Calcium ferrate-ozone for enhanced removal of methylene blue: An innovative hybrid system

Textile and paper industries produce hazardous dyes, especially methylene blue (MB), which harms the environment. Industrial coloured dyes are difficult to degrade with conventional wastewater treatment processes. Alternative wastewater treatment technologies that breakdown these coloured dyes are needed. This study examined how calcium ferrate (CaFeO₄), ozone (O₃), and their hybrid system degrade methylene blue (MB). Batch tests examined MB degradation under different pH and reaction time conditions at a given temperature and oxidant concentration. The degrading efficiency and performance of CaFeO₄ were measured by measuring MB absorbance at 665 nm using UV–Vis spectroscopy. After 2 and 60 min at pH 2, the average removal efficiencies were 98.52% and 99.91%. Under the same reaction conditions, degradation efficiency was very poor above pH 4. O₃ treatment was highly effective at pH 2 and 12, with 99.03% and 99.99% elimination efficiency, respectively. Calcium ferrate and ozone synergistically degraded 99.7% in 30 s, promising fast and effective wastewater treatment. Thus, the hybrid system outperformed single treatments in removal percentage and reaction time, giving it an alternate remediation method.