Equipment design for water treatment geothermal hot spring bath in Leilem Village, North Sulawesi

Indonesia has 40% of world’s geothermal potential. The utilization of geothermal potential is not only used for electrical power plant, but also direct usage such as tourism. One of geothermal tourism in Indonesia is a hot spring in Leilem Village, North Sulawesi. Leilem’s geothermal hot spring has high level of acidity that potentially cause skin’s damage. To overcome this problem, this research designs a sustainable technology to increase pH level by reacting the water with limestone (CaCO₃). The water was classified as sulfate water because it contains high concentration of acid sulfate (H₂SO₄) and has the pH level below than 3. The reaction is assumed to obey Arrhenius’ Law. Runge Kutta method is applied to calculate the reaction constants which will be verified using experimental data. The equipment can be designed based on these constants. As a result, the equipment can increase the pH level up to 4 which is the most suitable pH level for bath.