RESEARCHES RELATED TO THE BIOLOGICAL STAGE FROM WASTEWATER TREATMENT PLANTS

  

I.C MOGA, G. PETRESCU, B.D. NĂSĂRÎMBĂ, A. DIACONU

 

 

ABSTRACT. – Researches related to the biological stage from wastewater treatment plants. In the present study a model for the oxygen concentration profiles in a mobile bed biofilm reactor (MBBR) is proposed. By using a material with a large specific surface area (m²/m³) high biological activity can be maintained using a relatively small reactor volume. Small parts made of special materials with density close to the water density, are immersed in the bioreactors. The biofilm carriers are kept in suspension and even mixed with the help of air bubbles generated by the aeration system. Water oxygenation is a mass transfer process of oxygen from gas/air to the liquid mass. It can be used in wastewater treatment in order to remove the organic matter, in the biological stage. The functioning of aerobic processes depends on the availability of sufficient quantities of oxygen. In wastewater treatment plants, submerged bubbles aeration is most frequently accomplished by dispersing air bubbles in the liquid. The main purpose of this study is to determine the concentration of dissolved oxygen using mathematical modeling and numerical simulations. The aim of the study is to find the optimum dimension and position of the aeration pipes for maintaining the oxygen concentration in the limits indicated in the literature. Experimental determinations (measurements of the DO concentration) have also been realized. The oxygen profile concentration, in a MBBR reactor, was determined.

 

Keywords: aeration system, dissolved oxygen, MBBR, wastewater treatment.

 

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