title: Comparative study of ground water treatment plants sludges to remove phosphorous from wastewater.
abstract: Alum- and iron-based sludge obtained from water treatment plant produced during a unit treatment process (coagulation and flocculation) have been widely tested as a low-cost adsorbent to remove phosphorous (P) from wastewater. However, the effectiveness of iron-based sludge generated from the oxidation of iron which naturally occurs in the ground water has not been investigated. Moreover, influences of dominant metals ions comprised in the treatment plants sludges on P adsorption capacity and rate from wastewater are not yet known. This study, therefore, employed four different groundwater treatment plants sludges iron-based (from the oxidation of iron) and alum-based (from coagulation and flocculation process) to determine their P adsorption capacities and adsorption rates from the synthetic wastewater (SWW) and secondary effluent wastewater (SEWW). Although metals ions concentrations were the highest in the iron-based sludge amongst the sludge used in this study, it appeared to have the lowest P adsorption capacity and adsorption rate. A good correlation between aluminium to iron mass ratio and adsorption capacity for both types of waters were noted. However, a poor relation between aluminium to iron mass ratio and adsorption rates for the SEWW was observed. Further, the tested sludges were found to have a better P removal efficiency and adsorption capacity from the SEWW than from the SWW. Thus, this study demonstrates the ground water treatment plants sludges could be a low cost and effective adsorbent in removing P from wastewater.
authors.affiliation: Department of Civil Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia; Institute for Infrastructure Engineering, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia. Electronic address: b.kc@westernsydney.edu.au.
authors.forename: K C
authors.initials: KC
authors.lastname: Bal Krishna
authors.affiliation: Department of Civil Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia; Infra Tech Pacific, Pty Ltd, 32 Honeyeater Circle, Wembley, Perth, WA 6014, Australia.
authors.forename: Ashok
authors.initials: A
authors.lastname: Aryal
authors.affiliation: Water Corporation, WA, Australia.
authors.forename: Troy
authors.initials: T
authors.lastname: Jansen
mesh_terms: D000327:Adsorption; D000534:Alum Compounds / Q000737:chemistry; D000535:Aluminum / Q000737:chemistry; D060587:Groundwater / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D008670:Metals / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry / Q000302:isolation & purification*; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry; D018508:Water Purification / Q000379:methods*; D014904:Western Australia
chemical_list: D000534:Alum Compounds; D000535:Aluminum; D007501:Iron; D008670:Metals; D010758:Phosphorus; D012722:Sewage; D062065:Wastewater; C041524:aluminum sulfate
keywords: Adsorption isotherm; Adsorption kinetics; Alum sludge; Iron sludge; Phosphorus