The removal efficiency of iron and manganese from pre-ozonated groundwater using limestone filter

This paper investigates the suitability of limestone to attenuate Fe and Mn from pre-ozonated groundwater samples using batch study and fixed column bed. The effects of limestone dosage, shaking speed, contact time, and pH on the removal efficiency of Fe and Mn are discussed. Pre-ozonated groundwater samples were prepared to present actual samples from Pintu Geng water treatment plant. A general characterization for groundwater as well as for limestone was conducted. In addition, the breakthrough and exhaustion points for limestone were determined. Results showed that limestone has good potential to remove more than 90% of Fe and Mn at optimum dosage of 40 g. The removal percentage for both metals was also affected by changing the contact time, where the maximum removal of Fe and Mn was observed at 90 and 120 minutes, respectively, at pH 8 and shaking speed of 350 rpm. The breakthrough time and exhaustion time of Fe were 40 hours and 210 hours, respectively. However, faster breakthrough time (30 minutes) and exhaustion time (16 hours) were observed for Mn sorption. The findings showed that an integrated ozone-limestone adsorption process significantly enhanced the removal of Fe and Mn up to 99.5% and 92%, respectively.