Experimental study on removing Cr from aqueous solutions by coal fly ash carbon with adsorption

Power plant fly ash can be maked with better adsorption capacity of coal fly ash carbon, To study the effect of different pH, dosage, time, temperature, solution concentration, adsorption methods on Cr removal by coal fly ash carbon.The results showed that the adsorption reaction is endothermic process; With the acidity of pH=2, the maximum adsorption capacity of Cr (Ⅵ) was 4.67 mg/g at 25 ℃ constant temperature, with the ratio of Cr and coal fly ash carbon is 250, and the contacing time over 120 min; Using NaOH solution to desorb Cr from the Cr-saturating coal fly ash carbon, the concentration of 0.05 mol/L is the most effective, desorb rate is 129%. Wastewater produced by discards printed circuit boards wet process, which Cr (Ⅵ) concentration is 0.62mg/L, in the above condition, the removal rate of Cr (Ⅵ) is 95.16%; If under the condition of natural pH, Cr (Ⅵ) removal rate can reach 91.94%, also meet the integrated wastewater discharge standard. The treatment of metal containing wastewater by coal fly ash carbon has a promising future.