Experimental Study On Electrokinetic Reinforcement And Remediation Of River Sludge

The urban river network is widely distributed in the coastal areas of China,which produces a large amount of river silt.Due to the characteristics of high moisture content,low strength and high compressibility,river silt often needs drainage consolidation before its secondary treatment.Electroosmosis method has many advantages that drainage rate is not affected by the particle size of soil and transports contaminants effectively,which provides a better solution for river silt treatment.But at the same time,the electroosmosis method also has the problems of low efficiency and high energy consumption in the late stage.Based on the research methods and achievements of predecessors,in order to improve the electroosmotic effect and efficiency,this paper carries out laboratory experimental research on river silt electroosmotic reinforcement and remediation.The main work of this paper is as follows.1.Based on the equivalent voltage and electroosmotic transport volume,the drainage rate,final moisture and energy consumption of constant voltage and constant current power supply modes were compared.The characteristics of electroosmotic drainage stability of constant current modes were verified,which served as the experimental basis for the follow-up test of electroosmotic ion transport.2.The reinforcement effects of single electroosmosis and electroosmosis with fulvic acid were compared under constant current power supply modes,at the same time,the differences of transport of Cu2+,Zn2+ ions were compared.Based on the changes of electroosmotic transport and heavy metal transport,the reinforcement and remediation of river silt by electroosmosis are discussed.It is found that the addition of fulvic acid has obvious effects on electroosmotic drainage and heavy metal ion transport.3.Indoor simulated electroosmosis-solidification combined consolidation test was used to reinforce river silt,which compares the unconfined compressive strength and microscopic characteristics between single consolidation and combined consolidation.The results show that electroosmosis drainage plays an important role in the later strength growth of solidified soil under the electroosmosis-solidification combined treatment;With the same ratio of solidifying agent,the combined treatment is more conducive to the formation of cements and hydration products than single solidification.