为了研究粉煤灰活性炭的吸附性能,以原粉煤灰和纯活性炭作对照,比较3种吸附剂在不同时间、pH和投加量下处理含Cu(Ⅱ)废水的性能.结果表明,在pH 5,吸附时间60 min的条件下,纯活性炭、粉煤灰活性炭和粉煤灰对含Cu(Ⅱ)废水的去除率依次为100%、97%和78.7%,粉煤灰活性炭吸附性能接近纯活性炭.Cu饱和的粉煤灰活性炭,用0.2 mol.L-1浓度的HCl清洗解吸效果最好.在饱和吸附和解吸重复10次后,再生粉煤灰活性炭的吸附容量下降20%,接近活性炭的18%,充分说明粉煤灰活性炭有较好的可再生性.粉煤灰制成粉煤灰活性炭,用于含金属废水的治理,不仅效果好、成本低,还是粉煤灰资源化的重要途径,有广阔的应用前景.
Coal ash released from power plants contains unburned carbon, which can be extracted and made into activated carbon through the flotation-concentration method. In order to study its adsorbing capability, the experiment of using this activated carbon to remove Cu (Ⅱ) from Cu-containing wastewater under different reaction time, pH and inputs, was carried out, with the original coal ash and pure activated carbon being served as controls. The results showed that the rates of Cu (Ⅱ) removal from the Cu-containing wastewater treated with the pure activated carbon, the activated carbon made from coal ash and the original coal ash are 100%, 97% and 78.7%, respectively, under the reaction condition of pH 5 and 60 minutes, which suggests that the adsorption capability of the activated carbon made from coal ash is close to that of the pure activated carbon. Using HC1 solution to desorb Cu (Ⅱ) from the Cu-saturating activated carbon, the concentration of 0. 2 mol- L^-1 is the most effective. The adsorbing capability of the regenerated activated carbon made from coal ash decreases by 20% after alternating between the saturating adsorption and desorption of Cu (Ⅱ) for ten times, which is close to that of the pure activated carbon by 18%. This fully suggests that the activated carbon made from coal ash also has the advantage of good reproducibility. Therefore, using the activated carbon made from coal ash for the recovery of metal-containing wastewater not only has perfect effects, but also is low cost. Moreover, this is also a good way for the reclamation of coal ash and hence has a promising future.