The Research On Pretreatment Of Activated Sludge By Dielectric Barrier Discharge

As China's industrial sewage and domestic sewage discharges increase year by year,the sewage treatment plant's sludge has also increased substantially.It is difficult to handle and the processing costs are high.It has become a serious environmental and social problem due to the traditional landfill method.If the mud is placed directly on the landfill without special treatment,it will be difficult to maintain due to the shortage of land resources and the increase of production.Therefore,it is an inevitable choice to adopt a certain method of sludge pretreatment.In this dissertation,the sludge of the Jiulong Lake Sewage Treatment Plant in Nanchang City was taken as the object of study.The dielectric barrier discharge plasma technology was applied to the pretreatment of sludge.The discharge voltage and discharge frequency during the process of sludge treatment were investigated.The effects of various parameters such as pH,H₂O₂ and Fe²⁺dosage,and discharge time on the cracking effect of the sludge were analyzed under different spacings and different sludge concentrations.The experimental results show that when the sludge is treated with dielectric barrier discharge alone,the experimental results obtained by optimizing the response surface are:discharge voltage 10 kV,discharge frequency 10 kHZ,plate spacing 6mm,sludge concentration 10 g/L,discharge time 18 min,The highest amount of SCOD released was 203.1%more than the original sludge.Combining the apparent and microscopic changes of the sludge floc after breaking,when using the dielectric barrier discharge alone,the sludge flocs will break and the structure will become more loose,not only loose but also porous,and the pores and channels will also become larger,with active microorganismsdis appear.The sludge is scanned using Fourier,and some functional groups of the treated sludge will also change.When the Fenton reagent was added during the dielectric barrier discharge treatment,the cracking effect of the sludge was changed.At a pH of 3,the dosage of H₂O₂ was 12 g/L,H₂O₂/Fe²⁺=3:1,and the discharge time was 12 min.Under the conditions,the cracking effect of sludge was better.SCOD,NH₃-N,and TP were increased by 16%,27.5%,and 44.90%,respectively,compared with the case without Fenton,and the addition of Fenton reagent can shorten the cracking effect.time needed.After the sludge was treated with dielectric barrier discharge alone,the SV₃₀0 of the sludge was reduced from 21%of the original sludge to 17%,and the MLVSS/MLSS was reduced from 0.94 of the original sludge to 0.85.After adding the Fenton reagent,the SV₃₀0 was replaced by the original sludge.From 21%to 11%,the MLVSS/MLSS was reduced from 0.94 in the original sludge to 0.67,indicating that both methods increased the sedimentation and stability of the sludge,but after adding Fenton reagent,the dielectric barrier discharge cracked the sludge.The effect is more thorough.