The effect of nickel loading ratio in Fe/Ni bimetallic on H2O2 production and metronidazol removal in the heterogeneous fenton process

The advanced treatment requirements of iron ions and sludge encountered in the homogeneous Fenton process, the formation of sludge containing very high amounts of iron, and the lack of reusability of the catalyst make the heterogeneous Fenton process attractive. In this thesis, nano Fe/Ni bimetallic synthesis was carried out at three different nickel loading rates, 1%, 3.5% and 10%, in order to investigate the potential of using nano-sized zero-valent iron-based bimetallic in the heterogeneous Fenton process. The effects of different Ni loading rates within bimetallic on hydrogen peroxide and radical formation and Metronidazole antibiotic removal in the Fenton process were investigated. Surface characterization analysis of the synthesized bimetallic particles were carried out. In the heterogeneous Fenton process, Fe(II), Fe(III), total Fe, H2O2, dissolved oxygen, metronidazole, total organic carbon and the degradation products of metronidazole were analyzed. According to the results obtained from the study, although increasing the Ni loading ratio caused an increase in the amount of H2O2 formed in situ and high Metronidazole removal efficiencies, it resulted in lower total organic carbon removal efficiency and the formation of less Metronidazole intermediates. At the end of the 120-minute reaction, the highest Metronidazole and TOC removal were determined as 99% and 45%, respectively, with 0.5 g/L 1% Ni loaded bimetallic at pH:3 conditions. It was concluded that the loss of catalyst was not much due to the low iron solubility from the experimental series performed at three different nickel loadings, and thus it was appropriate to use the nFe/Ni bimetallic in the heterogeneous Fenton process.