A Study Of Grit And Organics Removal Efficiency Of The New Rotational Flow Grit Chamber

The new rotational flow grit chamber, which has advantage of higher efficiency of grit removing, less land occupation, lower energy consumption, higher efficiency of organics separation, is used widely in wastewater treatment. Combining of the national project "863", we researched grit and organics removal efficiency of the new rotational flow grit chamber. On the base of the analysis of vortex dynamics, the experimental results were explained.There are some factors influencing the efficiency of grit and organics removal generally, such as diameter of emery particle, hydropower condition of the entrance, number of the agitating blade laminas, rotate speed of the agitating blade and distance between the agitating blade and base. Through the single-factor experiments and orthogonal experiments in wastewater treatment plant and in the laboratory, we discussed the influence of the five important factors on the efficiency of the grit and organics removal and the optimum conditions were chosen. The test results indicate that number of the agitating blade laminas is the predominant factor to the grit removing and hydraulic retention time is the predominant factor to organics removal and distance between the agitating blade and base is the extremely predominant factor to organics removal. In the design and operation control of wastewater treatment plant, if we have special requirements on grit removing, The optimum condition is the number of the agitating blade laminas 6, the residence time 50s, the maximum linear speed of the agitating blade is 0.354m/s and the distance between the agitating blade and base 40mm. if we have special requirements on organics, the optimum condition is the number of the agitating blade laminas 4, the residence time 50s, the maximum linear speed of the agitating blade is 0.354m/s and the distance between the agitating blade and base 50mm.