• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.179-186
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• 2010

In biological wastewater treatment, high lipid concentrations can inhibit the activity of microorganisms critical to the treatment process and cause undesirable biomass flotation. To reduce the inhibitory effects of high lipid concentrations, a two-phase anaerobic system, consisting of an anaerobic sequencing batch reactor (ASBR) and an upflow anaerobic sludge blanket (UASB) reactor in series, was applied to synthetic dairy wastewater treatment. During 153 days of operation, the two-phase system showed stable performance in lipid degradation. In the ASBR, a 13% lipid removal efficiency and 10% double-bond removal efficiency were maintained. In the UASB, the chemical oxygen demand (COD), lipid, and volatile fatty acid (VFA) removal efficiencies were greater than 80%, 70%, and 95%, respectively, up to an organic loading rate of 6.5 g COD/l/day. No serious operational problems, such as significant scum formation or sludge washout, were observed. Protein degradation was found to occur prior to degradation during acidogenesis.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.676-679
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• 2003

Long time over 6 month was required to form granuler sludge, which is critically necessary for UASB reactor. By feeding both high molecular cationic polymer and anionic silica sol to conventional digestion sludge, granular sludge was obtained within 5 minutes. Succession adaptation was performed for granular sludge for 30 days. $80{\sim}90%$ COD removal efficiency was shown with granular sludge, which was comparable with that of typical UASB granular sludge.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.508-511
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• 2000

In situ hybridization with fluorescent oligonucleotides(FISH) was used to detect and localize microorganisms in the granules of lab-scale upflow anaerobic sludge blanket(UASB) reactors. An UASB reactor was seeded with mesophilically-grown($35^{\circ}\;C$) granular sludge, and thermophilically($55^{\circ}\;C$) operated by feeding with a synthetic wastewater. Sections of the granules were hybridized with 16S rRNA-targeted oligonucleotide probes for Eubacteria, Archaeabacteria, and specific phylogenetic groups of methanogens. FISH clearly showed the layed structure of thermophilic granules, which was consisted of outer bacterial cells and inner archaeal cells. Methanoseata-, Methanosarcina-like cells were also found to be localized inside the granules. These results demonstrated FISH was useful in studying the spatial organizations of methanogens and in situ morphologies and metabolic functions in thermophilic granular sludges.

• Journal of Microbiology and Biotechnology
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• v.6 no.1
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• pp.30-35
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• 1996

Distillery wastewater was used in a thermophilic laboratory-scale two stage anaerobic digester to test the effects of the redox potential of the first acidogenic reactor on the performance of the system. The digester consisted of first a acidogenic reactor and the an upflow anaerobic sludge blanket (UASB) reactor. The digestor was operated at a hydraulic retention time (HRT) of 48 h. Under these conditions, about 90% of the chemical oxygen demand as measured by the chromate method ($COD_{cr}$) was removed with a gas production yield of 0.4 l/g-COD removed. The redox potential of the acidogenic reactor was increased when the reactor was purged with nitrogen gas or agitation speed was increased. The increase in reduction potential was accompanied by an increase in acetate production and a decrease in butyrate formation. A similar trend was observed when a small amount of air was introduced into the acidogenic reactor. It is believed that the hydrogen partial pressure in the acidogenic reactor was decreased by the above mentioned treatments. The possible failure of anaerobic digestion processes due to over-loading could be avoided by the above mentioned treatments.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.993-997
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• 2007

The upflow anaerobic sludge blanket (UASB) reactor can be effective for treating simple organic compounds containing high concentration of ammonia nitrogen. The chemical oxygen demand (COD) removal efficiency was about 80% at ammonia nitrogen concentration up to 6,000 mg-N/L. This result also showed that it would be possible to treat propionate effectively at free ammonia nitrogen concentration up to 724 mg-N/L if sufficient time was allowed for adaptation. However the specific methanogenic activity (SMA) of granule was lower than that of granule in the reactor with lower ammonia nitrogen concentration. At 8,000 mg-N/L, the inhibition of high ammonia concentration was observed with evidence of increase of the volatile suspended solids (VSS) concentration in the effluent. It might be ascribed to the decrease in the content of extracellular polymer (ECP), which resulted to the sloughing off of obligated proton-reducing acetogens and heterogenotrophic methanogens from the exterior of granular sludge. This caused a great portion of the finely sludge to be easily washed out. Therefore, failure to maintain the balance between these two groups of microorganism cause accumulation of the hydrogen partial pressure in the reactor, which could have inhibited the growth of acetate utilizing methanogens.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.18-25
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• 2009

Nitrogen removal and methane production from piggery wastewater were investigated in two-phase anaerobic digestion (TPAD) coupled with biological nitrogen removal (BNR) process at $35^{\circ}C$. Methane production rate was about $0.7L/L{\cdot}day$ at organic loading rate (OLR) of $1.2g{\cdot}TCOD/L{\cdot}day$ in methanogenic UASB. Conversion efficiency of the removed TCOD into methane in UASB was as high as 72% and overall TCOD removal efficiency in this system was over 97%. Ammonia nitrogen were stably removed in BNR system and overall efficiency were 98%. With recirculation of the nitrified final effluent to TPAD, nitrogen oxides were completely removed by anaerobic denitrification in the acidogenic reactor, which did not inhibit the acidogenic activities. Overall TN removal efficiency in the TPAD-BNR system was as high as 94%.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.4
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• pp.45-54
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• 1996

Effects of temperature on the efficiency of the Upflow Anaerobic Sludge Blanket(UASB) process for treatment of wastewater from a starch and related products manufacturing industry were investigated using laboratory scale reactors equipped with two types of Gas-Solid Separator(GSS). Both fresh digested sludge and granular sludge stored nearly for one year at room temperature were good as a seeding material. The reactors seeded with aged granular sludge showed slow start-up, however, lowered activity at the initial period was recovered gradually. The GSS with an inner cylinder was proved to be effective in liquid-solid separation compared to the conventional type. Although the rate of organic removal and gas production per unit volatile suspended solids in the reactor reduced significantly as the temperature varied from 35 to $20^{\circ}C$, possibility of operation at low temperatures was shown as a result of gradual buildup of volatile suspended solids in the bed. Stable operation with a reduced efficiency was possible at a COD loading of $5-8kg/m^3/day$ at a temperature as low as $20^{\circ}C$.

• Journal of the Korean GEO-environmental Society
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• v.9 no.2
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• pp.23-29
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• 2008

It has been mentioned that CSTR (Completely Stirred Tank Reactor) and UASB (Upflow Anaerobic Sludge Blanket) processes, the existing anaerobic processes, have problems in the treatment of highly concentrated particulate organic wastewater (HCPOW). Therefore, this paper discusses the treatment possibility of distillery wastewater which is a typical HCPOW using ADEPT (anaerobic Digestion Elutriated Phased Treatment) process. In the comparison of CSTR and ADEPT, ADEPT produced much higher gas than that of CSTR removing more organic matters and suspended solids in ADEPT process, ADEPT had no effect on the decrease in pH by volatile fatty acids and showed steady pH in spite of relatively short HRT. In the results of removal rate according to recycle ratios between 6Qin and 2Qin in ADEPT, 6Qin showed high removal rate during the operation time. Therefore it appears that ADEPT had an applicability for the treatment of distillery wastewater. ADEPT could be a economical process, due to the short HRT, the energy recovery by the methane production, and the utilization for carbon source of produced organic acid from the ADEPT-acid reactor.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.523-533
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• 2000

A two-phase anaerobic reactor with submerged membrane system was developed for increasing acidogen concentration and methane recovery. The membrane used was mixed esters of cellulose of $0.5{\mu}m$ pore size and $0.8m^2$ of effective surface area. The methanogenic reactor comprised of UASB (Upflow Anaerobic Sludge Blanket) and AF (Anaerobic Filter). COD removal efficiency was 70~80% and the methane content in the biogas increased up to 90% for the submerged membrane system in the anaerobic reactor. As the cake resistance of membrane caused a serious problem, stainless steal prefilters (40, 53, $63{\mu}m$) and air backwashing methods were applied to minimize the cake resistance effectively. Among the tested prefilters. the $63{\mu}m$ prefilter showed the best performance for reduction of cake resistance and a successful long-tern operation. By cleaning with alkali first and acidic solution later. the permeate flux decreased by long term operation was recovered to 89% of that with a new membrane.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.419-422
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• 2004

Textile wastewater from the Pusan Dyeing Industrial Complex (PDIC) was treated utilizing a two-stage continuous system, composed of an upflow anaerobic sludge blanket reactor and an activated Sludge reactor. The effects of color and organic leading rates were studied by varying the hydraulic retention time and influent glucose concentration. The maximum color load to Satisfy the legal discharge limit of color intensity in Korea (400 ADMI, unit of the American Dye Manufacturers Institute) was estimated to be 2,700 $ADMI{\cdot}L^{-1}\;day^{-1}$. This study Indicates that the two-stage anaerobic/aerobic reaction system is potentially useful in the treatment of textile wastewater.