title: Removal of arsenic and iron removal from drinking water using coagulation and biological treatment.
abstract: Effects of biological activated carbon (BAC), biological aerated filter (BAF), alum coagulation and Moringa oleifera coagulation were investigated to remove iron and arsenic contaminants from drinking water. At an initial dose of 5 mg/L, the removal efficiency for arsenic and iron was 63% and 58% respectively using alum, and 47% and 41% respectively using Moringa oleifera. The removal of both contaminants increased with the increase in coagulant dose and decrease in pH. Biological processes were more effective in removing these contaminants than coagulation. Compared to BAF, BAC gave greater removal of both arsenic and iron, removing 85% and 74%, respectively. Longer contact time for both processes could reduce the greater concentration of arsenic and iron contaminants. The addition of coagulation (at 5 mg/L dosage) and a biological process (with 15 or 60 min contact time) could significantly increase removal efficiency, and the maximum removal was observed for the combination of alum and BAC treatment (60 min contact time), with 100% and 98.56% for arsenic and iron respectively. The reduction efficiency of arsenic and iron reduced with the increase in the concentration of dissolved organics in the feedwater due to the adsorption competition between organic molecules and heavy metals.
authors.affiliation: School of Civil, Environmental and Chemical Engineering, RMIT University, G.P.O. Box 2476, Melbourne, 3001, Australia E-mail: biplob_02ce@yahoo.com.
authors.forename: Biplob Kumar
authors.initials: BK
authors.lastname: Pramanik
authors.affiliation: Department of Civil Engineering, Ahsanullah University of Science and Technology, Tejgaon Industrial Area, Dhaka-1208, Bangladesh.
authors.forename: Sagor Kumar
authors.initials: SK
authors.lastname: Pramanik
authors.affiliation: Department of Civil and Structural Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Selangor, Malaysia.
authors.forename: Fatihah
authors.initials: F
authors.lastname: Suja
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry*; D060766:Drinking Water / Q000032:analysis*; D007501:Iron / Q000737:chemistry*; D029588:Moringa oleifera / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D002606:Charcoal; D007501:Iron; D001151:Arsenic