Environmental Technology ( IF 2.8 ) Pub Date : 2020-05-28 , DOI: 10.1080/09593330.2020.1770869 Faiza Rehman 1 , Waqas Ahmad 1 , Murtaza Sayed 2
ABSTRACT
This study reports the comparative removal of an emerging contaminant diclofenac sodium (DCF) by UV-254 nm-based advanced oxidation processes (AOPs), i.e. UV/S2O82−/Fe2+, UV/HSO5−/Fe2+ and UV/H2O2/Fe2+ processes. The results demonstrated that by applying [DCF]0 = 0.30 mM and [H2O2]0 = [S2O82−]0 = [HSO5−]0 = 3 mM, kapp values were 0.082, 0.166, 0.221, 0.485 and 2.014 min−1 for UV-only, UV/Fe2+, UV/H2O2/Fe2+, UV/S2O82−/Fe2+ and UV/HSO5−/Fe2+ processes, respectively. At different [DCF]0 from 0.30 to 0.90 mM, the degradation rate was increased from 0.01 mM min−1 to 0.12 mM min−1, while the corresponding kapp values were decreased from 2.01 min−1 to 1.04 min−1. The removal performance of the applied AOP was significantly influenced by the presence of natural water contaminants (NO3−, Cl−, HCO3−, SO42− and humic acid (HA)) and [pH]0. The inhibition of these natural water contaminants on the removal of DCF by UV/HSO5−/Fe2+ process was in the order of HA > NO2− > SO42− > HCO3− ≈ Cl− > NO3−. Furthermore, seven (07) degradation products (DPs) of DCF were explored by UPLC-MS/MS and accordingly degradation pathways of DCF were suggested. The practical applications of the proposed AOPs towards the removal of DCF were further strengthened by calculating total organic carbon removal and toxicity assessment.
中文翻译:
基于UV/S2O82−/Fe2+、UV/HSO5−/Fe2+和UV/H2O2/Fe2+的高级氧化工艺去除双氯芬酸钠的机理研究
摘要
本研究报告了通过基于 UV-254 nm 的高级氧化工艺 (AOP),即 UV/S 2 O 8 2- /Fe 2+、UV/HSO 5 - /Fe比较去除新兴污染物双氯芬酸钠 (DCF) 2+和 UV/H 2 O 2 /Fe 2+工艺。结果表明,通过应用 [DCF] 0 = 0.30 mM 和 [H 2 O 2 ] 0 = [S 2 O 8 2− ] 0 = [HSO 5 − ] 0 = 3 mM,k app对于仅 UV、UV/Fe 2+、UV/H 2 O 2 /Fe 2+、UV/S 2 O 8 2− /Fe 2+和 UV 的值为 0.082、0.166、0.221、0.485 和 2.014 min -1 /HSO 5 - /Fe 2+分别处理。在不同的 [DCF] 0从 0.30 到 0.90 mM 时,降解速率从 0.01 mM min -1增加到 0.12 mM min -1,而相应的k app值从 2.01 min -1减少到 1.04 min -1. 所应用的 AOP 的去除性能受天然水污染物(NO 3 -、Cl -、HCO 3 -、SO 4 2-和腐殖酸 (HA))和 [pH] 0的存在显着影响。这些天然水污染物对通过 UV/HSO 5 -/Fe 2+过程去除 DCF 的抑制顺序为 HA > NO 2 - > SO 4 2- > HCO 3 - ≈ Cl - > NO 3 -. 此外,通过 UPLC-MS/MS 探索了 DCF 的七 (07) 种降解产物 (DP),并相应地提出了 DCF 的降解途径。通过计算总有机碳去除和毒性评估,进一步加强了所提出的 AOP 在去除 DCF 方面的实际应用。