Study On Sludge Lysis And Reduction By Coupling Acid/Alkali With Ozone

The treatment and disposal of a large amount of excess sludge put pressure on sewage treatment and the ecological environment.In this paper,based on the ozone contact lysis of the bubble column,the oxidation and the acid-base pretreatment of the sludge were investigated experimentally to explore the relevant mechanism of alkali-ozone sludge lysis under the low-dose ozone dosage,and then to investigate the sludge.Effect of lysate backflow on sewage biochemical treatment effect and sludge production.Based on the release of intracellular organic matter and changes in sludge concentration,acid-base pretreatment of sludge can achieve a certain lysis effect,and the stronger the acidity and alkalinity,the more significant the lysis effect.The amount of organic matter released in the alkaline hydrolysis group?p H 12?and the degree of sludge cracking were higher than those in the acid hydrolysis group?p H 2?,indicating that the alkaline lysis sludge lysis is more advantageous.In addition,compared with the simple ozone lysis method,the bubble column ozonation device shows better sludge cracking lysis rate and ozone utilization efficiency due to its suitable height-diameter ratio and good solid-liquid phase mixing.The experiment further compares and discusses the advantages of the alkali-ozone coupling to lysis alone.Among them,the optimal operating parameters of the alkali alone are the dosage of 0.1 g Na OH/g MLSS and the initial sludge concentration of 12 g/L.The lysis effect is good at a reaction time of 100 min,and then enters the stage of slow hydrolysis.Under the coupling condition of alkali-ozone,the use of lower ozone dosage?0.018 g O₃/g MLSS?can increase the solubilization rate of organic matter by 15%compared with the ozonation treatment alone,while greatly reducing ozone consumption.In addition,after 40 minutes of reaction,the amount of polysaccharides and proteins and other macromolecular organic materials can reach 57 mg/L and 179 mg/L,which not only provides a carbon source for the recessive growth of microorganisms,but also effectively reduces the cost of cell disassembly.Ozone demand reduces pretreatment time.By running the SBR system in parallel,it was found that the sludge lysis backflow had a certain effect on the sewage treatment system.The experimental group operated stably for 30 days under the condition of adding sludge lysis unit.Compared with the control group,it was found that the effluent COD,ammonia nitrogen,sludge characteristics and other indicators were slightly higher than the control group,and the need for additional phosphorus removal facilities to prevent The total phosphorus content in the effluent is relatively high.In addition,the sludge production of the experimental group decreased by 66.3%,indicating that the alkaline-ozone coupled lysis method can effectively reduce the remaining sludge of SBR.