SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Qi Wang,Liwei Luo,Nan Huang,Wenlong Wang,Yuzhou Rong,Zhiwei Wang,Yi Yuan,Ao Xu,Jianglei Xiong,Qianyuan Wu,Hongying Hu
This study evaluated the evolution of low molecular weight organic compounds in ultrapure water (UPW) production using a pilot-scale UPW production system and an ultrafiltration–reverse osmosis (UF–RO) system. During UPW production, a dissolved organic carbon (DOC) removal efficiency of 99.4% was achieved with a feedwater DOC level of 1.42 mg/L. The pretreatment , make-up, and polishing stages accounted for 85.3%, 13.7%, and 0.4% of DOC removal, respectively. Urea, trichloromethane, and dibromochloromethane persisted throughout UPW production process, contributing 24.7%, 9.2%, and 22.6%, respectively, to the final effluent DOC level of 8.1 μg/L. The pretreatment and make-up stages of the UPW production process could remove N -nitrosodimethylamine, chloral hydrate, dichloroacetonitrile, and tribromomethane. The UF–RO system could remove approximately 90% of DOC. However, the proportion of halogenated disinfection by-products (DBPs) in the DOC increased by 1.4–4.5 times in the RO effluents. RO could completely reject haloacetaldehydes. However, RO could not completely remove trichloromethane, tribromomethane, bromodichloromethane, and dibromoacetonitrile, which remained the main halogenated DBPs in the RO effluents.
研究领域:
环境科学
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水处理工程
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2025
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IF 11.3
Youn-Jun Lee,Sung-Hyo Jung,Chang-Gu Lee
Low-molecular-weight organic pollutants present in feed water pose a significant challenge to maintaining ultrapure water (UPW) quality, as they are not readily removed by conventional treatment processes. Urea is a low-molecular-weight, nonionic, persistent organic pollutant resistant to conventional UPW production processes. Therefore, suitable oxidation technologies must be explored to convert urea to inorganic nitrogen ions, which are more easily removed in post-UPW treatment steps. In this study, the far-UVC (peak wavelength centered at 222 nm) coupled persulfate (PS) activation system was used for the effective oxidation of urea to nitrate (NO 3 − ). In the degradation of urea (10 μM, PS 0.4 mM, pH 7), far-UVC/PS systems (k urea,222/ PDS= 1.69 × 10 −3 cm 2 ∙mJ −1 , k urea,222/PMS = 2.69 ×10 −4 cm 2 ∙mJ −1 ) were found to be superior to conventional 254 nm LPUV/PS systems (k urea,254/PDS = 1.07 ×10 −4 cm 2 ∙mJ −1 , k urea,254/PMS = 7.01 ×10 −5 cm 2 ∙mJ −1 ). The far-UVC/PDS system showed the highest efficiency, achieving complete urea removal after 5241.0 mJ∙cm −2 of irradiation. The dominant role of SO 4 •− in urea degradation was systematically investigated, with urea removal showing a strong correlation with the steady-state concentration of SO 4 •− . Moreover, the evolution of inorganic nitrogen species and the reduction of total organic carbon were examined to assess the applicability of the system as a pretreatment technology in UPW production. The results provide valuable insights into the integration of the far-UVC process for the removal of low-molecular weight pollutants during UPW production.
研究领域:
环境工程
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水处理化学
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高级氧化技术
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分子生物学
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环境光化学
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水质净化
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DOI
PubMed
高影响因子
Water Reuse
·
2022
·Vol. 12
·期 3
·332-345
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IF 0
Jiang Shilong,Xiong Jianglei,Cheng Song,Cao Jiashun,Yuan Runbo
Conventional spectrophotometric methods were unable to accurately detect urea concentrations below 100 μg/L. A modified spectrophotometric method was developed to determine the trace urea in the ultrapure water (UPW) production process of the semiconductor manufacturing industry. This method was optimized based on the dosage of chemical agents, length of the optical path, and mode of the water bath. Metal ions were added to promote the stability of the chromogenic system. A calibration graph was observed with ideal linearity in the range of 0.8–100 μg/L. The detection and quantification limits of urea were 0.24 and 0.80 μg/L, respectively. The distribution of urea in raw water for the UPW production process was observed and the urea in tap water was 10–20 μg/L. The urea of municipal reclaimed water was 24–40 μg/L, which was twice that of industrial reclaimed water at 10–18 μg/L. The total removal rate of urea by the UPW production process was 50–70%. Reverse osmosis membranes played a critical role in the removal of urea (over 30%). The urea in the final UPW produced from tap water was approximately 4.1 μg/L, which creates a potential risk of excessive total organic carbon. A spectrophotometric method for the determination of trace urea during ultrapure production process was first established. Stability of the absorbance in the color reaction was increased by doping metal ions. The urea concentration of municipal reclaimed water was twice that of industrial reclaimed water. The urea removal efficiencies in each unit of the ultrapure water production process were explored.
研究领域:
分析化学
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环境科学
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水处理
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半导体制造
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分光光度法
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DOI
TRIBOLOGY INTERNATIONAL
·
2023
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IF 6.2
Bo Wang,Dagang Wang,Liang Tang,Hailang Chong,Wei Xu,Xinxin Zhang,Chunlei Zhang,Dianlong Tan,Xia Zhao,Dekun Zhang,Shirong Ge
The coupling effect of dead load, vehicle load, wind load and corrosive environment in the main saddle causes bending tribo-corrosion-fatigue behaviors between the wires and the saddle material in the suspension bridge . A self-made wire test rig was developed for the bending tribo-corrosion-fatigue test between the wire and saddle material in 3.5% NaCl solution and ultrapure water. The tribological properties (friction coefficient, wear mechanism, wear profile, volume loss, etc.), electrochemical corrosion behaviors (Tafel polarization curve , Nyquist diagram) and effect of fatigue load were revealed. The interaction of tribo-corrosion-fatigue was quantitatively analyzed by different types of volume loss, and its mechanism was discussed. The results demonstrated that a synergy of the three becomes more significant with the increasing fatigue load.
研究领域:
土木工程
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腐蚀科学
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材料科学
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产品关联
DOI
高影响因子
Journal of Cleaner Production
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2023
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IF 11.1
Qi Wang,Nan Huang,Wenlong Wang,Yunpeng Wu,Song Xue,Hongwei Xu,Zhuo Chen,Yinhu Wu,Qianyuan Wu,Hongying Hu
Urea in the ultrapure water production process threatens semiconductor manufacturing . This work proposed a urea removal strategy involving the VUV/UV/chlorine process in an acidic solution to achieve high-efficiency urea removal. VUV/UV/chlorine could thoroughly remove urea of 2 mg/L within 9 min at pH 3. A TN removal rate of 70% and a dissolved organic carbon removal rate of 84% were achieved in the urea degradation process . The decrease in pH and the increase in oxidant dosage could improve urea removal efficiency. The presence of chloride anion could improve urea removal by 55–85%. Based on the radical probe and quenching experiments, free radicals accounted for more than 90% of urea removal. •Cl 2 − and •OH were calculated to contribute approximately 36% and 22%, respectively, to urea removal. •Cl and •ClO together contributed less than 32%. The chlorination of urea was responsible for less than 10% of urea removal. Nitrogen in urea was transformed efficiently into inorganic nitrogen (N 2 , ammonium, and nitrate with a rough ratio of 6:1:1.1). Organic chlorine products formed in the urea degradation process took up less than 3% in all chlorine element and was converted into chloride anion finally.
研究领域:
环境科学
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水处理
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化学工程
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DOI
高影响因子
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