• 상하수도학회지
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• 제13권4호
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• pp.27-34
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• 1999

An experimental study on improvement of the paper-mill wastewater treatment using the pure oxygen activated sludge process was conducted. The effects of hydraulic retention time(HRT) and BOD loading on organic removal efficiency were investigated. The BOD removal efficiencies were above 90% under all examined HRTs except for HRT of 3 hours. The increase of HRT from 3 hours to 6 hours, and to 12 hours significantly improved BOD and COD removal efficiencies, respectively. However, additional increase of HRT did not affect organic removal efficiency. F/M ratio change at fixed HRT did not affect organic removal efficiency. However, F/M ratio investigated in this study(0.11~1.98kgBOD/kgMLVSS/day) was 5 times greater in maximum than that of conventional activated sludge process, which implies that pure oxygen activated sludge process can treat wastewater with high organic strength. Under the same HRT, the volumetric BOD loading change cause no effect on organic removal efficiency also.

• Environmental Engineering Research
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• 제16권4호
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• pp.213-218
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• 2011

The two-stage intermittent aeration activated sludge process (IAP) and dynamic-flow intermittent aeration activated sludge process (DFP) were investigated for the nutrient removal of domestic wastewater. Three sets of IAP and one set of DFP were operated. The fermented settled sludge taken from the primary settling tank was added to two IAP and one DFP as an external electron donor, with one IAP, in which an external carbon source was not added, as a control. All the systems were operated at a sludge retention time of 20 days and a hydraulic retention time of 12 hr. A Higher denitrification rate was observed with the fermented settled sludge for the denitrification compared to the process without the addition of the organic source. The result indicates that the fermented acid from the primary domestic sludge has been proved to be an excellent electron donor for denitrification and biological phosphorus removal with IAP and DFP in treating relatively low C/N ratio(Carbon / Nitrogen ratio) wastewater. Phosphate accumulating organisms have a capability of competing with denitrifiers in the presence of volatile organic acids under anoxic conditions.

• KSBB Journal
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• 제16권2호
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• pp.133-139
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• 2001

질소를 포함한 난분해성 오염불칠을 다량 함유한 축산폐수 (양돈폐수)의 오염물질을 효과적으로 처려를 위해서 생물학적 인 처리방안으로 활성슬러지 공정 및 입상활성란이 채워친 BACC 담제를 이용한 생물반응가에서의 유기물질 및 질소의 제거능에 때하여 조사하였다. 축산폐수를 일반 활성슬러지 공정으로 처려 할 경우 유압수를 희석하여 BOD 유입농도 약 600 mgfL의 폐수를 처리할 때 유출수의 BOD를 100 mgfL 이하로 유지하고자 할 경우 체류시간올 8일 이상 운전 해야하는 것으로 나타났다. 그러나 BACC 생물반응기에서 축산폐수를 처리할 때 체류시간이 200 시간일 때 유출수획 BOD, $COD_{Cr} $, TKN의 농도는 각각 94, 75, 64.3%의 제거효율을 나타내었다. BACC 생물반응기와 활성슬러지 공정을 비교 할 때 용적부하 0.3일 때 BOD 비기질제거속도가 활성슬러지 공정에서는 0.14 gBOD removedf L.day이고 BACC 생물반응기는 0.27 gBOD removed/L.day로서 통일부하에서 높은 제거효율을, 고부하에서도 안정된 제거효율을 나타내고 있기 때문에 BACC 생물반응기가 부하변통 및 고부하의 폐수처리에서 활성슬러지 공정보다 우수한 것으로 평가되었다.

• 한국환경보건학회지
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• 제25권3호
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• pp.23-28
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• 1999

Phosphate removal through adsorbent, such as activated alumina, powdered aluminum oxide, flyash, blasted furnace slag and other materials, is commonly and widely practiced. The purpose of this study was to improve the removal efficiency of phosphorus in waste sludge earned at seafood processing factories. To investigate the utility and the feasibility of this sludge disposal process, experiment was carried out with a batch process. As a result, phosphate removal appears to increase with increasing adsorbent does, but shows no changes at an adsorbent does over 5g/l. With increasing ratios of initial phosphate concentration to adsorbent does, the amount of removed phosphate is increased while phosphate removal(%) is decreased. Wasted sludge, treated with zinc chloride chemically, represented a better efficiency than the untreated activated sludge and zinc chloride itself, when they reacted with phosphate solution.

• 한국폐기물자원순환학회지
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• 제35권8호
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• pp.701-708
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• 2018

Chemical batch tests were conducted to investigate the amount of nutrients that were released from the wasted activated sludge during microwave heating. For this study, three types of activated sludge were obtained from $A_2/O$, MLE and oxidation ditch (OD) processes. Polyphosphate-accumulating organisms in the activated sludge have a unique trait: they releases phosphate from the cell when they are exposed to high temperatures. The sludge obtained from the $A_2/O$ process released the largest amount of phosphate, followed by those from the MLE and OD processes. The release of phosphate increased with increasing polyphosphate content in the sludge under strongly alkaline or acidic conditions. Furthermore, ammonia and heavy metals were released with phosphorous. The largest amount of ammonia was observed from the sludge obtained from the MLE process. The release of heavy metals strongly depends on the pH conditions. Therefore, the chemical analysis results strongly suggest that both phosphorus and ammonia react with $Mg^{2+}$ or $Ca^{2+}$ to form metal complexes such as magnesium ammonium phosphate or hydroxyapatite under alkaline conditions.

• 한국환경과학회지
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• 제4권3호
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• pp.259-267
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• 1995

This study was conducted to evaluate the effects of pressure and dissolved oxygen concentration on the activated slut비e and to determine the optimum depth of deep shaft process. Some results from this study were summarized as follows. 1. It is considered that low sludge product in the activated sludge system maintaining high dissolved oxygen concentration is attributed to the increase of endogeneous respiration rate caused by the increase of aerobic zone in the sludge floe. 2. The increase of dissolved oxygen concentration does not affect to the increase of organic removal efficiency greatly and therefore the limiting factor is the substrate transfer into the inner part of floe. 3. The yield coefficient, Y is decreased in proportion to the increase of oxygen concentration. In this study, Y values arre ranged from 0.70 to 0.41 according to the variation of dissolved oxygen concentration from 18.0mg/$\ell$ to 258 mg/$\ell$. 4. The optimum depth of deep shaft process should be determined within the limits of non-toxicity to the microorganism and it is about loom in this study.

• 생명과학회지
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• 제33권1호
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• pp.82-90
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• 2023

하수와 산업폐수를 처리하는데 생물학적 공정이 전세계적으로 이용된다. 생물학적 공정은 복합미생물로 구성된 슬러지를 사용한다. 슬러지 미생물이 성장함에 따라 폐수처리공정에서는 잉여슬러지가 발생한다. 잉여슬러지의 일부는 미생물을 보충하기 위해 폐수처리공정에 반송되지만 나머지는 폐기물로서 처리된다. 매년 전세계적으로 폐수발생이 증가함에 따라 폐수처리장의 수도 증가하여 많은 양의 폐슬러지가 생산된다. 따라서 폐슬러지에 대한 관리와 처리가 중요하다. 폐슬러지 처리비용은 폐수처리장 총운영비의 50-60%를 차지한다고 보고되었다. 슬러지 분해기술은 폐슬러지의 부피를 최소화하고 유용한 성분(예, P, N, 용해성 유기물)을 회수할 수 있는 새로운 기술이다. 물리적, 화학적, 그리고 생물학적 처리 또는 복합 처리에 기반을 둔 다양한 슬러지분해방법들이 개발되었다. 본 총설은 슬러지 분해방법들 중에서 비교적 덜 연구된 산 가수분해에 의한 슬러지 분해에 대해 중점적으로 다루었다. 본 총설에서 다룬 정보는 폐슬러지 처리를 위한 더 나은 기술을 개발하고 이식하는데 유용하게 사용될 것이다.

• 한국환경과학회지
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• 제8권4호
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• pp.533-538
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• 1999

Fuzzy algorithm of automatic control for dissolved oxygen(DO) concentration in the aeration tank of an activated sludge process is proposed. Among variables repirometry and air flowrate are selected as significant input factors and the relationship with DO is estimated using a multiple regression model. The DO concentration and the amount of repirometry are fuzzified and the fuzzy rule base are determined. Using the fuzzy algorithm, the change of amount of air flowrate are determined and the change of amount of DO is derived.

• 한국물환경학회지
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• 제25권4호
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• pp.530-538
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• 2009

The Oxic-Settling-Anaerobic (OSA) treatment process, a modified Conventional Activated Sludge (CAS) process, was developed for the purpose of sludge reduction. The insertion of a sludge holding tank into a sludge return line, an anaerobic reactor, forming an OSA process, may provide a cost-effective way of reducing excess sludge production during a process. The OSA process was evaluated for its sludge reduction ability by kinetic parameter and mass balance, with an observed excess sludge reduction of 63.5%, as $P_{X.VSS}$, compared with the conventional activated sludge process.

• Applied Biological Chemistry
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• 제45권1호
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• pp.25-29
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• 2002

활성슬러지에 의한 생물학적 폐수처리에 있어 주된 관리인자는 유기물의 효율적인 제거와 슬러지의 침강성을 일정치 이하로 유지하는 것이다. 식품폐수의 하나인 고농도의 대두가공폐수를 일반적인 활성슬러지법을 적용한 결과 최적 F/M비(food-to-microorganism ratio)는 0.24(kg-BOD/kg-MLVSS day)였으며 그 이상의 농도인 0.48(kg-BOD/kg-MLVSS day)에서는 슬러지 팽화현상이 발생하여 고농도의 식품폐수처리에는 효율적이지 못하였다. 이를 개선하기 위하여 응집보조제(NaOH)를 활용하여 유입폐수의 pH를 9.0으로 조절한 결과, 2.88(kg-BOD/kg-MLVSS day)의 고농도 폐수를 유입하여도 슬러지의 팽화현상없이 SVI(sludge volume index)를 150 이하로 유지하였다. 이것은 최대 허용부하를 일반적인 활성슬러지법에 비하여 7.2배 높일 수 있는 효율적인 방법으로 평가되었다.