HCO3-和NO3-对水中双氯芬酸紫外光解的影响

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Abstract

The influence of bicarbonate (HCO₃^-) and nitrate (NO₃^-) on the photolysis of diclofenac (DCF) under UV-254nm irradiation was investigated in this study. The effects of HCO₃^- dose and NO₃^- dose on the degradation of DCF in UV/NO₃^-/HCO₃^- system were also explored. Finally, the degradation products and reaction mechanism of DCF by UV/NO₃^-/HCO₃^- were studied. The results show that the presence of HCO₃^- almost had no effect on DCF photolysis in the studied conditions. The presence of NO₃^- could significantly enhance the degradation of DCF due to the role of generated hydroxyl radical (HO^•) through the excited NO₃^- under UV irradiation. Compared to DCF degradation by UV photolysis in the presence of only HCO₃^- or NO₃^-, the coexist of HCO₃^- and NO₃^- could further increase the removal of DCF, which could probably ascribe to the formation of carbonate radical (CO₃^•-) through the reaction between generated HO^• and HCO₃^-. The presence of CO₃^•- and its role on DCF degradation were confirmed by adding methanol, a scavenger of HO^•, in UV/NO₃^-/HCO₃^- system. The removal of DCF in UV/NO₃^-/HCO₃^- system might include three different reaction pathways, i.e., direct UV photolysis, HO^• oxidation and CO₃^•- oxidation, and the contribution of direct UV photolysis and free radical oxidation to DCF removal in this system was 25% and 75%, respectively. The degradation efficiency of DCF increased gradually with the increase in NO₃^- dose in UV/NO₃^-/HCO₃^- system, because the increase of NO₃^- dose could enhance the steady-state concentration of generated HO^• in this system. The increase of HCO₃^- dose had little influence on DCF removal in UV/NO₃^-/HCO₃^- system. Eleven transformation products were detected in the degradation of DCF by UV/NO₃^-/HCO₃^- using a liquid spectrometer coupled with a quadrupole time-of-flight tandem mass spectrometer (LC-QTOF/MS). According to these identified reaction products, the probable reaction mechanism of DCF in UV/NO₃^-/HCO₃^- system was proposed showing five different degradation pathways, including dechlorination-hydrogenation, dechlorination-cyclization, decarboxylation, formylation and quinonization.

Key words： diclofenac UV photolysis bicarbonate nitrate carbonate radical

Received: 04 September 2017

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X505

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	LIU Yi-qing
	SHI Hong-le
	FU Yong-sheng

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LIU Yi-qing,SHI Hong-le,FU Yong-sheng. The influence of bicarbonate and nitrate on the photolysis of diclofenac under UV irradiation[J]. CHINA ENVIRONMENTAL SCIENCECE, 0, (): 1329-1335.

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http://www.zghjkx.com.cn/EN/ OR http://www.zghjkx.com.cn/EN/Y0/V/I/1329

[1]	Halling-Sorensen B, Nors Nielsen S, Lanzky P F, et al. Occurrence, fate and effects of pharmaceutical substances in the environment-a review[J]. Chemosphere, 1998,36(2):357-393.
[2]	Daughton C G, Ternes T A. Pharmaceuticals and personal care products in the environment:agents of subtle change?[J]. Environmental Health Perspectives, 1999,107(Supplement 6):907-938.
[3]	Perez-Estrada L A, Malato S, Gernjak W, et al. Photo-Fenton degradation of diclofenac:identification of main intermediates and degradation pathway[J]. Environmental Science & Technology, 2005,39(21):8300-8306.
[4]	Zhang Y, Geiben S U, Gal C. Carbamazepine and diclofenac:Removal in wastewater treatment plants and occurrence in water bodies[J]. Chemosphere, 2008,73(8):1151-1161.
[5]	史瑞,张付申.碱催化水热氧化法处理废弃双氯芬酸钠类药物[J]. 中国环境科学, 2017,37(4):1386-1393.
[6]	Vieno N M, Harkki H, Tuhkanen T, et al. Occurrence of pharmaceuticals in river water and their elimination in a pilot-scale drinking water treatment plant[J]. Environmental Science & Technology, 2007,41(14):5077-5084.
[7]	王月,熊振湖,周建国.杯
[4]	芳烃修饰Amberlite XAD-4树脂去除水中双氯芬酸[J]. 中国环境科学, 2012,32(1):81-88.
[8]	于万禄,熊振湖,马华继.Photo-Fenton法降解水中新型污染物双氯芬酸及降解产物的毒性评价[J]. 环境科学学报, 2009,29(10):2070-2075.
[9]	Letzel M, Metzner G, Letzel T. Exposure assessment of the pharmaceutical diclofenac based on long-term measurements of the aquatic input[J]. Environment International, 2009,35(2):363-368.
[10]	张楠,刘国光,刘海津,等.双氯芬酸在水环境中光降解的初步研究[J]. 环境化学, 2013,32(1):42-47.
[11]	Buser H R, Poiger T, Muller M D. Occurrence and fate of the pharmaceutical drug diclofenac in surface waters:rapid photodegradation in a lake[J]. Environmental Science & Technology, 1998,32(22):3449-3456.
[12]	Chen Y, Hu C, Hu X X, et al. Indirect photodegradation of amine drugs in aqueous solution under simulated sunlight[J]. Environmental Science & Technology, 2009,43(8):2760-2765.
[13]	Keen O S, Love N G, Linden K G. The role of effluent nitrate in trace organic chemical oxidation during UV disinfection[J]. Water Research, 2012,46(16):5224-5234.
[14]	Buxton G V, Greenstock C L, Helman W P. Critical review of rate constants for reactions of hydrated electrons, hydrogen atoms and hydroxyl radicals (•OH/•O-) in aqueous solution[J]. Journal of Physical and Chemical Reference Data, 1988,17(2):513-886.
[15]	Neta P, Huie R E, Ross A B. Rate constants for reactions of inorganic radicals in aqueous solution[J]. Journal of Physical and Chemical Reference Data, 1988,17(3):1027-1284.
[16]	Canonica S, Kohn T, Mac M, et al. Photosensitizer method to determine rate constants for the reaction of carbonate radical with organic compounds[J]. Environmental Science & Technology, 2005,39(23):9182-9188.
[17]	Wu C, Linden K G. Phototransformation of selected organophosphorus pesticides:roles of hydroxyl and carbonate radicals[J]. Water Research, 2010,44(12):3585-3594.
[18]	Liu Y, He X, Duan X, et al. Significant role of UV and carbonate radical on the degradation of oxytetracycline in UV-AOPs:Kinetics and mechanism[J]. Water Research, 2016,95:195-204.
[19]	Kim I, Tanaka H. Photodegradation characteristics of PPCPs in water with UV treatment[J]. Environment International, 2009,35(5):793-802.
[20]	Lekkerkerker-Teunissen K, Benotti M J, Snyder S A, et al. Transformation of atrazine, carbamazepine, diclofenac and sulfamethoxazole by low and medium pressure UV and UV/H2O2 treatment[J]. Separation and Purification Technology, 2012,96:33-43.
[21]	Yu H, Nie E, Xu J, et al. Degradation of diclofenac by advanced oxidation and reduction processes:kinetics studies, degradation pathways and toxicity assessments[J]. Water Research, 2013,47(5):1909-1918.
[22]	Chen S N, Cope V W, Hoffman M Z. Behavior of CO3•- radicals generated in the flash photolysis of carbonatoamine complexes of cobalt (Ⅲ) in aqueous solution[J]. The Journal of Physical Chemistry, 1973,77(9):1111-1116.
[23]	Kim I, Yamashita N, Tanaka H. Photodegradation of pharmaceuticals and personal care products during UV and UV/H2O2 treatments[J]. Chemosphere, 2009,77(4):518-525.
[24]	邱慧敏,耿金菊,韩超.亚磷酸盐在硝酸根溶液中的光氧化过程及影响因素[J]. 中国环境科学, 2016,36(5):1442-1448.
[25]	展漫军,杨曦,鲜啟鸣.双酚A在硝酸根溶液中的光解研究[J]. 中国环境科学, 2005,25(4):487-490.