Liu Yong-Qiang, Wu Wei-Wei, Tay Joo-Hwa, Wang Jian-Long
Institute of Environmental Science and Engineering, Nanyang Technological University, 18 Nanyang Drive, Singapore 637723, Singapore.
Bioresour Technol. 2008 Jun;99(9):3919-22. doi: 10.1016/j.biortech.2007.07.041. Epub 2007 Sep 10.
The formation and long-term stability of nitrifying granules in a sequencing batch reactor was investigated in this study. The results showed that nitrifying granules with a size of 240 microm and SVI of 40 ml g(-1) were formed on day 21 at a settling time of 10 min. Maintaining settling time at 15 min from day 57 to 183 did not affect the physical characteristics of sludge and the fraction of suspended floc in the sludge. In addition, nitrifying granules could tolerate the fluctuations of nitrogen loading rate from 0.72 to 1.8 g l(-1)d(-1) during 2 months without the change of physical characteristics. However, it was observed that complete nitrification to nitrate and partial nitrification to nitrite by sludge converted each other corresponding to the change of the influent NH4+-N concentration. Thus, an appropriate method is needed to maintain a stable complete nitrification or partial nitrification under the conditions with changing influent NH4+-N concentrations and nitrogen loading rates.
本研究考察了序批式反应器中硝化颗粒的形成及其长期稳定性。结果表明，在沉降时间为10分钟的情况下，第21天形成了尺寸为240微米、污泥体积指数为40毫升/克的硝化颗粒。从第57天到183天，将沉降时间维持在15分钟，并未影响污泥的物理特性以及污泥中悬浮絮体的比例。此外，在2个月内，硝化颗粒能够耐受0.72至1.8克/升·天的氮负荷率波动，而其物理特性未发生变化。然而，观察到污泥对硝酸盐的完全硝化和对亚硝酸盐的部分硝化会随着进水NH4+-N浓度的变化而相互转换。因此，需要一种合适的方法，以在进水NH4+-N浓度和氮负荷率变化的条件下维持稳定的完全硝化或部分硝化。
