The Most Effective Methods to Purify Water for Safe Drinking in Third-

By Minchan Kim

Abstract

The purpose of this research study was to determine the most effective, accessible, and low-cost water purification method for underdeveloped and rural countries, especially in ones that do not have the infrastructure to support large scale water purification systems. The four purification methods that will be tested are water boiling, solar disinfection, iodine tablets, and moringa seeds.

Through this experiment, it was found that using moringa seeds is overall the best way to lower the turbidity of contaminated water, with its resulting turbidity at 66 and most stable pH at 6.0, which falls into the category of drinking water. Although the turbidity did not fully meet ideal drinking water standards, if used at a larger, but still controlled volume, it could yield better results. In addition, moringa seeds work by clumping up bacteria and pathogens and sinking to the bottom of the water, and as seen in the photo in the conclusion, the top of the water showed a noticeable clarity when compared to the control group. Therefore, it can be concluded that out of the methods that were tested in this experiment, moringa seeds are the most efficient method of purifying water.

Introduction

Water pollution is a serious issue, as millions of people around the world are affected by it every day, especially in underdeveloped or rural areas. About 1.2 billion people lack access to safe drinking water, and 2.6 billion people lack proper sanitation, which leads to many deaths each year (Shannon et al., 2008). In fact, nearly 4000 children die daily from unsafe drinking water (Shannon et al., 2008). Because of this, it’s important to study different ways to purify water and find the most efficient and safest way to make potable water. It is crucial to study water purification methods like boiling, iodine treatment, solar disinfection, and moringa seeds.

In this research study, four different water treatment methods will be tested, being boiling, iodine treatment, solar disinfection, and moringa seeds. These four methods were chosen as they are simple, inexpensive, and feasible ways to purify water, even in underdeveloped countries. These methods of purifying water could be highly beneficial to people in low-income countries and neighborhoods where access to clean water remains a daily challenge. According to global statistics, millions of people die each year from waterborne diseases, and pinpointing the best method for preventing this can save countless lives. This experiment will seek to find the water purification method that provides the best results in making water potable and easily accessible. This paper will explore four methods of purifying water specifically, water boiling, solar disinfection, iodine tablets, and moringa seeds.

Literature Review

Governments often use advanced purification systems, such as large-scale filtration plants and chemical processing systems. However, these methods are too expensive and not sustainable for everyday use in the selected countries. These systems are often inaccessible to the general public, especially in the poor or rural areas.Studying water purification methods is important to combat the detrimental effects of water pollution and the harmful effects of consuming such water. Methods such as boiling and chemical disinfection with iodine tablets are common, but other ways such as moringa seeds can also be used as a sustainable alternative.

The boiling water method, as stated by the WHO, is sufficient to deactivate pathogenic bacteria, viruses, and protozoa (WHO, 2015). In fact, just boiling for only 1 minute at above 65°C can reduce bacteria count by 90% and a quote from WHO states, “Viruses are inactivated at temperatures between 60 °C and 65 °C, but more slowly than bacteria. However, as shown for poliovirus and hepatitis A, as temperatures increase above 70 °C, a greater than 5 log inactivation (99.999% reduction) is achieved in less than 1 minute” (WHO, 2015).These quotes shows just how incredibly effective boiling water can be, even in such a short period of time. Boiling effectively reduces virus and bacteria count and when heated to a rolling boil, WHO considers the water potable and safe.

Iodine tablets, specifically Aquatabs, are a widely accepted method of chemical disinfection of water purification. As seen by the quote, “Aquatabs are small tablets that when dissolved in water, kill harmful microorganisms. They work in just 30 minutes, reducing 99.9999% of bacteria, 99.99% of viruses, and 99.9% of giardia cysts,” (Aquatabs US, n.d.). This demonstrates that Aquatabs are highly effective against a broad spectrum of pathogens, making them a reliable option for ensuring safe drinking water. In addition, their incredible ease of use makes them favorable for quick and easy water purification.

Solar disinfection is a simple, chemical-free method of purifying water using sunlight. This is seen in the quote, “Generally, UVA radiation from the sun is lethal against bacteria, as is UVB radiation against bacteria, viruses, and protozoa. No adverse effect on the water’s taste has been observed. However, it is recommended that the treated water is consumed within the 24 h following exposure since bacteria can regrow in the dark while the water is stored and cooling. Water turbidity decreases the solar disinfection efficiency and prolongs treatment time. An additional benefit is that since the water is generally treated and then stored in the same container, there is a decreased risk of recontamination” (Garcia-Gil et al, 2021). This shows how the prolonged ultraviolet light not only kills a variety of pathogens, but also decreases turbidity. This is an extremely easy way for underdeveloped countries to obtain purified water.

Like the other methods, moringa seeds are also considered an efficient and cheap method of purifying water. However, an important consideration is that moringa seeds, which grow on the moringa oleifera trees, have a limitation to certain types of countries that are tropical. Still, scientists have discovered that moringa seeds are quite effective at clarifying water. Specifically, as author Swaler has cited, “in recent years, the water-clarifying ability of Moringa powder was found to be due to a positively-charged protein called the Moringa Oleifera Cationic Protein (MOCP). When you crush the seeds and add them to water, this protein will kill some of the microbial organisms and cause them to clump together and settle to the bottom of the container” (Swaler, 2015). This shows how the seeds contain naturally coagulation properties that can neutralize suspended particles in the water, allowing for safe drinking water at the top.

This research paper addresses the question of which of these following methods would be the most effective method of purifying water in third world countries. Specifically, this is a comparative study of these four methods of water purification. Based on the literature, boiling water is likely the cheapest and most effective method among these options, as high temperatures effectively kill a wide range of pathogens.

Methodology

Methods being tested:

Solar Disinfection (SODIS)
Iodine Tablets Addition (Aquatabs)
Water Boiling
Moringa Seeds Addition

Materials:

Unfiltered Water
Measuring Cup
Soil
Shovel
Measuring Spoon
Stirring Spoon
Scale
Safety Goggles
pH Strip Test
Turbidity Tester
Heat Source
Sun
Aquatabs (Iodine Solution)
Pot / Beaker
Moringa Seeds
Hammer
Envelope

**For this experiment, safety goggles will be worn at all times.

Experimental Procedures:

Prepare contaminated water: Add 2 grams of soil to 500 ml of fountain water in a glass beaker. Stir thoroughly, and wait 15 minutes for soil particles to settle before testing
Purification methods:

Boiling: Pour the entire mixture into a pot, making sure no dirt particles are left behind. Place the pot on a stove, and turn the heat to “8” and wait for large bubbles to appear from boiling, making sure it is not just small bubbles on the edges. Then, boil for 1 minute before pouring the contents back into the glass beaker. Wait 15 minutes for the soil particles to settle, then measure Total Dissolved Solids (TDS) and pH
Iodine Tablets: Acquire a tablet of Aquatabs, then cut in half. Add the half tablet into the contaminated water, stir thoroughly, and wait 30 minutes. Then, measure TDS and pH
Solar Disinfection: Place the glass beaker outside, making sure it is in a place where it can receive adequate sunlight for 6 hours. After waiting 6 hours, measure TDS and pH
Moringa Seeds: Acquire one moringa seed, then remove the outer shell until only the white part remains. Place the naked seed in an envelope and use a hammer to crush the seed into powder. Then, apply the powder into the contaminated water and stir thoroughly. Wait 1 hour, then measure TDS and pH

Control Group:

Purpose: To set a baseline for turbidity and pH and compare the effectiveness of purification methods
Procedure:

Add 2 grams of soil to 500 ml of fountain water in a glass beaker. Stir thoroughly, and wait 15 minutes for soil particles to settle before testing
Do not apply any purification methods
Test for TDS and pH

Body / Analysis

Control Group

For the control group, place a 500 ml cup of contaminated water in a beaker. Then, measure the pH and the turbidity of the water and check for any odors or visible signs of bacteria.

Left: 500 ML of water measured precisely

Right: 2 grams of soil measured, taken from backyard

Left: Turbidity of control group is 123, measured 15 minutes after soil particles settle

Right: pH of control group is estimated to be 6.25

Boiling Water

For the boiling method, a 500 ml cup of contaminated water will be placed in a pot on a heat source, and be boiled on a stove with a stopwatch. Turn the stove onto “number 8” and bring the water to a rolling boil and boil for 1 minute. After that, remove the pot using gloves, and let it cool for 15 minutes before testing. Then, measure the pH and the turbidity of the water and check for any odors or visible signs of bacteria.

Left: Water shown inside pot on stove

Middle: Turbidity of water measured immediately after finishing boiling, at 374

Right: Turbidity of water measured 15 minutes later, at 298

Left: Turbidity of water measured 1 hour later, at 95

Right: pH of water tested 1 hour after, estimated to be around 6.25

Solar Disinfection

For the solar disinfection method, 500 ml of contaminated water will be placed in direct sunlight for 6 hours Position the bottle horizontally so that sunlight penetrates the water evenly. After exposure, measure the pH and turbidity of the water and check for any odors or visible signs of bacterial contamination.

Left: Contaminated water shown out in the sun in the balcony

Middle: Turbidity of water measured 6 hours later, at 125

Right: pH of water measured 6 hours later, estimated to be around 6.5

Iodine Tablets

For the iodine tablet method, cut one iodine tablet in half, and add one of the halves to 500 ml of contaminated water. Stir the water for 1 minute and let it sit for 30 minutes to ensure full disinfection. After the waiting period, measure the pH and turbidity, and check for any odors or visible signs of bacteria. Note any changes in taste or coloration.

Left: Aquatabs product shown

Middle: Aquatab tablet broken in half, as one tablet is used to treat 1 liter of water

Right: Turbidity of water measured 15 minutes later, at 246

Left: Turbidity of water measured 30 minutes later, at 87

Right: pH of water measured, estimated to be around 6.5

Moringa Seeds

For the moringa seed method, grind one dry moringa seed into a fine powder and add to 500 ml of contaminated water and stir for 5 minutes. Let the mixture settle for 1 hour. Then, measure the pH and turbidity and examine the water for any odors or visible bacterial growth.

Left: Moringa seeds source shown

Middle: One single Moringa seed selected (shell later removed)

Right: Moringa seed placed inside envelope and crushed to powder with a hammer

Left: Powder shown inside envelope

Middle: Turbidity measured after 1 hour, 66

Right: pH measured after 1 hour, estimated to be 6.0

Experiment Data

	Control Group	Boiling Water	Solar Disinfection	Iodine Tablets	Moringa Seeds
Turbidity	123	95	125	87	66
pH	6.25	6.25	6.5	6.5	6.5
Odor	Yes	Yes	Yes	Yes	No

Counterargument / Limitations

Method-Specific:

Boiling water: Requires pot and a heat source, which are materials that may not be available. In underdeveloped countries, a fire will most likely be used as a heat source instead of a stove, which may yield different results. Carries the risk of burn or accidental fire. Boiling larger amounts of water take time, and may be inconvenient for serving larger groups of people
Iodine Tablets: May alter taste and may not remove turbidity or chemicals. Cost and supply may present barriers in some underdeveloped regions
Solar Disinfection: Efficiency depends on sunlight intensity and weather conditions. It is slower than other methods and may be ineffective in cloudy conditions
Moringa Seeds: Only viable in tropical regions where the trees grow; effectiveness can depend on the age of seeds and preparation method

Experimental Limitations:

Only turbidity and pH were tested; no microbiological tests conducted. This limits the ability to definitively conclude pathogen removal.
Sample size was small, only 500 ml, so results might not correlate with larger, more realistic amounts
Environmental factors such as sunlight intensity, water composition, and temperature were not strictly controlled

General:

Type of acquirable equipment, sunlight intensity, water composition, and temperature may be different in developing countries

Potential Bias:

Odor test might be dependent on the individual

Discussion

Through experiment observations of all four tested water purification methods of boiling, iodine tablets, solar disinfection, and moringa seeds it is concluded that moringa seeds are the best method for water purification. This is because after this experiment was completed, the results of the moringa seeds had the lowest turbidity at 66 NTU and the most stable pH at 6.0.

For most of the methods, it was observed how the dirt didn’t really dissipate for the majority of the methods. Thus, it was found that these four methods are likely used to kill bacteria, but not get rid of dirt. Odors remained for all methods besides moringa seeds, which had no odor. From this, we can infer that moringa seeds were not only the most successful at disinfecting the water, but also improved the odor, as well. This indicates that in regions where moringa seeds are available, they could serve as a low-cost, sustainable solution for improving drinking water quality beyond simple pathogen removal. Still, moringa seeds are only available in tropical areas where the moringa oleifera trees grow. In non-tropical areas, iodine tablets would serve as the best alternative, having a turbidity of 87 NTY and pH at 6.0.

The superior performance of moringa seeds can be explained by their natural coagulating properties. As seen in the quote, “In recent years, the water-clarifying ability of Moringa powder was found to be due to a positively-charged protein called the Moringa Oleifera Cationic Protein (MOCP). When you crush the seeds and add them to water, this protein will kill some of the microbial organisms and cause them to clump together and settle to the bottom of the container” (Swales, 2015). This process removes both microbial organisms and suspended particles, resulting in clearer and odor-free water. In contrast, boiling, iodine tablets, and solar disinfection were effective primarily at killing microorganisms but did not significantly reduce turbidity or remove odors, which made moringa seeds the only purification method to remove odors. In addition, it clearly showed water clarity on the surface of the water, with the soil particles having settled to the bottom thanks to the moringa seeds’ coagulation properties that clump negatively charged molecules like soil and bacteria and sink to the bottom. This left nearly clear water at the top of the glass beaker, while the other 3 methods still had murky water throughout the beaker.

Conclusion

This study compared four water purification methods: boiling, iodine tablets, solar disinfection, and moringa seeds. They were tested and evaluated based on their effectiveness on improving the quality and turbidity of the contaminated water. Based on the experimental results, moringa seeds emerged as the most effective method, producing the lowest turbidity at 66 NTU, most stable pH at 6.0, and the only method that produced odorless water. These results demonstrate that moringa seeds not only disinfect water by reducing pathogens, but also improve clarity and remove odors due to their natural coagulating properties.

In regions where moringa seeds are not accessible, iodine tablets serve as the best alternative, providing rapid chemical disinfection and producing moderately clarified water with the second lowest turbidity of 87 NTU along with the same, stable pH of 6.0 Boiling and solar disinfection were effective at killing microorganisms but did not significantly improve water clarity or remove odors, highlighting that these methods are most suitable for microbial inactivation rather than complete purification.

Overall, this study demonstrated that the most effective water purification method in third world countries depends on both environmental availability and specific goal of the treatment. Moringa seeds are ideal in tropical areas where the clarity and odorlessness of water is the goal, while iodine tablets are ideal for quicker and faster water purification in non-tropical areas. Despite having higher turbidity, boiling and solar disinfection are still solid methods of killing pathogens in water. Combining methods could further optimize water safety and quality. These findings provide guidance for selecting the best water purification methods to improve access to safe drinking water in underdeveloped countries.

In the end, moringa seeds have produced clear water at the top of the beaker, safe for drinking.

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