粉煤灰活性炭吸附含Cr废水试验研究

利用电厂粉煤灰可制备出具有较高吸附性能的粉煤灰活性炭.研究了不同pH值、投加量、时间、温度、溶液浓度、脱附方法条件下粉煤灰活性炭对Cr(Ⅵ)吸附性能的影响.结果表明,吸附反应为吸热过程;当粉煤灰活性炭掺入比为1∶250、pH值为2、25℃恒温振荡120 min时,粉煤灰活性炭最大吸附容量能达到4.67 mg/g;Cr饱和的粉煤灰活性炭,用0.05 mol/L浓度的NaOH脱附效果最佳,脱附率为129%.废弃印刷线路板湿式处理工艺中产生的废水,含Cr(Ⅵ)0.62 mg/L,在上述条件下,Cr(Ⅵ)去除率达95.16%;若在自然pH条件下,Cr(Ⅵ)的去除率能达到91.94%,均符合污水综合排放标准.粉煤灰活性炭用于含金属废水的处理有着广阔的应用前景.

Removing Cr from aqueous solutions by coal fly ash carbon with adsorption

Power plant fly ash can be used to prepare coal fly ash carbon with strong adsorption capacity. The impact of coal fly ash carbon on Cr adsorption capacity is studied under the condition of different pH, dosage, time, temperature, solution concentration, adsorption methods. The results show that the adsorption re-action is endothermic process;with the acidity of pH=2, the ratio of Cr and coal fly ash carbon of 250 , and the contacting time over 120 min, the maximum adsorption capacity of Cr （Ⅵ） can hit 4.67 mg/g at 25 ℃ constant temperature. 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 with desorb rate of 129 %. Wastewater produced by discards printed circuit boards wet process,in which Cr（Ⅵ） concentration is 0.62 mg/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%, both meet the integrat-ed wastewater discharge standard. The treatment of metal containing wastewater by coal fly ash carbon has a promising future.