敌草隆在市售草木灰及生物质电厂灰上的吸附特性研究

Sorption characteristics of diuron on merchant biomass ash and biomass power plant ashes

对1种市售草木灰及3种生物质电厂灰的表面性质及化学组成进行表征,研究了它们对农药敌草隆的吸附等温线及吸附动力学特征.结果表明,无论市售生物质灰还是生物质燃料燃烧后的废灰,对敌草隆的吸附均为复杂的多反应过程,这与它们复杂的空洞结构和化学组成有关.BET表面积标化吸附量显示,微孔和中孔较多的电厂灰1和电厂灰3,单位表面积的体积饱和吸附量较高,表明表面积及孔径分布是影响吸附不可忽视的重要因素.有机碳含量标化吸附系数显示,饱和烷烃及芳香烃类非极性化合物含量较高的电厂灰的标化吸附系数均大于羧基等极性化合物含量较高的市售生物质灰,表明有机质含量及有机质的化学组成,尤其是非极性有机物的含量是影响疏水性有机化学品吸附容量的重要因素.以上结论暗示着生物质电厂灰在污染底质原位治理方面具有很大的应用潜力.

The surface characteristics and chemical compositions of 1 merchant biomass ash and 3 biomass power plant ashes were measured.The sorption isotherms and kinetics of one pesticide-diuron were examined.The data demonstrated that the sorption models of diuron on both merchant biomass ash and biomass fuel ashes were complex multi-reaction process.It was presumably due to their complex space configuration and chemical compositions.BET surface area-normalized maximal sorption quantities showed that power plant ash1 and 3 with the highest micro-and meso-pores exhibited the highest surface area-normalized saturated sorption quantity,implying that surface area and pore size distribution of sorbents were crucial factors determining saturated sorption quantities.The organic carbon content-normalized sorption capacities indicated that the power plant ashes,which contained higher contents of paraffin and aromatic hydrocarbons,exhibited higher normalized sorption capacities than merchant plant ash,which had higher content of carboxyl groups.It was implied that the organic carbon content and chemical composition,especially the content of non-polar organic matter,strongly influenced the sorption capacity of hydrophobic organic chemicals.The results indicated that the biomass power plant ashes can be used at in-situ sorbent amendments of contaminated sediment.