Degradation Study of Artificial Food Dyes by Singlet Oxygen (1O2) using a Spectral Simulator with an RGB LED Lamp

Dyes are highly resistant to degradative processes. When discharged into urban effluents, they absorb part of the visible electromagnetic spectrum of sunlight, causing damage to aquatic biodiversity and the environment in general. In the literature, some traditional methods of treating industrial effluents are found, based on precipitation, coagulation and adsorption techniques. Another degrading route is photochemical techniques. The present study intends to verify the viability of photochemical degradation by singlet oxygen (O-1(2)) for artificial food dyes allowed in Brazil by the National Health Surveillance Agency (ANVISA). Nine artificial colors were studied: twilight yellow, amaranth, azorubin, patent blue v, erythrosine, ponceau 4r, tartrazine, fast green and red 40. In addition to building a low-cost solar spectral simulator with RGB LED that enables studies within the laboratory. The results demonstrated the efficiency of the simulator and the considerable degradation for most of the studied dyes, mainly red 40 (34%), twilight yellow (21.1%) and ponceau 4r (19.9%).

Automated summary

Dyes discharged into urban effluents can cause damage to aquatic biodiversity and the environment. Traditional methods of treating industrial effluents include precipitation, coagulation, and adsorption techniques, while photochemical techniques offer another degrading route. This study explores the feasibility of photochemical degradation by singlet oxygen for artificial food dyes allowed in Brazil and demonstrates the efficiency of the degradation process for most of the studied dyes.