Effectiveness of Moringa oleifera seed as a coagulant in domestic wastewater treatment

Abstract

An investigation on the effectiveness of Moringa oleifera seed for the treatment of domestic sewage was carried out in 15 litres plastic pots. Completely randomized design (CRD) experimental design was adopted. The treatments included: the control culture (no Moringa seed), 2 g of Moringa oleifera, 4 g of Moringa oleifera and 6 g Moringa oleifera. Physical, bacteriological and chemical properties of domestic sewage were investigated before and after treatment. The turbidity value was reduced drastically for the treatments. Water hardness was reduced from 64.2 mg/l to 36 mg/l for the treatments. Alkalinity was reduced from 148 mg/l to 114 mg/l for the treatments, total solids were reduced from 1280 mg/l to 1129 mg/l for the treatments, suspended solids were reduced from 384 mg/l to 306.3 mg/l for the treatments, dissolved oxygen was reduced from 124.8 mg/l to 112.7 mg/l for the treatments, dissolved solids were reduced from 896 mg/l to 820.3 mg/l for the treatments, and acidity was increased from 0.84 to 2.02 for the treatments. The pH value was reduced from 9.6 to 7.5 for the treatments. BOD was reduced from 96.5 mg/l to 80.2 mg/l for the treatments and COD was reduced from 81.6 mg/l to 72 mg/l for the treatments. Generally, the results showed that the higher the quantity of Moringa oleifera seed applied to sewage, the better the purification of the sewage.