Method of Correlation Coefficient Optimization Used in UV-vis Spectrophotometric Analysis for Effluent in Catalytic Ozonation

A wavelength selection method for spectrophotometric analysis, named correlation coefficient optimization (CCO), was employed for reagent-free analysis of organics (humic acid) in real sewage. The modeling set of CCO uses the effluent in the ozonation process of humic acid (HA) solution. In order to verify the relationship between HA concentration and absorbance at the selected wavelength, HA solutions with different mass concentrations were prepared as a validation set. The study showed that the absorbance at 300 nm could be a good quantitative indication of HA concentration. In addition, the absorbance at 300 nm was applied to analyze the HA concentration in the ozonation process. The decomposition of HA fits the pseudo-first-order kinetic model and has a linear relationship with pH and (T – 20)² (T is reaction temperature).