Optimization of operating conditions for the application of Moringa oleifera (Zogale) seeds extract in water disinfection using response surface methodology

Abstract

Good quality dry seeds of Moringa oleifera were selected and the seed coat and wings were removed manually. The kernel was ground to fine powder using the coffee mill attachment of the Moulinex domestic food blender. The ground powder was then sieved through 210 µm sieve. The seed powder was de-fatted using hexane in electro-thermal Soxhlet extractor. Moringa seeds extract was obtained using the de-fatted seed cake and aqueous extraction. Different preparations of Moringa extract were added to 10 mL of the Escherichia coli suspension and incubated for 2 h without agitation. Survival of bacterial cells was assessed by making dilution series of bacterial suspensions, plating on nonselective LB medium agar dishes, and incubating for 48 h at 37°C. Duplicates were made of every individual assay. Colonies were counted on dishes and the bacterial cell survival ratio was estimated by comparison to a control experiment where no Moring extract was added. The bacterial removal was optimized by varying the mixing time, mixing speed, and Moringa seeds extract dosage. Statistical optimization was conducted by using central composite design (CCD). The experimental data was analyzed using statistical software DESIGN EXPERT, V6.4.8 DEC 10 2002 for Windows. The response surface model was used to determine the optimum operating condition that yields the highest antimicrobial compounds activities from M. oleifera seeds extracts. A cubic model was fitted to the data. The standard deviation for the cubic model was 0.56, with R 2 = 0.9999 and adjusted R 2 = 0.9994. The analysis of variance (ANOVA) showed that the effects of mixing time, mixing speed and Moringa dosage were significant (p < 0.05) in the extraction process. The Quadratic model was used in predicting the responses and the optimal conditions were determined as 31 min mixing time, 85 rpm mixing speed and 3.25 mg/mL Moringa dosage. The results show that the predicted and experimental values were not significantly different and it was thus concluded that the model obtained can be used to optimize the process of antimicrobial bioactive compound extraction from de-fatted M. oleifera seeds.

A simple and effective method for Escherichiacoli inactivation in aqueous medium using natural based superparamagnetic coagulant

“…Table 1 shows the absence of E. coli in all treated raw water samples, due to their inactivation, both in the supernatant and in the sludge, indicating the bactericidal activity of the compounds present in the extract of MO seeds, a fact already reported in other studies 22,23 . According Mangale Sapana et al, 7 MO seeds have antimicrobial properties due to recombinant proteins that are capable of flocculating gram‐positive and gram‐negative bacterial cells, causing the microorganisms to be removed by sedimentation in the same way as the removal of colloids in properly coagulated and flocculated water, as can be seen in Figures 2a,b.…”

Effects of storage of Moringa oleifera seed powder on turbidity removal from medium turbid water

“…oleifera seeds were procured from "Muda-Lawan" market, Bauchi City in northeast Nigeria. The seeds were de-husked manually with the aid of mortar and pestle; the clean kernels were then milled into fine powder with the aid of a manual grinding machine, the powder was sieved through 210 µm BS sieve as described by Bichi (2013); Alo et al (2012) and Bichi et al (2012).…”

Rainwater Harvesting Quality Assessment and Evaluation: Iium Case Study

“…The defatted powder was added into a beaker containing 1000 ml of distilled water. The solution was mixed using a stirrer at 85 rpm for different periods of mixing time set for experiment optimization [16].…”

“…The percentage of bacterial removal was set as the response of this study. The dosage of seeds in the beaker was varied from 2.75 mg/ml to 3.75 mg/ml while the mixing time was varied from 21 minutes to 41 minutes [16].…”

“…There are a few treatments that can be used to treat the rainwater harvested from the roofs, such as filtration and UV treatment [6]. Moringa oleifera seeds can be used as a disinfectant that can remove microbes in water and act as a coagulant [7]. The main objective of this study is to estimate the volume of rainwater that can be harvested from the roof of one building (E0) at the Faculty of Engineering, IIUM over the course of one year.…”