This paper presents the results of research on the possibility of photodecolourization of trace amounts of copper complexes of chlorophyllins (E141(ii) commercial dye) in water (sewage). Experiments were carried out in model UV-VIS/E141 (ii)/TiO 2 /H 2 O and UV-VIS/E141(ii)/H 2 O systems. The degree of decolourization of the dye was determined spectrophotometrically. The loss of dye in a UV-VIS/E141(ii)/TiO 2 /H 2 O system was directly proportional to the initial substance concentration and ranged from 55% to 82%, depending on the initial concentration of the dye in the solution. Kinetic studies confirmed that over a range of examined concentrations of dye E141(ii), the photocatalytic decolourization process occurs in accordance with the commonly acknowledged Langmuir-Hinshelwood model. The course of changes in pH upon exposure indicates the formation of acidic derivatives of chlorophyllins. We found that the amount of photodegradable dye strongly depends on the initial pH of the solution. The increase of the pH of the solution inhibited the process of photocatalytic decolourization of E141(ii), whose yield reached a minimum value at pH 8. Results of this study confirm that the photocatalytic processes can be an alternative to traditional methods of food industry sewage treatment.

Th e research results on the possibility of anthocyanins' traces degradationobtained from Vitis vinifera L. grapes peel (commercial colouring agent E163 WS) contained in water (sewage) are presented in this paper. Experiments were conducted in the model photocatalytic systems: UV/E163/H 2 O/TiO 2 and UV/E163/H 2 O. Th e level of the colour degradation was estimated on spectrophotometric measurements. Th e amount of mineralized colour in UV/E163/H 2 O/TiO 2 system was inversely proportional to the initial concentrations in the examined solution. Th e E163 colourant loss expressed as absorbance decrease of tested solutions, which was a result of photocatalytic degradation ranged from 40% to 88%, depending on the initial concentration of colourant in the solution. On the basis of the conducted kinetics analysis it was found that in the range of the studied concentration of E163 WS colourant the photocatalytic process reveals substantial deviations from the generally accepted Langmuir-Hinshelwood model. Th is is among others due to the so-called a homogeneous photodegradation of substrate (in UV/E163/H 2 O system) -45-68% in relation to the process occurring in the heterogeneous system, UV/E163/H 2 O/ TiO 2 . Th e examined conduction of variations in pH during illumination showed the formation of acid derivatives of anthocyanins photooxidation. Th e research results indicate that photocatalytic processes belonging to so-called advanced oxidation processes (AOP) may constitute an alternative to the traditional methods for sewage treatment of the food industry.Keywords: water quality, photocatalysis, photolysis, TiO2, anthocyanins, E163 WS.