Tratamento de água para reúso no beneficiamento de soro de leite

Abstract

The environmental perspectives regarding the consumption of water resources have been pushing for reuse of water. In food industries where water use is a key factor in the process steps, recovery and reuse becomes a challenge, as water must have potability standards so that it can come in contact with food and / or equipment . In the whey protein and lactose recovery process, the diafiltration steps are responsible for the high water consumption, since the water used should be in sufficient quantity for the purification of the concentrate product. Diafiltration is a process that, when not properly planned, makes recovery of whey compounds somewhat costly from a sustainability standpoint. This work evaluated the treatment and the quality of the residual waters of the diafiltration of the protein and lactose in the process of beneficiation of whey. The proposed procedure for the treatment of wastewater consists of using a reverse osmosis membrane followed by adsorption with activated carbon. After the proposed treatment, the residual waters of the diafiltration of the protein and the residual waters of the lactose diafiltration presented 100% removal for color and turbidity, 99.53 and 99.90% of COD and 99.72 and 99.63% of COT. The results of the microbiological analysis for the diafiltration residual waters of the protein and the lactose diafiltration residual waters showed absence of fecal coliforms and Escherichia coli in 100 ml of sample. The reverse osmosis presented a strong potential for the recovery of wastewater diafiltration process of whey processing. Activated charcoal as a complementary step was fundamental for the removal of organic micropollutants responsible for the characteristic odor of diafiltration waters. The recovered wastewater reached the potability standards set forth in Ministry of Health Consolidation Ordinance No. 5 and European Directive 95/83 EC. Thus, the use of recovered water in this study can be directed to any purpose, contributing to the reduction of consumption of drinking water.