title: Effect of humic acid on sorption of technetium by alumina.
abstract: Sorption of technetium by alumina has been studied in absence as well as in presence of humic acid using (95)Tc(m) as a tracer. Measurements were carried out at fixed ionic strength (0.1M NaClO(4)) under varying pH (3-10) as well as redox (aerobic and reducing anaerobic) conditions. Under aerobic conditions, negligible sorption of technetium was observed onto alumina both in absence and in presence of humic acid. However, under reducing conditions (simulated with [Sn(II)] = 10(-6)M), presence of humic acid enhanced the sorption of technetium in the low pH region significantly and decreased at higher pH with respect to that in absence of humic acid. Linear additive as well as surface complexation modeling of Tc(IV) sorption in presence of humic acid indicated the predominant role of sorbed humic acid in deciding technetium sorption onto alumina.
authors: Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, Maharastra, India.
authors: S
authors: S
authors: Kumar
authors: N
authors: N
authors: Rawat
authors: A S
authors: AS
authors: Kar
authors: B S
authors: BS
authors: Tomar
authors: V K
authors: VK
authors: Manchanda
mesh_terms: D000327:Adsorption; D000332:Aerobiosis; D000537:Aluminum Oxide / Q000032:analysis* / Q000737:chemistry; D000693:Anaerobiosis; D002621:Chemistry / Q000379:methods*; D003102:Colloids / Q000737:chemistry; D006812:Humic Substances / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008962:Models, Theoretical; D011199:Potentiometry / Q000379:methods; D013499:Surface Properties; D013667:Technetium / Q000032:analysis*
chemical_list: D003102:Colloids; D006812:Humic Substances; D013667:Technetium; D000537:Aluminum Oxide