Abstract. In this study, the ability of wheat straw to adsorb neutral red (NR) from aqueous solution was investigated in a fixed-bed column. The effects of the flow rate, the influent concentration of NR and bed depth on breakthrough curves, were studied. The adsorption quantity was 26.4 mg/g at initial NR concentration of 50 mg/L, flow rate of 10.0 mL/min and bed depth of 8.0 cm. The Thomas model was applied to fit the experimental data and the results showed that it was available to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design using nonlinear regression.

ABSTRACT It is essential to remove 2,4-dichlorophenol (DCP) from solution. In this paper, wheat straw (WS) was modified by a cationic surfactant, cetyltrimethyl ammonium bromide (CTAB), to improve adsorption capacity for the removal of DCP from aqueous solutions in batch mode. Several experimental factors like initial pH, common salts concentration, contact time, solution temperature were evaluated. Solution pH within 4-9 was in favor of adsorption and common salts had slight effect on adsorption quantity. The adsorption capacity was up to 45.5 mg g -1 and the process was exothermic. Henry equation was better to fit the adsorption equilibrium data. DCP-loaded MWS can be regenerated by 0.1 mol L -1 NaOH. It was concluded that MWS may be good adsorbent to remove DCP from solution.