温度、pH值及盐度对龙须眼子菜吸附镉、铅的影响

Influence of temperature, pH value and salinity on cadmium ( Ⅱ ) and lead( Ⅱ) adsorption by Potamogeton pectinatus

以龙须眼子菜（Potamogeton pectinatus）干样为材料，研究了不同温度、pH值和盐度对龙须眼子菜吸附镉、铅离子的影响。结果表明，不同温度及不同pH值下龙须眼子菜对镉吸附符合Langmuir模型，对铅的吸附符合Freundlich模型。与5℃、10℃、30℃处理相比，20℃时龙须眼子菜对镉、铅的吸附能力较强。当其它条件不变时，在pH值为3～7的范围内，龙须眼子菜对镉的吸附随pH值升高而增加，对铅的吸附随pH值升高而减少。在0．5～10g·L^-1的盐度范围内，随着溶液盐度的增加龙须眼子菜对镉吸附减少，但对铅的吸附却增加。龙须眼子菜是一种对镉、铅有很强的吸附能力的沉水植物，对温度、酸碱度、盐度适应范围也很广，因而可作为生物吸附剂用于含镉、含铅废水的处理。

The adsorption of Cadmium （Ⅱ） and lead（Ⅱ） ions onto dried Potamogeton pectinatus, a submerged aquatic plant, was studied under different values of temperature, intitial pH and salinity. The equilibrium was well described by Langmuir model for cadmium （ Ⅱ ） and Froundlich model for lead （ Ⅱ ）. Compared with the condition of 5 ℃, 10 ℃ and 30 ℃, the maximum adsorption of Cd and Pb was determined at 20 ℃. With the pH value ranged from 3 to 7, Cd adsorption increased and Pb decreased in P. pectinatus. Inversely, as salinity increases from 0.5 g·L^-1 to 10 g·L^-1, the adsorption of Cd decreased and Pb increased in P. pectinatus. P pectinatus can adsorb large amount of Cadmium （Ⅱ） and lead （ Ⅱ ） ions and is of wide adaptability for temperature, pH value and salinity. So it can be used as a biosorbent for purification of the metal-bearing wastewater.