Wastewater from the textile and leather industry has an average pH value much higher than 11-12, so a neutralization process is required before the wastewater is treated or discharged into the environment or sewage.
Neutralization by carbon dioxide (CO₂) from chimneys boilers is done by intercepting the flue gas through special pipes, cooling it and conveying it to the storage tank where the wastewater is stored. The CO₂ fed into the storage tank through special pumps enables the reduction of pH from 12 to 9, for which more acid consumption would otherwise be required.
Why is high wastewater pH a problem?
A pH 11 in wastewater indicates a highly alkaline environment. On the pH scale, the neutral value is 7, which means that wastewater has a high concentration of hydroxide ions (OH-) compared to hydrogen ions (H+).