Aplicação de processo oxidativo Fenton-Fotocatalisado seguido de adsorção no tratamento de efluente de laticínio.

Abstract

The effluent from the processing of milk and its derivatives is considered a waste with high polluting power due to the complexity of its composition. Without proper treatment, this effluent can cause major problems for the environment. This work aimed to evaluate the efficiency of an advanced oxidative process (POA), Photo-Fenton type, coupled to an adsorption process, in activated carbon bed (CA), to reduce the organic load of the effluent. The effluent was characterized according to the parameters: conductivity, pH, chemical oxygen demand (COD), solids (total, total soluble) and oils and greases. The activated carbon used is commercial type and was characterized for mesoporosity, microporosity, zero charge pH, acidic and basic Boehm groups, x-ray diffraction, and a kinetic and equilibrium modeling was performed. Through DCCR factorial planning (23+ 6 axial points + 3 experiments at the central point) different concentrations of H2O2 and Fe2+ were determined to formulate Fenton solutions, and contact time (solution + effluent) to optimize the POA, having as a factor response to reduction of COD. It was observed that with the Fenton-Photocatalyzed treatment, it managed to remove a maximum of 79% of the COD concentration. After the photo-oxidative treatment, the samples were filtered in an activated carbon bed and, through the kinetic and equilibrium studies, it was found that the activated carbon used has the capacity to remove 1666.6 mg.O2 for each 1 g of CA, which confirmed that this activated charcoal is an excellent adsorbent to be used in the treatment following the Foto-Fenton treatment. The initial COD of the effluent was 628 mg.O2.L-1, however, when the Fenton-Photocatalyzed/Adsorption coupled treatment in activated carbon bed was applied, the efficiency for removal of organics from the treatment reached 99% reduction in the concentration of COD, indicating that the studied system causes a strong and efficient reduction in the content of organic compounds present in the dairy effluent.