In order to quantitatively assess the amount of organic carbon (OC) released by clayey aquitard to adjacent aquifers during compaction,the background values of OC in borehole sediments were used as the constraint condition in the study area of the Chen Lake Wetland. The physical simulation experiments of natural sedimentation and artificial compaction were carried out by collecting surficial undisturbed silt,and a mathematical model representing the difference of release amount of OC at different depths was established. Under natural deposition conditions,sediment OC was released with pore water through mineralization and reduction dissolution of associated minerals;the concentration contribution of OC to the underlying aquifer (about 50-80 m) from clayey aquitard (about 20 m) is 6.99-11.19 mg/L under compaction,which is about 3.9 times of OC release amount under advection and diffusion. Under artificial compaction condition represented by land subsidence,the concentration contribution of organic carbon is 0.19-2.02 mg/L under compaction,which is higher than that of advection and diffusion in the same period. Compaction release of clayey aquitard pore water is an important source of OC in groundwater,which should be paid more attention in the study of natural inferior groundwater.
维普
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