کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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35893 | 45113 | 2007 | 7 صفحه PDF | دانلود رایگان |
In this study sludge wash-out was evaluated as a strategy to start-up the Anammox process in order to establish it in a shorter period of time. Sludge from a domestic wastewater treatment plant (WTP) was used to seed two (RI and RII) anaerobic sequencing batch reactors (ASBR). During the start-up period RI was operated as a continuous stirred tank reactor (CSTR) using a dilution rate of 0.2 d−1, which promoted the sludge wash-out. After this period, the remaining sludge was retained in the reactor. The reactor RII was operated as an ASBR throughout the study period with a high cell retention. The performance of the two reactors in terms of nitrogen removal was compared over a period of 380 days. During the last RI operation phase the specific nitrogen removal rate increased exponentially, attaining values of 85 mg N/g TSS d. However, a rate of 190 mg N/g TSS d in the batch test under optimal conditions was achieved. The specific nitrogen removal rate remained almost constant for RII with a mean value of 6 mg N/g TSS d being observed during the operation period. The rate for the RII batch test was 20 mg N/g TSS d. These results confirm that the higher total suspended solids (TSS) in RII (reactor with high cell retention) was not effective in terms of N removal improvement. Anammox-like bacteria were found using fluorescence in situ hybridization (FISH) in reactor RI after 225 days and a new Anammox species was identified.
Journal: Process Biochemistry - Volume 42, Issue 12, December 2007, Pages 1579–1585