Implementation of Fenton process on wastewater from a cheese-making factory

In this work, the performance of Fenton oxidation on whey, the high strength fraction of cheese-dairy wastewater, was studied. For this reason, factorial experimental design was used to study the main variables affecting the Fenton process, as well as their interactions. A 24 factorial design was performed in order to estimate the effects of the following parameters: the ratio FeSO4·7H2O/H2O2 (X1), the hydraulic retention time (X2), the pH (X3), and the temperature (X4). The oxidation was carried out batch wise in an agitated, temperature- and pH-controlled glass reactor. At the end of the experiment, samples were taken from the effluent of the reactor and were analyzed in terms of COD, TOC, total Kjeldahl Nitrogen (TKN), total phosphorous, and fats and oils. The highest percentage of TOC efficiency measured was 33% in the experimental point (X1, X2, X3, X4) = (2/3, 1, 3.4, 20). Concentration of fats presented high reduction that reached 57%. Phosphorous removal was also high in all experiments, while nitrogen removal did not have high fluctuations. The results from the statistical processing of the experimental data enlightened the oxidation mechanism.