Experimental Study On The Improvement Of River Sludge By The Electric Method Combined Admixture

As the rapid growth of world's population and rapid economic development,the environmental pollution problem is becoming more and more serious.Dredging method is used to dredging rivers,this process produces a large number of river sludge,The moisture content of the sludge is high,and it is difficult to dewater,this makes the transportation and stack of the sludge to be limited.And river sludge contains rich in nutrients such as nitrogen,phosphorus and potassium,the utilization of land use has become a hot spot in today's research.But heavy metals of the city in sewage sludge is becoming the key factor of restricting sludge for agricultural use.EK method has the advantages of low processing cost,high efficiency of repair and simple post-processing,but its drawbacks are that energy consumption is too large,effect time is long as well.Lime is a common curing agent of heavy metals of sewage sludge,The author thinks that the function mechanism of electroosmosis can promote the reaction between quick lime and sludge,improving the dewatering efficiency of sludge and repairing efficiency of the heavy metals at the same time.Through the experimental research,we can explore the feasibility of sludge combined quick lime with electroosmosis.This experiment studied the dredging sludge of Chao hu lake project of Hefei,Anhui province in three different methods : with quick lime only,with electric method only and quick lime-electroosmosis joint processing.Compare the effect of the three methods by the moisture content,shear strength and heavy metal content of the sludge changed.In this paper,the use of electric method combined with admixture of river sludge dewatering depth and repair,removal of heavy metals in sludge use of technology and sludge dewatering technology will be beneficial exploration,the main contents are as follows:1.To study the efficiency and effectiveness of combined dehydration of EK method and admixture.2.To study the efficiency and effectiveness of combined repairing the sludge of EK method and admixture.3.To study the influence of additive mixing ratio to sludge dewatering and heavy metals repairing.4.To study the basic physical and mechanical properties of sludge under different mixing ratio.This experimental study shows that:(1)All these three methods can make the sludge dewatering,but the quick lime-electroosmosis joint method can make the depth of sludge dewatering,and can reduce energy consumption,and can enhance the mechanical properties of sludge.so it is the best solution.(2)When dealing with sludge by the quick lime-electroosmosis joint way,different amount of quick lime has great effects on the sludge dehydration effect,when the quicklime mixing ratio is 2%,the dehydration effect is the best.(3)Through the test of heavy metals,all these three methods can make repair of heavy metals cadmium,chromium and lead in sewage sludge,but the effect of the quick lime-electroosmosis joint way is best,especially for chromium and cadmium.(4)By the quick lime-electroosmosis joint way,it can improve the repair efficiency of sludge of cadmium,chromium and lead,and reduces the acid sludge at the same time,according to this test,when the quicklime mixing ratio of 2%,the method will achieve the best effect.