Caustic soda replacement

The best alternative to caustic soda depends on the wastewater treatment process and neutralisation requirements. Omya offers several caustic soda replacement technologies, including the Neutrasorb range (calcium carbonate and magnesium-based solutions) and Omya Neutramaxx (concentrated milk of lime):

When treating low-pH wastewaters that require bulk neutralisation, Omya Neutrasorb solutions are often selected due to their buffering effect and controlled pH adjustment.

For applications requiring stronger pH correction and neutralisation performance, Omya Neutramaxx delivers a neutralisation capacity equivalent to 50% caustic soda and 1.7 times the capacity of a 30% caustic soda solution.

Concentrated milk of lime is one of several solutions available for wastewater treatment, alongside lime-based and magnesium hydroxide-based technologies. Omya Neutramaxx is a concentrated, highly reactive milk of lime with a neutralisation capacity equivalent to 50% caustic soda. Unlike conventional lime products, it remains homogeneous for more than 3 months without settling, supporting reliable dosing, simplified storage and reduced maintenance.

In a trial at a meat and pasta production facility, Omya Neutramaxx successfully replaced sodium hydroxide for pH adjustment while maintaining comparable pH control with less pH fluctuation. The trial* also reported 11% lower product consumption, improved sludge characteristics and a 21% reduction in sludge disposal volume compared with sodium hydroxide. 

*Based on data from an Omya customer field trial. Results may vary according to wastewater characteristics and operating conditions.

Excessive sludge volumes during pH neutralisation are often caused by over-dosing and poor sludge settling or dewatering. Omya Neutramaxx supports faster settling and improved dewatering of precipitated sludge, with reduced flocculation dosages reported versus conventional treatments. This helps improve sludge handling efficiency and reduce the operational burden associated with sludge management.

Total cost is not just the chemical purchase price. It also includes dosing efficiency, reduced coagulant and flocculant requirements, handling and PPE requirements, sludge disposal costs, and exposure to price volatility.

While caustic soda prices are increasingly affected by supply constraints, energy costs and market volatility, calcium-based solutions such as Omya Neutramaxx provide a more stable alternative. Omya Neutramaxx combines a neutralisation capacity equivalent to 50% caustic soda with improved sludge settling and dewatering, helping reduce downstream sludge handling and disposal requirements.

Operators can reduce their exposure to caustic soda price volatility by diversifying toward alternative pH control solutions with more stable pricing. Caustic soda prices are increasingly affected by supply constraints, regional capacity changes and upstream energy costs, creating uncertainty for wastewater treatment operations. Omya Neutramaxx is a calcium-based alternative that helps reduce dependence on volatile chlor-alkali markets while providing a more predictable cost base for a core treatment chemical.

When selecting a milk of lime supplier, operators should evaluate neutralisation performance, storage stability, safety, supply reliability and total cost of ownership. Omya Neutramaxx combines a neutralisation capacity equivalent to 50% caustic soda with exceptional storage stability, remaining homogeneous for more than 3 months without settling in unstirred conditions. It is non-corrosive, not classified as a dangerous good, and helps reduce exposure to the price volatility commonly associated with caustic soda.