Study on Application of Water Granulated Slag in Rare-Earth Ammonia-Nitrogen Wastewater

摘要

This paper aims to study the technological conditions and adsorption mechanism of the rare-earth ammonia-nitrogen wastewater adsorption by unmodified water granulated slag and modified water granulated slag. The results showed that the optimum adsorption reaction time is around 60min for both of unmodified and modified slag; the optimum dosage of unmodified slag is 0.015g/mL, whereas it is 0.01g/mL for modified slag, correspondingly, the removal rate of ammonia-nitrogen could attain to (59.9±2.49) ％ and (79.24±1.21) ％ associated with unmodified slag and modified slag respectively. The ammonia-nitrogen removing process conducted by unmodified water granulated slag fits the Freundlich adsorption isothermal equation, conforming to physical adsorption. By contrast, the ammonia-nitrogen removing process accomplished by modified water granulated slag fits the Temkin adsorption isothermal equation and this process should be chemical adsorption.