粉煤灰对二价金属离子的吸附特性

考察了粉煤灰对二价金属离子的吸附性能.结果表明，粉煤灰可有效吸附水溶液中的重金属离子.吸附由易到难次序为：Pb>Cu>Cd>Zn.随pH升高，去除率增加.吸附在约60 min内达到平衡.等温吸附数据符合Freundlich模型，但在pH=4.5时表现为单一线性区，而在pH= 6和pH=8时表现为2个线性区.粉煤灰对金属离子的吸附明显受到其它共存离子的影响，Cd与Pb之间存在较强的协同吸附作用.对实际废水的测试表明，粉煤灰可同时有效去除工业废水中多种金属离子.

Adsorption properties of fly ash towards bivalent metal ions

The experiments were performed to evaluate the use of coal fly ash particles as an adsorbent for bivalent metal ions.The results show that coal fly ash is very effective for the adsorption of heavy metal ions in aqueous solutions.Adsorption of heavy metals is favorable in the order Pb>Cu>Cd>Zn.With increasing pH,the removal percent of metal ions increase.Adsorption equilibrium is achieved in about 60 min.The isotherm adsorption data correspond with the Freundlich model well.However,the adsorption isotherm data appear as one linear region at pH=4.5 and two distinct linear regions at pH=6 and pH=8.When various heavy metals coexist,the adsorption of a particular heavy metal ion is influenced significantly by other ions.It is exhibited significant synergistic effect between Cd and Pb during adsorption process.The results of the tests using real wastewater reveal that fly ash is effective in the simultaneous removal of various heavy metals in metal industrial wastewater.