Active project-based learning methodology: development of an educational pilot plant for a water treatment station using Moringa oleifera as a coagulant

Abstract

This study presented the construction of a low-cost prototype for a Water Treatment Plant, using Moringa oleifera Lam seeds as a natural coagulant in the coagulation and flocculation stages. The prototype used accessible materials, PVC piping, and recycled components. Raw water was collected from the Rio Negro (Manaus-AM), while Moringa oleifera seeds were processed into powder for application in the treatment. The system followed the stages of coagulation, flocculation, sedimentation, filtration, and disinfection. The efficiency of the prototype was evaluated through physicochemical analyses. In the raw water, the following parameters were observed: pH 6.43, color 254 UC, turbidity 217 NTU, TDS 18 mg/L, SS 502 mg/L, and TS 520 mg/L. After coagulation, the values reduced to color 130 UC, turbidity 23.5 NTU, TDS 14 mg/L, SS 246 mg/L, and TS 260 mg/L. During flocculation, small variations in the parameters occurred, and after sedimentation, the values adjusted to color 152 UC, turbidity 24.5 NTU, TDS 18 mg/L, SS 272 mg/L, and TS 290 mg/L. Filtration showed good results in impurity retention, while chlorine disinfection contributed to the improvement of the microbiological quality of the water. The results demonstrated that the prototype is effective in reducing turbidity and organic matter, highlighting the potential of Moringa oleifera as a biodegradable and low-cost coagulant. Furthermore, the project provided an enriching practical experience for students, integrating theory and practice in a collaborative manner.