渍水土壤中硒迁移行为的研究

用土柱模拟4种加硒处理的土壤还原淋溶过程，研究了硒在土壤中的迁移和积累。结果表明，未加硒处理（土壤背景硒）的溶液中硒的迁移以有机硒占优势，Se(Ⅵ）及Se（Ⅳ）占的比例很小；土壤富野酸硒由上层向下层迁移。外源蛋白硒的处理的溶液中硒迁移为有机硒，部分外源硒以富里酸硒积累在下层土壤。外源Se(Ⅵ）和Se（Ⅳ）处理的溶液中硒迁移量只占加入量的0．2％和0．4％，硒迁移的主要形态前者为有机硒，后者为Se(Ⅳ）和有机硒；外源Se（Ⅵ）和Se(Ⅳ）的绝大部分以富里酸硒的形态积累于土壤，其积累量Se（Ⅵ）处理高于Se(Ⅳ）处理，上层土壤高于下层土壤。

STUDY ON MOBILITY OF SELENIUM IN WATERLOGGING SOIL

Four simulated reductive leaching experiment of earth column were conducted to study mobility and accumulation of selenium in waterlogging soil.In the percolation solution of the unadded sele- nium treatment,organic selenium was the major mobile form and the proportion of selenate and selenite was small.Fulvic acid-Se of the upper soil layer was mobilized to the lower soil layer.In the percolation solution of the added leaf protein-Se treatment,organic selenium was mobilized by water and most of the added selenium was lost.A little fulvic acid-Se was accumulated to the lower soil layer.In the percolation solution of the added selenate and selenite treatment,the mobile amounts of selenium were only 0.2% and 0.4% of the added selenium,respectively.In the percolation solution of the added selenate treatment,organic selenium was the major mobile form.In the percolaton solution of the added selenite treatment,selenite was the major mobile form and organic selenium took the second place.Fulvic acid-Se was the major form of the accumulated selenium.There are more accumulated selenium in the added selenate treatment than in the added selenite treatment and more accumulated selenium in the upper soil layer than in the lower soil layer.