Choosing between aluminum sulfate , and PAC (Poly Aluminum Chloride) in water treatment is a common question for businesses and wastewater treatment plants. Both types of chemicals are effective coagulants, but each is suitable for different water source conditions, quality requirements, and budgets. In this article, we will analyze the advantages and disadvantages and guide you when to use alum and when to choose PAC for the best treatment efficiency.
Overview of PAC and Aluminum Sulfate
PAC (Poly Aluminum Chloride) chemical
What is PAC chemical?PAC is a high molecular coagulant with the formula [Al₂(OH)nCl₆₋n]m (1 ≤ n ≤ 5, m ≥10), containing a high aluminum content of 24% to 31%. PAC is used in:
- Treatment of domestic and drinking water.
- Industrial wastewater treatment, washing water.
- Especially effective with wastewater containing a lot of suspended solids such as in paper and dyeing factories.
Using:
- Mix 10-20% PAC solution before adding to water.
- Dosage ranges from 20-200 g/m³ depending on the nature of wastewater and the amount of suspended solids.
Aluminum Sulfate Chemical
Aluminum sulfate, formula Al₂(SO₄)₃.18H₂O, is a popular coagulant chemical with low cost, easy to find and use. Aluminum sulfate is applied in:
- Industrial wastewater and domestic wastewater treatment.
- Pond wastewater treatment.
Comparison of PAC and Aluminum Sulfate
| Criteria | CAP | Aluminum Sulfate Alum |
|---|---|---|
| Coagulation efficiency | 4-5 times higher, creating large, easy-to-settle flocs. | Lower efficacy, larger doses required. |
| Effect on pH | Little pH fluctuations, no or very little need for pH adjustment chemicals. | Significantly reduces pH, requiring NaOH addition for adjustment, increasing cost. |
| Solubility | Dissolves quickly in water, saving preparation time. | Dissolves slower, requiring longer stirring time. |
| Amount of sludge | Significantly reduces sludge volume and is easy to handle. | Creates more sludge, which is more difficult to manage. |
| Cost of use | The initial cost is higher but with savings in operating costs and additional chemicals, the total cost is often lower over the long term. | Cheaper than PAC, but higher operating costs due to the need for more supporting chemicals and difficulty in managing sludge. |
| Convenience | Simple to use, no complicated equipment required. | Easy to use, suitable for small systems, do not require high water quality. |
When Should PAC Be Used?
PAC is the optimal choice in the following cases:
- Water source with high turbidity: PAC is more effective in treating industrial wastewater containing suspended solids or organic matter, such as in the paper and textile dyeing industries.
- High quality requirements for treated water: Suitable for treating domestic water, drinking water or industries requiring high standards such as food production.
- Reduce operating costs: Due to its high efficiency and low impact on pH, PAC helps reduce the cost of chemical adjustment and sludge management.
Outstanding advantages of PAC:
- Coagulation efficiency is 4-5 times higher.
- Less need for flocculants, cost saving.
- Easy to handle and operate.
When Should Aluminum Sulfate Be Used?
Aluminum sulfate alum is an economical and simple solution in the following cases:
- Low turbidity water source: Suitable for domestic wastewater treatment or water supply that does not require high standards.
- Limited budget: Alum has low cost, suitable for projects that need to optimize initial costs.
- Simple processing system: Effective in small systems or systems that do not require constant pH adjustment.
Disadvantages of alum:
- Reduces water pH, requiring NaOH addition for adjustment, increasing operating costs.
- Lower coagulation efficiency, larger dosage required and more sludge generated.
Conclude
Choosing between PAC chemicals and aluminum sulfate depends on the following factors:
- Water source characteristics: Water with high turbidity or requiring high output water quality should use PAC.
- Budget: If an economical solution is needed and high efficiency is not required, alum is the right choice.
- Long-term operating costs: Although PAC has a higher initial cost, total operating costs are typically lower due to reduced chemical additions and sludge.
To ensure optimal efficiency and cost savings, contact Loc Thien Investment and Development Company Limited – leading supplier of water treatment chemicals, helping you choose the most suitable solution.
Contact information:
- Headquarter: 452/6B Provincial Road 10, Binh Tri Dong, Binh Tan, Ho Chi Minh City
- Hotline: (+84) 979 891 929
- Email: locthien@locthien.vn
- Website: hoachatcoban.net
Contact us today for a free consultation and detailed quote!
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