Industrial facilities generate wastewater that often contains acidic contaminants, heavy metals, or organic compounds. These effluents must be treated before discharge to comply with environmental regulations. One of the most effective and widely used chemicals for pH adjustment in wastewater treatment is caustic soda flakes (sodium hydroxide – NaOH).

Why pH Control Matters in Wastewater Treatment

Maintaining a neutral or slightly basic pH is essential to:

• Precipitate heavy metals
• Improve biological treatment performance
• Meet discharge standards
• Prevent pipe corrosion and environmental harm

Acidic wastewater must be neutralized before it enters municipal sewers or natural water bodies.

How Caustic Soda Flakes Work

Caustic soda flakes are a strong base. When dissolved in water, they dissociate into hydroxide ions (OH⁻), which react with acidic components such as:

• Sulfuric acid
• Hydrochloric acid
• Nitrates and other acid-forming compounds

This reaction increases the pH of the solution, making it safer for further treatment or discharge.

Advantages of Using Caustic Soda Flakes Over Liquid NaOH

• High purity (≥98%)
• Longer shelf life
• Safer and cheaper to transport
• Precise dosing by on-site dissolution
• Easier bulk storage for remote facilities

Because they are in solid form, flakes eliminate the risks associated with leaks or spills common in transporting liquid NaOH.

Typical Use in Industrial Wastewater Systems

Caustic soda flakes are used in industries such as:

• Petrochemicals
• Textiles
• Mining and metallurgy
• Electronics
• Paper and pulp

In these facilities, NaOH is applied to adjust influent pH levels, prepare the water for flocculation and sedimentation, and protect biological systems in secondary treatment.

Dosage and Application

The correct amount of caustic soda flakes depends on the volume and acidity of the wastewater. Generally, flakes are dissolved in water to create a 10–30% NaOH solution, which is then dosed automatically into the system via a pH controller.

Safety and Handling

Although effective, caustic soda is corrosive. Operators must:

• Wear PPE (gloves, goggles, apron)
• Use ventilated mixing tanks
• Store flakes in dry, sealed packaging
• Rinse equipment after use to avoid buildup

Conclusion

Caustic soda flakes provide a reliable, economical, and efficient solution for pH control in industrial wastewater treatment. Their stability, purity, and ease of handling make them a preferred choice across a wide range of industries.

Iran Caustic Soda, a subsidiary of Shetab Gostar Nadin Trading Co., supplies high-quality NaOH flakes with complete export documentation and secure packaging.