异养耦合硫自养反硝化脱氮性能及动力学研究

Study on Performance and Kinetics of Heterotrophic Coupling Sulfur Autotrophic Denitrification

在COD浓度为0,30,60,90 mg/L下,考察了异养耦合硫磺和黄铁矿为填料的自养反硝化工艺脱氮性能,同时探讨了异养及自养反硝化过程对氮去除的贡献率及其降解动力学.结果表明,当COD浓度为30 mg/L时,R1(硫磺/黄铁矿分层填装)和R2(硫磺/黄铁矿混合填装)的NO3--N去除率分别为90.51%和97.13%.随着COD浓度升高至90 mg/L,R1和R2进水中的NO3--N几乎被完全去除,且R2在不同高度下的脱氮性能均优于R1.由于COD为30 mg/L时可促进硫自养反硝化过程的脱氮效果,因此R1和R2出水SO42-浓度分别由158 mg/L和178 mg/L升至188 mg/L和192 mg/L;随着COD投加浓度提升至90 mg/L,实现了异养与硫自养反硝化的耦合,此时出水SO42-浓度分别降至114 mg/L和125 mg/L.物料平衡计算表明,当COD浓度大于60 mg/L时,异养反硝化对脱氮的贡献率高于硫自养.动力学模型拟合表明,异养耦合硫自养反硝化过程符合修正的Logistic动力学模型.

At COD concentrations of 0,30,60 and 90 mg/L,the performance of autotrophic coupled with heterotrophic denitrification process which used sulfur and pyrite as filler was investigated.The contribution rate of heterotrophic and autotrophic denitrification process to nitrogen removal,as well as the NO3--N degradation kinetics were discussed.The results showed that the NO3--N removal rates of R1(layered filling of pyrite)and R2(mixed filling of pyrite)were 90.51%and 97.13%respectively when the COD concentration was 30 mg/L.Furthermore,as the COD concentration increased to 90 mg/L,the effluent of NO3--N of R1 and R2 was barely undetectable,and the performance of R2 was better than R1 at different heights.Since COD concentration of 30 mg/L can promote the performance of sulfur autotrophic denitrification,the effluent SO42-concentration of R1 and R2 increased from 158 mg/L and 178 mg/L to 188 mg/L and 192 mg/L,respectively.As the COD concentration increased to 90 mg/L,the coupling of heterotrophic and sulfur autotrophic denitrification process was realized.Meanwhile,the effluent SO42-concentration reduced to 114 mg/L and 125 mg/L,respectively.The material balance calculation showed that,when the COD concentration was greater than 60 mg/L,the contribution rate of heterotrophic denitrification to nitrogen removal was higher than that of sulfur autotrophic denitrification.The fitting of kinetic model showed that the heterotrophic coupled sulfur autotrophic denitrification process accorded with the modified logistic kinetic model.