Experimental comparison of electroosmotic consolidation of wenzhou dredged clay sediment using intermittent current and polarity reversal

The electroosmosis method is regarded especially suitable for the disposal of dredged clay sediment, but its excessive power consumption and electrode corrosion has limited its widespread application. Thus, intermittent current and polarity reversal are applied to offset its drawbacks. This study aims to examine the consolidation effect and internal relationship between the two approaches and optimize their time settings. Laboratory tests were performed with the same intermittent ratio and different reversal ratios. The test results demonstrated that intermittent current with comparatively greater intermittent times and a higher reversal ratio achieved a better drainage effect during the electroosmosis process and soil uniformity after test and the drainage in the reverse direction was lesser than that in the forward direction. The drainage effect during the power-off mode for 1 h was equivalent to that in the reverse electrifying mode for 0.2-0.25 h. Sharp increases in the current were induced by each intermittent current and polarity reversal. Although the polarity reversal approach improved the drainage effect, it partly increased the energy consumption. Compared with the intermittent current approach, reducing the reverse electrifying period to improve soil consolidation is feasible for application to engineering practice.