Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 27, 1998
Publication Date: N/A
Technical Abstract: Citrate derivatives of corn gluten meal (CGM) and distillers' dried grains (DDG) were generated by reactive extrusion of 1:1 w/w ratios of each with citric acid (CA) by two passages, at 20 rpm, of each mixture through a Brabender-Plasti-Corder PL 2000, single screw, 30:1 L/D fitted with 1/1 screw and no die; zone temperatures were 140, 200, and 196 deg C. Citrate derivatives were each finely ground, water-washed at pH 2 to yield acid insoluble derivatives. The equilibrium binding capacity, in mmol/g product, with Pb2+, Cd2+, Ag+, Zn2+, Cu2+, Co2+, Ni2+, Fe2+, Mn2+ were: 1.51, 0.67, 0.78, 0.45, 0.97, 0.40, 0.68, 0.85, 0.35 for CGM/CA; 1.48, 1.06. 0.65, 0.77, 1.20, 0.68, 0.61, 0.63, 0.52 for DDG/CA. These derivatives possessed a metal-binding capacity equivalent to 30-35% of a petroleum-based, sulfonic acid type cation exchange resin. These derivatives can potentially be used to not only add micronutrients to soils sbut also to remove toxic metals from industrial wastewater.