研究了不同制备条件下,板栗壳活性炭对重金属离子Cu2+和Cd2+的静态吸附性能。以板栗壳为原料,采用ZnCl2活化法制备活性炭,使用X-射线衍射、扫描电镜、氮气吸附等方法对活性炭进行表征;比较了活性炭内部结构对Cu2+和Cd2+的吸附性能影响;同时考察了吸附温度、溶液pH值等对Cu2+和Cd2+的吸附性能的影响。研究结果表明:板栗壳制备活性炭最佳条件为ZnCl2活化浓度30wt%,料液比1:6,炭化温度600"C,炭化时间3h;同时发现板栗壳活性炭是一种具有较多孔隙的无定型炭材料,所制备的活性炭平均孔径为2-6nm,孔容为0.04~0.14cm3/g,比表面积可以达到1500m2/g以上;板粟壳活性炭对重金属离子的吸附性能主要由本身的比表面积和孔容大小决定,且同时受吸附温度和溶液pH值的影响,上述条件制备的活性炭吸附Cu2+的最佳条件为温度25℃,溶液pH值为6.5;吸附Cd2+的最佳条件为温度25~C,溶液pH值为7.5。
Adsorption performance of heavy metals ions, copper ions and cadmium ions, by chestnut shell activated carbon was researched in this paper. The activated carbon was prepared with chestnut shell as raw material by the zinc chloride activation method. The prepared activated carbon was characterized by X-ray diffraction, nitrogen adsorption, scanning electron microscopy and so on. Meanwhile the adsorption performance of copper ions and cadmium ions by chestnut shell activated carbon was investigated under different conditions, such as internal structure of activated carbon, adsorption temperature and pH value. The results showed that the optimal preparation conditions of chestnut shell activated carbon were as follows, concentration of zinc chloride was 30wt%, solid-liquid ratio was 1:6, activation temperature was 600℃, and carbonization tirnc was 3h. Microcrystallinc structure of graphite could be found in the SEM images of chestnut shell activated carbon, the pore size of activated carbon was 2-6nm, the pore volume was 0.04-0.14cm3/g, and the specific surface area was up to 1500m2/g or more. Adsorption properties of heavy metal ions was not only mainly determined by BET surface area and pore volume size of chestnut shell activated carbon, but also simultaneously affected by the adsorption temperature and pH value of the solution. The optimal conditions for copper ions and cadmium ions were pH value of 6.5 and 7.5, respectively, under room temperature of 25℃.