Synthesis of quaternary ammonium rice straw lignin and its adsorption properties for PtCl62-

The quaternary ammonium rice straw lignin (QARSL) with anion exchange functional groups was synthesized based on rice straw through pretreatment, phenolation, polycondensation, chloration and amination reactions and it was characterized by FTIR, SEM and TG-DSC. The effects of adsorption time, initial concentration of PtCl2 6 and concentration of hydrochloric acid on the adsorption properties of QARSL for PtCl2 6 were investigated. Furthermore, the kinetic and adsorption isotherm models were explored. The selectivity for PtCl2 6 in different concentrations of hydrochloric acid solution was also studied. The results showed that QARSL was loose and had excellent thermal stability. The equilibrium time of adsorption was 420 min and the maximum adsorption capacity was 0.54 mol center dot kg 1. Moreover, the adsorption process could be described by pseudo-second-order kinetic model and adsorption isotherm could be simulated by Langmuir model, which indicated that the process of adsorption was adsorption of chemical single molecule layer. QARSL was of excellent selectivity for PtCl2 6 when the concentration of hydrochloric acid was 0.5 mol . L-1. [GRAPHICS] .