Tratamento de efluentes da indústria de processamento de carnes utilizando flotação por ar dissolvido e processos de oxidação avançada

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The use of wastewater treatment processes with high efficiency of organic matter removal is considered one of the most important steps to achieve lower pollution loads in meat processing industries. As a primary treatment, dissolved air flotation processes (DAF) using coagulation-flocculation are generally applied. Additionally, the utilization of high efficiency procedures as advanced oxidation processes (AOP) has become an alternative for high elimination rate of degradation of the organic contaminants present in these wastewaters. Nevertheless, analytical practices as physicochemical and chromatographic methods, as well as biodegradability and toxicity analysis, might play an important role to guarantee pollution limits under control, allowing the discharge of these liquids according to the restricted environmental regulations. This work approaches the physicochemical treatment of the meat industry wastewater by dissolved air flotation and advanced oxidation processes, to promote the elimination of organic contaminants in the wastewater, including residues of veterinary drugs, phthalates, and polyacrylamide polymers (PAM) used as coagulation aids for flotation purposes. The results showed that the treatment with DAF and AOPs presented high elimination rates of organic matter, and significant reduction of toxicity and coliform bacteria. Among the AOPs applied to the wastewater, the photo-Fenton process present the best elimination results, confirmed by the chromatographic methods. Besides, the chromatographic analysis detected the presence of phthalates and phenolic compounds on the effluent by GC-MS, and antibiotics and nitrosamine by LC-MS. On the other hand, the characterization of the sludge generated in the wastewater treatment verified that theses solid wastes might be disposed onto land for agricultural purposes without significant damage to the environment. For the degradation of PAMs, the processes photo-Fenton and H2O2/UV achieved better elimination efficiencies compared to Fenton reaction and potassium ferrate oxidation. From these results, considering the oxidation conditions investigated, a new mechanism for PAM degradation was proposed, including the simultaneous reactions that degrade the molecules, such as photolysis, hydrolysis and chemical oxidation by the ?OH radicals.

ASSUNTO(S)

engenharia quimica aguas residuais - purificação - oxidação lodo - avaliação residuos industriais carne - industria - aspectos ambientais

ACESSO AO ARTIGO

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