The application of biodegradable chelates in the preparation of Ni–TiO2/Al2O3 photocatalysts by the Double Impregnation Method

•TiO2 in the anatase form occurs over the surface of Al2O3 as agglomerates with crystals about 2 Å.•Dopants are introduced and adsorbed over Al2O3 creating some mixed alumina–dopant oxides.•H2O2 seemed not to influence the WL photo removal and TX was the most sensitive to the presence of H2O2.•The highest k1 were obtained for EDDS–Ni, with highest Ti:Ni ratio and uniform Ni surface coverage.

Ni–TiO2/Al2O3 photocatalysts prepared by Double Impregnation Method using a new biodegradable chelates e.g. S,S-ethylenediaminedisuccinic acid (EDDS), tetrasodium salt of N-(1,2-dicarboxyethyl)-d,l-aspartic acid (available as product Baypure CX 100) and poly(aspartic acid) (available as product Baypure DS), instead of typically used EDTA, were tested in the photo removal of typed pollutants. The physicochemical properties of the studied photocatalysts were determined by BET, XRD, SEM/EDX, XPS, UV–vis/DRS and Raman spectroscopy. EDDS–Ni photocatalyst obtained the highest activity and enabled the 99% removal of phenol (Ph), Triton X-100 (TX) and wash-up liquid (WL). Although, beside EDDS–Ni, the best results of Ph and TX photo oxidation were obtained using TiO2/Al2O3, the new photocatalysts were appropriate for the decomposition of more complicated compositions of wastewater. The surface modification by Ni is connected with the affordability of TiO2 and the excess of Ni in comparison to Ti (above 1:1) may inhibit the photo oxidation of TX. The adverse effect was observed in case of Ph and WL removal. 2 h treatment has resulted in the significant decomposition of pollutants and was economically justified.