Application of an aqueous nanometric aluminum oxide suspension for fluoride remediation

A nanometric aluminum oxide suspension synthesized from AlCl₃ (solution) has been discussed for its potential application as a low cost fluoride remediation system. The phase synthesized was identified as AlO (JCPDS card no: 75–0278) and ε-Al₂O₃ (JCPDS card no: 35–0121). The isoelectric point of the suspension was at pH 7.61. Optimum remediation pH was determined to lie in between 6.5 to 7.0. The maximum loading capacity was predicted to be 110 mg/g from Langmuir isotherm and 127 mg/g from Freundlich isotherm. Presence of interfering ions in a simulated real water matrix does not appreciably alter the remediation capacity. Eight real water samples were found to be effectively remediated with triplicate % r.s.d falling in between 0.1 to 1.3.