Comparative study of the coagulation efficacy of Moringa Oleifera seeds extracts to alum for domestic wastewater treatment of Ain Aouda City, Morocco

¹ Laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water and Environment (LS3MN2E-CERNE2D), Department of Chemistry, Faculty of Sciences, Mohammed V University in Rabat, Avenue IbnBattouta, B.P. 1014, Rabat 10000, Morocco.
² International Institute of Water and Sanitation, National Office of Electricity and Drinking Water (IEA-ONEE), Avenue Mohamed BelHassan El Ouazzani, B.P. Rabat-Chellah 10002 / Rabat, Morocco.
³ Central Laboratory for water quality control, National Office of Electricity and Drinking Water (ONEE), Avenue Mohamed BelHassan El Ouazzani, B.P. Rabat-Chellah 10002 / Rabat, Morocco.
⁴ Water treatment and reuse structure, Civil hydraulic and environmental engineering laboratory, Mohammadia School of Engineers, Mohammed V University in Rabat, Avenue IbnSina B.P 765, Agdal-Rabat, 10090 Morocco.

^* Corresponding author: naif.naif.2017@gmail.com

Abstract

This research aimed to investigate the performance of seeds extract of Moringa Oleifera (MO) as an eco-friendly coagulant and an alternative practice in enhancing primary domestic wastewater effluent treatment by coagulation/flocculation, and sedimentation. The seeds of Moringa Oleifera were dried, crushed, and sieved, the content of oil was extracted with n-hexane as a solvent employing soxhlet apparatus (electro thermal) then used the residue as domestic wastewater coagulant. Jar tests were conducted for improve the primary treatment of domestic wastewater effluent from the wastewater plant of Ain Aouda city, Rabat, Morocco. For this reason, perform of coagulation tests was comparative with using aluminium sulphate (alum). Moringa Oleifera seeds extract at the optimal dose of 250 mg/L shows encouraging results, by comparison with the use of alum (150 mg/L). In reality, in terms of TSS reduction 95.5% and 96.8%, while turbidity reduction 97.5% and 98.1% were obtained for MO seeds extract and alum, respectively. But, the reduction rate of COD and BOD of Alum was somewhat higher than that of MO seeds extract 81.8% and 76.8% for COD, while were 75.5% and 72% for BOD respectively. Differently from alum, observed that increase in the extract of MO seeds dosage happened a slight change in pH value, decrease conductivity, and three times less bulky quantity of sludge than alum. For avoiding the numerous disadvantages associated with the use of chemical coagulants, the usage of Moringa Oleifera seeds extracts is recommended.