The effect of bed depth on adsorption ability of natural zeolite to removal methylene blue (MB) from aqueous solution in the fixed-bed column was studied. The results showed that the increase in column height favored the MB removal form solution. The equilibrium uptake of MB onto unit mass zeolite increased with the bed depth growth. The experimental data were fitted to Yan model using linear and nonlinear regression analysis, respectively. The experimental points and the predicted curves using the Yan model were compared and the error analysis was performed. The results indicated that Yan model were good to predict the breakthrough curves and both two methods can be used to obtain the parameters of Yan model and to predict the breakthrough curves.

Adsorption of copper ion and methylene blue (MB) ion from aqueous solution was performed by natural wheat straw (NWS) and modified wheat straw (MWS) with citric acid (CA) in fixed-bed column. Adsorption behaviors of single system and binary system were compared at same experimental condition. There was higher adsorption capacity of MWS for binding Cu2+ and MB. In the binary system of Cu2+ and MB coexisted in solution, there was competitive adsorption. The adsorption quantity of Cu2+ or MB decreased with MB or Cu2+ existed. NWS and MWS can simultaneously adsorb Cu2+ and MB from mixtures.

Comparison analysis of linear least square method and nonlinear least square method for estimating the kinetic parameters was made using the experimental column data of Light green adsorption onto a cationic surfactant hexadecylpyridinium bromide (CPB) modified peanut husk (MPH) at different flow rate and initial concentration. The data were fitted to Thomas model equations using linear and non-linear regressive analysis, respectively and the error analysis was performed. The results showed that both methods are suitable to predict the breakthrough curves using Thomas model parameters and the nonlinear method is better.

The adsorption studies of 4-chloro-2,5-dimethoxy nitrobenzene (CDNB) from aqueous solution on pyrolytic char activated by ammonium dihydrogen phosphate from pine sawdust have been performed. Several experimental parameters like initial pH, NaCl concentration, contact time solution temperature were evaluated. Solution pH within 2-7 is favor of adsorption and it is advantage of adsorption at higher temperature. Langmuir, Freundlich and Temkin isotherm models were used to fit the experimental data and Temkin model was better. The adsorption capacity was up to 33.8 mg·g1at 323 K. The process is spontaneous and endothermic and physical action is major mechanism.

The effect of contact time and the determination of the kinetic parameters of adsorption of methyl orange (MO) from aqueous solution onto Iron-Oxide-Coated-Zeolite (IOCZ) powder are important in understanding the adsorption mechanism. The effect of contact time on adsorption quantity was studied at different initial concentration and temperature, respectively. The pseudo-second-order model was adopted to fit the experimental data using non-linear regressive analysis and it was used to predict the adsorption behavior. The results showed that the process of adsorption MO was endothermic and chemisorption. The pore diffusion was not significant.