• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.65-66
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• 2005

Anaerobic digestion is one of the well-known methods for biological treatment handling of concentrated organic matter such as swine $wastewater.^{1)} The anaerobic digestion can reduce organic loading but also hydrolyze non-biodegradable organic $matter.^{2)}$ The feces from the scrapper-type barn are usually collected to make compost and the urine is discarded with swine-slurry wastewater by ocean-dumping or treated by biological methods. The lagoon, aerobic digestion, anaerobic digestion, SBR, $A^{2}/O$, and UCT have been applied for treating swine $wastewater.^{3)} In this study, as a result of the analysis of swine wastewater, the total and soluble chemical oxygen demand was 130g/L and 60g/L, respectively. And the volatile fatty acid as chemical oxygen demand equivalent was 45g/L, which was 75% of soluble chemical oxygen demand. Before everything else, ammonia nitrogen concentration was 6.5 g/L. From biochemical acidogenic potential test, it was concluded that the enhanced acidification process to manage swine waste should be operated in the ammonia nitrogen concentration of less than 1.2 g/L. In the result of seeding ratio experiments with artificial $wastewater^{4)}, the lag period of acidogens was taken the long time because of the inhibition by the $ammonia^{5)}$, however no difference of period by the seeding ratio was not shown. The Haldane-based biokinetics were also evaluated using a method of fourth order Runge-Kutta $approximation.^{6,7)}$ The nonlinear least squares (NLLS) method with a 95% confidence interval was also used. The ranges of maximum microbial growth rate, ${/mu_{max}}$, and half saturation coefficient, $K_{s}$, for acidogenesis of various seeding ratio with artificial wastewater were 6.1 ~ 12.6 $d^{-1}$ and 45,000 ~ 53,500 mg glucose/L, respectively. Also, the methanogenic microbial yield coefficient, Y, and microbial decay rate coefficient, $k_{d}$, and inhibition substrate concentration, $K_{si}$, for the reactors were determined to be 0.32 ~ 0.465 ${/mu}g$/mg glucose; 0.42 ~ 1.01 $d^{-1}$ and 51,500 ~ 55,600 mg glucose/L, respectively.

• Environmental Engineering Research
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• 제19권1호
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• pp.47-57
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• 2014

The aim of this paper was to study the effect of five different waste combinations (C/N 15, C/N 20, C/N 25, C/N 30, and control) of sewage sludge coupled with sawdust and cattle manure in a pilot scale rotary drum reactor, during 20 days of the composting process. Our results showed that C/N 30 possesses a higher temperature regime with higher % reduction in moisture content, total organic carbon, soluble biochemical oxygen demand and chemical oxygen demand; and higher % gain in total nitrogen and phosphorus at the end of the composting period implying the total amount of biodegradable organic material is stabilized. In addition, $CO_2$ evolution and oxygen uptake rate decreased during the process, reflecting the stable behavior of the final compost. A Solvita maturity index of 8 indicated that the compost was stable and ready for usage as a soil conditioner. The results indicated that composting can be an alternate technology for the management of sewage sludge disposal.

• 대한환경공학회지
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• 제31권8호
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• pp.649-654
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• 2009

산소소비속도 측정에 의한 미생물 호흡률 분석방법에 의해 하수의 유기물질과 미생물 분율을 평가하였다. 하수의 유기물과 미생물 분율은 생물학적 공정의 모델링을 위한 중요한 기초자료이다. 본 연구에서 하수의 유기물 분율을 측정한 결과, 미생물에 의해 분해가 빠른 유기물, 분해가 느린 유기물, 분해되지 않는 용존성 유기물, 분해되지 않는 고형 유기물과 종속영양미생물의 분율은 각각 26.6%, 41.5%, 8.5%, 14.7% 및 8.7%였다. 또한, 질소 분율을 측정한 결과, 질산성 질소, 암모니아성 질소, 용존성 비분해 유기성 질소, 용존성 분해 유기성 질소 및 분해가 느린 유기성 질소의 분율은 각각 약 3.7%, 64.9%, 4.7%, 9.4% 및 17.4%였다.

• Membrane and Water Treatment
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• 제9권3호
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• pp.181-188
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• 2018

A sidestream contains the filtrate or concentrate from the belt filter press, filter backwash and supernatant from sludge digesters. The sidestream flow, which heads back into the sewage treatment train, is about 1-3% less than the influent flow. However, the sidestream can increase the nutrient load since it contains high concentrations of phosphorus and nitrogen. In this study, the removal of PO4-P with organic matter characteristics and bacteriological changes during the sidestream treatment via ladle furnace (LF) slag was investigated. The sidestream used in this study consisted of 11-14% PO4-P and 3.2-3.6% soluble chemical oxygen demand in influent loading rates. LF slag, which had a relatively high $Ca^{2+}$ release compared to other slags, was used to remove $PO_4-P$ from the sidestream. The phosphate removal rates increased as the slag particle size decreased 19.1% (2.0-4.0 mm, 25.2% (1.0-2.0 mm) and 79.9% (0.5-1.0 mm). The removal rates of dissolved organic carbon, soluble chemical oxygen demand, color and aromatic organic matter ($UV_{254}$) were 17.6, 41.7, 90.2 and 77.3%, respectively. Fluorescence excitation-emission matrices and liquid chromatography-organic carbon detection demonstrated that the sidestream treatment via LF slag was effective in the removal of biopolymers. However, the removal of dissolved organic matter was not significant during the treatment. The intact bacterial biomass decreased from $1.64{\times}10^8cells/mL$ to $1.05{\times}10^8cells/mL$. The use of LF slag was effective for the removal of phosphate and the removal efficiency of phosphate was greater than 80% for up to 100 bed volumes.

• 공업화학
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• 제23권2호
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• pp.228-231
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• 2012

본 연구에서는 혐기성 생물 반응조에서 35일 동안 배양된 하수슬러지와 판지슬러지를 혼합한 후, 초음파 파쇄기를 이용한 고농도 유기성 폐기물의 회분식 혐기 소화 공정에서 메탄 생산 특성이 고찰되었다. 초음파 파쇄기의 진폭이 높아질수록 Soluble Chemical Oxygen Demand (SCOD)가 증가함으로써 판지슬러지의 효과적 가용화가 이루어졌다. 또한, 메탄 생산성 향상을 위한 초음파 파쇄기의 최적 진폭이 $142.5\;{\mu}m$임을 구하였으며, 혐기소화 기간이 길러질수록 메탄 생산량은 증가하였다. 그리고, 바이오매스 변화(6000, 9000, 12000 mg/L)에 의한 혐기성 소화처리가 이루어졌을 때, 미생물 농도가 높아질수록 메탄 생산량이 모두 증가함을 알 수 있었다. 이러한 실험 결과들은 판지슬러지와 하수슬러지가 혼합된 고농도 유기성 폐기물의 혐기성 소화 공정에 의한 메탄 생산성을 향상시키는 자료로 활용될 수 있을 것이다.

• 유기물자원화
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• 제17권1호
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• pp.96-102
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• 2009

본 연구에서는 혐기성 소화 성능 향상을 위해 초음파 및 알칼리 전처리에 의한 폐활성 슬러지의 가용화 효과를 조사하였다. 초음파 및 알칼리 전처리는 세포벽의 파괴로 인하여 모세관 흡입 시간을 증가시킬 뿐만 아니라 상등액의 용존성 화학적 산소요구량, 단백질 및 탁도 농도를 증가키는 것으로 나타났다. 알칼리와 초음파 전처리를 병행한 슬러지 가용화가 초음파 전처리만을 수행한 경우에 비해 용존성 화학적 산소요구량과 단백질 증가가 높은 것으로 나타났다. 알칼리와 초음파 전처리를 동시에 수행한 경우 폐활성 슬러지의 고형물 농도 증가에 따라 가용화 효율이 감소하는 것으로 조사되었다.

• 유기물자원화
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• 제20권1호
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• pp.71-77
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• 2012

농업 바이오매스의 혐기소화 적용성을 위해 가장 많은 양이 발생하는 볏짚을 원료로 하여 전처리에 따른 볏짚의 가수분해과정에서 가용성 화학적 산소요구량 (SCOD)의 변화 특성을 조사하였다. 전처리 조건으로는 4 종류의 볏짚 크기, 4 종류의 온도, 2 종류의 초음파처리 및 알칼리를 처리하였다. 분해지표인 SCOD 용출량은 입자 크기가 작을수록, 반응 온도가 높을수록, 알카리를 처리하였을 때 높게 나타나 볏짚의 분해가 증진되는 것으로 나타났다. 5% NaOH를 처리한 경우 $35^{\circ}C$에서는 SCOD가 최고 9,000 mg $L^{-1}$로 증가하였으며, $55^{\circ}C$에서는 최고 6,000 mg $L^{-1}$까지 증가하였다가 감소하는 경향을 보였다. 또한 40 kHz의 초음파를 조사하여 3 cm 이하의 크기로 절단된 볏짚의 SCOD를 증진시킬 수 있는것으로 나타났으며, 온도에 관계없이 150 rpm의 교반속도에서 SCOD 용출량이 가장 높게 나타났다.

• 한국지반환경공학회 논문집
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• 제11권10호
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• pp.49-55
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• 2010

에너지원 및 다양한 화학제품의 원료로 유류의 소비량이 증가함에 따라 유류의 유출사고가 빈번하게 발생하고 있다. 유류오염 지하수 처리를 위해 용존공기부상법이 사용되어지고 있으나 용해성 기름을 효과적으로 제거하지 못하고 있는 실정이다. 따라서 지하수내 주오염원인 자유상 유류와 친수성(oil-in water) 또는 친유성 에멜젼(water-in oil) 상태의 기름과 용해성 기름을 효과적으로 저감하는 것이 필요하다. 본 연구에서는 용존공기부상법에 펜톤 산화 공법을 사용하여 효과적인 유류 오염 지하수 처리를 연구하였다. 펜톤 실험 결과 TPH(Total Petroleum Hydrocarbon) 제거를 위한 최적 조건은 pH 3, $H_2O_2$ 주입농도 25mM과 $Fe^{2+}$ 주입농도 25mM으로 나타났다. DAF와 펜톤 산화 실험을 수행한 결과 7분내에 TPH(Total Petroleum Hydrocarbon)와 COD(Chemical Oxygen Demand) 농도가 각각 1.5mg/L와 40.0mg/L 이하로 감소하는 것으로 나타났다. 하지만 펜톤 산화 반응으로 인하여 슬러지 농도가 약 5배 가량 증가하여 후단에 침전조를 설치하는 것이 바람직하다.

• Environmental Engineering Research
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• 제11권3호
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• pp.134-142
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• 2006

The treatment of high-strength swine wastewater by anaerobic digestion combined with an aquatic plant system was investigated. Anaerobic digestion of swine wastewater gave volatile solids (VS) removal efficiencies of 43.3%, 52.1% and 54.5% for hydraulic retention times (HRTs) of 20, 30, 40 days, respectively. The removal efficiencies of VS, total chemical oxygen demand (TCOD) and soluble chemical oxygen demand (SCOD) decreased with increasing VS volumetric loading rate (VLR). Higher organic removal efficiency was observed at longer HRTs for the same VS volumetric loading rate. As VS volumetric loading rate increased, biogas production increased and the methane content of the biogas decreased. Experiments using duckweed (Lemna species) as an aquatic macrophyte gave the following results. In the case of nitrogen, removal efficiency was above 60% and effluent concentration was below 10.0 mg/L when the influent ammonia-N loading was about $1.0\;g/m^2/day$. In the case of phosphorus, removal efficiency was above 55% and effluent concentration was below 2.0 mg/L when the influent $PO_4$-P loading was about $0.15\;g/m^2/day$. In addition, crude protein and phosphorus content of duckweed biomass increased from 15.6% to 41.6% and from 0.8% to 1.6%, respectively, as the influent nutrient concentration increased. The treatment of high-strength swine wastewater by anaerobic digestion combined with an aquatic plant system offers good performance in terms of organics and nutrient removal for relatively low operation and maintenance costs. The results indicate that under appropriate operational conditions, the effluent quality is within the limits set by Korean discharge criteria.

• 한국환경보건학회지
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• 제23권1호
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• pp.28-33
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• 1997

This study was carried out to investigate factors affecting anaerobic digestion enhancement of waste activated sludge(WAS). In order to this investigation, the degradability and rupture of microorganisms cell present in WAS, and mesophilic anaerobic digestion(MAD) of these compounds, were also evaluated. The micro-organisms cell in WAS were ruptured by a mechanical jet stream and smashed under pressure of 30 bar. The rupture level of micro-organisms cell in WAS were determined using phosphate, soluble protein and soluble chemical oxygen demand (SCOD)concentrations. It was found that the rupture level of micro- organisms cell within WAS increased with increasing pretreatment times, and the pretreated WAS once under pressure of 30 bar resulted in an increase in VS removal and methane production of 5%, 9% over the intact WAS of 35%, 71%, respectively, in batchwise MAD of 6-day and 14-day retention time. With the pretreatment and MAD of 6-day retention time used, mesophlic bioconvertibility as the biogasification of WAS were found to be significantly higher biogas of 1, 850 ml than 300 ml under intact WAS. In conclusion it can be stated mechanical pretreatment enhances WAS bioconvertibility, while under identical treatment conditions, resulted in a considerable decrease in the bioconvertibility of intact WAS.