生物质炭对溶液中Cd^(2+)的吸附

Adsorption of Cd^(2+) in aqueous solution by biochars

以玉米秸秆、稻壳在350~500℃制成的生物质炭作为吸附剂,研究其对溶液中Cd2+的吸附特性。通过模拟实验,考察了初始p H、生物质炭用量、吸附时间和Cd2+的起始浓度对吸附的影响。结果表明,2种生物质炭对Cd2+的吸附反应适应p H范围较宽(4.0~7.0);玉米秸秆炭和稻壳炭对Cd2+的吸附速度较快,分别在10和20 min时达到吸附平衡;玉米秸秆炭对溶液中Cd2+的吸附遵循Langmuir等温线模型,而稻壳炭对Cd2+的吸附遵循Freundlich等温线模型。在实验设定的条件下,玉米秸秆炭对溶液中Cd2+的吸附能力强于稻壳炭。

Biochars were produced from corn straw,rice husk respectively,at 350 ~ 500℃. Through simulation experiments,adsorpions of Cd2 +in aqueous solution by two biochars were investigated,and effects of p H values,biochars doses,contact time and initial concentrations of Cd2 +on the adsorptions were investigated. The results indicated that the adsorption reactions for Cd2 +removal could be carried by wide adaption range of p H( from4 to 7). The adsorption reactions were quick and the adsorption equilibrium times were 10 minutes and 20 minutes on corn straw biochar and rice husk biochar,respectively. The adsorptions of Cd2 +in aqueous solution were well described by Langmuir adsorption model on corn straw biochar,while Freundlich adsorption model on rice husk biochar. Under designed test conditions,corn straw biochar had better adsorption capability on Cd2 +in aqueous solution than rice husk biochar.