生物炭/铁质黏土矿物复合材料介导乳酸钠还原六价铬的机理研究

采用热解法与浸渍—共热解法分别制备原始生物炭(PB)和生物炭/铁质黏土矿物复合材料(PFB),并将PB和PFB作为电子穿梭体介导弱电子供体乳酸钠还原六价铬[Cr(Ⅵ)]。通过测定PB和PFB电化学活性及导电性,以及生物炭介导Cr(Ⅵ)还原的反应动力学,比较PB和PFB的电子穿梭效能,并通过相应的表征分析探究PFB作为电子穿梭体介导乳酸钠还原Cr(Ⅵ)的作用机理。结果表明,PFB具有更高的比电容和电荷传递速率,可作为电子穿梭体促进乳酸钠还原Cr(Ⅵ)。

The primary biochar(PB)and iron-clay biochar composite(PFB)were prepared by pyrolysis and impregnation co-pyrolysis,respectively,and the reduction of hexavent chromium[Cr(Ⅵ)]was mediated by weak electron donor sodium lactate using PB and PFB as electron shuttles.Through measuring the electrochemical activity,conductivity and the reaction kinetic of biochar mediated reduction of Cr(Ⅵ)to compare the electron shuttle efficiency of PB and PFB,and the mechanism of PFB as electron shuttle mediated reduction of Cr(Ⅵ)by sodium lactate was explored through corresponding characterization analysis.The results show that PFB has higher specific capacitance and charge transfer rate,and can act as electron shuttle to promote sodium lactate to reduce chromium hexavalent.