Moringa oleifera Lam as a Biocoagulant in the Treatment of Water from the Amazon River in the Amazon Region, Brazil

Biocoagulants derived from Moringa oleifera Lam seeds are a sustainable alternative for water clarification, but require preparation adapted to the treatment of the dark waters of the Amazon River. This study compared the effectiveness of three coagulant preparation methods from moringa seeds: powder (B1), saline solution (B2), and aqueous solution (B3) in the clarification of samples collected on the shore of Macapá (Amapá—AP), Brazil. The tests were performed using a jar test (fast mixing of 100 rpm for 3 min and slow mixing of 20 rpm for 15 min), with dosages of 20 to 200 mg·L−1, and sedimentation times between 10 and 60 min. The optimized conditions were: 80 mg·L−1/20 min (B1), 40 mg·L−1/30 min (B2), and 40 mg·L−1/40 min (B3). The maximum removals achieved by clarification were as follows: apparent color (92.6%), turbidity (79.4%), chloride (70.9%), ammonia (81.2%), aluminum (99.1%), copper (85.4%), iron (85.8%), and manganese (100.0%). The saline solution was the most efficient. Filtration brought additional improvements to the treated water. It was found that the moringa coagulant was effective in removing contaminants from the waters of the Amazon River, standing out as a green, sustainable, and low-cost technology. However, disinfection would be necessary to improve its microbiological quality.