Abstract: In order to improve removal efficiency of nitrogen, to enhance nitrogen removal process for low C/N ratio wastewater, and to accomplish denitrification, primary sludge was used as carbon source and NO_x^--N was added into primary fermentation system(PF) in this study.By investigating the variation of VFAs(volatile fatty acids)accumulation, NO_x^--N removal amount and VSS(volatile suspended solids) reduction, the fermentation and denitrification capacity of 4 different electron acceptor systems were contrasted.The results showed that VFAs had little accumulated for sole NO₃^--N and combined of NO₂^--N and NO₃^--N systems, while for sole NO₂^--N and anaerobic systems VFAs showed great accumulation, indicating that the use of carbon source was better for NO₃^--N and combined system.The total amount of removing electron acceptor for sole NO₃^--N, combined NO₂^--N and NO₃^--N and sole NO₂^--N systems were 1692 mg稬^-1,1330 mg稬^-1, 1223 mg稬^-1, respectively.Clearly sole NO₃^--N system had the best denitrification ability.Additionally, all these electron acceptor systems, with more than 60% VSS reduction, showed a great sludge reduction capacity, especially for NO₃^--N system, which reached about 67.9%, even though little decreased compared to the anaerobic system.In summary, for primary fermentation and denitrification system, using NO₃^--N as electron acceptor can achieve the best nitrogen removal efficiency and sludge reduction performance.

Key words: primary sludge, fermentation, denitrification, sludge reduction

摘要： 为了解决低C/N比污水的脱氮问题,本研究将NO_x^--N引入到初沉污泥厌氧发酵系统,利用初沉污泥厌氧发酵过程释放的有机碳源完成反硝化,以达到利用初沉污泥作为碳源强化污水脱氮的目的。通过对系统中VFAs积累、NO_x^--N去除及VSS变化情况的考察,对比研究了4种不同电子受体类型初沉污泥厌氧系统发酵性能、反硝化能力。得出:在34 d的发酵期里,NO₃^--N型系统以及NO₂^--N、NO₃^--N混合型系统中没有出现明显VFAs积累,而在NO₂^--N型系统和纯厌氧系统中出现了不同程度的VFAs积累,说明在试验条件下,NO₃^--N型和混合型系统发酵过程所释放的碳源能得到较好的利用;各系统中NO_x^--N还原总量分别为1692 mg·L^-1(NO₃^--N型)、1330 mg·L^-1(混合型)、1223 mg·L^-1(NO₂^--N型),表明NO₃^--N型系统反硝化能力最强;此外,虽然各NO_x^--N系统中的VSS减量程度相对于厌氧系统稍有降低,但各系统均达到了60%以上的高VSS减量水平,其中NO₃^--N型系统VSS减量67.9%,在各NO_x^--N系统中最高。综上,NO₃^--N型初沉污泥厌氧发酵系统能同时取得相对最好的反硝化脱氮及污泥减量性能。

关键词: 初沉污泥, 发酵, 反硝化, 污泥减量