Over-exploitation of Groundwater, and its Impact on Phreatic Aquifer System, Surface Water Bodies and Rural Water Supply Schemes in Malur Taluk, Kolar District, Karnataka - A Case Study

摘要

The remediation of soils co-contaminated with heavy metals (HMs) and hydrophobic organic compounds(HOCs) is urgent. In this paper, the simultaneous removal of phenanthrene and Ni(II) co-contaminantsfrom sandy soil column by 3250 mg/L of Triton X-100 (TX100) and 0.1 mol/L of citric acid (CA) flushingwas conducted. The removal effects were compared and discussed when CA after TX100 (TX100/CA), TX100 after CA (CA/TX100), and a mixture of TX100 and CA (TX100-CA) were used as flushingagents. The maximum concentrations of phenanthrene in effluent solutions appeared when the porevolume number (PVN) of influent was 3, 17.5 and 4 while those of Ni(II) occurred at 12.5, 2 and 2.5 ofPVN during TX100/CA, CA/TX100 and TX100-CA flushing, respectively. The total removal efficienciesof phenanthrene were upto 93.7%, 94.5%, and 93.1%, while those of Ni(II) were 80.2%, 80.4% and80.7% due to TX100/CA, CA/TX100 and TX100-CA flushing, respectively. Larger PVN was requiredfor TX100/CA and CA/TX100 to clean phenanthrene and Ni(II) efficiently. The removal efficiencies ofcontaminants increased with PVN in Sigmoidal Model. The results showed that flushing using nonionicsurfactant and organic acid is promising for in-situ remediation of soils contaminated with HMs andHOCs.