Cooperative adsorption of L-tryptophan and sodium ion on a hyper-cross-linked resin: Experimental studies and mathematical modeling

•pH-dependent adsorption isotherm model for L-Trp-was developed.•L-Trp± is the most favorable form for L-Trp-adsorption on resin XDA-200.•Surface diffusion model with coadsorption of Na+ and L-Trp- was established.•The dynamic separation process of L-Trp-with coadsorption of Na+ was simulated.