A new research article on a different topic, adhering to the standard scientific structure.

Investigating the Efficacy of Moringa Oleifera Leaf Extract as a Natural Coagulant for
Turbidity Reduction in Drinking Water

Abstract

Access to safe drinking water remains a global challenge, particularly in developing regions.1
Conventional water treatment methods can be costly and energy-intensive.2 This study
explores the efficacy of Moringa oleifera leaf extract as a natural coagulant for turbidity
reduction in synthetic turbid water samples. Varying concentrations of M. oleifera extract
were tested against kaolin-based turbid water, and their performance was compared to that
of aluminum sulfate (alum), a common chemical coagulant. Turbidity was measured before
and after treatment using a turbidimeter. Results indicate that M. oleifera extract achieved
significant turbidity removal, with optimal performance observed at specific concentrations,
approaching the efficacy of alum.3 These findings suggest that M. oleifera leaf extract holds
promise as an environmentally friendly, sustainable, and potentially cost-effective alternative
or supplement to conventional coagulants for water purification.

1. Introduction

Globally, millions lack access to safe and readily available drinking water, leading to
widespread waterborne diseases (WHO, 2019).4 Turbidity, caused by suspended solids such
as clay, silt, and organic matter, is a key indicator of water quality and a primary target in water
treatment processes.5 High turbidity not only makes water aesthetically unappealing but also
provides a protective environment for microorganisms and interferes with disinfection
processes (APHA, 2017).6

Conventional water treatment often relies on chemical coagulants like aluminum sulfate (alum)
and ferric chloride to aggregate suspended particles, which then settle out.7 While effective,
these chemicals can have drawbacks, including the production of large volumes of sludge,
potential for residual chemical presence in treated water, and high procurement costs,
especially for rural communities in developing countries (Ndabigengesere et al., 1995).

The search for natural, sustainable, and affordable alternatives has led to interest in
plant-based coagulants.8 Moringa oleifera, a widely cultivated tropical tree, has garnered
significant attention for its diverse applications, including its traditional use in water
purification.9 The seeds of M. oleifera are well-documented for their coagulating properties
(Jahn, 1986).10 However, the coagulating potential of M. oleifera leaves, which are more readily
available year-round and in larger quantities, has been less extensively studied for water
treatment. This study aims to investigate the efficacy of M. oleifera leaf extract in reducing
turbidity in water, assessing its potential as a sustainable natural coagulant.

2. Materials and Methods

Fresh Moringa oleifera leaves were collected from a local farm in Accra, Ghana. The leaves
were air-dried in the shade, ground into a fine powder using a domestic blender, and stored in
an airtight container.

Preparation of M. oleifera Leaf Extract:

A stock solution of M. oleifera leaf extract was prepared by dissolving 5 grams of the dried
leaf powder in 100 mL of distilled water. This mixture was stirred vigorously for 30 minutes,
allowed to settle for 1 hour, and then filtered using Whatman filter paper No. 1 to obtain the
crude extract. Serial dilutions were made from this stock solution to achieve various test
concentrations (e.g., 50 mg/L, 100 mg/L, 200 mg/L, 300 mg/L, 400 mg/L).
Preparation of Synthetic Turbid Water:
Synthetic turbid water was prepared by adding calculated amounts of kaolin clay to distilled
water to achieve an initial turbidity of approximately 250 NTU (Nephelometric Turbidity Units).
This initial turbidity level is representative of moderately turbid surface water sources.
Jar Test Procedure:
A standard jar test apparatus was used to evaluate coagulation performance. Six beakers,
each containing 500 mL of the synthetic turbid water, were set up for each experimental run.
1.​ Beaker 1: Control (no coagulant added).
2.​ Beaker 2-5: Varying concentrations of M. oleifera leaf extract.
3.​ Beaker 6: Commercial aluminum sulfate (alum) at a typical dosage (e.g., 30 mg/L) for
comparison.

The coagulants were rapidly mixed (200 rpm) for 1 minute for rapid dispersion, followed by
slow mixing (30 rpm) for 20 minutes to promote floc formation. The mixtures were then
allowed to settle for 60 minutes. After the settling period, samples were carefully collected
from 2 cm below the water surface.

Turbidity Measurement:
Turbidity of the initial turbid water and the treated water samples was measured using a Hach
2100Q turbidimeter. All measurements were performed in triplicate, and average values were
used for analysis. Turbidity removal efficiency was calculated using the formula:

Turbidity Removal Efficiency (%)=Initial Turbidity(Initial Turbidity−Final Turbidity)​×100

3. Results

The initial turbidity of the synthetic water samples consistently measured 250 ± 5 NTU. The
control sample (no coagulant) showed negligible turbidity reduction (<5%) after the settling
period.

M. oleifera leaf extract demonstrated a significant capacity for turbidity reduction.11 Figure 1
illustrates the turbidity removal efficiency at different concentrations of M. oleifera extract.

Figure 1: Turbidity Removal Efficiency of Moringa oleifera Leaf Extract vs. Alum
(Figure 1 would typically be a bar chart showing turbidity removal percentage on the y-axis
and coagulant type/concentration on the x-axis. It would show increasing efficiency for M.
oleifera up to an optimal point, and then a slight decrease, alongside the efficiency of alum.)
Results showed an increasing trend in turbidity removal with increasing M. oleifera extract
concentration up to an optimal point. The highest turbidity removal efficiency for M. oleifera
extract was observed at a concentration of 300 mg/L, achieving an average removal of 88.5%
± 1.2%. At this optimal concentration, the final turbidity of the treated water was
approximately 28.7 NTU.

For comparison, the commercial alum at a dosage of 30 mg/L achieved a turbidity removal
efficiency of 95.2% ± 0.8%, resulting in a final turbidity of approximately 12.0 NTU. While alum
performed slightly better, the performance of the M. oleifera leaf extract at its optimal
concentration was remarkably close, indicating its significant potential. Higher concentrations
of M. oleifera extract (e.g., 400 mg/L) showed a slight decrease in efficiency, possibly due to
restabilization of particles or insufficient charge neutralization.

4. Discussion

This study provides compelling evidence that Moringa oleifera leaf extract can effectively
reduce turbidity in water, performing comparably to conventional chemical coagulants like
alum. The mechanism of coagulation by M. oleifera is primarily attributed to the presence of
water-soluble proteins that act as natural polyelectrolytes, neutralizing the negative surface
charges of the suspended particles, leading to their aggregation and subsequent
sedimentation (Ndabigengesere et al., 1995; Folkard & Sutherland, 2002).

The observed optimal concentration for turbidity removal is consistent with the general
behavior of coagulants, where an insufficient dose may not fully neutralize particle charges,
and an excessive dose can lead to charge reversal and restabilization of particles, thus
reducing efficiency. The slight drop in efficiency at higher M. oleifera concentrations suggests
that optimizing the dosage is crucial for practical application.

The advantages of using M. oleifera leaf extract are numerous. It is a natural, biodegradable
material, reducing the environmental impact associated with chemical sludge disposal. It is
also locally available and cultivable in many tropical and subtropical regions, offering a
sustainable and potentially cost-effective solution for water treatment, especially in remote or
underserved communities. Unlike alum, M. oleifera also has antimicrobial properties, which
could offer an additional benefit in water purification, although this aspect was not
specifically tested in this study (Jahn, 1986).12

Future research should focus on optimizing the extraction method to maximize the yield and
potency of the coagulating proteins, assessing its efficacy across a wider range of water
qualities (e.g., varying pH, alkalinity, and initial turbidity), evaluating the long-term stability of
the treated water, and conducting pilot-scale studies to determine its feasibility for real-world
application. Furthermore, a comprehensive cost-benefit analysis comparing M. oleifera to
conventional coagulants in a local context would be invaluable.

5. Conclusion

This research demonstrates the significant potential of Moringa oleifera leaf extract as a
natural and effective coagulant for turbidity reduction in water. At its optimal concentration, M.
oleifera leaf extract achieved high turbidity removal efficiencies comparable to that of
commercial alum. Given its natural origin, sustainability, and widespread availability, M.
oleifera leaves represent a promising and environmentally friendly alternative for
decentralized water treatment, particularly in communities where access to conventional
treatment facilities is limited.

References
●​ APHA (American Public Health Association). (2017). Standard Methods for the
Examination of Water and Wastewater. American Public Health Association.
●​ Folkard, G., & Sutherland, J. (2002). Moringa oleifera as a natural flocculant for water
purification. In Proceedings of the 2nd International Workshop on Moringa Oleifera, Dar
es Salaam, Tanzania.
●​ Jahn, S. A. A. (1986). Traditional water purification in tropical developing countries:
Existing methods and potential application. GTZ, Eschborn, Germany.13​

●​ Ndabigengesere, A., Narasiah, K. S., & Talbot, P. J. (1995). Active agents and mechanism
of coagulation of turbid waters using Moringa oleifera. Water Research, 29(2), 703-710.
●​ WHO (World Health Organization). (2019). Progress on household drinking water,
sanitation and hygiene 2000-2017: Special focus on inequalities. World Health
Organization.