【摘要】 研究了钢渣-蒙脱石复合吸附剂对废水中Cd2+的吸附性能,并探讨了影响吸附的因素和吸附机理.结果表明,钢渣蒙脱石质量比为1∶1的复合吸附剂对Cd2+的吸附效果优于钢渣及蒙脱石对Cd2+的单一吸附.当温度为25℃,废水pH=6~7时,1.2 g钢渣-蒙脱石复合吸附剂对100 mL Cd2+溶液(100 mg·L-1)吸附60 min后,Cd2+的去除率可达到96.99%.钢渣-蒙脱石复合吸附剂对镉离子的吸附反应符合二级动力学方程,可决系数为0.9991;符合Langmuir方程,可决系数为0.9725.对Cd2+的理论饱和吸附量为12.45 mg·g-1.溶液中Pb2+、Cu2+的存在会降低复合吸附剂对Cd2+的吸附量,且Cd2+受Cu2+的影响较大.吸附饱和的钢渣-蒙脱石颗粒材料用1 mol·L-1的氯化钠溶液再生效果好.更多还原

【Abstract】 The adsorption behavior of Cd2 +from aqueous solution was investigated using a composite adsorbent derived from steel slag and montmorillonite. The adsorption capacity of composite adsorbent was enhanced compared with that of the steel slag or montmorillonite alone. The removal rate of Cd2 +reached 96. 99% at loading rate of 12 g·L- 1composite adsorbent( initial Cd2 +concentration of 100 mg·L- 1) within 60 min in the condition of 25 degrees Celsius and p H value from 6 to 7. The coefficient of determination( R2= 0. 9991) agreed well with pseudo second-order kinetics.The adsorption isotherms of composite adsorbent for Cd2 +could be described by the Langmuir isotherm model( R2= 0. 9725). The value of maximum adsorption capacity was 12. 45 mg·g- 1based on the analysis of Langmuir model. Further analysis indicated that the Cd2 +adsorption was influenced by Pb2 +and Cu2 +ions,which occupied adsorptive sites on the adsorbent surface. And competitive effect of Cu2 +ions on Cd2 +adsorption was stronger than that of Pb2 +ions in aqueous solution. The regeneration effect for the adsorbent was optimized using 1 mol·L- 1Na Cl solution.更多还原