Environmental Science-Water Research & Technology
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2020
·Vol. 6
·期 10
·2766-2775
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IF 3.449
Huan Qi,Qing Lin,Mengyi Chen,Xiaobin Liao,Jie Chen,Fei Li,Baoling Yuan
Daminozide (DMNZD) has been found to be an important ozone-reactive N-nitrosodimethylamine (NDMA) precursor; however, the influence of humic acid (HA) on NDMA formation from daminozide during ozonation is unclear. In this study, the impacts of HA on NDMA formation from daminozide at various oxidation conditions (ozone dosages, pH) and other water components (bicarbonate ion (HCO3−), sulfate ion (SO42−)) were investigated. In addition, its implications for water treatment plants are discussed. The results indicated that low levels of HA (≤0.6 mg L−1) facilitated NDMA formation and its molar yield was maximized at 0.1 mg L−1 HA (8.5%), while a high concentration of HA (>0.6 mg L−1) had an inhibition role. The NDMA amount increased with increasing pH and showed a peak at pH 8. With 0.1 mg L−1 HA, NDMA was raised from 3.0% to 23.1% with ozone increasing from 0.5 to 4 mg L−1; HCO3− competed with daminozide for ozone and cut down NDMA formation, whereby 160 μM HCO3− reduced NDMA conversion from 8.5% to 6.5%; however, with the increase in SO42− from 0 to 20 μM, NDMA conversion was augmented from 8.5% to 17.8%. Based on the results of LC/MS/MS and GC/MS analyses, NDMA transformation pathways with/without HA are proposed.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2023
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IF 2.6
Pengshuai Zhang,Jixiu Deng,Xiaoyu Jiang,Liang Xu,Yu Huang,Han Sun,Mi Gao,Xianghan Wang,Yulong Gao,Kangning Fan,Lu Zhang,Shuoye Yang
In the present study, solubility of daminozide was determined in twelve neat solvents (N,N-Dimethylformamide (DMF), 2-methoxyethanol, N-Methyl-2-pyrrolidone (NMP), 2-ethoxyethanol, Acetonitrile (MeCN), 2-propoxyethanol, methanol, ethanol, n -propanol, i -propanol, n -pentanol, 2-butoxyethanol) by using the gravimetrical method under the pressure of 0.1 MPa and temperature from 283.15 to 323.15 K. The maximum solubility value (10 2 x 1 ) of daminozide was found in NMP at 323.15 K (10.04), while the minimum solubility value (10 2 x 1 ) of daminozide was found in n -pentanol at 283.15 K (0.0149). At the temperature of 298.15 K, the order of the experimental solubility values (100 x 1 ) of daminozide in twelve neat solvents was: NMP (5.523) > DMF (3.294) > methanol (1.395) > 2-methoxyethanol (0.7839) > ethanol (0.5515) > 2-ethoxyethanol (0.3816) > n -propanol (0.2175) > i -propanol (0.1099) > 2-propoxyethanol (0.1083) > 2-butoxyethanol (0.0632) > MeCN (0.0386) > n -pentanol (0.0344). Five models including van't Hoff model, Buchowski-Ksiazczak λh model, NRTL model, UNIQUAC model and Jouyban model were employed to correlate and analyze the experimental solubility of daminozide. Based on the principle of similar compatibility, the miscibility of daminozide in the selected solvents was discussed with the help of Hansen solubility parameters ( HSPs ). Finally, the apparent thermodynamic properties were investigated and results indicated that the dissolution mechanism of daminozide in all selected solvents was an entropy-driven and endothermic process.
研究领域:
化学
·
药学
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产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Linfang Li,Qing Lin,Xiaobin Liao,Tianze Liu,Huan Qi,Qingsong Li,Menglan Gao,Jing Zou,Zhenming Zhou,Mingzhi Huang,Zhimin Yang
The widespread amines have been found to generate carcinogenic nitro-dimethylamine (NDMA) during ozonation, it's urgent to search effective methods to control its formation. This work investigated the performance and mechanisms of bimetallic organic framework (MIL-100(Fe-Mn)) on reducing NDMA production during ozonation of daminozide (DMNZD). The results demonstrated that NDMA concentration raised from 27.6 to 248.4 μg/L when ozone dosages enhanced from 0.5 to 4 mg/L; while just slightly increased from 0.9 to 3.7 μg/L when MIL-100 (Fe-Mn) was added, with a reduction rate up to 98.5 %. When catalyst dosages increased from 0 to 200 mg/L, NDMA reduction rates enhanced from 54.5 to 97.4%. Moreover, neutral conditions facilitated the exploitation of MIL-100(Fe-Mn) during ozonation. Water bodies containing high concentrations of CO 3 2− , HA, and Br − should be avoided to prevent high NDMA risk. MIL-100(Fe-Mn) enhanced the transformation of ozone molecular (O 3 ) to hydroxyl radical (·OH) other than superoxide radicals (·O 2 − ) and singlet oxygen ( 1 O 2 ). EPR and scavengers quenching experiments verified that ·OH played important roles in NDMA reduction. Except ·OH, hydrogen radicals (·H) were detected in catalyzed ozonation system for the first time. The results would provide new insights for NDMA risks control during ozonation.
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
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Xiaobin Liao,Xingji Bai,Huan Qi,Fei Li,Baoling Yuan
N-nitrosodimethylamine (NDMA) has recently been discovered to generate from daminozide (DMNZD) during ozonation . Moreover, its formation is affected by the presence of bromine ion (Br − ) in water, but the mechanism is still unclear. In this study, the effect of Br − on NDMA formation from DMNZD during ozonation at various oxidation conditions (ozone dosages, pH) and distinct water parameters was studied. In addition, the transformation pathways with/without Br − were determined. The results demonstrated that low levels of Br − promoted NDMA formation from DMNZD during ozonation. When Br − dosages increased from 0 to 1 μM, the concentration of NDMA augmented from 138 to 195.5 μg/L. However, when Br − concentration raised to 100 μM, NDMA amounts dropped to 80 μg/L. Increasing pH can raise the ratio of deprotonated DMNZD no matter with or without Br − , and promote its reaction with O 3 molecular to achieve the maximum NDMA formation at pH = 7. The amounts of NDMA decreased dramatically (from 155 to 74 μg/L) when HCO 3 – dosages increased from 0 to 160 μM with 0.1 μM Br − , however, its concentration increased remarkably (from 155 to 225 μg/L) with increasing SO 4 2− (from 0 to 20 μM). Low levels of HA (0.1–0.2 mg/L) boosted NDMA formation while relatively abundant of HA (≥0.4 mg/L) suppressed its formation. In addition, the presence of NOM inhibited NDMA formation from DMNZD during ozonation no matter Br − existed or not. Based on the results of LC/MS/MS, GC/MS and IC-MS, the transformation pathways of DMNZD with/without Br − during ozonation were proposed. This study provided new insights into the role of Br − on NDMA formation from typical amine compounds during ozonation.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
高影响因子
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