Structural Measures to Improve the Efficiency of Biological Wastewater Treatment Plants

The purpose of this paper is to test of certain structural measures to improve the efficiency of the biological wastewater treatment plants by preliminary adding of oxygen to fresh wastewater and rising of the pretreatment level. The paper compares the possibilities of increasing the oxygen content in wastewater by hydraulic jet, and by straining through a percolator with draught. The comparison is based on results obtained by testing on physical models in laboratory conditions. In both cases, several scenarios were analyzed, with different combinations of structural and hydraulic parameters (number of discharge outlets, outlet size, jet velocity and angle, size of percolator padding, etc.). Based on determined results of dissolved oxygen input (increment of dissolved oxygen concentration), the percolator was selected as the clement of higher efficiency and applied on the pilot biological plant for treatment of sanitary wastewater. Based on determined efficiency of wastewater treatment during the period of two years, interpolation of the percolator as pretreatment of wastewater in biological treatment plants may be assessed as justified and useful solution.