State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, People's Republic of China.
Environ Sci Pollut Res Int. 2015 Aug;22(16):12633-43. doi: 10.1007/s11356-015-4542-3. Epub 2015 Apr 26.
Dissolved organic nitrogen (DON) has become a growing concern due to its contribution to eutrophication and nitrogenous disinfection byproducts (N-DBPs) formation. However, information of DON in membrane bioreactors (MBRs) is very limited. In this study, occurrence, transformation and fate of DON in an MBR system were systematically investigated. MBR sludge showed a larger hydrolysis rate of particle organic nitrogen (PON) and also a higher transformation rate of DON to nitrate compared to conventional activated sludge (CAS). For long-term experiments, MBR achieved higher DON removal efficiency at low temperature than CAS; however, at high temperature, the effluent DON concentrations were almost the same in both systems. Batch tests on DON biodegradability showed that DON concentration increased and large molecular weight DON accumulated after 3-h aeration at low temperature, while DON concentration continuously decreased with the increase of aeration time at high temperature. The obtained results provide insights in DON removal in MBRs for meeting increasingly stringent regulations in terms of nitrogen removal.
溶解有机氮（DON）因其对富营养化和含氮消毒副产物（N-DBPs）形成的贡献而受到越来越多的关注。然而，膜生物反应器（MBR）中 DON 的信息非常有限。在这项研究中，系统地研究了 MBR 系统中 DON 的发生、转化和归宿。与传统活性污泥（CAS）相比，MBR 污泥对颗粒有机氮（PON）的水解速率更大，DON 向硝酸盐的转化速率也更高。对于长期实验，MBR 在低温下比 CAS 具有更高的 DON 去除效率；然而，在高温下，两个系统的出水中 DON 浓度几乎相同。DON 生物降解性的批量测试表明，在低温下曝气 3 小时后，DON 浓度增加，大分子量 DON 积累，而在高温下，随着曝气时间的增加，DON 浓度不断降低。这些结果为满足日益严格的氮去除法规下 MBR 中 DON 去除提供了深入了解。
