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This study aimed to evaluate the effect of Moringa oleifera Lam extract on the removal of total solids (TS), total suspended solids (TSS) and chemical oxygen demand (COD), in different filter media for treating wastewater of dairy cattle breeding (DCW). The moringa seed extract was obtained by grinding 50 g of seeds in one liter of distilled water and, after passing the solution through a quantitative paper filter of 25 microns, 60 mL of the extract were added to wastewater from cattle breeding before the filtration process in organic filters made of thin coal, bamboo leaves, eucalyptus leaves, gliricidia branches and sawdust. This was followed by the completely randomized experimental design, adopting a factorial of 5 x 2. Aliquots of filtered effluent were collected and the total solids (TS) concentrations, total suspended solids (TSS) and chemical oxygen demand (COD) were determined. It was found that the increase in the efficiency of removal of COD and total solids can be attributed to the coagulating power of the moringa seed extract, wherein the filter medium with bamboo leaves presented the best performance, showing potential for use as alternative filter material in the primary treatment of DCW. Objetivou-se avaliar o efeito do extrato de Moringa oleifera Lam na remoção de sólidos totais (ST), sólidos em suspensão totais (SST) e demanda química de oxigênio (DQO), em distintos meios filtrantes, no tratamento da água residuária de bovinocultura de leite (ARB). O extrato de sementes de moringa foi obtido triturando-se 50 g de sementes em um litro de água destilada e, após passar a solução em papel de filtro quantitativo de 25 µm, foram adicionados 60 mL do extrato à água residuária de bovinocultura, antes do processo de filtração em filtros orgânicos constituídos por fino de carvão, folhas de bambu, folhas de eucalipto, ramos de gliricídia e serragem de madeira. Seguiu-se o delineamento experimental inteiramente aleatorizado, adotando um esquema fatorial de 5 x 2. Alíquotas do efluente filtrado foram coletadas, e determinaram-se as concentrações de sólidos totais (ST), sólidos em suspensão totais (SST) e demanda química de oxigênio (DQO). Verificou-se que o aumento na eficiência de remoção de sólidos totais e DQO pode ser atribuído ao poder coagulante do extrato de sementes de moringa, sendo que o meio filtrante com folhas de bambu apresentou melhor desempenho, demonstrando potencial de utilização como material filtrante alternativo no tratamento primário de ARB.

The efficiency of nopal cactus to remove color in river and artificial waters for human consumption was evaluated. The performance of nopal was compared with that of aluminum sulfate coagulant and a cationic flocculant.The river water was cha- racterized by high color, low turbidity, alkalinity and hardness, and a high percentage of dissolved oxygen. The cactus leaves showed no activity as unique coa- gulant to be evaluated only in river water. In artificial water, as a sole treatment (45 mg/l), an efficiency of 94% in color removal was observed, slightly higher than that of the conventional treatment (20 mg/l Al2 (SO4)3 and 2 mg/l of cationic flocculant) with a removal of 89%. However, water treated with nopal left a residual COD value doubled (21 mg/l) compared to con- ventional treatment. In the treatment of artificial water, nopal as a flocculant showed a color removal of 92% and a residual COD of 31.5 mg /l applied at a dose of 22.5 mg/l and 7 mg/l of Al2 (SO4)3. The nopal was not very effective to remove the color produced by humic substances in waters of low turbidity and alkalinity, but its applicability as a coagulant/flocculant in waters of high turbidity and alkalinity is promising. It is recommended to extract the active ingredients of natural products to reduce the organic load of treated water and prevent the formation of disin- fection byproducts. El estudio evaluó la eficiencia del cactus de la tuna para remover el color en agua de río y agua artificial para el consumo humano. Se comparó su desem- peño con el coagulante sulfato de aluminio y un floculante catiónico. El agua fluvial se caracterizó por presentar alto color, baja turbidez, alcalinidad y dureza y alto porcentaje de oxígeno disuelto.Las hojas de tuna no mostraron actividad como coagulante único al ser evaluadas en agua de río. Se observó una eficiencia de remoción de color del 94% en agua artificial, cuando se aplicó como tratamiento único (45 mg/l), poco superior al tra- tamiento convencional (20 mg/l Al2(SO4)3 y 2 mg/l del floculante catiónico) con una remoción del 89%.Sin embargo, el agua tratada con tuna dejó un valor de DQO residual del doble (21 mg/l) con relación al tratamiento convencional. En el tratamiento de agua artificial, la tuna como floculante mostró una remoción de color del 92% y una DQO residual de 31,5 mg/l aplicada a una dosis de 22,5 mg/l y 7 mg/l de Al2(SO4)3.La tuna fue poco efectiva para remover el color generado por sustancias húmicas en aguas de baja turbidez y alcalinidad, pero su aplicabilidad como coagulante/floculante en aguas de alta turbidez y alcalinidad es promisoria.Se recomienda extraer los principios activos de productos naturales para reducir la carga orgánica del agua tratada y evitar la formación de productos secundarios de desinfección.