The production of cushy bath towels and bathrobes generates large quantities of alkaline wastewater. That water must be neutralized with an acid to counteract its corrosive action. The classic way to accomplish this is with sulfuric acid. The more eco-friendly way to neutralize wastewater is with carbon dioxide (CO2).
First the CO2 is metered directly into the pipeline connecting the neutralization basin to the biological stage of the water treatment plant. If necessary, additional turbulence is created in the wastewater to help the CO2 dissolve better. This method is also safer and easier to control than adding mineral acids such as hydrochloric, sulfuric or nitric acid.