Optimization of Cr(Ⅵ)Removal by Nanoscale Zero-Valent Iron on Modified Diatomite via Response Surface Methodology
In recent years,nanoscale zero valent iron(NZVI)has been widely used in research on the removal of Cr(Ⅵ)from water due to its high reducibility and high specific surface area.This article uses chitosan modified diatomaceous earth(CDt)to load NZVI and prepare diatomaceous earth supported nano zero valent iron(NZVIA CDt),and optimizes its conditions for removing Cr(Ⅵ)from water using response surface methodology.A response surface design(Box-Behnken Design,BBD)was conducted with four response factors:load ratio(mass ratio of CDt to NZVI),temperature,reaction time,and pH value of the reaction solution.The removal rate of Cr(Ⅵ)in water was used as the response value,and a response surface model was established.The analysis results show that the model has a good fit throughout the regression region,and the four factors have a significant impact on the Cr(Ⅵ)removal rate(F value is 146.83).The order of influence is solution pH value＞load ratio＞reaction time＞temperature.The optimal removal conditions obtained through model optimization are:load ratio of 3:1,temperature of 30 ℃,reaction time of 35 minutes,pH=4,and the predicted maximum removal rate of Cr(Ⅵ)is 97.81％.The prediction results of the model were validated through three parallel experiments,and the predicted values were higher than the actual values with an absolute error of 1.93％,indicating a good fit between the predicted values and the actual values.This study optimized the reaction conditions for removing Cr(Ⅵ)from water using NZVI CDt,providing data support and theoretical basis for the practical application of NZVI CDt.
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万方数据
维普
