生物质竹炭对水中Cd2+的吸附行为研究

摘要

以竹炭和经化学改性竹炭作为吸附剂，研究其对水溶液中Cd2+的吸附特性，探讨了竹炭对Cd2+的吸附热力学和吸附动力学性质，通过单因子优化实验探讨了温度、竹炭投加量和pH值对吸附效果的影响。结果表明：竹炭及改性竹炭对Cd2+的吸附动力学过程符合准二级动力学模型，在18h可达到平衡；其等温吸附曲线符合Langmuir方程，最大吸附量分别为10．18mg/g和16．71mg/g；两者对Cd2+的吸附受温度的影响较小；竹炭及改性竹炭的最佳投加量分别为0．8g、0．6g；pH对竹炭及改性竹炭吸附Cd2+的影响较大，在pH 2~6范围时，竹炭及改性竹炭对Cd2+的吸附量随pH的增加而增加。%Bamboo charcoal and chemically modified bamboo charcoal are picked as adsorbent to study the adsorption of Cd2+in a-queous solution. Through the single factor optimization experiment,adsorption isotherm,kinetics and effect factors such as tempera-ture,dosage and pH are investigated. Sorption kinetics of Cd2+ onto bamboo charcoal followed pseudo second order kinetics model, and equilibrium can be achieved in 18h. Adsorption isotherm fit well with Langmuir equation,and the maximum adsorption amounts of Cd2+ on bamboo charcoal and chemically modified bamboo charcoal are 10. 18 mg/g and 16. 71 mg/g,respectively. The influence of temperature on the adsorption of Cd2+by the both is little. The best dosages of bamboo charcoal and chemically modified bamboo charcoal are 0. 8g and 0. 6g,respectively. The pH effect on the adsorption of Cd2+by bamboo charcoal and chemically modified bam-boo charcoal is strong,when pH is 2 to 6,the adsorption of Cd2+increases with pH.