DOI 10.35776/VST.2021.10.05
UDC 66.063.8

Grigor’eva Anastasiia, Abiev Rufat, Lobanov Fedor, Тарарыков Олег Юрьевич

Developing efficient methods of mixing during chemical treatment of wastewater suspension

Summary

In recent years the problem of wastewater sludge disposal has become more and more urgent for the municipal economy. The results of a study of the process of sludge suspending with Dezolak, a lime-containing agent, are presented; the size of solid inclusions is determined to provide for calculating the required rotation speed of the mixing device: the average Sauter particle diameter was 55 μm, the density of the solid phase was 2211 kg/m³. For effective chemical suspending the angular velocity of the mixer should be more than 0.03 m/s. The main similarity criteria for scaling the apparatus were investigated; it was determined that while choosing a mixer, the Froude criterion Fr should be taken into account, since that very indicator was practically constant for the three investigated reactors. Based on the work done, it was determined that the ratio of power to the volume of the mixed liquid cannot be a criterion for calculating devices equipped with GMS mixing devices: for these mixers, a decrease in the mixing power with an increase in the size of the device is valid.

Key words

wastewater , mixer , sludge utilization , lime mixing , lime-containing chemical