Study On The Adsorption Characters Of Steel Slag In Wastewater Treatment

Development of an inexpensive and easily available adsorbent has been active in adsorption study. In this paper, the adsorption properties and adsorption mechanism were investigated by experiments, which may provide the theory bases the development of steel slag's adsorbent.Based on the adsorption experiments of heavy metals onto steel slag , the effects on the adsorption of Pb2+> Cr3+ of many factors, such as the mesh of steel slag , pH, the absorbent's dosage, contact time and the initial ionic concentration were studied. The experimental results indicated that the steel slag had a high removal rate of Pb2\ Cr3+. For Cr3+, under the operation conditions that its initial concentration of Cr3+ was below 400mg/l, adsorption time was 50 minutes and the quality ratio of Cr3+ to steel slag equaled 1/300, the effluent could be effectively treated to fit in with the needs of national drainage standards. For wastewater containing Pb2+, its removal efficiency came up to 94%, under the conditions of 50?00mg/l of Pb2+, 1/200 of Pb2+/slag. In addition, the adsorption of heavy metals onto steel slag could adapt to wide pH. Comparing with activated carbon, the steel slag showed more high removal efficiency of Cu2\ Pb2\ Cr3+% Zn2+.Based on the adsorption experiments of organic compounds, the adsorption of phenol and aniline onto steel slag were tested. The results showed that the steel slag had more high adsorptive efficiency for aniline than that for phenol. The steel slag modified by CTMAB demonstrated a good adsorption ability of phenol. The removal of phenol onto modified steel slag was related with the concentration of CTMAB .The adsorption mechanism of steel slag was complicated and involved many forces, but the ion-exchange was the chief adsorption form. The steel slag can selectively adsorb some ions, which was relative to ionic charge, ionic radius and effective hydrated ionic radius. The adsorption process of Cr3+ met with Freundlich equation, and the adsorption process of Pb2+ met with Langmuir equation .