Comparison of the salt extract from Moringa oleifera seed in relation to Opuntia cochenillifera, tannin, FeCl3, Al2(SO4)3 and FeSO4 as coagulants in coffee effluent treatment
Coffee is one of the most important export products and most consumed beverages in Brazil. Coffee beans can be processed by three ways: wet, semi-moist and dry. The execution of these processes generates wastewater from the washing and the skimming process of the grains. The amount of wastewater and the organic load generated varies according to the processing method employed, and the wet process is the largest effluent generator. The effluent of the coffee industry has characteristic high organic load, color, conductivity, and low turbidity value (near zero), which makes the treatment very difficult. The present paper focuses on the comparison of the performance of Moringa oleifera (MO) seed extract to other coagulants in the treatment of the effluent generated by the coffee bean process. The treatment is carried out by the processes of coagulation, flocculation and sedimentation. In order to make the comparison with MO seed extract, three different inorganic coagulants ferric chloride (FeCl3), aluminum sulfate (Al2(SO4)3), ferrous sulfate (FeSO4) and two organics, (Opuntia cochenillifera, and tannin) at dosages of 30 and 300 mL L‑1 were used. The sampling was done at 10, 20 and 30-min intervals and the parameters apparent color, turbidity, conductivities, total dissolved solids (SDT) and pH were measured. According to the results, none of the coagulants used showed good performance at low concentration, including the MO coagulant. Using the dosage of 300 mL L‑1 of coagulant, MO was efficient in the removal of color and turbidity; however this caused negative changes in the conductivity and the total dissolved solids. In general, the results indicated that, under the conditions applied in the treatment of the coffee industry effluent, the organic coagulant MO presented poor performance compared to the other coagulants. Hence, more studies with coagulant extracted from Moringa oleífera seed are needed to be done to apply in the treatment of coffee effluent.
de Araujo, Á.A., Parra, J.H., Theodoro, J.D.P., Mendonça, J.L. and Bergamasco, R. (2021). Comparison of the salt extract from Moringa oleifera seed in relation to Opuntia cochenillifera, tannin, FeCl3, Al2(SO4)3 and FeSO4 as coagulants in coffee effluent treatment. Acta Hortic. 1306, 277-284
organic coagulant, inorganic coagulant, coagulation process