铬酸盐的活性炭吸附行为

Adsorption Behavior of Chromate onto Activated Carbon Particles

为研究变价元素在活性炭颗粒上的吸附行为及吸附过程中的价态变化 ,以阐明高价金属盐阴离子的活性炭吸附实质 ,我们观察了铬酸盐在活性炭颗粒上的吸附情况以及外界条件对吸附作用的影响。结果发现铬酸盐既可被活性炭颗粒直接吸附 ,又可被活性炭颗粒还原 ;其吸附和还原均强烈依赖于 p H值和泵速。铬酸盐的还原产物主要为 Cr( ) ,Cr( )也可在 p H>4的条件下被吸附并被 1 %硫酸水溶液洗脱。

In this paper, the adsorption behavior of chromate onto activated carbon particles was studied as a function of pH, flow rate and the concentration of tested anion. The results showed that chromate anion was not only reduced but also adsorbed by activated carbon particles. the percentages of reduction and adsorption were strongly dependent on the pH value and the flow rate. In the medium of pH<10, chromate anion could be adsorbed directly onto the activated carbon particles and the adsorbed chromate could be eluted from activated carbon particles by 1mol/L NaOH without valence change. The reduced product of chromate anion was mainly Cr(Ⅲ),Cr(Ⅲ) could be adsorbed in the pH>4 medium by the activated carbon particles and eluted with 1%H 2SO 4.