Considering the diversity and the unexplored potential of regional aquatic flora, this study aimed to identify and analyze the potential of native aquatic macrophytes to reduce the organic matter of dairy wastewater (DW) using experimental constructed wetlands. The dairy wastewater (DW) had an average chemical oxygen demand (COD) of 7414.63 mg/L and then was diluted to 3133.16 mg/L (D1) and to 2506.53 mg/L (D2). Total solids, COD, temperature, and pH analyses were performed, and the biochemical oxygen demand (BOD) was estimated from the COD values. The best performance in the reduction of the organic matter was observed for Polygonum sp. (87.5% COD and 79.6% BOD) and Eichhornia paniculata (90% COD and 83.7% BOD) at dilution D1, on the 8th day of the experiment. However, the highest total solids removal was observed for Polygonum sp. (32.2%), on the 4th day, at dilution D2. The total solid (TS) concentration has also increased starting from the 8th day of the experiment was observed which may have been due to the development of mosquito larvae and their mechanical removal by sieving, thus changing the steady state of the experimental systems. The macrophytes Polygonum sp. and E. paniculata were considered suitable for the reduction of organic matter of DW using constructed wetlands.

Resumo. O soro de leite é o subproduto dos laticí-nios e pode ser visto como coproduto, devido ao seu grande valor agregado em matéria orgânica, que, se não tratada adequadamente, pode causar severos impactos ambientais. O objetivo deste trabalho foi avaliar a produção de etanol, a partir da fermentação do soro de leite, em laticínios de pequeno porte. A levedura Saccharomyces cerevisiae foi utilizada para promover a fermentação alcoólica do soro. Foram realizadas as análises físico-químicas do soro in natura e após a retirada da proteína (desproteinação do soro) pelo método de acidez térmica. As análises realizadas foram: acidez em ácido láctico, cinzas, lactose, proteínas, gordura e extrato seco total. Os resultados preliminares caracterizaram o soro obtido como do tipo ácido, apresentando acidez de 0,12% em ácido láctico, além disso, foi constatado relevante conteúdo orgânico, com 5,66% de extrato seco total, 4,1% de lactose e 1,2% de proteínas. A fermentação foi conduzida em biorreatores laboratoriais, em triplicata por 24h, considerando as entradas de substrato, concentração de sacarose e concentração de inóculo. As variáveis monitoradas foram a produção de etanol, a temperatura e o pH do meio. O experimento foi conduzido com a adição de100 g.L -1 de sacarose e 6,0 g.L Abstract. Whey is a dairy by-product and can be view as a co-product due to its high valuable organic content, which can cause environmental harassment if it is not treated adequately. The aim of this study was to evaluate the ethanol production by fermentation of cheese whey in small companies. The yeasts Saccharomyces cerevisiae were used to provide the alcoholic fermentation. The analyses of acidic on acid lactic, ashes, lactose, protein, fat and total dry extract were determined. The preliminary results characterized whey as an acid type showing 0.12% on acid lactic, moreover, relevant organic content was observed with 5.66% of total dry extract, 4.1% lactose content and 1.2% of protein.The fermentation was performed in laboratorial bioreactors on triplicate for 24h and the parameters monitored were the ethanol production, temperature and pH in the media considering substrate, sucrose and inoculums incoming. The experiment was conducted with the addition of 100g.L -1 of sucrose and 6.0g.L -1 of inoculums. The medium ethanol production found was 5.3% (v/v)± 0.1, with pH showing stability during the process with low variations. The utilization of Saccharomyces cerevisiae for alcoholic fermentation has shown a satisfactory ethanol produc-