Effects of simulated in-situ electrokinetic remediation on physicochemical properties and phosphorus migration of sediments

The effect of simulated in-situ electrokinetic remediation (EKR) on phosphorus release from contaminated sediments was investigated. The effects of different anode materials (iron, aluminum, graphite and stainless steel) on the physicochemical properties and phosphorus migration were compared. The results showed that aluminum anode had the best inhibition effect on phosphorus release from sediments, and the highest inhibition rate of phosphorus release was 78.20% compared with non EKR, but the sustainability was poor, and the performance of iron anode is generally stable. The phosphorus in the sediments generally shows the migration trend from cathode to anode. After EKR, the Oxidation-Reduction Potential (ORP) of the sediment decreased with the increase of normalized distance from anode. The anaerobic environment of the sediment on iron anode was the most serious, and the lowest was -616mV. The ORP of the sediment from the anode area to the middle area of other electrodes was effectively improved. The pH of the sediment increases gradually from anode to cathode, and is characterized by acidification in the anode area and alkalization in the cathode area. Iron and stainless steel electrodes have more acidic areas, showing better electrolysis efficiency.