Adsorbable organic halogens（AOX） are a general indicator for the total amount of compounds containing organically bonded halogens. AOX concentrations and components were investigated along the wastewater treatment p...Adsorbable organic halogens（AOX） are a general indicator for the total amount of compounds containing organically bonded halogens. AOX concentrations and components were investigated along the wastewater treatment process in four large-scale pharmaceutical factories of China, and genotoxicity based on the SOS/umu test was also evaluated. The results showed that AOX concentrations in wastewater of four factories ranged from 4.6 to 619.4 mg/L, which were high but greatly different owing to differences in the raw materials and products. The wastewater treatment process removed 50.0%–89.9% of AOX, leaving 1.3–302.5 mg/L AOX in the effluents. Genotoxicity levels ranged between 2.1 and 68.0 μg 4-NQO/L in the raw wastewater and decreased to 1.2–41.2 μg 4-NQO/L in the effluents of the wastewater treatment plants（WWTPs）. One of the main products of factory I, ciprofloxacin, was identified as the predominant contributor to its genotoxicity. However, for the other three factories, no significant relationship was observed between genotoxicity and detected AOX compounds.展开更多
Sulfapyridine(SPY)is a ubiquitous environmental contaminant belonging to the sulfonamide antibiotics.Previous studies showed that hydroxylamine(HA)can improve the performance of advanced oxidation processes(AOPs)by pr...Sulfapyridine(SPY)is a ubiquitous environmental contaminant belonging to the sulfonamide antibiotics.Previous studies showed that hydroxylamine(HA)can improve the performance of advanced oxidation processes(AOPs)by promoting Fe(Ⅱ)regeneration,yet the reaction mechanisms were not elucidated.Therefore,the role of HA and the degradation mechanisms of SPY were systematically studied therein.The SPY degradation efficiency increased from 77.5%to 91.6%after HA was added.With radical scav-enger experiment,a function of HA to promote·OH production for SPY degradation was clarified.The major radical from SO_(4)^(·-) and·OH to·OH with addition of HA in Fe(Ⅱ)/potassium peroxydisulfate(PDS).Results showed that alkali,acid condition and high PDS concentration all contributed to SPY degradation.According to experimental results,density functional theory(DFT)was used to calculate the degradation pathway of SPY.Rate-limiting path was obtained by comparing the rate constants calculated from the transition-state theory.The cleavage of CeC bond in benzene ring with the slowest rate was essential to degrade SPY,which not only promotes the mineralization of SPY,but also prevent the production of toxic TPs effectively.This study provides valuable insight into the SPY degradation in HA/Fe(Ⅱ)/PDS.展开更多
基金funded by National High-Tech Research and Development Program(863)of China(No.2013AA062705-1)
文摘Adsorbable organic halogens（AOX） are a general indicator for the total amount of compounds containing organically bonded halogens. AOX concentrations and components were investigated along the wastewater treatment process in four large-scale pharmaceutical factories of China, and genotoxicity based on the SOS/umu test was also evaluated. The results showed that AOX concentrations in wastewater of four factories ranged from 4.6 to 619.4 mg/L, which were high but greatly different owing to differences in the raw materials and products. The wastewater treatment process removed 50.0%–89.9% of AOX, leaving 1.3–302.5 mg/L AOX in the effluents. Genotoxicity levels ranged between 2.1 and 68.0 μg 4-NQO/L in the raw wastewater and decreased to 1.2–41.2 μg 4-NQO/L in the effluents of the wastewater treatment plants（WWTPs）. One of the main products of factory I, ciprofloxacin, was identified as the predominant contributor to its genotoxicity. However, for the other three factories, no significant relationship was observed between genotoxicity and detected AOX compounds.
基金supported by the China Postdoctoral Science Foundation(No.2023M733167)the National Natural Science Foundation of China(No.52170093)+5 种基金by the Zhejiang Provincial Natural Science Foundation(No.LY22E080010)the Science and Technology Project of Zhejiang Province(No.2022C02038)the Basic Public Welfare Research Program of Zhejiang Province(LZJWZ22C030002)the Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(LZJWZ23E090007)the Science Foundation of President of the Zhejiang Institute of Hy-draulics and Estuary(ZIHE 22Q009)the Zhejiang Province Science and Technology Plan Project(RC2223,RC2224).
文摘Sulfapyridine(SPY)is a ubiquitous environmental contaminant belonging to the sulfonamide antibiotics.Previous studies showed that hydroxylamine(HA)can improve the performance of advanced oxidation processes(AOPs)by promoting Fe(Ⅱ)regeneration,yet the reaction mechanisms were not elucidated.Therefore,the role of HA and the degradation mechanisms of SPY were systematically studied therein.The SPY degradation efficiency increased from 77.5%to 91.6%after HA was added.With radical scav-enger experiment,a function of HA to promote·OH production for SPY degradation was clarified.The major radical from SO_(4)^(·-) and·OH to·OH with addition of HA in Fe(Ⅱ)/potassium peroxydisulfate(PDS).Results showed that alkali,acid condition and high PDS concentration all contributed to SPY degradation.According to experimental results,density functional theory(DFT)was used to calculate the degradation pathway of SPY.Rate-limiting path was obtained by comparing the rate constants calculated from the transition-state theory.The cleavage of CeC bond in benzene ring with the slowest rate was essential to degrade SPY,which not only promotes the mineralization of SPY,but also prevent the production of toxic TPs effectively.This study provides valuable insight into the SPY degradation in HA/Fe(Ⅱ)/PDS.
