Continuing the previous article on Poly Aluminum Chloride (PAC) which is a crucial chemical in the...
Introduction
Have you ever heard the term PAC in the world of water treatment? PAC or Poly Aluminum Chloride is a very popular chemical used in various clean and waste water treatment plants. Many people know PAC only as a water purifier, but actually its role is much broader. This article will thoroughly discuss what PAC is, its functions, benefits, workings, and applications in various fields.
By understanding PAC, you can find out why industries, households, and even the government, rely on this material to improve water quality. In addition, this knowledge is also useful for anyone who wants to keep the environment clean and healthy.
What is PAC?
PAC stands for Poly Aluminum Chloride, an aluminum-based coagulant that has the ability to bind colloidal particles in water. It comes in the form of a pale yellow powder or a yellow to light brown liquid. Its main property is that it is able to accelerate the process of settling suspended particles, so that water becomes clear faster.
Unlike conventional alum, PAC has the advantage of a more stable acidity (pH) level. This makes it more effective to use in various water conditions, both with high and low turbidity levels.
History and Background of PAC
The use of coagulants in water treatment is not new. Since ancient times, humans have used alum to purify water. However, the need for efficiency and better results encouraged chemists to develop new compounds. This is how PAC became known and mass-produced in the 20th century.
Drinking water industries in various countries immediately adopted PAC because the results were faster, required less dosage, and produced less sludge than alum. To this day, PAC continues to be the standard in many modern water treatment plants.
Composition and Characteristics of PAC
PAC is usually available in two main forms: powder and liquid.
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PAC Powder
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Pale yellow to beige in color.
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Easily soluble in water.
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Generally used for large-scale installations.
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Liquid PAC
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Light yellow to brown in color.
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More practical for small doses.
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Widely used in household or small industrial applications.
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Important characteristics of PAC:
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Relatively stable pH (around 4-5).
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Low but effectivedosage.
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Leaves less sludge than alum.
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Reacts quickly thus speeding up the treatment process.
How PAC Works in Water Treatment
PAC works through two main processes:
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Coagulation
Aluminum ions in PAC neutralize the negative charge on colloidal particles. Because the charge is gone, the dirt particles no longer repel, but instead draw closer to each other. -
Flocculation
Once the charge is neutralized, the particles will combine to form large clumps (flocs). These flocs are heavier and settle easily, so they can be separated from the water.
With this mechanism, murky water can turn clear in a short time.
Benefits of PAC in Various Sectors
1. Drinking Water Treatment
PAC is widely used by PDAMs and private drinking water companies to produce clean water that is suitable for consumption.
2. Industrial Liquid Waste Treatment
The textile, paper, food, and petrochemical industries use PAC to reduce COD, BOD, and TSS levels in liquid waste.
👉 Read also: Liquid Waste Treatment Technology
3. Household Wastewater Treatment
PACs are also effective for reducing environmental pollution from household waste.
👉 Check out this article: Household Wastewater Treatment: An Effective Solution for Urban Environments
4. Paper and Textile Industry
PACs help improve the quality of process water, resulting in better product yields.
5. Oil and Gas Industry
PAC is used to treat oil production waste so as not to pollute the environment.
Advantages of PAC Over Other Coagulants
Why do many people prefer PAC over alum or other coagulants? Here's why:
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High efficiency: Less dosage, more maximum results.
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Less sludge: Easy to dispose of, no new problems.
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Fast reaction time: Shorter treatment process.
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Stable pH: Does not affect the pH of the water too much.
Dosage and How to Use PAC
The use of PAC must be adjusted according to water conditions.
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Initial analysis
Test the water quality to determine the correct dosage. -
Rapid mixing
PAC is mixed into the water with rapid agitation to mix well. -
Flocculation
After that, do slow stirring so that the particles agglomerate. -
Settling
Allow the flocs to settle to the bottom of the tank. -
Filtration
The clear water is filtered for cleaner results.
👉 Read more about dosing systems: Functions of Dosing Pump in Water and Sewage Treatment
Environmental Impact and Safety of PAC
PACs are relatively safe to use if the dosage is correct. However, if used in excess, it can increase the aluminum content in water. Therefore, monitoring water quality is very important so as not to cause negative effects on human health and the environment.
Tips for Choosing Quality PAC
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Choose PAC from a trusted manufacturer.
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Pay attention to the Al2O3 content (usually 28-31%).
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Choose the form as needed (powder/liquid).
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Store in a dry place to prevent clumping.
Challenges in Using PAC
Although there are many advantages, there are some challenges:
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Price can be higher than alum.
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Requires precise dosage setting.
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Must be handled with care as it is corrosive.
Conclusion
PAC or Poly Aluminum Chloride is a highly effective modern coagulant for water and sewage treatment. With its advantages in efficiency, pH stability, as well as its ability to produce less sludge, PAC is becoming a top choice in various industries.
However, the use of PAC must remain measured and monitored to avoid adverse effects on health and the environment. With a good understanding, PAC can help keep water quality fit for consumption and environmentally friendly.
