• Journal of Korean Society on Water Environment
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• v.20 no.5
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• pp.480-487
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• 2004

This study was conducted to find the effect of electron acceptors on the formation of granular sludge by using four different types of electron acceptors. The phosphorous uptake, denitrification, and sulfate reduction in anoxic modes were simultaneously occured because of the presence of the polyphosphate accumultating organism(PAO) that utilize nitrate and sulfate as an electron acceptor in the anoxic zone. Denitrirying phosphorous removal bacteria(DPB) was enriched under anaerobic/anoxic/aerobic condition with a nitrate as an electron acceptor, and desulfating phosphorous removal bacteria(DSPB) was enriched under anaerobic/anoxic/aerobic condition with a sulfate as an electron acceptor. Polyphosphate accumulating organism(PAO) were enriched in the anaerobic/aerobic SBR. PAO took up acetate faster than DPB and DSPB during the aerobic phase. The sludge with nitrate and sulfate as an electron acceptors grew as a granules which possessed high activity and good settleability. In the anaerobic/aerobic modes, typical floccular growth was observed. In the result of bench-scale experiment, simultaneous reactions of phosphorus uptake, denitrification and sulfate reduction were observed under anoxic condition with nitrate and sulfate as an electron acceptors. These results demonstrated that the anaerobic/anoxic modes with nitrate and sulfate as an electron acceptors played an important role in the formation of the sludge granulation.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.2
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• pp.49-54
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• 2011

This study was conducted to evaluate the performance of methane fermentation from effluent of hydrogen fermentation reactor in anaerobic baffled reactor (ABR) and anaerobic sequencing batch reactor (ASBR). Two reactors were operated at organic loading rate of $1.0kg\;COD/m^3{\cdot}d$ and hydraulic retention time (HRT) of 20 day. Methane production rates of ABR and ASBR for start-up periods were 0.04 L/L/d and 0.19 L/L/d, respectively, whereas maximum methane production rates of ABR and ASBR were 0.25 L/L/d and 0.31 L/L/d, respectively. Removal rates of chemical oxygen demand (COD) in ABR and ASBR for start-up periods were 89% and 92%, respectively. After startup periods, removal rates of COD and volatile solids (VS) in ABR and ASBR were maintained over 90%. The specific methanogenic activity (SMA) increased as microorganism acclimated to the substrate.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.680-688
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• 2004

A sequencing batch reactor (SBR) was operated to investigate the degradation and removal of non-ionic surfactant, nonylphenol ethoxylates (NPEOs) in wastewater using lab scale experimental apparatus. About 5mg/L of NPEO was introduced and only < 0.1mg/L of NPEOs and nonylphenol(NP) in total was detected in treated effluent. In the effluent, long chain ethoxylates (NPEO12-15) were not detected, but short chain ethoxylates (NPEO1,2) were in relatively high concentration. NPEOs in the mixed liquor disappeared more rapidly in anaerobic condition than in aerobic condition.

• Journal of Korean Society on Water Environment
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• v.29 no.3
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• pp.377-382
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• 2013

Enriching anammox bacteria (AMX) in a lab-scale granular sequencing batch reactor using local digester centrate, we observed the significant enrichment of the filamentous-like bacterial population. These bacteria were revealed as novel bacterial species (termed CHL) belonging to Chlorobi/Bacteroidetes phyla via Denaturing Gradient Gel Electrophoresis (DGGE). Further, niche differentiation of AMX and CHL quantification was observed in granule and filament biomass, suggesting AMX was dominant in the granule and CHL was dominant in the filament. Therefore, it was confirmed the structural role of CHL was indeed to aid the granule formation of the AMX. In parallel, the physiological role of CHL was suspected to degrade biopolymers in the digester centrate using nitrate as an electron acceptor.

• Journal of Environmental Health Sciences
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• v.28 no.3
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• pp.49-54
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• 2002

This study was conducted to evaluate the feasibility and characteristics of poly acrylamide (PAA) immobilized sludge as a microbial entrapment bead for wastewater treatment. In the PAA method of immobilized sludge, it was found that the optimum acrylamide concentration for actual wastewater treatment was to be 12%. When the sequencing batch reactor (SBR) was operated during 30 days, removal efficiencies of TOC and phosphate was 95% and 70ft, respectively. From this research, repeated cycle of anaerobic and aerobic conditions is required to enhance the removal of TOC and phosphate. During the operation, immobilized cells could be used without being disrupted.

• Journal of Korean Society on Water Environment
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• v.33 no.3
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• pp.302-310
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• 2017

The morphological characteristics of granules developing in anaerobic-anoxic (An-Ax) and anaerobic-aerobic (An-Ox) sequencing batch reactors (SBRs) were examined. The granules developed in the both SBRs after 200 days of laboratory operation. The average diameters of the granules were $2.2{\pm}1.7mm$ in the An-Ax SBR and $0.4{\pm}0.3mm$ in the An-Ox SBR. To determine the possible factors affecting morphology of granules a comparative analysis of various operating conditions from reference data indicated that the availability and type of electron acceptors is a key factor determining the granulation process and granular morphology.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.26-35
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• 2020

BACKGROUND: Microbes that govern a unique biochemical process of oxidizing ammonia into dinitrogen gas, such as anaerobic ammonium oxidation (anammox) have been reported to play a pivotal role in agricultural soils and in oceanic environments. However, limited information for anammox bacterial abundance and distribution in the terrestrial habitats has been known. METHODS AND RESULTS: Phylogenetic and next-generation sequencing analyses of bacterial 16S rRNA gene were performed to examine potential anammox bacteria in paddy soils. Through clone libraries constructed by using the anammox bacteria-specific primers, some clones showed sequence similarities with Planctomycetes (87% to 99%) and anammox bacteria (94% to 95%). Microbial community analysis for the paddy soils by using Illumina Miseq sequencing of 16S rRNA gene at phylum level was dominated by unclassified Bacteria at 33.2 ± 7.6%, followed by Chloroflexi at 20.4 ± 2.0% and Acidobacteria at 17.0 ± 6.5%. Planctomycetes that anammox bacteria are belonged to was 1.5% (± 0.3) on average from the two paddy soils. CONCLUSION: We suggest evidence of anammox bacteria in the paddy soil. In addition to the relatively well-known microbial processes for nitrogen-cycle, anammox can be a potential contributor on the cycle in terrestrial environments such as paddy soils.

• Journal of Environmental Health Sciences
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• v.30 no.2
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• pp.84-91
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• 2004

Biological nutrient removal(BNR) from wastewater was performed by adopting various process configurations. The simultaneous biological organics, phosphorus and nitrogen removal of synthetic wastewater was investigated in a sequencing batch biofilm reactor (SBBR). The other reactor was operating as a reference, without biofilm being added. The cycling time in SBR and SBBR was adjusted at 12 hours and then certainly included anaerobic and aerobic conditions. Both systems has been operated with a stable total organic carbon(TOC), nitrogen and phosphorus removal performance for over 90 days. Average removal efficiencies of TOC and total nitrogen were 83% and 95%, respectively. The nitrification rate in SBR was higher than that in SBBR. On the contrary, the denitrification rate in SBBR was higher than that in SBR. The phosphorus release was occurred in SBBR, however, not in SBR because of the inhibition effect of NO$_3$$^{[-10]}$ .

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.286-289
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• 2001

Anaerobic ammonium oxidation with nitrite to $N_2$(anammox) is a recently discovered microbial reaction with interesting potential for nitrogen removal from wastewater. Here we investigated the microbial community structure in the sequencing batch reactor(SBR) with an anammox activity. The SBR was optimized for the enrichment of a very slowly growing microbial community and showed that possibility of anaerobic ammonium oxidation. Fluorescence in situ hybridization(FISH) analysis revealed that anaerobic ammonium oxidizers were Candidatus Brocadia anammoxidans and Candidatus Kuenenia stuttgartiensis. Furthermore, Nitrosomol1as spp. of the ${\beta}$ -subclass of Proteobacteria was also present within the anaerobic SBR microorganisms.

• Journal of Environmental Science International
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• v.7 no.6
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• pp.867-873
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• 1998

Laboratory study was conducted to provide basic data for operating anaerobic sequencing batch reactor(ASBR) process for treatment of nightsoil. The experiments were concerned with digestion characteristics, settleabiltity and dewaterability of digested sludge in ASBR system. Completely-mixed dally-fed control reactor without solid-liquid separation step was also operated to evaluate the baseline performance since the nature of nightsoil was changed with time. In all case, gas production from the ASBR shows 1.3 to 1.44 times higher than that from control, in spite of almost similar trend in organics removal. During thickening period, remarkable decrease in surface settling velocity was observed at the ASBRs compared with the control. In case of the ASBR run, flotation of mixed digested sludge was not occurred. Also, ultimate thickened volume of ASBRs increased 1.2~1.5 times compared with control. Dewaterability of digested sludge without conditioning decreased when the completely-mixed daily-fed reactor for ASBR run was converted to the ASBR. However, improvement of dewaterability of digested sludge from the ASBRs was observed as a result of addition of FeCl$_3$ to digested sludge for conditioning.