title: The influence of pH on manganese removal by magnetic microparticles in solution.
abstract: An extensive experimental work is reported that aims to assess the efficiency in manganese (Mn) removal from aqueous solution by carbonyl iron microparticles using magnetic separation techniques. A set of batch experiments are performed to explore the effect of pH, adsorbent concentration, surface coating and contact time for achieving the highest Mn removal efficiency. Mn removal efficiency is extremely high (>98%) for pH values larger than 9 as a result of the chemisorption of Mn oxides onto magnetic microparticles. In contrast, Mn removal efficiency for pH < 9 was significantly reduced as Mn remains as a soluble cation. In this manuscript we demonstrate that the efficiency clearly increases when increasing the adsorbent concentration and when using MnOx(s) coated magnetic particles instead of bare particles. Desorption rates from Mn-loaded magnetic particles at different pHs were always lower than 15%. Furthermore, Mn removal efficiency remained at a very high value (>95%) when reused particles were employed in the adsorption process.
authors: Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, 18071, Spain; Instituto del Agua, Universidad de Granada, 18071, Spain.
authors: A
authors: A
authors: Funes
authors: Departamento de Física Aplicada, Facultad de Ciencias, Universidad de Granada, 18071, Spain.
authors: J
authors: J
authors: de Vicente
authors: Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, 18071, Spain; Instituto del Agua, Universidad de Granada, 18071, Spain.
authors: L
authors: L
authors: Cruz-Pizarro
authors: Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, 18071, Spain; Instituto del Agua, Universidad de Granada, 18071, Spain. Electronic address: ivicente@ugr.es.
authors: I
authors: I
authors: de Vicente
mesh_terms: D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D060328:Magnetic Phenomena; D008345:Manganese / Q000737:chemistry*; D017895:Manganese Compounds / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D017895:Manganese Compounds; D010087:Oxides; D012996:Solutions; D014874:Water Pollutants, Chemical; D008345:Manganese; C027424:manganese oxide; D007501:Iron
keywords: Magnetic particle; Magnetic separation gradient; Manganese removal; Water quality