Restoring biocoenotic species composition in aerated structures following prolonged downtime

Abstract

A study was carried out into the dynamics of species composition for immobilised sludge with inert brush filtering following prolonged bioreactor downtime. The experimental part was carried out using microscopic analysis. The start of a bioreactor with sludge adapted to wastewater provides a specified degree of purification within a stated period of time. The experiment was carried out in a physical bioreactor model presenting a transverse vertical section of an industrial bioreactor aerotank. The dynamic dependency of the quantitative increase in biocoenotic species composition during the recovery period is obtained. The dynamics of biocoenosis is determined by the example of ciliate vital activity. A mathematical expression for calculating the ciliate movement speed during biocoenosis recovery is obtained. In culturing the biocoenosis under aerobic conditions, the rate of mass change for immobilised sludge with brush filtering is presented. The application of bioreactors with immobilised sludge under brush filtering provides for the biological treatment of sewage through the creation of aerobic conditions and cyclic transfer of immobilised sludge to freely floating sludge using air medium bubble aeration. In ten days, the microorganism species composition increased to the initial 6 species having a physiological biocoenosis state characterised as satisfactory.