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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.

•Degradation of atrazine was investigated in UV, UV/H2O2, UV/HSO5− and UV/S2O82− AOPs.•UV/S2O82− process was found to be more efficient as well as more economical.•The pH affected UV/S2O82− but had no significant influence on UV, UV/H2O2 and UV/HSO5−.•Second order rate constants of atrazine with SO4− and OH were found to be comparable.•Degradation mechanism was investigated by GC–MS and LC–MS/MS analysis. Degradation of atrazine was investigated under UV-254nm irradiation, alone or in combination with peroxides, i.e., hydrogen peroxide, persulfate (PS) or peroxymonosulfate (PMS). UV/PS was found to be the most efficient process in this study, which was probably due to its higher radical quantum yield under UV irradiation, considering atrazine’s comparable second order rate constant of 2.59×109M−1s−1 and 2.25×109M−1s−1 with sulfate radical and hydroxyl radical, respectively. The pH values showed no significant effect on direct photolysis of atrazine, with observed UV fluence based pseudo-first-order rate constant (kobs) of 7.59×10−4, 7.73×10−4 and 6.72×10−4cm2mJ−1 at pH 3.0, 5.7 and 11.0, respectively. Performance of UV/H2O2 and UV/PMS were more independent of initial pH values while that of UV/PS appeared to be more efficient at neutral pH condition. UV/PS was observed as a less energy consumption process. Eight new degradation by-products were identified in this study, namely, 2-chloro-4-acetamido-6-(2-hydroxy-isopropylamino)-s-triazine (CDHT), 2-hydroxy-4-(2-hydroxy-ethylamino)-6-isopropylamino-s-triazine (ONIT), 2-chloro-4-vinylamino-6-isopropylamino-s-triazine (CVIT), 2-hydroxy-4-vinylamino-6-(2-hydroxy-isopropylamino)-s-triazine (OVHT), 2-hydroxy-4-acetamido-6-isopropenylamino-s-triazine (ODPT), 2-hydroxy-4-(2-hydroxy-ethylamino)-6-vinylamino-s-triazine (ONVT), 2-hydroxy-4-(2-hydroxy-ethylamino)-6-methylamino-s-triazine (ONMT) and 2-chloro-4-vinylamino-6-amino-s-triazine (CVAT). Potential degradation pathways were further proposed. 252 393 403