JOURNAL OF HAZARDOUS MATERIALS
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2016
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IF 4.836
Jingxin Yang,Ji Li,Wenyi Dong,Jun Ma,Jie Cao,Tingting Li,Jiayin Li,Jia Gu,Pingxin Liu
Degradation of atrazine (ATZ) by ozonation in the presence of hydroxylamine (HA) was experimentally investigated in this study. The results showed approximately 80% of ATZ was degraded by ozonation in the presence of HA, while only 20% was degraded by ozonation alone. The obvious inhibition of the ATZ degradation by tert -butanol suggested the enhanced ATZ degradation by ozone/HA was primarily attributed to OH. The OH yield was determined to be 25.8%. Additionally, the optimum HA dosage for the ATZ degradation was 4 μM, when the ozone dosage was 20 μM. The effects of pH, bicarbonate and temperature on ATZ degradation by ozone/HA were investigated in details. Most importantly, the enhanced ATZ degradation by ozonation in the presence of HA was still observed in real water especially at acidic pHs. Furthermore, the potential mechanism of OH formation during the reaction of ozone with HA was proposed herein. Nine products were identified by UPLC/Q-TOF-MS system. The ATZ degradation involved dealkylation, dechlorination-hydroxylation and olefination. The evolutions of the concentrations of three available transformation products including deethylatrazine, deisopropylatrazine and deethyldeisopropylatrazine in ozone/HA were evaluated and compared with that in ozonation alone.
研究领域:
环境科学
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化学
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PubMed
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2019
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IF 3.261
Binyang Zhang,Mengdie Chen,Dongya Li,Haiming Xu,Dongsheng Xia
FeOCl was prepared by a partial thermal decomposition method to effectively catalyze hydrogen peroxide under the visible light for the degradation of toxic organic wastewater. The combination of DRS and VB-XPS indicated that FeOCl is a narrow band gap catalyst with visible light absorption capacity (Eg =1.63 eV). The degradation rate constant of RhB in FeOCl/H 2 O 2 /Vis system is about 13.4 times that of FeOCl/H 2 O 2 system. Compared to other heterogeneous Photo-Fenton systems, the oxidant utilization efficiency in FeOCl/H 2 O 2 /Vis system is higher. In addition, FeOCl has stable Photo-Fenton activity in a wide pH range (3.0–9.0). The content of Fe(II) increased after 5 cycles reaction through the ESR and XPS characterization, which proves that the electron transfer of Fe(III)/Fe(II) was improved during the reaction. After quantitative analysis of the ·OH generated in the reaction, the formation rate of ·OH in FeOCl/H 2 O 2 /Vis system is increased about 30% compared with FeOCl/H 2 O 2 /dark system. These results indicate that visible light excites FeOCl to generate produces photogenerated electron-hole pairs, accelerating the cycle of Fe(III)/Fe(II), promoting the production rate of ·OH, and enhancing the catalytic efficiency of FeOCl.
研究领域:
环境科学
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催化化学
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DOI
高影响因子
Journal of Physical Chemistry C
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2015
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IF 4.772
Xianqiang Xiong,Haihang Chen,Yiming Xu
Various methods that aim to improve the photocatalytic activity of TiO2 have been reported in the literature. Herein, we report that addition of CuWO4 into the aqueous suspension of TiO2 can result in significant enhancement in the rate of phenol degradation. As the amount of CuWO4 increased, the rate of phenol degradation increased and then decreased. A maximum rate of phenol degradation observed with 2 wt % CuWO4 was about 2.83 times that in the absence of CuWO4. A similar result was also observed with CuO. However, six consecutive tests showed that CuWO4/TiO2 was much more stable than CuO/TiO2, due to the very high stability of CuWO4 against photocorrosion. The improved activity of TiO2 is not due to CuWO4 and CuO themselves and also does not match their solubility in aqueous solution. Moreover, for the generation of OH radicals, and for the decomposition of H2O2 in aqueous solution, CuWO4/TiO2 was also more active than TiO2. Through a (photo) electrochemical measurement, a possible mechanism is proposed, involving electron transfer from the irradiated TiO2 to CuWO4 that facilitates the charge separation of TiO2 and consequently accelerates reactions at interfaces.
研究领域:
环境科学
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材料科学
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化学
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高影响因子
CHEMOSPHERE
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2017
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IF 4.208
Ivan P. Pozdnyakov,Tamara E. Romanova,Xiaojiao Cai,Victoria A. Salomatova,Victor F. Plyusnin,Ping Na,Olga V. Shuvaeva
Photooxidation of As(III) in ternary As(III) – Fe(III) – Fulvic acid system at pH 4 was investigated by optical spectroscopy, steady-state photolysis (365 nm) and atomic-emission spectrometry with inductively coupled plasma techniques. It was found that at all values of [FA]/[Fe] ratio the main photoactive species is OH radical formed by photolysis of Fe(III) hydroxocomplexes. Addition of fulvic acid leads to mainly negative effect on As(III) photooxidation due to the following reasons: (i) slow dark reduction of photoactive Fe(III) species with formation of scattering particles and photoinert Fe(II) species; (ii) formation of photoreductive Fe(III)-FA complexes incapable to oxidize As(III), (iii) competition of both FA and Fe(III)-FA complexes for UVA quanta with FeOH 2+ complex and for OH radicals with As(III). Aging of ternary system is also very important parameter leading to one order decrease of quantum yields of both Fe(II) formation and As(III) photooxidation.
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
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2019
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IF 5.108
Jiajie Xu,Guodong Dai,Biyu Chen,Donglin He,Yue Situ,Hong Huang
An efficient heterogeneous photocatalytic process coupling photocatalysis and Fenton-like process was carried out, where the Fenton-like cycle could be driven by self-produced H 2 O 2 rather than extra H 2 O 2 addition. It was revealed that C 3 N 4 por exhibited good performance at H 2 O 2 production in pure water, which was enhanced up to eight times than bare g-C 3 N 4 . Fenton-like cycle was constructed in Ti 3+ -TiO 2 -C 3 N 4 por as C 3 N 4 por severed as H 2 O 2 donator, while the Ti 3+ -TiO 2 was able to provide photoinduced electrons for the Fenton-like process, resulting in the generation of much more OH radical. In addition, ESR spectra were performed to confirm the promotion of the Fenton-like cycle and much more OH radical was detected in Ti 3+ -TiO 2 -C 3 N 4 por than Ti 3+ -TiO 2 -C 3 N 4 due to the great improvement in H 2 O 2 production of C 3 N 4 por. What’s more, the feasible photocatalytic mechanism of Ti 3+ -TiO 2 -C 3 N 4 por composite was also proposed.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
WATER RESEARCH
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2019
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IF 7.913
Xinran Zhang,Pengfei Ren,Weiguang Li,Yu Lei,Xin Yang,Ernest R. Blatchley
The presence of ammonium (NH 4 + ) in drinking water treatment results in inhibition of disinfection efficiency and formation of nitrogenous disinfection by-products. Our previous study found monochloramine (NH 2 Cl) photolysis under 254 nm UV irradiation can be effective for removal of NH 4 + ; however, the mechanisms of NH 4 + degradation in this process were unknown. The kinetics and fundamental radical chemistry responsible for NH 4 + removal in the UV/NH 2 Cl process were investigated in this study. The results showed that the pseudo first-order rate constant for NH 4 + degradation in the UV/NH 2 Cl process ranged between 3.6 × 10 −4 to 1.8 × 10 −3 s −1 . Solution pH affected radical conversion and a higher NH 4 + degradation efficiency was achieved under acidic conditions. The effects of chloride were limited; however, the presence of either bicarbonate or natural organic matter scavenged radicals and inhibited NH 4 + removal. NH 2 Cl photolysis generated an aminyl radical (NH 2 • ) and a chlorine radical (Cl • ) that further transformed to a chlorine dimer (Cl 2 •- ) and a hydroxyl radical (HO • ). The second-order rate constants for Cl • and Cl 2 •- reacting with NH 4 + were estimated as 2.59 × 10 8 M −1 s −1 and 3.45 × 10 5 M −1 s −1 at pH 3.9, respectively. Cl • , Cl 2 •- , and HO • contributed 95.2%, 3.5%, and 1.3% to NH 4 + removal, respectively, at the condition of 3 mM NH 2 Cl and pH 7.5. Major products included nitrite and nitrate, possibly accompanied by nitrogen-containing gases. This investigation provides insight into the photochemistry of NH 4 + degradation in the UV/NH 2 Cl process and offers an alternative method for drinking water production.
研究领域:
环境科学
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饮用水处理
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PubMed
高影响因子
Royal Society Open Science
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2018
·Vol. 5
·期 6
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IF 2.504
Xiangyun Han,Xi Zhang,Lei Zhang,Mei Pan,Jinlong Yan
The photodegradation of benzothiazole (BTH) in wastewater with the coexistence of iron oxides and oxalic acid under UV light irradiation was investigated. Results revealed that an effective heterogeneous photo-Fenton-like system could be set up for BTH abatement in wastewater under UV irradiation without additional H2O2, and 88.1% BTH was removed with the addition of 2.0 mmol l−1 oxalic acid and 0.2 g l−1 α-Fe2O3 using a 500 W high-pressure mercury lamp (365 nm). The degradation of BTH in the photo-Fenton-like system followed the first-order kinetic model. The photoproduction of hydroxyl radicals (·OH) in different systems was determined by high-performance liquid chromatography. Identification of transformation products by using liquid chromatography coupled with high resolution tandem mass spectrometry provided information about six transformation products formed during the photodegradation of BTH. Further insight was obtained by monitoring concentrations of the sulfate ion (SO42−) and nitrate ion (NO3−), which demonstrated that the intermediate products of BTH could be decomposed ultimately. Based on the results, the potential photodegradation pathway of BTH was also proposed.
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
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2017
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IF 6.198
Shenyu Lan,Jinxi Feng,Ya Xiong,Shuanghong Tian,Shengwei Liu,Lingjun Kong
Piezo-catalysis was first used to degrade a nondye pollutant, 4-chlorophenol (4-CP). In this process, hydrothermally synthesized tetragonal BaTiO3 nano/micrometer-sized particles were used as the piezo-catalyst, and the ultrasonic irradiation with low frequency was selected as the vibration energy to cause the deformation of tetragonal BaTiO3. It was found that the piezoelectric potential from the deformation could not only successfully degrade 4-chlorophenol but also effectively dechlorinate it at the same time, and five kinds of dechlorinated intermediates, hydroquinone, benzoquinone, phenol, cyclohexanone, and cyclohexanol, were determined. This is the first sample of piezo-dechlorination. Although various active species, including h+, e–, •H, •OH, •O2–, 1O2, and H2O2, were generated in the piezoelectric process, it was confirmed by ESR, scavenger studies, and LC-MS that the degradation and dechlorination were mainly attributed to •OH radicals. These •OH radicals were chiefly derived from the electron reduction of O2, partly from the hole oxidation of H2O. These results indicated that the piezo-catalysis was an emerging and effective advanced oxidation technology for degradation and dechlorination of organic pollutants.
研究领域:
环境科学
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材料科学
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2022
·
IF 14.224
Ning Chen,Mengyuan Geng,Danyu Huang,Mengxi Tan,Zipeng Li,Guangxia Liu,Changyin Zhu,Guodong Fang,Dongmei Zhou
Many studies have examined the redox behavior of ferrous ions (Fe(II)) sorbed to mineral surfaces. However, the associated hydroxyl radical ( • OH) formation during Fe(II) oxidation by O 2 was rarely investigated at circumneutral pH. Therefore, we examined • OH formation during oxygenation of adsorbed Fe(II) (Fe(II) sorbed ) on common minerals. Results showed that 16.7 ± 0.4–25.6 ± 0.3 μM of • OH was produced in Fe(II) and α/γ -Al 2 O 3 systems after oxidation of 24 h, much more than in systems with dissolved Fe(II) (Fe 2+ aq ) alone (10.3 ± 0.1 μM). However, • OH production in Fe(II) and α -FeOOH/ α -Fe 2 O 3 systems (6.9 ± 0.1–8.3 ± 0.1 μM) slightly decreased compared to Fe 2+ aq only. Further analyses showed that enhanced oxidation of Fe(II) sorbed was responsible for the increased • OH production in the Fe(II)/Al 2 O 3 systems. In comparison, less Fe(II) was oxidized in the α -FeOOH/ α -Fe 2 O 3 systems, which was probably ascribed to the quick electron-transfer between Fe(II) sorbed and Fe(III) lattice due to their semiconductor properties and induced formation of high-crystalline Fe(II) phases that hindered Fe(II) oxidation and • OH formation. The types of minerals and solution pH strongly affected Fe(II) oxidation and • OH production, which consequently impacted phenol degradation. This study highlights that the properties of minerals exert great impacts on surface-Fe(II) oxidation and • OH production during water/soil redox fluctuations.
研究领域:
环境科学
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化学
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Yang Zong,Wenjie Ji,Yu Xie,Deli Wu
The mineralization of organic pollutant by O 3 is prone to be restricted by the accumulative production of oxalate (OA) that is recalcitrant to the attack of hydroxyl radical ( OH). Herein, it was interestingly found that the presence of 0.5 mM Ni(II) enhanced the mineralization efficiency of EDTA by O 3 under alkaline conditions by 22.8%, with the promoting effect of Ni(II) augmented as the increasing loading of Ni(II). Based on the results from scavenging experiment, chemical probe detection and XPS characterization, it was verified that except for the commonly recognized reactive oxidants (i.e., OH and O 3 ) in EDTA mineralization, the overlooked Ni(III) species (i.e., NiOOH) also played an indispensable role in enhancing the mineralization of EDTA. The Ni(III) species was formed via the oxidation of decomplexed Ni(II) by OH and in turn collaborated with OH to decompose EDTA. More importantly, the generated Ni(III) species exerted higher affinity towards OH and O 3 -resistent oxalate, hence elevating EDTA mineralization. This study elucidated the significant role of Ni(III) species in promoting the mineralization efficiency of EDTA, and also proposed a new insight into elevating the treatment performance of ozonation via the collaborative oxidation mechanism-co-mediated by OH and Ni(III) species.
研究领域:
环境科学
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化学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Juying Li,Ying Liu,Yiqian Song,Li Cao,Yezhi Dou,Jia Yu,Yueqing Zhang,Jian He,Wei Dai,Cheng Yao,Deyang Kong
Due to the high toxicity, persistence and resistance of perfluorooctanoic acid (PFOA), developing convenient and efficient methods to degrade such highly recalcitrant contaminants is urgently needed. Herein, a visible light-responsive semiconductor carbon nitride (CN) was introduced to realize enhanced degradation of PFOA by providing the strong oxidizing radical •OH. In this study, 365 nm UV light and 456–760 nm visible light were applied as two comparable light sources, highlighting the fact that under simple visible light irradiation, both the degradation rate and defluorination rate of PFOA ultimately reached over 95 % with the aid of the Fe 3+ /CN system in at most 70 h. In addition, possible influencing factors, including the dosage of ferric ions (varying from 0–0.01 mol/L), the contaminant itself (ranging from 20 μg/L to 5 mg/L) and semiconductor CN (5–20 mg/L), were also investigated, and an accelerated reaction mechanism was proposed. Our results shed light on the most recent development of effective and sustainable technologies for PFOA breakdown in the environment.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2023
·
IF 6.8
Teng Wang,Lin Liu,Qingsong Zhao,Zhaofu Meng,Wenbin Li
To determine the fates of the persistent pollutants cadmium (Cd) and micro-plastics in agricultural soils, an in-depth understanding of the interactions between Cd and mulching film is required. In the present work, pot experiments are conducted under natural conditions to study the influence of various Cd concentrations on the aging process of polyethylene mulching film in soil collected from Changzhi, Shanxi Province. The results indicate that during 150 days, the aging degree of the mulch film increases gradually as the increased Cd concentration in the soil. Further, the results of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectrometry and X-ray photoelectron spectroscopy (XPS) demonstrate that the average vinyl index (VI) of the aging mulch film increases from 1.29 to 1.82, while the oxygen-to-carbon (O/C) ratio of the mulch film decreases significantly from 0.344 to 0.045, as the Cd concentration is increased from 0 to 10 mg kg –1 . When the aging time exceeds 90 days, the oxygen-containing functional groups (C–O and C O) generated consumed by the adsorbed Cd. In addition, electron paramagnetic resonance (EPR) measurements indicate that Cd both enhances the formation of hydroxyl radical ( · OH) on the surface of the mulch film and prevents the combination of · OH and electrons, thereby accelerating the aging of the mulch. Hence, the present study indicates that the presence of Cd will hasten the decomposition of mulch, which will inevitably result in the faster release of micro-plastics from the mulch into the soil environment.
研究领域:
环境科学
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土壤学
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PubMed
高影响因子
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