Abstract: Adsorption is convenient and practical in removing iron and manganese in groundwater. Test of adsorbing iron and manganese by natural zeolite was carried out. Results reveal that the adsorption of iron and manganese by natural zeolite complies with Freundlich’s isothermal adsorption formula, and the removal rates of iron and manganese increase with the increase of zeolite dosage. The higher concentration of original solution is, the larger adsorption amount of iron and manganese is; but with the concentration of original solution increasing, the removal rate of iron gradually reduces, whereas the removal rate of manganese tends to decrease when solution concentration is greater than 5 mg/L. Moreover, the optimum duration of adsorbing iron and manganese is 30 min and 20 min, respectively. As adsorption duration exceeds the optimum, the adsorption amounts both decrease. The test lasts for 70 days and proves that the natural zeolite could not effectively adsorb manganese, with the lowest manganese content in the effluent water over 0.1 mg/L, not reaching national standard (which is ≤ 0.1 mg/L); while the effect of removing iron is better than removing manganese, and the lowest iron content in effluent water approaches 0.0 mg/L, within the national drinking water standard (0.3 mg/L).

Key words: natural zeolite, adsorption performance, iron, manganese, groundwater