Paper Title
Efficiency of Upflow Water System in the Iron Removal From Aqueous Solution

Abstract
In some areas of Thailand, groundwater was color which was due to a compound of iron contamination. The domestic consumer complains of the brownish color which iron imparts to laundered goods.This article investigate the synthetic calcium hydroxy apatite, the system design of iron removal from water, and the removal of iron from water with calcium hydroxy apatite. The Fe2+ average concentration of 4.96 mg/L was prepared for the experiment. Iron removal system was consisted of glass column (diameter of 1.75 cm, height of 40 cm) and connected with plastic tube (diameter of 6.1 cm, height of 40.5 cm) in vertical plane. The 10 g of calcium hydroxyapatite was filled into the glass column. The direction of water was moved from the tip of glass column and up flow to plastic tube on the top. The average flow rate of the water was 0.40 mL/s. The treatment was continuous flow of 20 L/day. The experiment was stopped when the system was performed below 50 percent removal, and it was stopped at the water volume flow reached 48 L. It was found that the maximum efficiency of the treatment of Fe2+ removal up to 98.39 percent, the minimum efficiency was 46.98 percent, and the average efficiency was 85.18 percent. The Fe2+ was removed at 20.28 mg/g of calcium hydroxyapatite. Iron removal system had the ability to remove Fe2+ in the water efficiently. The results of this researchcan be applied to solve problems in the community that was affected by groundwater contaminated with iron. Index Terms� Upflow Water System, Iron Removal, Hydroxyapatite, Chemistry.