Removal of boron and iodine from optoelectronic wastewater using Mg-Al (NO3) layered double hydroxide

Mg-Al (NO3) layered double hydroxide (LDH) was used to treat optoelectronic wastewater that contains high concentrations of boron and iodine. LDH showed high efficiency in removing boron and iodine from wastewater; with higher affinity toward boron than iodine. The optimum pH for both boron and iodine removal was 9.0-9.2. The process was spontaneous, exothermic, and exhibited random behavior as revealed by thermodynamic parameters. The zeta potential of LDH shifted to negative value with increasing boron amount on the LDH surface. While iodine was mainly adsorbed onto LDH through electrostatic attraction, a combined mechanism of ion exchange and weak adsorption was proposed for boron removal. (C) 2010 Elsevier B.V. All rights reserved.