Adsorption isotherm and kinetic study of Bengkulu Kaolinite in removing ferrous cation by continuous operation

Abstract

Iron is a chemical element that is found in groundwater that can be suspended in the form of ferrous cations. Iron presence that exceeds the threshold can cause detrimental effects such as piping corrosion, bad smells, and health problems. According to observations, groundwater in Sukarame, Bandar Lampung, has smells and colors that indicate iron metal contamination. Hence, it is necessary to research reducing the iron content. The method used in this research is the adsorption method using kaolin adsorbent that has been activated by physical activation at 700°C. The adsorption was conducted continuously with various reactor heights of 20 cm, 15 cm, and 10 cm. The results showed that the most significant reduction in efficiency was found in the adsorption using reactors with a height of 20 cm by 92%. The adsorption phenomenon using a reactor height of 20 cm followed the Langmuir isotherm model (R2 = 0.9255) with an adsorption capacity of 17.03 mg/g. The kinetic data correlated well with the pseudo-second-order equation (R2 = 0.9313). It can be concluded that kaolin adsorbent can reduce iron levels, in which the adsorption using reactors with a height of 20 cm is the most effective.