Utilization of Hot-Spring-Water-Bound CO2 for Horticulture Plants Using Incubation Method

Abstract

This study focused on free carbon dioxide (H2CO3) contained in volcanic hot spring water. It was clarified whether free carbon dioxide can be emitted into the atmosphere and increase the CO2 concentration in greenhouses by using the incubation method. Factors influencing the increase in CO2 concentration were identified based on implementation time in a demonstration experiment, temperature and humidity in the incubator, the amount of hot spring water, and the contact area between the hot spring water and the air. An incubator with an inner volume of 2.17 × 107 mm3 was used in this study. The results showed that unrelated factors were the implementation time in the demonstration experiment, temperature, and humidity. There was a relationship with the amount of hot spring water. The increment of CO2 concentration in the air by free carbon dioxide increased proportionally by increasing the amount of water. Free carbon dioxide contained in hot spring water can be utilized by considering the volume of facility horticulture and plant factories. The ideal methods for utility are to replace the hot spring water every few minutes and to increase the contact area between the air and the hot spring water.