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To investigate effects of fluoride on lead adsorption by iron-oxide-coated sand (IOCS). Fluoride concentration varies at 0.5, 1.0 and 10 ppm from pH 4 to 10. At the same pH range, ionic strength varies at 0, 0.05 and 0.10 M. Lead and fluoride adsorption by IOCS could saturate within 24 hours. Lead adsorption would decline if the initial lead concentration increased. In contrast, fluoride adsorption would raise if the initial fluoride concentration increased. Both lead and fluoride adsorption was the function of pH. Lead adsorption was good from pH 5 to 8 and pH 6 was the optimum. fluoride adsorption was good at the low pH from 4 to 5 and it was worse for higher pH. lonic strength was not affected to Lead adsorption so Lead adsorption was the inner-sphere surface complex. After the experiment, adsorption of the lead and fluoride mixture was similar to lead or fluoride adsorption by IOCS. Therefore, fluoride adsorption would be the outer-sphere surface complex. And the optimal condition for lead and fluoride removal was at the 1/10 of lead/fluoride portion by mole and pH 6. When IOCS was applied for lead adsorption from the industrial wastewater. The optimal condition was different from the laboratory. The optimal pH was at 8 that was higher than the experimental pH because lead adsorption may be affected by the contamination of these industrial wastewater

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