摘要
研究了树皮原位固化落叶松单宁对水溶液中Cr6+的吸附特性。结果表明,Cr6+在该吸附剂上的吸附属于氧化还原吸附,即Cr6+首先被还原为Cr3+,然后被吸附。当温度为303 K、pH值2.0、Cr6+的初始质量浓度为297.3 mg/L时,该吸附材料对Cr6+的平衡吸附量为183.6 mg/g,随着温度的升高平衡吸附量增加。pH值对平衡吸附量的影响较大,静态吸附时,产生最大吸附容量的pH值为2.0,这是由于该pH值条件有利于Cr6+的还原反应。该吸附材料对Cr6+的吸附平衡符合Freundlich方程;吸附动力学可以用拟二级速度方程来描述。固定床吸附实验表明,当原料液的Cr6+质量浓度为232.4 mg/L,流出液的体积约为120个床层体积时达到穿透点。
The adsorption behaviors of Cr^6＋ by in situ immobilized larch tannin were investigated. It was found that the adsorption is characterized by redox adsorption, that is, Cr^6＋ is first reduced into Cr^3＋ and then adsorbed. The adsorption capacity of this adsorbent to Cr^6＋ was 183.6 mg/g at 303 K when initial concentration of Cr^6＋ was 297.3 mg/L and pH value was 2.0, and the adsorption capacity was increased with the increase of temperature. The optimal pH value for the adsorption of Cr^6＋ was 2.0 because the reduction of Cr^6＋ is accelerated under acidic condition. The adsorption isotherm of Cr^6＋ by in situ immobilized larch tannin can be described by the Freundlich equation. The data of adsorption rate can be well fitted by the pseudo-second-order rate model. The breakthrough point of Cr^6＋ in adsorption column was around 120 bed volumes when the inlet concentration of Cr^6＋was 232.4 mg/L.
出处
《林产化学与工业》
EI
CAS
CSCD
2007年第6期1-7,共7页
Chemistry and Industry of Forest Products
基金
国家自然科学基金资助项目(20476062)
国家杰出青年基金资助项目(20325619)
关键词
单宁
落叶松树皮
原位固化单宁
吸附
tannin
larch bark
in situ immobilized tannin
adsorption
