The Effect of Biofilm on the Water-Rock Contact Surface During Artificial Recharge
Artificial recharge is a crucial strategy for addressing groundwater over-exploitation.Significant physical,chemical,and biological gradients exist between the recharge water and the target aquifer during artificial recharge process.These gradients lead to intricate biogeochemical reactions at the water-rock contact surface,ultimately triggering aquifer clogging.While existing research on bioclogging primarily focuses on internal processes within the aquifer media,there remains a relative dearth of quantitative investigation into the biofilm formation patterns at the water-rock contact surface and their impact on the permeability of aquifer.In this study,an underground water source downstream of Dagu River in Qingdao City,Shandong Province was selected as the study area.A series of laboratory-scale percolation experi-ments were conducted to analyze the characteristics of bacterial growth and extracellular polymeric substance(EPS)secre-tion at the water-rock contact surface.Meanwhile,the temporal and spatial changes in the hydraulic conductivity of me-dia was also studied to reveal the effect of biofilm at the water-rock contact surface on aquifer bioclogging during the artificial recharge process.The results showed that the interfacial biofilm played a crucial role in the aquifer bioclogging,and disrupted the established biofilm could promptly restore the media permeability.The evolution of bioclogging at the water-rock contact surface included three stages:slow clogging,rapid clogging,and stable clogging.This study provides essential scientific insights and theoretical support for effective artificial recharge aquifers and ensuring sustainable ground-water resource utilization.
万方数据
维普
