Study of the eco-economic efficiency of electrochemical pH correction for reducing hardness salts

Summary

In industry, water recycling systems or units have been widely used to cool equipment and other industrial processes. One of the main problems associated with operating these systems is scale formation owing to the presence of hardness salts, such as calcium and magnesium compounds. Traditional addressing water hardness problems involves the use of chemicals such as phosphates and polyphosphates to bind calcium and magnesium ions, preventing their precipitation. Electrochemical pH correction provides for a more environmentally friendly solution. Changing water pH by electrolysis enhances the precipitation of hardness salts as insoluble compounds, that can be further removed from the system. The theoretical foundations and mechanism of water softening by electrochemical treatment are examined. It is noted, however, that direct reduction of hardness salts using electrochemical pH correction alone is not possible. It is expected that electrochemical methods can significantly enhance water softening processes and improve the efficiency. The eco-economic efficiency of the electrochemical pH correction method for the side stream filtration system of an industrial water recycling unit is estimated.

Key words

softening , electrolyzer , electrochemical treatment , water hardness , water recycling facilities , eco-economic efficiency