For many years, we have been involved in the development of separation and analytical methods for chemical substances using the properties of ions, as well as recycling methods for resources. Separation and concentration of harmful or useful ions are fundamental problems, and suppression or removal of harmful components from the waste, which is still difficult to solve, is a social problem in terms of recycling. The reaction system involving ions is the basis of chemical reactions, and the combination of acid-base reactions, complex formation reactions, and redox reactions is very profound. I would like to look back on what I have been working on with these themes.

Various methods using ion exchange resins are known for the purification of liquid starch sugar solutions that are used as sweeteners in many soft beverages. Ion exchange resin used in the purification process is generally maintained at 30 to 40°C, considering the heat resistance of the ion exchange resin and the inhibition of unwanted isomerization of liquid starch sugar solutions and other unwanted side reactions. However, there is concern about microbial contamination within the refinery equipment unit, even if the afore-mentioned temperature is considered appropriate. The liquid starch sugar purification system mentioned in this paper incorporates antibacterial measures into the conventional ion exchange purification process through alkali sterilization of the entire service tower that supplies the liquid starch sugar.