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In this research work, surface-modified nano zerovalent copper (nZVC) was prepared using a simple borohydride reduction method. The spectroscopic and crystallographic results revealed the successful synthesis of surface-modified nano zerovalent copper (nZVC) using solvents such as ethanol (ETOH), ethylene glycol (EG) and tween80 (T80). The as-synthesized material was fully characterized for morphological surface and crystal structural properties. The results indicated that EG provides an excellent synthesis environment to nZVC compared to ETOH and T80 in terms of good dispersion, high surface area and excellent catalytic properties. The catalytic efficiency of nZVC/EG was investigated alone and with peroxymonosulphate (PMS) in the absence of light. The degradation results demonstrated that the involvement of PMS synergistically boosted the catalytic efficiency of synthesized nZVC/EG material. Furthermore, the degradation products (DPs) of CBZ were determined by GC−MS and subsequently, the degradation pathways were proposed. The ecotoxicity analysis of the DPs was also explored. The proposed (nZVC/EG/PMS) system is economical and efficient and thus could be applied for the degradation of CBZ from an aquatic system after altering the degradation pathways in such a way that results in harmless products. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Gamma-radiation-induced degradation of ciprofloxacin (CIP) in aqueous solution and the factors affecting the degradation process have been investigated. The results showed that CIP (4.6 mg/L) was almost completely degraded at an absorbed dose of 870 Gy. The kinetic studies of aqueous solutions containing 4.6, 10, 15 and 17.9 mg/L indicated that the decomposition of CIP by gamma irradiation followed pseudo-first-order kinetics and the decay constant (k) decreased from 5.9  ×  10−3to 1.6  ×  10−3 Gy−1with an increase in CIP initial concentration from 4.6 to 17.9 mg/L. The effect of saturation of CIP solution with N2, N2O or air on radiation-induced degradation of CIP was also investigated. The effects of radical scavengers, such ast-BuOH andi-PrOH, showed the role of reactive radicals towards degradation of CIP in the order of. The apparent second-order rate constant ofwith CIP was calculated to be 2.64 × 109 M−1 s−1. The effects of solution pH as well as natural water contaminants, such as,,and, on CIP degradation by gamma-irradiation were also investigated. Major degradation products, including organic acids, were identified using UPLC-MS/MS and IC, and degradation pathways have been proposed. [ABSTRACT FROM AUTHOR]

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/S 2 O 8 2- /Fe 2+ , UV/HSO 5 - /Fe 2+ and UV/H 2 O 2 /Fe 2+ processes. The results demonstrated that by applying [DCF] 0  = 0.30 mM and [H 2 O 2 ] 0  = [S 2 O 8 2- ] 0  = [HSO 5 - ] 0  = 3 mM, k app values were 0.082, 0.166, 0.221, 0.485 and 2.014 min -1 for UV-only, UV/Fe 2+ , UV/H 2 O 2 /Fe 2+ , UV/S 2 O 8 2- /Fe 2+ and UV/HSO 5 - /Fe 2+ 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 k app 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 (NO 3 - , Cl - , HCO 3 - , SO 4 2- and humic acid (HA)) and [pH] 0 . The inhibition of these natural water contaminants on the removal of DCF by UV/HSO 5 -/Fe 2+ process was in the order of HA > NO 2 - > SO 4 2- > HCO 3 - ≈ Cl - > NO 3 - . 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.