Keywords: 
• mixed media /
• humic acid (HA) /
• groundwater /
• PRB

Abstract: Experimental batch study was conducted to remove humic acid (HA) from simulated groundwater using mixed media. The effects of ingredient, particle size, solid-liquid ratio, pH and temperature on HA removal efficiency were discussed. The concentration of HA was analyzed by UV-spectrometer. The results indicated that the efficiency of HA removal was above 95% at reaction time of 4 hours and initial pH of 6.34. When the reaction time was 1 hour, the removal efficiency increased with particle size decreasing. Both small and medium particle sizes performed better than the large one with regard to the removal when the reaction time varied from 2 to 6 hours. The efficiency had a positive correlation with solid-to-liquid ratio, but the removal efficiency could not limitlessly increase with solid-to-liquid ratio. When it changed between 1∶200 and 1∶50, the removal efficiency reached a plateau phase. Though pH had little effect on the removal efficiency, temperature had a significant effect on HA removal. The removal efficiency at 16.8℃ was lower about 5% than that at 35.0℃. It is effective and feasible to remove HA from groundwater by the mixed media, and the media can be applied for PRB（permeable reactive barrier）as a kind of potential reactive medium.