铁锰氧化物/坡缕石复合材料吸附磷的性能

将铁锰氧化物与坡缕石黏土结合制备了复合材料FO/P、MO/P和FMO/P,由静态吸附实验研究了复合材料吸附磷的性能,考察了氧化物与坡缕石质量比、焙烧温度、溶液p H值、离子强度和振荡时间对吸附量的影响,探讨了吸附动力学、吸附平衡和机理。结果表明,FMO/P的吸附性能优于FO/P和MO/P,铁锰氧化物与坡缕石黏土的质量比为0.1的FMO/P对20mg/L的磷溶液去除率可达95%,吸附量明显受溶液p H的影响,离子强度对吸附量影响较小,磷吸附在复合材料表面主要形成内层络合物,60 min可基本达吸附平衡,过程符合pseudo-second-order方程,具有化学吸附的性质,FMO/P吸附等温线符合Freundlich方程,有不均匀吸附的性质,饱和吸附量达49 mg/g。

Phosphate Adsorption Characteristics of Fe-Mn Oxide/Palygorskite Composites

The composites FO/P, MO/P and FMO/P were prepared by combining Fe-Mn oxide and palygorskite clay. The batch experiments were carried out to investigate adsorption characteristics of phosphate on composites namely adsorption kinetics, isotherm and mechanism, the effects of mass ratio of metal and palygorskite, calcination temperature, solution pH, ionic strength and vibration time. Results indicate that adsorption performance of FMO/P is better than FO/P and MO/P and its phosphate removal ratio attains 95% towards 20 mg/L phosphate solution when mass ratio of metal and palygorskite is 0.1.Adsorption is highly pH dependent while ionic strength has no significant effect and phosphate removal is achieved by the formation of inner-sphere surface complexes. Adsorption equilibrium can be reached in about 60 min and adsorption processes follow pseudo-second-order equation most effectively with the characteristic of chemical adsorption. Freundlich equation can be more suitable to describe adsorption isotherm of FMO/P, revealing higher heterogeneous adsorption and saturation adsorption capacity estimated from Langmuir equation reaches 49 mg/g.