The application of spectrophotometry method for measuring iron content of groundwater after Merapi Mountain eruption

The eruption of Merapi Mountain in Yogyakarta in November 2010 spewed a lot of material to the surface of the earth. These conditions could affect the chemical content in ground water, such as iron content. Therefore, in this research will be made an iron content measuring instrument that is used to measure iron content in ground water of Turi, Klangkapan, Kali Kuning and Umbul Pajangan after the eruption of Merapi Mountain. The measuring iron content in the groundwater in this research is using spectrophotometric method. Because iron is measured at wavelengths between 495-570 nm, so this system will work by using a green laser light source. The results of the data processing will be displayed on the LCD (Liquid Cell Display) in mg/l. The iron content instrument can measure the iron content 1-5 mg/l as well. The iron content instrument still needs improvement because it can not measure iron content below 1 mg/lin accordance with the results should be. The iron content of four springs are increasing with the rate between 19.17-305.7%. However, the iron content in the water in the four areas is safe for consumption because it is on the allowed threshold by the Ministry of Health (less than 0.3 mg/l).