生物炭墙对紫色土坡耕地中氟苯尼考迁移影响

采用实验室批量平衡实验，研究紫色土坡耕地土壤中氟苯尼考吸附-解吸特征及生物炭施用的影响，此外，开展野外坡底生物炭（重量占比5%）可渗透反应墙的构建试验，观测自然降雨条件下该反应墙对坡耕地小区中氟苯尼考随地表径流与下渗水迁移的影响.结果表明，氟苯尼考在紫色土中的等温吸附行为符合Freundlich方程，在低浓度范围内（<2mg/L），生物炭的施用一方面提高了其在紫色土中的吸附量，吸附过程可能以内扩散为主，另一方面，显著降低其解吸量；紫色土坡耕地中的淋溶作用是氟苯尼考的主要迁移方式；坡底生物炭（5%）渗透墙的构建有效地减控了其在紫色土中的淋溶迁移以及深层侧向迁移.

Effects of biochar-amended wall in a sloping farmland plot of purple soil on florfenicol transport

Sorption and desorption of florfenicol in a purple soil of sloping farmland and the effects of biochar amendment were investigated by laboratory batch experiment.The sorption isotherms can be well fitted by Freundlich isotherm.Permeable reactive walls with and without 5%(w/w) biochar application were constructed at the slope toes of field experimental plots,in which responses of florfenicol concentrations in surface runoff and soil water upon rainfall were monitored.At low aqueous florfenicol concentrations below 2mg/L,its sorption capacity on the purple soil was greatly enhanced by biochar amendment,and it was very likely that the sorption process in biochar-amended soil took place largely through intra-particle diffusion;on the other hand,its desorption was substantially reduced by biochar amendment.Leaching was the dominant pathway of florfenicol transport.Construction of 5%-biochar-amended permeable reactive wall can effectively reduce the leaching and lateral transport of florfenicol in deep layer of the purple soil.