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The removal of reactive black 5 (RB5) dye present in aqueous solution was studied by applying individual coagulation/flocculation (CF) and microfiltration (MF) processes as well as the combination of both processes (CF‐MF). In the CF process, three natural coagulants produced from Moringa oleifera Lam. seeds (MOS) were used: saline extract (ES) and the purified protein fractions of albumin (ALB) and globulin (GLO). In the MF process, a commercial polyethersulfone (PES) membrane was used. It was noticed that without the combination of both processes, the obtained RB5 removal was only 20.38% for ALB, 52.38% for GLO, and 12.50% for ES. However, when the CF process was combined with a microfiltration process, it was possible to achieve a higher textile dye removal, due to the formation of aggregates in the CF process larger than the pores of the microfiltration membrane. Especially with the ALB coagulant, the combined CF‐MF process achieved a removal greater than 95%. The results demonstrate the potential use of the purified proteins fractions of Moringa oleifera Lam. coagulant in combination with microfiltration process for water treatment. [ABSTRACT FROM AUTHOR]

The present research evaluates the groundwater nitrate concentration of the Maringá region (Paraná State, Brazil) aiming at nitrate removal by coagulation/flocculation using a natural coagulant obtained from the seeds of the Moringa oleifera Lam. plant (MO) combined with an activated carbon filter. Groundwater samples were collected in Maringá City metropolitan area and characterized by physicochemical analyses. The results showed groundwater NO3− concentrations ranging from 0-60 mg NO3− L−1. Thus, the nitrate variation in the water used in the coagulation/flocculation assays lay between 10-60 mg · L−1 of NO3−. In these assays both aqueous and saline MO raw extracts were added (concentrations between 0.25-11 g · L−1). Coagulation/flocculation treatment with aqueous MO extract presents nitrate removal of 73.3 %, and saline MO extract presents 85.4 %. The source that presented the highest nitrate concentration along with the ideal MO concentration in the coagulation/flocculation process was used for the coagulation/flocculation process followed by activated carbon filtration. The treatment with MO combined with the filter met Brazilian, American, and international potability standards for nitrate and turbidity. The present study reveals the presence of nitrate in the groundwater of the area and also enables new procedures for treating this kind of water in small rural properties and needy communities. [ABSTRACT FROM AUTHOR]