Optimize Operation of Partial Denitrification System for Simultaneous Treatment of Low C/N Municipal and Nitrate Wastewaters

摘要

In order to realize the simultaneous treatment of low C/N municipal and nitrate( NO3~--N) wastewaters,a sequencing batch reactor( SBR) was used to optimize the partial denitrification( PD),which the influent substrate and the anoxic reaction time were appropriately controlled. The carbon and nitrogen removal and the characteristic parameters of PD during long-term operation were studied. Experimental results showed that the PD showed stable characteristics of nitrogen and carbon removal and NO2~--N accumulation after an adaptation of 20 d with municipal wastewater used. The anoxic reaction time was extended from 50 to 70 min with the initial COD/NO3~--N decreased from 3. 0 to about 2. 5. When the influent NO3~--N was 117. 93 mg/L,the effluent NO2~--N and NAR were 23. 10 mg/L and 82. 26%,respectively,and the nitrogen and carbon removal rate reached 91. 76% and 65. 70%,respectively. The effluent NO2~--N/NH4~+ -N meantime reached 1.17-1. 22. Moreover,the cumulative concentration of NO2~--N and the system NAR increased linearly with the consumption of NO3~--N and COD,and the change trend was highly significant within 0-20 min,and gradually flattened.