Chinese company Mizuda has entered into a contract with Messer for the supply of carbon dioxide (CO2) to neutralise alkaline wastewater.

Besides the areas of green electricity generation and pharmaceuticals, the company, which was founded in 1993, is especially active in waste management and wastewater treatment.

The gas, supplied by Messer, will be used to neutralise alkaline wastewater. The high pH value of such wastewater has to be neutralised through the addition of an acid so that it can undergo further treatment or be discharged into the sewerage system.

A press release said Mizuda had previously been using sulphuric acid for this purpose. It continued, “However, elaborate safety measures are required when handling sulphuric acid. Its use is not only expensive, but also leads in wastewater treatment to the formation of odour-intensive hydrogen sulphide as well as mineral salts. By contrast, CO2 dissolves in water to form a weak acid – carbonic acid – without unwelcome side effects. This acid fulfils the task of neutralisation but is otherwise safe and harmless.”

The system that has been installed at Mizuda for pH regulation with CO2 has helped to reduce production costs. As a result, the company is now planning to work with Messer on other projects.