IV)) species as the major active species dominated the degradation process of SMX. The Co(II) species on the surface of C3N5-Co0.59 worked as a direct driver to rapidly and efficiently activate the PMS, producing various active species involved in the degradation process, while the photo-carriers generated by visible radiation act as another contributing force to regenerate Co(II) species and activate PMS. This study presented the heterogeneous C 3 N 5 -Co 0.59 /PMS/SMX-vis system is an effective strategy for the degradation of emerging pollutants and provides a promising novel ideal for the treatment of various organic pollutants in wastewater.
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高影响因子
Water
·
2022
·Vol. 14
·期 14
·2248
·
IF 3.53
Guowei Pang,Min Ji,Zhuoran Li,Zhengwu Yang,Xiaojie Qiu,Yingxin Zhao
In this work, an efficient cage-core peroxymonosulfate (PMS) catalyst was synthesized by applying an electrospinning–calcination process to the cobalt–zeolitic imidazole framework (ZIF-67) crystals for the catalytic degradation of dimethyl phthalate (DMP). The morphology and surface properties of the synthesized materials (ZIF-67, Z600 and ZP400/600/800) were well characterized. ZP600 showed great performance for the catalytic degradation of DMP in the initial pH range of 7.5–10.5. The removal rate of DMP could reach 90.4% in 60 min under optimum dosages of reagents (catalyst = 0.1 g/L, PMS = 0.5 mM, DMP = 6 ppm), and the mineralization degree of contaminant could reach 65%. By quenching experiments, it was determined that sulfate radical (SO4−·) and hydroxyl radical (·OH) dominated the degradation process. Moreover, due to the good magnetism, ZP600 could be easily separated from liquid and showed great reusability in five-cycle reaction experiments. Surprisingly, with the cover of cage-like polyacrylonitrile (PAN) fibers, the cobalt leaching amount of ZP600 decreased by about 87%. This study would expand the application of the electrospinning process in the development of functional materials for water purification.Keywords:elctrospinning;ZIF-67;peroxymonosulfate;cobalt leaching control
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危险品化学品经营许可证（带存储）