用高锰酸钾改性提高竹炭对Cu^(2+)的吸附能力

Cu^(2+) Adsorption Improvement of Bamboo Charcoal with KMnO_4

采用KMnO4溶液在回流状态下对竹炭进行改性,得到改性竹炭。比较研究了KMnO4浓度对Cu2+在竹炭上的吸附率-pH曲线的影响,并研究了KMnO4改性对竹炭吸附和解吸Cu2+性能的影响。静态吸附试验表明,KMnO4改性使竹炭对Cu2+吸附率-pH曲线及pH50向低pH偏移,当KMnO4溶液浓度为0.04mol/L时,改性效果最好;KMnO4改性使其投加量节省约2倍;竹炭对Cu2+的吸附均遵循Langmuir单分子层吸附规律,在相同Cu2+平衡浓度下,改性后的竹炭对Cu2+的吸附量提高约53%,升高温度能明显提高改性竹炭对Cu2+的吸附能力,40℃的饱和吸附量是25℃的1.69倍。KMnO4改性提高了竹炭从水中吸附重金属离子的能力,并改善了其解吸再生性能。

Bamboo charcoal （BC） was treated with KMnO4 solution under refluxing condition to prepare the new modified bamboo charcoal. The influence of KMnO4 concentration on the Cu2＋ adsorption rate-pH curves and pH50 was investigated. The modification with KMnO4 affected the adsorption and desorption capacity of bamboo charcoal to Cu2＋ . The results show that the Cu2 ＋ adsorption rate-pH curves and pH50 of bamboo charcoal move to low pH after modification with KMnO4. The best result achieved at 0.04 mol/L KMnO4. The modification with KMnO4 improves the adsorption rate of Cu2＋ and reduces the consumption of adsorbent about threefold than that of unmodified bamboo charcoal. The adsorption isotbermals of Cu2＋ over the modified and unmodified bamboo charcoal match to Langmuir monolayer adsorption. On the same condition of equilibrium concentration of Cu2 ＋ , the adsorption amount of Cu2 ＋ over bamboo charcoal modified with KMnO4 increases about 53% than that of the unmodified bamboo charcoal. Moreover, the Cu2＋ adsorption capacity of the modified bamboo charcoal can be improved obviously with the increase of temperature. At 40 ℃, the saturated adsorption amount of Cu2＋ is 169% as much as that of at 25 ℃. The modification of bamboo charcoal with KMnO4 not only increases the adsorption capability of bamboo charcoal to heavy metal ions, but also improves the ability of desorption-regeneration of bamboo charcoal.