It was tested that the excess sludge reduction rate could be 23 wt%in aerobic reactor that is inocula-ted with aquatic worms,called worm reactor, connected to sequencing batch reactor(SBR)based on effluent dis-charge standard requirments.The distribution of velocity field,volume fraction of air and turbulent intensity in worm reactor were numerically simulated by computational fluid dynamics(CFD)with the models of Eulerian two-phase flow and standard k-ε turbulence provided by ANSYS Fluent 16.0 software.The results showed that the internal flow field of worm reactor was suitable for worm ingestion of sludge when the aeration was about 0.2 m3/h and worms were placed in position P2 where worm density was 1.63 g/dm2.Subsequently,the sludge reduction rate a-chieved by the maximum of 23 wt%.This reduction rate was basically consistent with the predicted value of box-behnken design(BBD),which further proved the reliability of the numerical simulation.Therefore, CFD simula-tion may guide worm-reactor performance efficiently,and as well as lay the foundation for the future study of scale-up and engineering application of sludge reduction with worm-feeding.%构建以序批式反应器(SBR)为主体工艺,并联合蠕虫反应器的生活污水处理系统,在保证系统出水水质达标的前提下,蠕虫对SBR产生的剩余活性污泥摄食减量约23%(以质量计).利用ANSYS Fluent 16.0软件提供的欧拉两相流模型和标准k-ε湍流模型,对蠕虫反应器内部速度场、含气率以及湍流强度等进行了计算流体动力学(CFD)数值模拟.模拟结果表明,蠕虫反应器内曝气量约为0.2 m3/h、蠕虫投放在P2位置即蠕虫密度为1.63 g/dm2时,蠕虫反应器内部流场适合蠕虫减量污泥,减质最高达23%,与试验结果基本吻合.通过响应曲面法(BBD)进行试验,所得污泥减量率与BBD预测值基本相符,进一步佐证了数值模拟结果的可靠性.因此,利用CFD数值模拟可以指导蠕虫反应器优化运行,从而为蠕虫减量污泥系统的放大设计及工程应用奠定基础.
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