Ultrafiltration technique in conjunction with competing ligand exchange method for Ni–humics speciation in aquatic environment

Kinetic speciation and bioavailability of copper and nickel in mangrove sediments

“…The kinetic model proposed by Olson and Shuman (1985) was adapted (Chakraborty, 2012;Chakraborty et al, 2011Chakraborty et al, , 2012aChakraborty et al, , 2012bChakraborty et al, , 2013 to estimate kinetically distinguishable forms of Cu and Ni in the mangrove sediments. It is based on the assumption that each sediment sample consists of n different components, in which each component, M À sediment i , exists in equilibrium with its dissociation products: M 2+ or extractable M complexes, a naturally occurring heterogeneous complexant, sediment i .…”

“…The approaches include batch techniques (Beauchemin et al, 2002;Bermond and Varrault, 2004;Yu and Klarup, 1994), flow techniques (Beauchemin et al, 2002;Shiowatana et al, 1999;Silva et al, 2007), kinetic extraction methods (Chakraborty and Chakrabarti, 2006;Chakraborty et al, 2012aChakraborty et al, , 2012bChakraborty et al, , 2013Chakraborty et al, , 2011Chakraborty et al, , 2009, Diffusive Gradients in Thin Films technique Fangueiro et al, 2002;Town et al, 2009). However, the kinetic extraction method has been found to be a simple and sensitive technique (Chakraborty and Chakrabarti, 2006;Chakraborty, 2012).…”