关键词:

分段进水, 脱氮除磷, UCT, 物料平衡

Abstract:

The removal of wastewater nutrients in the modified UCT step feed process was investigated when treating municipal wastewater.Based on experimental data under steady-state conditions, the equations for calculating material balances of COD, nitrogen and phosphate were established.These three material distributions in the system were also evaluated.The results indicated that with stable effluent quality and good capacity of resistance to shock load, the effluent concentrations of COD，TN and TP were 43.5, 8.51, 0.29 mg·L^-1 on average, respectively, which the first level A discharge standard of pollutants for municipal wastewater treatment plant was met.Furthermore, according to calculation equations and transformation pathways of nutrients, it was found that approximately 67.1% of nitrogen was successfully removed during the denitrification process, including anoxic denitrification process and simultaneous nitrification and denitrification (SND) process, which greatly contributed to high nitrogen removal efficiency.COD consumed in the denitrification and phosphate release process accounted for 62.1%, which embodied the advantage of sufficient utilization of influent carbon sources.Both nitrogen and COD balance ratios were as high as 99.8%, which confirmed the validity of equations established.Phosphate removal was mainly achieved by the discharge of excess sludge, accounting for 71.7% of the total.

Key words:

分段进水, 脱氮除磷, UCT, 物料平衡