Enhancing Sludge Autolysis Reduction Technology by Combination of Ozone and Mechanical Crushing
Based on the concept of in-situ treatment of excess sludge,a set of experimental equipment for mechanical mix-ing,ozone and biochemical treatment was established,which used the ozone and mechanical crushing to strengthen sludge pyrolysis and autolysis to rapidly release intracellular organic substances.By changing the speed of the agitator,ozone mass concentration,ozone dosage and action time,and analyzing the changes of organic matter,total nitrogen mass concentration and total phosphorus mass concentration in the original excess sludge,the influence of various factors on the fragmentation,decomposition of excess sludge and the effect of combination methods on the reduction of excess sludge were investigated.The results showed that the best effect of sludge cytolysis was achieved with the six-blade disc turbines speed of 800 r/min,the ozone inlet volume of 1.6 L/min,the ozone concentration of 39 mg/L and the sludge treatment time of 30 minutes,that is,when the ozone dosage was 110 mg/g(relative to mixed liquor suspended solids).At this time,the activated sludge autolysis efficiency was 42.36%.Compared with ozone alone and mechanical crushing,the activated sludge autolysis effi-ciency was increased by 13.76%and 36.47%,respectively.Moreover,when ozone was combined with mechanical crushing,the soluble chemical oxygen demand(SCOD),total nitrogen mass concentration and total phosphorus mass concentration in the mixed liquid was increased from 45 mg/L,11 mg/L and 2.14 mg/L to 2596 mg/L,206.9 mg/L and 47 mg/L,respectively.The experiment has proved the feasibility of combination of ozone and mechanical crushing to enhance sludge autolysis re-duction,and provided a new integrated technology for sludge reduction.
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维普
