Controlling pH in Industrial Wastewater Neutralization

Sample article. Will be updated by the website admin.

Many industrial processes produce wastewater that is too acidic or too alkaline to be discharged or treated biologically. Neutralization brings the pH back into the range required by regulations and by downstream treatment.

Choosing the neutralizing agent

• Acidic wastewater: neutralized with an alkali such as caustic soda, available as liquid or flakes.
• Alkaline wastewater: neutralized with an acid such as hydrochloric acid or sulfuric acid.

Good practices for stable pH control

• Equalize flow first: a buffer tank smooths out sudden pH swings.
• Dose in stages: coarse adjustment followed by fine adjustment is easier to control.
• Mix well: poor mixing causes overshoot and wasted chemicals.
• Calibrate pH sensors regularly: the whole system depends on an accurate reading.

Safety first

Concentrated acids and alkalis are corrosive and react with heat when diluted. Always follow the Safety Data Sheet, use suitable personal protective equipment, and add chemicals to water, never water to chemicals.