Efluente de laticínios mineiros: avaliação de suas características, tratamento e do seu potencial biotecnológico

Abstract

The dairy industry has great economic importance for the state of Minas Gerais, the largest Brazilian producer of milk and its derivatives. Due to its activities, this sector generates high amounts of effluent. Environmental regulatory agencies do not allow such effluent to be disposed without prior and effective treatment. This study aimed to evaluate the characteristics of effluents from dairy products, both raw and treated, and to indicate the main treatments adopted by industries in this sector in the state of Minas Gerais. A high concentration of organic matter was found for raw effluents, up to 61,000 mg.L-1

for COD and 20,000 mg.L-1

for BOD5. High concentrations of oils and fats, in addition to nitrogen and phosphorus, were also reported. More than 60% of the raw effluent samples showed a BOD5/COD ratio above 0.4, demonstrating high biodegradability. In general, the treated effluents were in accordance with the disposal standards, showing removals above 70% and 75% for COD and BOD5, respectively. It was verified that all reported industries apply of biological treatments, mostly anaerobic and/or aerated lagoons. Regarding the treatments evaluated in bench scale, membrane bioreactor and ozone flotation were the most effective, removing more than 80% of BOD5. Research has been reported using

biotechnologically treated dairy effluents from Minas Gerais seeking to obtain value- added products, mainly microalgae, to obtain food and potential for biodiesel

production.