Lamda 365

The absorption spectra for each run of the CCRD were obtained and recorded after 9 h of treatment using a Lamda 365 PerkinElmer UV–visible spectrophotometer, UV–visible spectra of the synthetic solution of CQ at 150 mg L⁻¹ in 0.1 M Na₂SO₄ were initially recorded. The absorption spectra of the same solution were then recorded at different times when the FBER operate under optimal operating conditions. Also, all UV–visible spectra of samples were acquired between 200 and 400 nm, identifying 220 nm as the wavelength of maximum absorption of CQ. COD was determined according to standard methods for the analysis of wastewater [42 ], and the total organic carbon (TOC) was measured by a 6001 TOC analyzer Shimadzu for the optimal operating point of the electrochemical degradation of CQ. The pH of all synthetic wastewater solutions of CQ was measured by using a HI2210 Hanna potentiometer.