Soil organic carbon accumulation characteristics of fine-grained tailings remediation
Soilless in-situ remediation of copper and other bulk tailings is an effective way for its resourceful and harmless.The soil nutrient accumulation after rehabilitation is directly related to the later field management,and it is crucial to study its organic carbon and other important nutrient accumulation rules.Therefore,in this paper,based on a fine-grained copper tailings remediation site in Hubei,China,the study is conducted on the unremediated,one-year and two-year soil sampling at three depths:0-15 cm,15-30 cm,and 30-45 cm,respectively.Then,the six types of soil organic carbon of samples,namely,total organic carbon,easily oxidized organic carbon,particulate organic carbon,mineral-bound organic carbon,soluble organic carbon,and microbial biomass organic carbon,were measured and analyzed.The results show that:the fine-grained tailings soil after soil-less remediation would still accumulate soil organic carbon without the addition of exogenous organic matter;the main way of organic carbon accumulation in the tailings was the increase of inert organic carbon represented by mineral-bound organic carbon,and the elevation of inert carbon helps to fix the organic carbon;the particle size of the tailings agglomerates and the content of soil organic carbon were positively correlated,with inert organic carbon preferring the mineral-bound organic carbon,and inert organic carbon preferring the mineral-bound organic carbon.Inert organic carbon prefers to gather in the agglomerate structure with smaller particle size fine-grained tailings remediation process,resulting in the gradual increase of activity of soil carbon pool,and the remediation is more likely to occur in the transformation of organic carbon.In summary,this study showed that the soil organic carbon content increased significantly after the repair of tailings soil,and mainly accumulated in the form of inert organic carbon,which showed a huge carbon sink potential in the site.This study also clarified the cumulative characteristics of the various forms of soil organic carbon in the mining area after the site restoration,which can provide data support for guiding the tailings restoration work.
万方数据
维普
