CHEMOSPHERE
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2018
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IF 4.427
Lingfei Ma,Chaoyi Wang,Haipu Li,Fangyuan Peng,Zhaoguang Yang
Geosmin (GSM) and 2-methylisoborneol (2-MIB) are two common odor compounds in drinking water . In this paper, the performance of UV/chlorine was compared with that of chlorine and UV to degrade GSM (100 ng L −1 ) and 2-MIB (100 ng L −1 ) in water. UV/chlorine was further exploited, and a steady-state kinetic model was used to conduct a detailed study on efficiency, rate, reactive species and pathway. The results showed that UV/chlorine greatly could improve the removal ratio to 90% within 5 min, from approximately 20% with only UV or dark chlorine in 60 min. The removal ratio and rate depended on UV light intensity , free chlorine dosage, reaction time and water quality parameters (e.g. pH, concentrations of HCO 3 − and Cl − ). Among these factors, the first two obviously could accelerate the rate and increase the ratio. The degradation was also significantly improved in an acidic condition, while alkaline conditions and HCO 3 − had inhibitory effects, and Cl − created no difference. Contributions of OH and Cl to the degradation of 2-MIB and GSM were further revealed, and OH was found to be the most important reactive species. In the UV/chlorine process, 6 degradation byproducts of 2-MIB, including 1 alcohol, 2 ketones, and 3 olefins , were identified, and 14 degradation byproducts of GSM, including 6 ketones, 1 aldehyde, 2 alcohols, 3 naphthenes , and 2 olefins, were found by using solid-phase microextraction coupled to gas chromatography-mass spectrometry. The possible degradation pathways of GSM and 2-MIB in UV/chlorine thus were proposed.
研究领域:
环境科学
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饮用水处理
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产品关联
DOI
PubMed
高影响因子
Journal of Water Process Engineering
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2024
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IF 6.3
Ziang Zhao,Xiaojiang Huang,Zhiqiang Zhang,Heliang Pang,Xuan Wang,Ping Li,Chunbo Li,Jinsuo Lu
The problem of odor and taste caused by geosmin had been widely discussed globally. While existing water treatment processes were difficult to remove geosmin cleanly and efficiently, and the traditional aeration method of micro-nano bubbles (MNBs) led to low removal efficiency due to the low probability of collision between the bubbles and the contaminants. In this study, micro-nano bubble modification technique was used to improve the removal efficiency. Three surface modifiers, hexadecyl trimethyl ammonium bromide (CTAB), chitosan (CTS), and poly dimethyl diallyl ammonium chloride (PDADMAC), were selected for this study. The effects of the surface modifiers on the properties of MNBs and the effects of these changes on the removal efficiency of GSM were explored. The experimental results showed that when all three modifiers were dosed at 5 mg/L, the PDADMAC-modified MNBs had the best GSM removal effect of 70.9 %, while the Zeta potential of the effluent was lower at 4.17 mV, which had less influence on the downstream process, and was an ideal modifier. The contribution of various removal pathways to GSM removal was also explored through intermediate product analysis combined with variable control experiments. The experimental results showed that the enhanced removal of GSM was attributed to the enhanced capture of GSM by PDADMAC-modified MNBs and the enhanced oxidation of GSM by PDADMAC-modified MNBs. At the same time, the removal efficiency of this process in natural waters decreased by <5 % only. This study could provide data and theoretical support for the enhanced removal of olfactory compounds by modified MNBs for application in practical engineering.
研究领域:
环境科学
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水处理工程
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产品关联
DOI
高影响因子
Heliyon
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2023
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IF 4
Liangliang Tian,Xin Qu,Dongmei Huang,Yongfu Shi,Cong Kong,Yuan Wang
This research aimed to develop an effective method for detecting semivolatile earthy-musty odors without using the conventional sample processing equipment used for volatile compounds. The concurrent isolation of 2-methylisoborneol (2-MIB), trans -1,10-dimethyl-trans-9-decalol (geosmin, GSM), 2-isopropyl-3-methoxy pyrazine (IPMP), and 2-isobutyl-3-methoxy pyrazine (IBMP) in tap water was successfully achieved by employing a combination of n-hexane liquid‒liquid extraction (LLE) and silica solid-phase extraction (SPE) techniques. Gas chromatography–mass spectrometry (GC-MS) was utilized for the identification of these targets, with the inclusion of borneol (BN) as an internal reference. This robust method was optimized and validated. It was found that the method showed good linearity in the range of 0.5–100 ng/mL and produced good recoveries (84.6 %–103 %) with satisfactory relative standard deviations (1.50 %–10.1 %). The determined limits of detection (LODs) for the group of four substances were found to vary from 0.3 to 0.9 ng/L, whereas the limits of quantitation (LOQs) exhibited variations between 1 and 3 ng/L. The subsequent implementation of this methodology to evaluate the four previously described off-flavor chemicals in tap water resulted in satisfactory results.
研究领域:
分析化学
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环境科学
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水质检测
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DOI
PubMed
高影响因子
CHEMOSPHERE
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2022
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IF 8.943
Tan Meng,Xiao Su,Peizhe Sun
Geosmin (GSM) and 2-methylisoborneol (2-MIB) are representative musty/earthy odor compounds commonly present in surface water. In present study, the degradation of GSM and 2-MIB subject to different UV-based advanced oxidation processes (AOPs), including UV/H 2 O 2 , UV/S 2 O 8 2− , UV/chlorine, and UV/chloramine, in a phosphate-buffered saline (PBS) was conducted in a photoreactor with reflective inner surfaces and compared with that in an environmental water sample. A dynamic model to predict the degradation of GSM and 2-MIB in the photoreactor with reflective inner surfaces in the four UV-based AOPs was developed applying the second-order rate constants for the GSM and 2-MIB with primary reactive species (i.e., •OH, •Cl, and •SO 4 − ) determined in this study. The model was proven to successfully simulate the degradation of GSM and 2-MIB. In addition, 8, 7, 8, and 11 degradation intermediates were detected from UV/H 2 O 2 , UV/S 2 O 8 2− , UV/chlorine, and UV/chloramine in this study, and possible degradation pathways were proposed. This study is the first to report the degradation kinetics and formation products of GSM and 2-MIB in UV/chloramine. Research based on photoreactors with reflective inner surfaces may provide some guidance for eliminating GSM and 2-MIB in UV-based AOPs for full-scale engineering applications.
研究领域:
环境科学
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水处理工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2024
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IF 5.9
Miaomiao Yu,Sai Wang,Naili Wang,Yufeng Wu,Lirong Li,Xueqiang Lu
A dummy-template molecularly imprinted polymer (DMIP) based on magnetic carbon nanotubes was synthesized . The eluted polymers with an improved ultrasound assisted/oscillating (magnetic separation) method were successfully employed for the adsorption and separation of geosmin (GSM), an odorous compound in eutrophic waterbodies. The properties of the obtained composite materials were evaluated through a series of morphological and physicochemical characterization. The results showed that a thin and uniform imprinted shell (∼10–15 nm) effectively coated the surface of magnetic carbon nanotubes, exhibiting good adsorption efficiency and magnetic functionality. The binding performance and selectivity of Mag-MWCNTs @DMIPs as adsorbents for GSM were evaluated and compared with non-imprinted polymers. The maximum adsorption capacity of polymers for GSM, as determined by the Langmuir model, is 18.71 mg g −1 , which adsorption equilibrium reached in approximately 45 min. The adsorption thermodynamic parameters ΔG shown that the adsorption process was spontaneous. Selectivity and regeneration experiment further demonstrated the ability of Mag-MWCNTs @DMIPs to selectively separate trace GSM from complex matrices. The polymer obtained in this study can be used as an adsorbent for magnetic dispersion solid-phase extraction to preconcentration of trace GSM in natural water, facilitating the measurement of GSM.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Desalination and Water Treatment
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2024
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IF 1
Dacheng Sun,Yonglei Wang,Baosen Liu,Xinglin Wang,Mengchang Hu
A laboratory-scale study was conducted to investigate the degradation of Geosmin (GSM) utilizing an ozone micro-nano bubble system. The primary objectives of this research encompassed: (1) assessing the comprehensive characteristics of the ozone micro-nano bubble system, (2) evaluating the removal of GSM in water samples using the micro-nano bubble system, and (3) identifying the degradation pathways and primary intermediate products generated by GSM during the degradation process. The ozone micro-nano bubble system was compared with the conventional ozone bubble system in terms of initial particle size distribution, liquid phase ozone concentration, free radical generation efficiency, as well as ozone absorption and utilization rates. Furthermore, the elucidation of the degradation pathways for GSM was achieved through rigorous analysis of intermediate product formation. The comprehensive performance of the ozone micro-nano bubble system is better than that of the ozone traditional bubble system. The ozone absorption rate reached 95 % and the ozone utilization rate reached 91.25 % under the ozone micro-nano bubble system. It is worth noting that in pure water, the GSM removal rate of the micro-nano bubble system is 97.11 %. All in all, the ozone micro-nano bubble system can significantly enhance the utilization rate of ozone and improve the removal effect of pollutants. However, there are still some defects in the stability of the bubble particle size produced by the ozone micro-nano bubble system, which poses the next challenge we need to face.
研究领域:
环境科学
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水处理工程
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化学工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）