Alum for Water Purification: How to Use It, Benefits, and Effectiveness
Alum has long been known as an effective substance for purifying water. Whether used at a household scale or in industrial settings, alum plays an important role in water treatment. This article will cover in detail the uses of alum for water, including its benefits, how to use it, and how effective it is in removing dirt and sediment.
Cloudy water at home can be frustrating. One of the practical and inexpensive solutions that has been used for centuries is alum. This substance is commonly used to clarify water, both in households and in small-scale industries.
What Is Alum?
Alum (aluminium sulfate) is a white crystalline substance that dissolves easily in water. In water treatment, alum is known as a coagulant—meaning it works by binding tiny particles in the water that cause turbidity, gathering them into larger clumps so they can easily settle and be filtered out.
Benefits of Alum in Water Treatment
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Clarifies cloudy water: Binds clay, dust, and fine particles so they can settle.
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Reduces odor and unpleasant taste: Especially those caused by organic matter or microorganisms.
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Lowers levels of metals such as iron and manganese: Helps reduce heavy metal content.
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Stabilizes raw water quality: Useful for daily activities such as washing, bathing, or irrigation.
How to Use Alum to Purify Water
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Prepare an alum solution
Dissolve 10-50 grams of alum into 1,000 liters of clean water (adjust depending on the level of turbidity). -
Pour into cloudy water
Distribute the solution evenly into the water container. -
Stir well
Stir for 1-2 minutes to mix the coagulant with the particles. -
Let it settle
Leave it for 30-60 minutes to allow the impurities to settle at the bottom. -
Use the clear water
Take the water from the top layer, and filter again if necessary.
Note: Avoid using too much alum, as this may cause the water to taste bitter and become less pleasant to use.
How Effective Is Alum?
Alum is very effective for water that is turbid due to soil, clay, or organic matter. However, if the water is contaminated with chemicals, industrial waste, or pesticides, additional filtration—such as activated carbon, silica sand, or zeolite—is still required.
Is Alum-Treated Water Safe?
When used in the right dosage, alum-treated water is safe for non-drinking purposes such as bathing, washing, or watering plants. If intended for drinking, the water should undergo further filtration and, ideally, be tested in a laboratory to ensure safety.
Conclusion
Alum is a simple, affordable, and effective solution for clarifying water at home. It is easy to use and cost-efficient for everyday needs. However, for drinking water, make sure additional filtration steps are taken to ensure safety.
