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
ACS ES&T Water
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2022
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IF 0
Fan Yang,Jianwei Yu,Qi Wang,Chunmiao Wang,Yuning Du,Zhiyuan Liu,Lili Zhang,Zhengang Liu,Chuanyong Jing,Junwang Tang,Min Yang
Powdered activated carbon (PAC) is the most widely used adsorbent for removing odorants like 2-methylisoborneol (MIB) for drinking water purification. The hydrophobicity exhibited by the moieties of the carbon structure is known to be important for the adsorption of activated carbon. Here we propose a novel approach for regulating the hydrophobicity of the carbon surface by rearranging carbon atoms without changing the pore structures markedly through thermal transformation using Fe(NO3)3 as the catalyst. Five different PACs were transformed into hydrophobic porous carbons (HPCs) with 2.47–3.00 times the adsorption capacity and faster adsorption rates, accompanied by the surface free energy being decreased by 26.67–36.40%, the IG2/IG1 representing the degree of order being increased by 17.31–53.68%, the C–C(sp2)/C–C(sp3) being increased by 31.9–49.8%, and the oxygen content being decreased by 4.71–8.63%. The increase in ordered planar crystals dominated by sp2 carbons as well as the decrease in the number of heteroatoms in HPCs might be the main reason for its enhanced adsorption of MIB. Simulation based on reactive force field molecular dynamics indicated that MIB molecules tended to be adsorbed in ordered structures. This study provides a novel angle for improving the surface hydrophobicity of activated carbon, which may lead to the development of high-performance adsorbents.
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
International Journal of Electrochemical Science
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2023
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IF 1.5
Jia Du,Xu Peng,Yuting Xu,Li Fu,Di Cao,Qinghua Liu
Odorant substances have been detected in the drinking water of several countries and regions. Although the specific harm of these substances to the human body is not yet clear, they can lead to the decline of drinking-water sensory indicators. In addition, odorants also affect the development of the waterdependent beverage industry and aquaculture industry. Dimethyl isoborneol (2-MIB) is the most common odorant substance that causes soil mildew in drinking water. In this work, for the first time, we first report the electrochemical determination of 2-MIB based on an Au electrode. The electrochemical oxidation of 2-MIB can be achieved due to the excellent conductivity and electrocatalytic property of the Au electrode. The proposed electrochemical sensing method is simple, quick and reliable for 2-MIB determination.
研究领域:
环境科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Lei Li,Junyi Li,Cuiwen Zhu,Shuili Yu
2-Methylisoborneol (2-MIB), a major cause of taste and odor (T&O) in drinking water, tends to combine with the coexisting dissolved organic matter (DOM), resulting in the altering of the physico-chemical properties of 2-MIB, and its corresponding migration and removal behaviors during water treatment. In this study, dialysis and ultrafiltration were set up to differentiate bound and free 2-MIB, and the binding of different types of DOMs to 2-MIB was investigated. At 298 K, the Freundlich constants, K F ((ng/mg)(L/ng) 1/n ), representing the combination ability between 2-MIB and the model pollutants, followed the order hen egg-white lysozyme (HEL 22.52) > bovine serum albumin (BSA 19.23) > sodium carboxymethyl cellulose (CMC 9.69) > sodium alginate (SA 7.78), and humic substances exhibited a weak association with 2-MIB, indicating that aromatic structures provide few binding sites. The K F of natural organic matter (NOM 196.15) in real raw water was much larger than that of model pollutants owing to the complex composition and the wide molecular weight distribution. The major interactions between DOM and 2-MIB were van der Waals forces and hydrogen bonding, except that HEL were hydrophobic interactions. Common metal ions affected these associations and generally decreased K F . The findings in this study are of particular significance for the selection of proper strategy to maintain the water quality during the outbreak of T&O in the source.
研究领域:
环境科学
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化学
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产品关联
DOI
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
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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