[Removal of metal ions Cu2+, Cd+ and Pb+ from solutions by sorption on slag].
Batch experiments were carried out to investigate the adsorption kinetics and thermodynamic characteristics of heavy metal ions Cu2+, Cd2+ and Pb2+ on the electric are furnace (EAF) slag from Baoshan Steel Factory. Several kinds of techniques including XRD analysis, BET specific surface analysis and SEM/EDS analysis were employed to determine the physico-chemical and surface characteristics of slag. Results indicated that the adsorption rate of heavy metal ions on the EAF slag was relatively high, and the sorption rate followed the order Cd2+ > Pb2+ > Cu2+. The adsorption kinetics obeyed first-order kinetics model (R2 > 0.99). Adsorption isotherm experiment showed that adsorption isotherm of heavy metal ions on slag fitted Langmuir model, and the maximum adsorption capacity of Cu2+, Cd2+ and Pb2+ was 0.101, 0.058 and 0.120 mmol x g(-1), respectively. The adsorption of heavy metal ions on slag was a spontaneous reaction (deltaG0 < 0) with endotherm (delta H0 < 0) and the increase of enthopy (AS0 > 0). The effect of enthopy was the main driving force of the spontaneous adsorption reaction. The analysis results of SEM/EDS revealed the changes of surface morphology and chemical proportion before and after adsorption. Due to low-cost and high-efficiency, electric are furnace slag showed great potential for the treatment of heavy metal polluted wastewaters.
Chen
Xiao
X
School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. xchen82@hotmail.com
Hou
Wen-hua
WH
Wang
Qun-hui
QH
D000327:Adsorption; D002104:Cadmium / Q000737:chemistry / Q000302:isolation & purification*; D003300:Copper / Q000737:chemistry / Q000302:isolation & purification*; D007220:Industrial Waste / Q000517:prevention & control; D007854:Lead / Q000737:chemistry / Q000302:isolation & purification*; D013232:Steel / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods
D007220:Industrial Waste; D002104:Cadmium; D013232:Steel; D007854:Lead; D003300:Copper