CHEMOSPHERE
·
2020
·
IF 5.778
Tianxin Zhu,Jing Deng,Mengyuan Xu,Anhong Cai,Cheng Ye,Jun Li,Xueyan Li,Qiongsong Li
The degradation of N,N -diethyl- meta -toluamide (DEET) in aqueous solution by the UV/monochloramine (UV/NH 2 Cl) process was examined systematically in this study. DEET was resistant to UV photolysis and chloramination, while the synchronous combination of UV irradiation and NH 2 Cl can effectively eliminate DEET, which was caused by the generation of hydroxyl radicals and reactive chlorine species. The former played the critical role in DEET degradation, while the contribution of the latter can be ignored. Under all investigated experimental conditions, DEET degradation in the UV/NH 2 Cl process followed the pseudo-first-order kinetic model. The water quality parameters exerted the complicated impact. Reducing solution pH and raising water temperature both favored the DEET removal. The presence of sulfate, humic acid and fulvic acid accelerated the degradation, while the introduction of bicarbonate and high-concentration chloride retarded the removal. The plausible degradation pathways of DEET in the UV/NH 2 Cl process were proposed through the combination of QTOF/MS analysis and DFT calculation, and mainly involved in the cleavage of C–N bond, dealkylation, mono- and polyhydroxylation. The acute toxicity of reacted solution underwent a trend of first increasing and then decreasing with the prolonged irradiation time, which can be well illustrated by quantitative structure-activity relationship analysis. Electrical energy per order was employed to determine the energy consumption and the optimal conditions were determined as UV fluence of 369.9–493.2 mJ cm −2 and NH 2 Cl dosage of 5–20 mg L −1 .
研究领域:
环境科学
·
化学工程
·
毒理学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Chengcheng Xu,Jing Deng,Shijun Zhu,Xiao Ling,Songtu Shen,Hongguang Guo,Qiongfang Wang,Xueyan Li
The introduction of ascorbic acid (AA) into Fe(III)/PS system exhibited extremely high activity on the removal of N,N-diethyl- meta -toluamide (DEET) and other pollutants. The removal efficiency of DEET within 30 min reached 90.13%, its dynamic curve obeyed second-order kinetic model and the k obs was calculated to be 0.150 L·mg −1 ·min −1 . Compared with other reducing agents, AA was tested to be the most suitable. The optimal dosages of Fe(III), PS and AA were tested to be 0.1, 1.0 and 0.5 mM, respectively. Furthermore, the introduction of AA extended the working pH to 2.5–9.3. Common anions posed different degrees of inhibition on DEET degradation at relatively high concentration, while a small dosage of HCO 3 − (<1 mM) abnormally exerted a positive role. In terms of reaction mechanism, scavenger experiment and EPR observation illustrated that ·OH and ·SO 4 − dominated DEET degradation, yet slight Fe(Ⅳ) was also found during the reaction, which indicated that Fe(Ⅳ) may also contribute to DEET removal. Different from the rapid consumption of Fe(II) in Fe(II)/PS system, Fe(II) in Fe(III)/PS/AA system entered a dynamic equilibrium state in the later stage of the reaction, which can decompose PS to form ·SO 4 − continuously. Furthermore, the reduction and chelation ability of AA both functioned a key role. According to the degradation intermediates identified by LC-MS analysis, the degradation pathways of DEET could be divided into two directions, which covered opening benzene ring and removing side chain.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Anhong Cai,Jing Deng,Cheng Ye,Tianxin Zhu,Xiao Ling,Shuwen Shen,Hongguang Guo,Xueyan Li
N,N-Diethyl-3-methyl benzoyl amide (DEET) has been detected as an emerging pollutant in various water bodies because of its widespread use as an insect repellent. In this study, the combination of UV-LED 275 and iron-containing coagulant (FeCl 3 ) was used for the elimination of DEET in water. It was found that UV-LED 275 /FeCl 3 (98 %) system presented a favorable removal of DEET compared with UV 254 /FeCl 3 (59 %) and UV-LED 275 /Fe 2 (SO 4 ) 3 (81 %) processes at initial pH 3.5. DEET degradation by both UV-LED 275 /FeCl 3 and UV-LED 275 /Fe 2 (SO 4 ) 3 processes followed pseudo-first-order kinetics with the calculated pseudo-first-order rate constants ( k obs ) of 0.0105 and 0.0046 cm 2 mJ −1 , respectively. The results of ESR analysis and radicals quenching experiments indicated that hydroxyl radicals ( OH) and superoxide radicals (O 2 − ) were responsible for DEET degradation in UV-LED 275 /FeCl 3 process, and the former played the major role. An increase in FeCl 3 dosage was beneficial to the degradation. In the UV-LED 275 /FeCl 3 process, DEET degradation increased with a decrease in pH from 3.5 to 3.0, whereas it was almost completely suppressed with an increase in pH from 4.3 to 6.3. DEET degradation was almost unchanged after the introduction of NO 3 − , and it impeded after the addition of humic acid (HA), HCO 3 − , and SO 4 2− . The plausible degradation pathway mainly involved hydroxylation, cleavage of the C–N bond, acetylation , and dealkylation. Among the disinfection by-products (DBPs) evaluated, UV-LED 275 /FeCl 3 pretreatment generally increased the generation of trichloromethane, chloral hydrate, dichloroacetic acid, and trichloroacetic acid, which implied that further assessment of environmental risk was needed during its practical applications.
研究领域:
环境科学
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水处理
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Zhongqing Yu,Yabing Sun,Guyu Zhang,Chunxiao Zhang
This study investigated the degradation feasibility of N, N-diethyl-m-toluamide (DEET) in aqueous solution by water falling film dielectric barrier discharge (DBD) plasma under three different operating modes. The results exhibited that bubbling the gas of discharge area into DEET solution at the same time of DEET solution flowing through the discharge area (model-3) achieved better effect, the degradation efficiency and rate constant of 300 mL DEET solution with initial concentration of 20 mg/L could reach 76.8% and 0.0526 min −1 , respectively, after 27 min. In addition, the energy yield of model-3 was highest. The reactive species (H 2 O 2 , O 3 ) generated from the DBD system were measured, and the effects of different radical scavengers were analysed. Meanwhile, the removal efficiency of total organic carbon (TOC) in model-3 was much higher, could reach about 24%. The effects of various parameters such as discharge voltage, initial pH, gas bubbling flowrate and liquid circulation flowrate on the degradation of DEET in model-3 were further examined and it was also observed that higher discharge voltage, lower pH, larger gas bubbling flowrate and larger liquid circulation flowrate could promote the removal of DEET. Finally, the DEET degradation pathway was deduced based on HPLC-MS analysis and Gaussian calculation.
研究领域:
环境科学
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化学工程
·
等离子体技术
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产品关联
DOI
高影响因子
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY
·
2025
·
IF 4.3
Hua Zhang,Chenglong Liu,Yulu sun,Shuqiong Tang,Yan Lei,Weixin Zhang,Bo Cheng,Yan Zhao,Qiang Luo
N, N-Diethyl-meta-toluamide (DEET) is a widely used insect repellent that can be detected in water and soil worldwide. Although adverse reactions have been reported following the use of DEET - containing products, there are few toxicity studies. In this study, zebrafish were exposed to 0, 0.2 mg/mL, 0.25 mg/mL, and 0.3 mg/mL of DEET. With increasing exposure concentrations, zebrafish mortality increased and body length development was reduced. At 72 hours post fertilization (hpf), zebrafish exhibited pericardial edema, decreased heart rate, and yolk sac edema. Significant abnormalities in the looping morphology of the heart were observed, with the atrium and ventricle positioned along the midline, resulting in cardiac linearization. The expression levels of genes related to cardiac development ( myh6 , nppa , nkx2.5 , gata4 , tbx5a , vmhc ) increased. On the other hand, the quantity of neutrophils and macrophages exhibited a decrease, and the expression level of genes related to mediating inflammatory response ( myd88 , ifn-γ , tlr4 ) and inflammatory factor genes ( il-6 , il-8 , il-10 ) increased. In addition, DEET exposure caused a reduction in newly generated neurons at 24 hpf. At 72 hpf, the activity of acetylcholinesterase (AChE) was inhibited, and motor behavior show that the total distance and average speed were significantly reduced. Further research found that oxidative stress was activated, and reactive oxygen species (ROS) content increased significantly. In summary, DEET cause multiple toxicities to the heart, immune system, and nervous system during early developmental stages of zebrafish embryos, and these toxicities may be induced by oxidative stress.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Dong Wan,Chengjie Yu,Yafei Zhao,Gaofei Song,Wujuan Mi,Yuxuan Zhu,Changzi Liu,Yonghong Bi
Algal organic matter (AOM) significantly influences the photochemical behavior of dissolved organic matter in aquatic environments. This study investigated the effects of chlorination on the photophysical and photochemical properties of AOM derived from Microcystis aeruginosa , compared these alterations with those observed for natural organic matter (NOM), and examined their impact on the photodegradation of organic contaminants, with a particular focus on N,N -diethyl-m-toluamide (DEET) as a model substrate. The results demonstrated that chlorination substantially altered the photochemical reactivity of AOM. AOM and NOM exhibit distinct reactivities, reflecting their varied molecular compositions and functional groups. Specifically, chlorination reduced the aromaticity (SUVA 254 decreased by ∼42%) and molecular weight (decreased by ∼30%) of AOM, resulting in a shift of fluorescence peaks to lower wavelengths. It also enhanced the formation of singlet oxygen ( 1 O 2 ) and hydroxyl radical ( • OH). Chlorinated extracellular organic matter (EOM) exhibited a remarkable increase in • OH quantum yield, with a 200-fold enhancement at a high free available chlorine (FAC) dose (FAC/TOC ratio of 2.0). The photodegradation of DEET, involved H-abstraction and hydroxylation by • OH, was significantly accelerated in chlorinated EOM, highlighting the critical role of chlorinated AOM in driving photosensitized degradation processes. The findings emphasized the role of chlorination in altering AOM's photochemical properties, with significant implications for the enhanced transformation of contaminants in natural and engineered aquatic systems.
研究领域:
环境科学
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水处理工程
·
光化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2022
·
IF 4.598
Jieqi Feng,Hao Lan,Qibin Tao,Wenqing Chen,Qizhou Dai
In this study, a novel NCNS-Ce-PbO 2 electrode was prepared by electrodeposition method using the rare earth metal Ce and synthesized nitrogen-doped carbon nanosheets (NCNSs). Various characterization and electrochemical performance tests showed that the NCNS-Ce-PbO 2 electrode possessed a denser surface and smaller grains than other NCNS-PbO 2 and Ce-PbO 2 electrodes, with more active surface sites and thus could generate more hydroxyl radicals. N , N -diethyl-m-toluamide (DEET) was selected as the model contaminant to evaluate the electrochemical performance of the novel NCNS-Ce-PbO 2 electrode. The effects of initial pollutant concentration, current density, electrolyte concentration, and initial pH on the removal rates of DEET and chemical oxygen demand (COD) were investigated. Under optimal conditions, after degradation of 150 min, the removal rate of DEET and COD reached 100% and 80.52%, respectively. GC–MS was used to identify intermediate products in the degradation process. The degradation mechanism and possible degradation pathways of DEET with NCNS-Ce-PbO 2 electrode were discussed. The good stability of the NCNS-Ce-PbO 2 anode was confirmed by accelerated lifetime experiments.
研究领域:
环境科学
·
电化学工程
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHIC SCIENCE
·
2017
·Vol. 55
·期 6
·662-668
·
IF 0.984
Ma Xiaowei,Feng Fan,Yang Yang,Dang Xueping,Huang Jianlin,Chen Huaixia
Fe3O4@MIL-100 (MIL, Material Institut Lavoisier) core–shell magnetic microspheres were prepared and applied as the sorbent for the magnetic solid phase extraction (MSPE) of N,N-diethyl-m-toluamide (DEET) in baby toilet water for the first time. The synthesized magnetic metal–organic frameworks were characterized by transmission electron microscope, infrared spectroscopy and thermogravimetric analysis. The functionalized magnetic microparticles showed excellent dispersibility in aqueous solution. The MSPE conditions were investigated in detail. Under the optimized conditions, an MSPE–high performance liquid chromatography method for the determination of DEET was developed. The method was linear in the concentration range from 5 to 500 μg L−1 for DEET in baby toilet water and good linearity (r2 > 0.9998) was obtained for the calibration curve. The limit of detection was 1.5 μg L−1. Both the intra-day and inter-day precisions (relative standard deviations) were <3%.
研究领域:
分析化学
·
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
WATER RESEARCH
·
2026
·
IF 12.8
Liu He,Yong-qiang Fang,Jung-Hyun Son,Wen-Long Wang,Qian-Yuan Wu
Micro-O 3 /PMS increased DEET k o b s to 9.32 times that of millibubble O 3 . • PMS activation was co-controlled by O 3 mass transfer and O 3 -PMS reaction kinetics. • Increasing pH and PMS dosage promoted interfacial PMS activation. • ·OH and SO 4 ·- jointly contributed 81%∼98% to DEET oxidation. • Micro-O 3 /PMS showed EE/O of 1.63∼11.20 kWh/m 3 under all conditions. The ozone/peroxymonosulfate (O 3 /PMS) process can simultaneously generate hydroxyl radicals (·OH) and sulfate radicals (SO 4 ·- ), but its oxidative efficiency is often limited by ozone mass transfer and utilization. In this study, a ceramic-membrane-based Micro-O 3 /PMS system was developed for the degradation of N,N -diethyl- m -toluamide (DEET), a refractory micropollutant. Micro-O 3 /PMS achieved the highest DEET degradation rate constant ( k o b s ) of 7.95 × 10 3 M -1 and the lowest EE/O of 1.94 kWh/m 3 , with 2.64∼9.32-fold higher degradation kinetics and 46.4%∼85.7% lower energy demand than those of the comparison systems of Milli-O 3 , Milli-O 3 /PMS and Micro-O 3 . Compared with Milli-O 3 /PMS, the generation efficiencies of ·OH and SO 4 ·- in Micro-O 3 /PMS increased by 4.49 and 11.42 times, respectively. Microbubbles enhanced k L a , while the lower k L increased the Hatta number and extended PMS activation from the bulk liquid into the liquid film. Interfacial O 3 –PMS reactions enhanced O 3 absorption, creating positive feedback that promoted PMS activation and radical generation. Increasing the pH and PMS dosage further strengthened PMS interfacial activation, resulting in higher radical generation. Oxidant contribution analysis demonstrated that ·OH and SO 4 ·- were the dominant oxidants for DEET degradation under the tested conditions, jointly contributing 81%∼98%, whereas O 3 and other unquantified oxidation pathways made only minor contributions. As pH increased from 5 to 8, the k o b s of DEET increased from 1.57 × 10 3 to 9.36 × 10 3 M -1 , while EE/O decreased from 11.20 to 1.63 kWh/m 3 . When the PMS dosage increased from 50 to 200 μM, k o b s increased from 5.31 × 10 3 to 10.04 × 10 3 M -1 ; however, the lowest EE/O was obtained at 100 μM PMS, indicating diminishing energy benefits at higher dosages. Cl - , HCO 3 - /CO 3 2- , humic acid, and real water matrices inhibited DEET degradation and increased EE/O to 3.09∼9.00 kWh/m 3 . This study elucidates the ozone-microbubble-induced regulation mechanism of PMS activation and the characteristics of radical generation, confirms the application potential of Micro-O 3 /PMS for DEET control in water, and thereby provides a promising strategy for the removal of refractory micropollutants.
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DOI
高影响因子
Insects
·
2022
·Vol. 13
·期 12
·1077
·
IF 3.139
Weifeng Wu,Yu Yang,Yingmiao Feng,Xiaofei Ren,Yuling Li,Wenjiao Li,Jietong Huang,Lingjia Kong,Xiaole Chen,Zhongze Lin,Xiaohui Hou,Longlai Zhang,Yajie Chen,Zhaojun Sheng,Weiqian Hong
Simple SummaryDue to the environment and human health concerns of synthetic repellents, essential oils (EOs) as natural alternatives have received increased attention. In this study, the repellent activity of 60 commercial EOs againstAedes albopictuswas evaluated. In the initial screening, 8 active EOs including cinnamon, marjoram, lemongrass, bay, chamomile, jasmine, peppermint2, and thyme were selected. Twenty-one major constituents (>5% relative area) in the 8 active EOs were identified via gas chromatography-mass spectrometry (GC-MS) analysis. Cinnamaldehyde, citral and terpinene-4-ol displayed the highest repellent activity with more than 60% RR, which were more active thanN,N-diethyl-3-methyl benzoyl amide (DEET). Next, their nanoemulsions were prepared and characterized. In the arm-in-cage assay, cinnamaldehyde- and citral-based nanoemulsions have prolonged mosquito protection time compared with their normal solutions.AbstractMosquitoes are one of the most important disease vectors from a medical viewpoint in that they transmit several diseases such as malaria, filariasis, yellow and Dengue fever. Mosquito vector control and personal protection from mosquito bites are currently the most efficient ways to prevent these diseases. Several synthetic repellents such as DEET, ethyl butylacetylaminopropionate (IR3535) and 1-(1-methylpropoxycarbonyl)-2-(2-hydroxyethyl)piperidine) (Picaridin), have been widely used to prevent humans from receiving mosquito bites. However, the use of synthetic repellents has raised several environment and health concerns. Therefore, essential oils (EOs) as natural alternatives receive our attention. In order to discover highly effective mosquito repellents from natural sources, the repellent activity of 60 commercial EOs againstAe. albopictuswas screened in this study. Eight EOs including cinnamon, marjoram, lemongrass, bay, chamomile, jasmine, peppermint2, and thyme, showed a suitable repellent rate (>40%) at the tested dose of 10 μg/cm2. Then, their main constituents were analyzed by GC-MS, and the active constituents were identified. The most active compounds including cinnamaldehyde, citral and terpinen-4-ol, exhibited an 82%, 65% and 60% repellent rate, respectively. Moreover, the nanoemulsions of the three active compounds were prepared and characterized. In the arm-in-cage assay, the protection times of the nanoemulsions of cinnamaldehyde and citral were significantly extended compared with their normal solutions. This study provides several lead compounds to develop new mosquito repellents, and it suggests that nanoemulsification is an effective method for improving the duration of the activity of natural repellents.
研究领域:
昆虫学
·
药学
·
纳米技术
·
天然产物化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Jia-Ying Li,Rui Hu,Lili Shan,Zheng-Qian Liu,Sui-Qin Yang,Jingjing Yang,Fengyi Sun,Yu-Hong Cui
The performance of ultraviolet combined electrochemical (EC) process for treating chloride-containing (UV/EC/Cl - ) solution was evaluated based on the N, N-Diethyl-m-toluamide (DEET) degradation. The influences of operating conditions and water matrix on the DEET degradation were investigated, and the reaction mechanism of UV/EC/Cl - process was discussed based on the analysis of DEET degradation pathway, the detection of the steady-state concentrations of active free radicals and the analysis of free radicals scavenging. The observed reaction rate constant of DEET degradation in UV/EC/Cl - process (0.093 min −1 ) is significantly higher than that of UV/Cl 2 process (0.036 min −1 ), and the synergistic effect on the DEET degradation is remarkable in UV/EC/Cl - process. The current and chloride concentration have remarkable impact on the DEET degradation, while the initial pH, reaction temperature, and initial DEET concentration have slight influence on the DEET degradation. The impact of alkalinity on DEET degradation is more significant than that of ammonia, while sulfate and phosphate have slight effect on the DEET degradation. The active points attacked by free radicals on DEET molecule were predicted basing on density functional theory. During the DEET degradation, small molecular products are produced through a series of reactions such as hydrogen abstraction, substitution, dealkylation, and ring-opening. The steady-state concentrations of HO • and Cl • in UV/EC/Cl - process (1.57 × 10 -13 M and 2.37 × 10 -14 M, respectively) are higher than those of UV/Cl 2 process (1.23 × 10 -13 M and 1.07 × 10 -14 M, respectively), and HO • and Cl • play key roles in the DEET degradation during the UV/EC/Cl - process.
研究领域:
环境科学
·
化学工程
·
水处理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）