响应面优化Fe_3O_4@酵母固定床吸附及其类Fenton再生

Absorption optimization in fixed-bed using Fe_3O_4@ yeast composites by response surface methodological and their regeneration

通过静电自组装法制备Fe_3O_4@酵母,并对其进行SEM和XRD表征。以亚甲基蓝模拟染料废水,采用响应面方法(Response Surface Methodology,RSM)中Box-Behnken Design(BBD)设计法对溶液初始质量浓度、流速和p H等影响因素进行了优化。通过分析试验结果,建立了以去除率为响应值的二次多项式模型,预测最佳条件为亚甲基蓝初始质量浓度为101.21 mg/L,流速为5.48 m L/min,p H=10.75,去除率为63%,在此条件下做验证性实验3次,最终实测去除率均值为61.86%,与预测值具有良好的一致性。对亚甲基蓝去除率影响的大小顺序为X3>X2>X1,即溶液p H>溶液流速>溶液初始质量浓度。对Fe_3O_4@酵母复合微球的多相类Fenton再生进行了研究,基于酵母菌的生物吸附和纳米Fe_3O_4的非均相Fenton反应的耦合作用,Fe_3O_4@酵母复合材料具有良好的可再生性。

Fe3O4@ yeast composites are synthesized by a simple electrostatic-interaction-driven self-assembly heterocoagulation. The composites are characterized by field emission scanning electron microscopy（ FE-SEM） and powder X-ray diffraction（ XRD）. The obtained Fe3O4@ yeast composites are then used in an up-flow packed column to remove the model water contaminant methylene blue dye（ MB） by consecutive biosorption-heterogeneous Fenton oxidation regeneration. The optimization is performed by using Box-Behnken Design（ BBD） type of response surface methodology（ RSM）. The secondary polynomial regression model is established with removal rate as response parameter.Under the optimal conditions,the removal rate is 61. 86%,which is very close to the predicted value of 63%. The in-situ regeneration of the contaminant-loaded Fe3O4@ yeast microspheres in multiple cycles is studied through triggering the heterogeneous Fenton-like reaction catalyzed by the supported magnetite,owing to coupled interaction of biosorption features of yeast cells and the excellent Fenton catalytic properties of Fe3O4 nanoparticles.