SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Qianhui Mao,Qi Li,Huimin Li,Shoujun Yuan,Jibiao Zhang
This study investigated the reactivity and mechanism of paraben oxidization by chlorine dioxide. Degradation kinetics of methylparaben (MeP) and propylparaben (PrP) followed pseudo-first-order kinetics, and were studied in a pH range of 4.0–7.0 at 15 ± 1 °C. The k app values were 84.3 M −1 ·s −1 and 83.2 M −1 ·s −1 for MeP and PrP, respectively, when pH value was 5.0 and the temperature was 15 ± 1 °C. The rate constants depended on the solution pH, temperature, humic acid, and HCO 3 – concentrations. At pH values of 4–5.0, k app increased slowly, while at a pH value of 7.0, k app increased rapidly. The reaction rate constants increased with increasing temperature. Furthermore, the reaction rate was inhibited by humic acid addition, while the reaction rate increased after addition of HCO 3 – . Two main degradation products were identified by GC–MS and the reaction pathways were proposed.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Yiqun Chen,Pinya Deng,Pengchao Xie,Ran Shang,Zongping Wang,Songlin Wang
We evaluated the degradation of methylparaben (MeP) and ethylparaben (EtP), two representative parabens, using the heat-activated persulfate system in a laboratory. Both sulfate and hydroxyl radicals contributed to the removal of the two parabens. The degradations of both MeP and EtP were improved by increasing the heating temperature or persulfate dose in accordance with a pseudo-first-order reaction model. The oxidation efficiency of parabens was found to be pH-dependent; decreasing in the order pH 5.0 > 7.0 > 9.0. The presence of chloride, bicarbonate , or humic acid was found to inhibit the degradation of the two parabens to some extent because of competition for the reactive radicals, with humic acid having the most serious effect. Dealkylation of the methyl unit, decarboxylation of the carboxylic group, and subsequent hydrolysis are proposed to be involved in the degradation pathway of MeP. The results suggest that the heat-activated persulfate system might be efficiently applied in the treatment of paraben-containing water samples. This was also supported by the results of applying this system to treat a real water sample containing both MeP and EtP.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Bin Zhao,Min Sun,Zhiqiang Guo,Liang Wang,Yiran Qian,Xiaojia He,Jixiang Li
Endocrine disrupting compounds (EDCs) have been increasingly detected in drinking water sources, and pose severe threat to human health. Polyamide (PA) based nanofiltration (NF) membrane has great potential for EDCs removal from water, but the removal of hydrophobic EDCs is not satisfying due to strong hydrophobic affinity. In this study, UiO-66-NH 2 /PA membranes were prepared by predepositing hydrophilic UiO-66-NH 2 onto the substrate prior to interfacial polymerization. The UiO-66-NH 2 aggregates increased the permeable area and strengthened the “gutter effect”. Therefore, the pure water flux of UiO-66-NH 2 /PA increased by 115% compared with that of the thin-film composite (TFC) membrane, and its rejection of Na 2 SO 4 was 96%. The hydrophilicity-enhanced PA film reduced its adsorption of EDCs and decreased the driving force for EDCs diffusion. Moreover, the UiO-66-NH 2 -induced hydrophilic nanochannels, including the interfacial gaps between PA film and UiO-66-NH 2 aggregates, the gaps in UiO-66-NH 2 aggregates, and the inherent pores in UiO-66-NH 2 crystals, alleviated the hydrophobic affinity and effectively restricted EDCs diffusion. The rejection rates of methylparaben, propylparaben, bisphenol A, and benzylparaben by the optimal UiO-66-NH 2 /PA were 50%, 67%, 75%, and 85%, respectively, and the water/benzylparaben selectivity was 4.4 times as high as that of TFC. The results demonstrate that incorporating hydrophilic metal-organic frameworks (MOFs) can improve the membrane hydrophilicity and create hydrophilic nanochannels, and is an effective strategy to enhance EDCs removal by nanofiltration.
研究领域:
环境科学
·
水处理
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2023
·
IF 6.8
Yunyang Li,Na Zheng,Siyu Sun,Sujing Wang,Xiaoqian Li,Jiamin Pan,Muyang Li,Le Lang,Zelin Yue,Binbin Zhou
Parabens (PBs), a class of endocrine-disrupting chemicals (EDCs), are extensively used as additives in personal care products (PCPs); however, distinguishing between endogenous and exogenous contamination from PCPs in hair remains a challenge. We conducted a comprehensive analysis of the levels, distribution patterns, impact factors, and sources of PBs in 119 human hair samples collected from Changchun, northeast China. The detection rates of methylparaben (MeP), propylparaben (PrP), and ethylparaben (EtP) in hair samples were found to be 100%. The concentration of PBs in hair followed the order of MeP (57.48 ng/g) > PrP (46.40 ng/g) > EtP (6.80 ng/g). The concentration of PrP in female hair was significantly higher (65.38 ng/g) than that observed in male hair (7.82 ng/g) ( p < 0.05). The levels of excretion rates of MeP ( ER MeP ) and excretion rates of PrP (ER PrP ) in the hair-dying samples (ER MeP : 17.89 ng/day; ER PrP : 14.15 ng/day) were found to be 2.52 and 2.40 times higher, respectively, compared to the non-hair-dying samples (ER MeP : 7.09 ng/day; ER PrP : 6.05 ng/day). However, the system exposure dosage (SED) results revealed that although hair dyes exhibited higher PBs, human exposure was found to be lower than certain PCPs. The results of the correlation analysis revealed that toner, face cream, body lotion, and hair conditioner were identified as the primary sources of PBs in male hair. Furthermore, the human exposure resulting from the utilization of female hair dye and serum exhibited a positive correlation with hair ER MeP and ER PrP levels, indicating in the screening of samples, excluding hair samples using hair dye and haircare essential oil can effectively avoid the interference caused by exogenous contamination from PCPs.
研究领域:
环境科学
·
公共卫生
·
毒理学
·
化学分析
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2016
·Vol. 23
·期 22
·23081-23091
·
IF 2.76
Mao Qianhui,Ji Feng,Wang Wei,Wang Qiquan,Hu Zhenhu,Yuan Shoujun
The reactivity and fate of parabens during chlorination were investigated in this work. Chlorination kinetics of methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP) were studied in the pH range of 4.0 to 11.0 at 25 ± 1 °C. Apparent rate constants ( k
app ) of 9.65 × 10 −3 M -0.614 ·s −1 , 1.77 × 10 −2 M -1.019 ·s −1 , 2.98 × 10 −2 M -0.851 ·s −1 , and 1.76 × 10 −2 M -0.860 ·s −1 for MeP, EtP, PrP, and BuP, respectively, were obtained at pH 7.0. The rate constants depended on the solution pH, temperature, and NH 4
+ concentration. The maximum k
app was obtained at pH 8.0, and the minimum value was obtained at pH 11.0. The reaction rate constants increased with increasing temperature. When NH 4
+ was added to the solution, the reaction of parabens was inhibited due to the rapid formation of chloramines. Two main transformation products, 3-chloro-parabens and 3,5-dichloro-parabens, were identified by GC-MS and LCMS-IT-TOF, and a reaction pathway was proposed. Dichlorinated parabens accumulated in solution, which is a threat to human health and the aqueous environment.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PEST MANAGEMENT SCIENCE
·
2023
·
IF 4.1
Jingsheng Zhang,Yanwei Xia,Jiayong Liang,Changlu Wang,Hualong Qiu,Yurong He,Tao Ma,Lei Wang,Desen Wang
BACKGROUND The bites and blood sucking of bed bugs ( Cimex spp.) (Hemiptera: Cimicidae) pose a serious threat to human physical and mental health. Application of an effective repellent can prevent or reduce bed bug bites. Previous studies on repellent screening mainly focused on Cimex lectularius L. In this study, we investigated the repellent effect of two safe food additives, ethyl anthranilate (EA) and butyl anthranilate (BA), against Cimex hemipterus (F.), and also explored the role of antennae and mouthparts on C. hemipterus perception of repellents. RESULTS Both EA and BA had a strong repellent effect against tropical bed bugs and their repellency was similar or lower than that of N , N -diethyl-3-methyl benzoyl amide, depending on whether or not a CO 2 source was present. EA had higher repellency than BA and exhibited repellency to C. hemipterus for 3 days when a CO 2 source was present. C. hemipterus avoided resting on 20% EA- and BA-treated harborages. Applying 20% EA and BA on rabbit skin significantly reduced the blood intake of C. hemipterus within 2 h. C. hemipterus could perceive EA and BA after their antennae or mouthparts or both antennae and mouthparts were removed. CONCLUSION Both EA and BA had strong repellency against C. hemipterus , with EA being more repellent. Ablation of antennae and mouthparts did not affect the perception of EA and BA by C. hemipterus . © 2023 Society of Chemical Industry.
研究领域:
昆虫学
·
害虫控制
·
化学生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2020
·
IF 6.785
Bo Wang,Shuai Zheng,Yan Huang,Ying Wang,Zhenyu Zhu,Ran Ma,Yu Zhao,Xijie Yin,Jing Su,Juan Xiong,Benli Zhang,Youping Zhou
The 18O/16O (and 15N/14N) ratio of natural nitrate (NO3–) and nitrite (NO2–) can be used to extract valuable information about their source and fate as environmental contaminants, their metabolism as macronutrients in plants and animals, and their behavior in the N biogeochemical cycle. We developed an accurate, precise, sensitive (minimum sample size: 0.2 μg NO3–-equivalent), and reliable (minimal oxygen exchange, loss, or gain) method to selectively isolate and purify nitrate and nitrite from natural water, soil, air, and plant materials by strong anion exchange (SAX) for low- to normal-salinity samples or strong cation exchange (SCX) for high-salinity samples, followed by quantitative conversion to their respective benzyl esters, which can be separated and individually analyzed for δ18O (and potentially δ15N) by gas chromatography (GC)/pyrolysis/GC/isotope-ratio mass spectrometry (IRMS). The method compares favorably with the currently popular bacterial denitrification and chemical reduction methods, in terms of sensitivity and reliability, and has the potential to simultaneously measure δ15N and δ18O of nitrate and nitrite from natural samples of various origins.
研究领域:
环境科学
·
生物地球化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Yidong Zhou,Zhijian Ke,Jiazhuo Zhang,Wenbin Chang,Yarong Cui,Yimiao Chen,Yirui Huang,Chunli Xia,Wenjia Zhong,Zifa Deng,Dayong Jin
Microorganisms are constantly evolving to resist the toxicity of artificial antibiotics and preservatives released into the environment. Parabens, a group of alkyl and aryl esters of p -hydroxybenzoate, are a class of widely used antimicrobial preservatives, particularly effective against Gram-positive bacteria and fungi. Previous studies have reported the degradation of parabens by numerous Gram-negative strains and activated sludge, with degradation processes often involving transesterification. However, the physiological significance of transesterification has received little attention. Here, a Gram-positive bacterium, Microbacterium sp. S1037 was isolated and characterized for its ability to degrade eight parabens and completely mineralize them through p -hydroxybenzoate and protocatechuate ( β -ketoadipate pathway). Moreover, strain S1037 also possesses the ability of paraben-transesterification. Alcohols compete with water molecules for the active center of enzymes, accelerating the transesterification of parabens and inhibiting hydrolysis. Considering that the fate of the transesterification product is still hydrolysis, we speculated and proved that such a “superfluous” mechanism is a detoxification strategy, and could be used in the bioremediation of parabens in wastewater. Microbial transesterification of parabens has been reported worldwide, and we speculated that it might be a common detoxification choice in the evolution of microorganisms worldwide.
研究领域:
微生物学
·
环境科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Xiao Feng,Tingting Chen,Yuqiao Yin,Yingjie Xu
By a comparative study of the concentration-dependent IR spectra of methyl benzoate (MB)/methanol- d 4 and MB/ n -hexane mixtures, it is found that the infrared wavenumber ( υ ˜ ) of ester group (O C O) of MB in the former system decreased exponentially with the increase of mole fraction of MB ( x 1 ), while that of the latter system decreased linearly, suggesting that H-bonding interaction plays an important role in the microstructure of MB/methanol- d 4 mixture. Therefore, to explore the microstructure and characterize the strength of H-bonding interaction of MB/methanol mixture, the excess infrared wavenumber of a group ( υ ˜ group E ) is proposed, showing that υ ˜ O − D E of methanol- d 4 presents an S shape with a minimum value at x 1 ≈ 0.4 and a maximum value at x 1 ≈ 0.8, respectively. Furthermore, the absolute value of υ ˜ O − D E (| υ ˜ O − D E |) of the former is greater than that of the latter, suggesting that H-bonding interaction in methanol- d 4 molecules is stronger than that between methanol- d 4 and MB. While both υ ˜ C = O E and υ ˜ C − O E of MB show a negative deviation with minimum values at x 1 ≈ 0.4, and | υ ˜ C = O E | is larger than | υ ˜ C − O E |, indicating that C O is directly involved in H-bonding interaction with O D, resulting in the change of υ ˜ C − O E through the electronic conjugation effect. To confirm the microstructure obtained from IR spectra, densities, speeds of sound , and viscosities of MB/methanol mixture are measured and excess properties are calculated. The results show that both excess molar volumes and isentropic compressibility deviations have a negative deviation with a minimum value at x 1 ≈ 0.4, which is good consistent with x 1 corresponding to the minimum value of υ ˜ O − D E , υ ˜ C = O E , and υ ˜ C − O E , respectively. Moreover, viscosity deviations exhibit a negative deviation with a minimum value at x 1 ≈ 0.8, which is good consistent with x 1 corresponding to the maximum value of υ ˜ O − D E .
研究领域:
物理化学
·
光谱学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 5
·915
·
IF 3.9
Xiaofeng Yu,Chunjie Shi,Yueling Cheng,Yejing Zhu,Renyuan Song,Shengfei Hu
Methyl benzoate (MB) compounds are prepared by reacting various benzoic acids with methanol using an acidic catalyst. In this study, the solid acids of zirconium metal solids fixed with various substances were studied. We determined that zirconium metal catalysts with fixed Ti had the best activity. The catalytic synthesis of a series of MB compounds using titanium zirconium solid acids was studied. The direct condensation of benzoic acid and methanol using a metallic Lewis acid without other auxiliary Bronsted acids is reported for the first time.Keywords:methyl benzoate;solid acid;catalysis
研究领域:
有机化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2020
·
IF 2.369
Jinbo Ouyang,Jian Chen,Limin Zhou,Zhirong Liu,Chuntao Zhang
The solubility data of propylparaben in polar and apolar solvents were first measured at T = (283.15–323.15) K using the shake flask method. The results show that solubility of propylparaben in all selected solvents increases proportionally with temperature, and at a high temperature (323.15 K), propylparaben is most soluble in acetone, followed by isopropanol, 1-propanol, ethanol, methanol, ethyl acetate, 1-butanol, butyl acetate, methyl acetate, isobutanol, acetonitrile, and water. To mathematically represent the experimentally measured solubility data, the modified Apelblat model, Wilson model, and NRTL model were applied. The difference between experimentally measured and predicted values was described by the percentage of averaged relative deviation. The best correlation of solubility versus temperature with the highest accuracy was obtained using the modified Apelblat model. Dissolution thermodynamics of propylparaben in different solvents at different temperatures were calculated and discussed to study the dissolution mechanism of propylparaben in different solvents.
研究领域:
药学
·
物理化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2018
·
IF 2.795
Chen Lu,Jiaming Hu,Yuning Meng,Aidong Zhou,Feng Zhang,Zhibing Zhang
To resolve the defects of acetic acid solvents for the liquid-phase oxidation of toluene to benzaldehyde with oxygen, a low-corrosive and green method was developed by introducing benzyl benzoate into the reaction. It was found that compared with the case of acetic acid, benzyl benzoate showed gratifying effect on the oxidation of toluene to benzaldehyde. The reaction was more active in the initial stage of oxidation, and the generated benzaldehyde was protected from further oxidation due to the synergistic effect of benzyl benzoate along with toluene-derived products benzyl alcohol and benzyl bromide. Benzyl benzoate inhibited the esterification of benzyl alcohol, while benzyl bromide promoted the formation of benzyl alcohol. Therefore, considerable benzyl alcohol concentration could be maintained and high benzaldehyde selectivity could be achieved under high toluene conversion.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）