Simulation And Experiment Of Excess Sludge Disintegration By Using Underwater Explosion Method

The excess sludge disintegration in one of the important means of sludge reduction and reclamation.Previous sludge disruption methods exist disadvantages,like high energy consumption and high-cost.Underwater explosion can produce strong shockwave to disintegrate sludge and also produce a series of physical and chemical effects in a short time.Studies have shown that the shockwave has deactivation effect on bacteria.High temperature and oxidant have degradation effect on the organic macromolecules.Besides,some explosives,like TNT and RDX,are low-cost and easily available.Thus,the research launched a series of simulations and experiments on the excess sludge disintegrated by underwater explosion.There are high expectations on sludge disintegration by the means of underwater explosion.First of all,using classical theory and simulation software of underwater explosion to design the all simulation analysis models.According to the results of simulation,the models show the characteristic of shockwave in the confined spaces and the effects on peak pressure with different situations.The situations include that different explosive kinds(TNT and RDX),mesh generations,boundary conditions,explosive types,detonation point's locations and explosive doses(10g,30g,50g,70g)in the container,radius of which is lm.Then,the research study the effect on the container size,radius of which is 0.5m.Also revolve around the design of 10g,30g,50g and 70g explosives.In the simulation,explosive equation uses JWL equation of TNT and RDX,the water environment equation uses Shock equation.This research only study the first phase,that is shockwave decay phase,affect on sludge excess.Depends on the results of simulation,the disintegration experiments are designed to comfirm the effect on the sludge excess.The experiment container is a steel cylindrical casket,and there suspends the stoste bag of sludge excess(2L)on the top of casket.The explosive and igniter in the bag.After the disintegration,the disintegrated excess is recycled to detect the parameters in the disintegrated sludge excess.According to the results of simulations,a simple preliminary experiment studies the effect on which is lOg and 70g dose of explosive explode in the 20g/L excess sludge.And then studys the effects on different MLSS(20g/L,30g/L,40g/L,50g/L)in the same dose(70g).The experiment shows the respective results of the different dose in order to verify the degree of disintegration.With concentration of excess sludge increasing,Soluble Chemical Oxygen Demand(SCOD),protein and peptidoglycan are all increasing in the disintegrated sludge..But depends on the disintegrated ratio,the disintegrated degree do not increase linearly with the increase of concentration of excess sludge.According to the partical size,the shockwave of underwater explosion barely cut the sludge below the partical size 20?m.