-This paper evaluates the pore blocking mechanism of two ultrafiltration membranes with different geometries (tubular and spiral wound) when dairy wash water is filtered. The work evaluated the effect of transmembrane pressure and the cross-flow velocity with a 3 2 experimental design using classical Hermia's models and the resistance-in-series model. The resistance-in-series analysis identified external fouling on the surface of both membranes, but the tubular membrane showed higher reversible fouling, while the reversible and irreversible resistances of the spiral wound membrane averaged 41% and 45%, respectively. Cake formation is the model that best represents ultrafiltration in the spiral wound membrane at all transmembrane pressures and cross-flow velocities. In the tubular membrane, at the lowest cross-flow velocity (0.79 m.s -1 ), the cake formation model fitted the experimental data best. However, at higher cross-flow velocities (1.42 and 2.23 m.s -1 ), the best fit of flux data was obtained with the complete pore blocking model. In addition, the tubular membrane apparently had a two-step pore blocking: "pore blocking" as the initial governing mechanism followed by "cake formation".

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Work aimed to identify the effluent is generating areas in a dairy company for purpose of changing concept pollution prevention. methodology consisted measuring volumes and collecting samples effluents production sectors. analysis was conducted by sector, order those which generated excessive amounts effluents. results show that dry products (powdered milk powdered whey) are greatest generators BOD, nitrogen phosphorus, while fluid form (UHT milk, formulated UHT, pasteurized cream) butter produced large quantities oils grease. solids recovery, waste segregation water reuse can be applied with saving potential as much R$ 28,000 ($ 11,200) per month only raw materials also environmental gains in pollution prevention

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RESUMOMuitos indivíduos deixam de consumir leite pelo fato de haver alguma restrição, normalmente, por dois motivos: intolerância à proteína ou intolerância à lactose. Esta última atinge quase a metade da população mundial. O objetivo deste trabalho foi avaliar um processo híbrido combinando ultrafiltração (UF), nanofiltração (NF) e hidrólise enzimática para a obtenção de leite pasteurizado com reduzido teor de lactose. Leite desnatado foi ultrafiltrado em unidade piloto de filtração por membranas, separando duas correntes: permeado e retido. A corrente do permeado da ultrafiltração foi coletada e armazenada sob refrigeração para posterior utilização no processo de nanofiltração. A corrente do permeado da NF foi, então, reincorporada na do retido da UF, na qual estavam presentes proteínas, gordura, sais minerais e vitaminas do leite. No produto resultante, foi realizada a hidrólise enzimática com o uso da enzima betagalactosidade. O produto final foi pasteurizado a 75 ºC por 15 s. Análises físico-químicas e microbiológicas foram realizadas para caracterização do produto, tendo tais parâmetros sido definidos com base na legislação e em outros estudos científicos. O produto final apresentou-se dentro dos parâmetros exigidos pela legislação, tendo a redução de lactose chegado a 93% em relação ao teor inicial, representando uma boa alternativa para as indústrias de laticínios, agregando valor ao produto e dispondo um alimento alternativo para os consumidores com intolerância à lactose. Palavras-chave: Separação por membranas. Lactose. Hidrólise enzimática. ABSTRACTMany individuals fail to consume milk because there is some restriction, usually for two reasons: protein intolerance or lactose intolerance. The latter reaches almost half the world's population. The aim of this study was to evaluate a hybrid process combining ultrafiltration (UF), nanofiltration (NF) and enzymatic hydrolysis to obtain pasteurized milk with reduced lactose content. Skim milk was ultrafiltered in a pilot unit membrane filtration, separating two streams: penetration and retention. The current ultrafiltration permeate was collected and stored under refrigeration for later use in nanofiltration process. The NF permeate stream was then remixed with the UF retentate, which were present in the protein, fat, minerals and vitamins of milk. In the resulting product, enzymatic hydrolysis was carried out with the use of the enzyme betagalactosidade. The final product was pasteurized at 75 °C for 15 sec. Physical-chemical and microbiological analyzes were performed for characterization of the product, and such parameters have been defined based on legislation and other scientific studies. The final product was within the parameters required by the legislation, and the reduction of lactose reached 93% compared to the initial rate, representing a good alternative to dairy industries, adding value to the product and providing a food alternative for consumers with lactose intolerance.