LITHOAUTOTROPHIC NITROGEN REMOVAL WITH ANAEROBIC GRANULAR SLUDGE AS SEED BIOMASS AND ITS MICROBIAL COMMUNITY

We used in situ hybridization with fluorescently labeled rRNA-targeted oligonucleotide probes concurrently with microscopic examinations and methane measurements to characterize the microbial community of an anaerobic hybrid reactor treating pentachlorophenol (PCP) with a mixture of fatty acids (propionic, butyric, acetic and lactic) and methanol. Archaeal cells detected with probe ARC915 prevailed in anaerobic granular sludge without and with the addition of PCP in a range of 2.0 to 21.0 mg/L to the reactor. This group accounted for 81 and 90% of the DAPI-stained cells before and after the addition of 21 mg/L of PCP, respectively. In these conditions, cells detected with the Methanosarcinales specific probe (MSMX860) were the only methanogenic Archaea found and accounted for 59 to 87.6% of the DAPI-stained cells. No cells were detected by the Methanomicrobiales (MG1200), Methanobacteriaceae (MB1174) and Methanococcaceae (MC1109) specific probes. Bacterial cells detected with probe EUB338 were found in very low numbers, which ranged from 5.7 to 1.0% of the DAPI-stained cells. This finding agrees with the scanning electron microscope examinations, in which cells morphologically resembling Methanosaeta and Methanosarcina were predominantly observed in the granular sludge. Results contributed to the investigation of the importance of the methanogens during PCP degradation.

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Assessment of Inocula and N-Removal Performance of Anaerobic Ammonium Oxidation (ANAMMOX) for the Treatment of Aged Landfill Leachates

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.2391 ◽

2012 ◽

Vol 518-523 ◽

pp. 2391-2398

Author(s):

Yan He ◽

Gong Ming Zhou ◽

Min Sheng Huang ◽

Min Tong

Keyword(s):

Activated Sludge ◽

Nitrogen Removal ◽

Removal Rate ◽

Granular Sludge ◽

Nitrogen Loading ◽

Anaerobic Granular Sludge ◽

Landfill Leachates ◽

N Removal ◽

Start Up ◽

Anammox Process

Three kinds of seeding sludge, i.e. conventional activated sludge, anaerobic granular sludge and the nitrifying activated sludge from the nitritation reactor treating aged leachates were evaluated in batch mode to screen the optimized inoculum for the rapid start-up of ANAMMOX reactor. The feasibility of the ANAMMOX process for the treatment of aged leachates was also investigated in a modified upflow anaerobic sludge blanket (UASB, 0.05m3). The batch experiments revealed that the nitrifying activated sludge from the nitritation reactor could respectively achieve the NRR (nitrogen removal rate) of 0.0365 kg N/(m3.d) and the ARR (ammonium removal rate) of 0.013 kg N/(m3.d) on day 12, which were greatly higher than those of the other two tested sludge samples. The mixture of the aforementioned nitrifying activated sludge and anaerobic granular sludge was established as an effective inoculum for the prompt start-up of ANAMMOX reactor. The maximum total nitrogen removal rate of 0.826 kg N/(m3.d) could be obtained for the treatment of “old” leachates under NLR (nitrogen loading rate) of 1.028 kg N/(m3.d). It is concluded that the N-removal performance of ANAMMOX process is still to be improved for actual engineering application to aged landfill leachates.

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Nutrient removal and microbial granulation in an anaerobic process treating inorganic and organic nitrogenous wastewater

Water Science & Technology ◽

10.2166/wst.2004.0378 ◽

2004 ◽

Vol 50 (6) ◽

pp. 207-215 ◽

Cited By ~ 9

Author(s):

Y.-H. Ahn ◽

H.-C. Kim

Keyword(s):

Nitrogen Removal ◽

Nutrient Removal ◽

Granular Sludge ◽

Synthetic Wastewater ◽

Anaerobic Granular Sludge ◽

Ammonium Oxidation ◽

Ammonium Removal ◽

Activity Test ◽

Nitrite Nitrate ◽

Inorganic And Organic

The sustainable anaerobic nitrogen removal and microbial granulation were investigated by using a laboratory anaerobic granular sludge bed reactor, treating synthetic (inorganic and organic) wastewater and piggery waste. From inorganic synthetic wastewater, lithoautotrophic ammonium oxidation to nitrite/nitrate was observed by an addition of hydroxylamine. Also, the results revealed that the Anammox intermediates (particularly, hydrazine) contents in the substrate would be one of the important parameters for success of the anaerobic nitrogen removal process. The results from organic synthetic wastewater show that if the Anammox organism were not great enough in the startup of the process, denitritation and anaerobic ammonification would be a process prior to the Anammox reaction. The anaerobic ammonium removal from the piggery waste was performed successfully, probably due to the Anammox intermediates contained in the substrate. This reactor shows a complex performance including the Anammox reaction and HAP crystallization, as well as having partial denitritation occurring simultaneously. From the activity test, the maximum specific N conversion rate was 0.1 g NH4-N/g VSS/day (0.77 g T-N/g VSS/day), indicating that potential denitritation is quite high. The NO2-N/NH4-N ratio to Anammox is 1.17. The colour of the biomass treating the piggery waste changed from black to dark red. It was also observed that the red-colored granular sludge had a diameter of 1-2 mm. The settleability assessment of the granular sludge revealed that the granular sludge had a good settleability even though it was worse than that of seed granular sludge.

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