Study on Adsorption of CrO_4~(2-) by FeOOH-Modified Diatomite

Adsorption of CrO42-by FeOOH-modified diatomite was investigated with a batch method in the study.The results indicated that,under the condition of pH value 1.0,mass concentration of Cr(Ⅵ) in wastewater lower than 100mg/L,dosage of the adsorbent 0.5g and adsorption equilibrium time about 30 min,the removal rate of Cr(Ⅵ) can reach 85%.Adsorption dynamics of Cr(Ⅵ) adsorption on the composite adsorbent can be well described by pseudo-second order equation.Not only Freundlich adsorption equation but also Langmuir adsorption equation can describe the adsorption process well.This may be attributed to the coexistence of monolayer adsorption and multilayer adsorption in the adsorption.