摘要：In this research, nitrogen and phosphorus adsorption characteristics of four substrates, includinglava, activated carbon, furnace slag and spongy iron, were studied through basic experiments.Meanwhile, adsorption kinetics, effects of different pH on adsorption performance, sequencing batchadsorption isotherm experiments and saturation analysis of substrates experiments were analysed.Moreover, the possible secondary pollution risks after four substrates saturation adsorption werediscussed. The results showed that Freundich and Langmuir models were favourably fit for thevariance on nitrogen and phosphorus adsorption characteristics of substrates. The order of ammonianitrogen adsorption capacity for four substrates was activated carbon>furnace slag>lava>spongyiron. In addition, judging from ammonia nitrogen desorption rates, the capacity of releasing ammonianitrogen for four substrates increased as an order of spongy iron>lava>furnace slag>activatedcarbon. Besides, the order of phosphorus adsorption capacity for four substrates was activatedcarbon>spongy iron>furnace slag>lava. And the capacity of releasing phosphorus after phosphorusdesorption for four substrates increased as an order of lava>spongy iron>furnace slag>activatedcarbon. In summary, after adsorption and desorption properties of four substrates were analysed, itcould be concluded that activated carbon was a more favourable filler for constructed wetlands.
