| The activated sludge treatment process was widely used to wastewater treatment due to its advantages which were better treatmeat effect and managing easily. However, the large amount of excess sludge was produced easily using activated sludge treatment. Without a proper treatment, direct or potential environmental contamination is produced.The conventional management and disposal methods of sewage sludge,cost and energy consumption of which were high,were under stronger public opposition and strieter regulatory pressure.Therefore, research and application of sludge reduction technology played an important role in the field of treatment and disposal of sludge.In a variety of sludge reduction technologies, sludge reduction technology of ozone oxidation was widespread concerned because of high disintegration efficiency, low energy consumption and less secondary pollution. To achieve zero sludge emissions, sludge cells were broken and organic matters were dissolved by use of ozone strong oxidizing, realizing the full recycling and second biochemical treatment of activated sludge.Thesis studied the sludge reduetion technology with cracking of ozone oxidation.Main points of the content were analysis of influence of different ozone dosages, reaction time, inlet air flow and the initial sludge concentrations on sludge reduetion. the change of some indexes in the process of sludge ozonation, such as MLSS、MLVSS、SCOD、 NH3-N、 TP、SV, was system investigated. The mechanism of the sludge ozonation reaction was discussed according to the change of those indexes.The optimum processing conditions were selected in order to provide some references for the sludge reduetion technology with cracking of ozone oxidation.In addition, pyrolysis analysis of sludge treated in the different conditions was carried out in the experiments to provide a theoretical basic for the properties of the ozonation sludge. Based on above studies, the main results were shown as follows:(1)In the sludge reduetion experiment with cracking of ozone oxidation,the best ozone dosage was about0.27gO3/gMLSS and the best reaction time was30min. At this moment, effect of sluge disintegration was the best.The MLSS decrease mostly by2.9g·L-(2)When inlet flow was greater at the same reaction time, effect of sluge disintegration of ozone oxidation was better. In the conditions of the inlet flow rate of2.0L/min, effect of sluge disintegration of ozone oxidation was best. With the increase of ozone dosage, MLSS reduced rate was slow to fast and then slow down. At the best ozone doses which was0.25g O3/g MLSS, MLSS reduction was1.42g/L; The concentration of SCOD, NH3-N and TP increased respectively626mg/L,10.7mg/L,1.068mg/L.(3) When inlet flow was2.0L/min and the reaction time was30min, effect of sluge disintegration of ozone oxidation was better with the initial concentration of the sludge increased.At the same ozone dosage, compared to the other two experimental groups which of initial sludge concentration were4gMLSS/L and6g of the MLSS/L, effect of sluge disintegration of ozone oxidation was best in the experimental group of initial sludge ccncentration of8gMLSS/L.At the optimal ozone dosage, MLSS reduction was3.86g/L.(4)ln the research of pyrolysis kinetic characteristics of the sludge untreated and treated, the activation energy required of sludge treated was lower than the activation eeergy required of sludge untreated in the organic thermal decomposition stage.There was significance to study zero emission technology of activated sludge by Ozone Oxidation to reduce sludge in theory.It also can supply reference for sludge reduction industrialization. |
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