Combined use of O3/H2O2 and O3/Mn2+ in flotation of dairy wastewater

Abstract

This work investigated the degradation of organic matter present in synthetic dairy wastewater by the combination of ozonation (ozone (O3)/hydrogen peroxide (H2O2)) and catalytic ozonation (ozone (O3)/manganese (Mn 2+ )) associated with dispersed air flotation process. The effect of independent factors such as O3 concentration, pH and H2O2 and Mn 2+ concentration was evaluated. For the flotation/O3/H2O2 treatment, the significant variables (p ≤ 0.05) were: O3 concentration (linear and quadratic effect), H2O2 concentration linear and quadratic effect, pH values (linear and quadratic effect) and interaction O3 concentration versus pH. For catalytic ozonation, it was observed that the significant variable was the linear effect of O3 concentration. According to the desirability function, it was concluded that the optimal condition for the treatment of flotation/O3/H2O2 can be obtained in acidic solution using O3 concentrations greater than 42.9 mg L -1 combined with higher concentrations of H2O2 to 1071.5 mg L -1 . On other hand, at pH values higher than 9.0, the addition of O3 may be neglected when using higher concentrations than 1071.5 mg L -1 of H2O2. For flotation/ozonation catalyzed by Mn 2+ , it was observed that metal addition did not affect treatment, resulting in an optimum condition: 53.8 mg L -1 of O3 and pH 3.6.Keywords: advanced oxidation processes, catalytic ozonation, physico-chemical treatment. Palavras-chave: ozonização catalítica, processos oxidativos avançados, tratamento físico-químico.

Degradation kinetics of organic matter in dairy industry wastewater by flotation/ozonation processes

“…In the case of the dairy industry, there has been an intensified use of flotation in recent years, either by dispersed or dissolved air (CARVALHO et al, 2018). Flotation is a process of wide application in the treatment of oily wastewater, as an alternative preliminary treatment in the dairy industry for the removal of fat from industrial wastewater, which can harm the functioning of the treatment system (METCALF; EDDY, 2015).…”

Tratamento biológico com lodo granular aeróbio de efluente de laticínio

“…Tabela O efluente sintético, apresentou altas concentrações de matéria orgânica 2647±300, 23 de DQO (mg L-1 ) e 1536 ± 30, 30 DBO (mg L-1 ), característica compatível com a pesquisa de outros autores que utilizaram o mesmo tipo de efluente (MUNIZ; BORGES; SILVA, 2020;HAMDANI et al, 2020;CARVALHO et al, 2018;NADAL, 2018). Também foram encontrados valores semelhantes as pesquisas de autores que analisaram efluente real de laticínio (MESSIAS, 2015;DANIEL, 2008).…”