Evaluation of a frugal process for water treatment: application of an advanced UV-Chlorine oxidation process in Côte d'Ivoire

Résumé

This study concerns the implementation of a frugal process for water treatment in Côte d'Ivoire. Decolorization and decontamination reactions were carried out using a combination of ultraviolet radiation and chlorine. Humic acid and phenol were used as model compounds to monitor process efficiency. These compounds were placed in the presence of a commercial bleach solution in a photo reactor. The photoreactor used was the rayonet with UV-C lamps at 254 nm. Various analyses were carried out, including UV/Vis spectrophotometry at specific wavelengths taken from the literature, 3D spectrofluorimetry (EEM emission-excitation matrices), and UV-coupled high-performance liquid. The experimental results showed an effective decomposition of humic acid and therefore a decolorization, but also consequent degradation of phenol under specific conditions. These effects are most pronounced when UV/chlorine is coupled, from t = 5 min (UV/chlorine) ≫ t = 60 min under UV ≫ t = 120 min under chlorine. Also, the production of secondary chlorination compounds due to the presence of chlorine was observed, and remains relatively very low during bleach photolysis reactions compared to other cases. The UV/chlorine combination has therefore proved highly effective as a water treatment application, and can be combined with existing treatment processes.

 Keywords: Decolorization; Decontamination; Frugal; Humic acid; Phenol; UV/Chlorine.