摘要
以重金属Cd为单一污染源的棕壤作为供试土壤,设定-10,-20,-30℃三个温度作为冻结温度,10℃作为融化温度进行土壤冻融循环试验。通过测定冻融作用后土壤团聚体粒径组成、土壤质量平均直径、土壤团聚体粒径中Cd的质量负载率以及赋存形态,研究冻融作用对棕壤团聚体稳定性及Cd在不同团聚体粒径中分布与赋存形态的影响。结果表明:(1)土壤经过冻融作用后,>2mm的团聚体比例显著增加(P<0.05),增加范围为38.4%~54.6%,土壤质量平均直径显著增加(P<0.05);(2)经过冻融作用后,重金属Cd主要富集在>2mm的团聚体粒径中,所占比例为51.2%~57.2%;(3)冻融作用使土壤及不同粒径团聚体中交换态Cd和有机结合态Cd含量显著降低(P<0.05),铁锰氧化物结合态Cd和残渣态Cd含量显著增加(P<0.05)。
Aggregate stability,cadmium distribution and transformation in bulk samples,and particle size fractions were studied of brown soil through freeze-thaw cycle method.The freezing conditions were implemented under-10,-20and-30℃,respectively,and the thawing condition was implemented under10 ℃.Soil aggregate particle size,soil mean mass diameter,grain size fraction cadmium loading,and the cadmium transformations in bulk soil and particle size fractions were measured.The results showed that：（1）Both the fraction of particles 〉2 mm and soil mean mass diameter increased significantly when soil experiencing freeze-thaw cycles,and the formerranged 38.4%-54.6%.（2）Cadmium mainly accumulated in particles〉2 mm,and it contributed 51.2% -57.2% of cadmium to the contents in bulk soil.（3）The exchangeable fraction of cadmium and the organically bound fraction of cadmium significantly decreased（P〈0.05）,and the Fe and Mn oxide bound fraction of cadmium and the residual fraction of cadmium increased significantly（P〈0.05）in bulk soil and particle size fractions for the soil experiencing freeze-thaw cycles.
出处
《水土保持学报》
CSCD
北大核心
2017年第4期298-303,共6页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(41301530)
农业部东北耕地保育重点实验室开放基金项目
农业部环境保护科研监测所开放基金项目
关键词
重金属CD
冻融强度
赋存形态
团聚体
棕壤
heavy metal cadmium
freeze-thaw cycles
transformation
aggregate
brown soil
