硝酸盐对厌氧生物膜和颗粒污泥的同时产甲烷反硝化性能影响研究

Influence of Nitrate on the Simultaneous Methanogenesis and Denitrification Reaction of Anaerobic Biofilm and Granular Sludge

为了研究硝酸盐对厌氧生物膜系统同时产甲烷反硝化反应的影响及其机制,拓展生物膜工艺在高氮有机废水中的应用,采用生物膜-污泥厌氧复合反应器和上流式厌氧污泥床培养具备同时产甲烷反硝化反应的功能微生物系统,并以间歇实验方法,对比研究硝酸盐对厌氧生物膜和颗粒污泥的同时产甲烷反硝化性能的影响.结果表明,硝酸盐对生物膜和颗粒污泥系统去除COD和反硝化反应均有影响,但硝酸盐浓度变化对颗粒污泥系统的影响比生物膜系统更大,生物膜表现出更强的降解能力和更高的耐性阈值.随着硝酸盐浓度从75 mg·L-1增加到600 mg·L-1,颗粒污泥对COD的降解速率从273.26mg·(h·g)-1降到0.1 mg·(h·g)-1,而生物膜从95 mg·(h·g)-1降至1.7 mg·(h·g)-1;同时,生物膜和颗粒污泥对硝酸盐的降解速率分别从21.43、22.31 mg·(h·g)-1增加到83.72、61.06 mg·(h·g)-1,随着硝酸盐的降解,生物膜表现出更强的恢复能力,最大值为712.44 mg·(h·g)-1.研究还发现亚硝酸盐积累是影响生物膜和颗粒污泥同时脱氮除碳功能的主要原因,在相同的硝酸盐浓度下,生物膜中亚硝酸盐的最大积累量仅为的颗粒污泥的1/10.因此,生物膜-污泥厌氧复合反应器可以作为高浓度含氮有机废水实现同时产甲烷反硝化工艺反应器一种重要选择.

The aims of this study are to further investigate the impact mechanism of nitrate on the simultaneous methanogenesis and denitrification（SMD） process of anaerobic biofilm,and to extend the application of the biofilm process in the treatment of high nitrogen and COD concentration organic wastewater.The SMD reactions were successfully carried out in a hybrid anaerobic biofilm and sludge reactor（HABSR） and an up-flow anaerobic sludge blanket（UASB）,and the influence of nitrate on the performance of simultaneous carbon and nitrogen removal in biofilm and granular sludge were investigated using batch tests.The results showed that the nitrate concentration could obviously affect the carbon and nitrogen removal in both biofilm and granular sludge,and the increase of nitrate concentration had more serious impact on the granular sludge,and the biofilm presented higher COD and nitrogen removal efficiency and stronger resistance to toxic materials than the granular sludge.As the nitrate concentration was increased from 75 to 600 mg·L-1,the COD removal rates were reduced from 273.26 to 0.1 mg·（h·g）-1 in granular sludge and reduced from 95 to 1.7 mg·（h·g）-1 in biofilm.At the same time,the denitrification rate of biofilm and granular sludge were increased form 21.43 and 22.31 mg·（h·g）-1 to 83.72 and 61.06 mg·（h·g）-1,respectively.The biofilm recovered the COD degradation rate more quickly and easily than the granular sludge,and the maximum COD removal rate reached 712.44 mg·（h·g）-1.The nitrite accumulation was observed to be the major cause that affected the simultaneous carbon and nitrogen removal of biofilm and granular sludge.It＇s found that the maximum nitrite accumulation in biofilm was only one tenth of that of the granular sludge at the same nitrate concentration.The HABSR was proved to be an important alternative for SMD reaction employed in the treatment of high nitrogen and COD concentration organic wastewater.