• 유기물자원화
• /
• 제29권4호
• /
• pp.99-106
• /
• 2021

본 연구는 혐기성 소화의 전처리로써 열가수분해와 고액분리가 결합된 공정의 성능을 평가하였다. 탈수케이크는 열가수분해를 통해 가용화되며, 이후 고액분리를 수행한다. 고액 분리된 액상은 혐기성 소화에 기질로써 이용되고 고형물은 열가수분해로 회수된다. 열가수분해의 가용화율(COD 기준)은 45.1-49.3%이며 고액분리와 결합한 공정은 76.1-77.6%로 나타났다. Dual-pool two-step model을 통해 도출된 메탄 발생 특성을 살펴보면 고액 분리된 액상의 전체 분해 가능한 물질 중 분해가 빠른 물질의 비(a)는 0.891-0.911로 열가수분해된 시료에 비해 높게 나타났다. 반면에 분해가 빠른 물질의 반응 속도(kF)는 유사하게 나타났다. 이를 통해 열가수분해와 고액분리가 결합한 공정은 열가수분해를 통해 분해가 빠른 물질을 생성하고, 고액분리를 통해 선별하는 것으로 나타났다.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XII)
• /
• pp.128-131
• /
• 2003

The effect of microwave irradiation on waste activated sludge was investigated in order to improve solubilization. a different levels of microwave irradiation time were varied within a range from 1 min to 15 min. When WAS was pretreated at 1, 3, 5, 7, and 15 min, the SCOD concentration increased according to microwave irradiation time. A simple batch procedure was used to measure the VFA potential, i.e. the amount of VFA that can be formed through digestion of organic constituent in sludge. At equilibrium point, TVFA in the case of 1, 3, 5, 7 and 15 min microwaved sludges was 8%, 122%, 243%, 279% and 232% higher than that in the case of raw sludge, respectively.

• Environmental Engineering Research
• /
• 제19권4호
• /
• pp.355-361
• /
• 2014

The wastewater treatment with a two-phase expanded granular sludge bed (EGSB) system for anaerobic degradation of acetate, benzoate, terephtalate and p-toluate from purified terephtalic acid (PTA) production was studied. The feasibility and effectiveness of the system was evaluated in terms of organic oxidation by chemical oxygen demand (COD), gas production, bacterial adaptability and stability in the granular sludge. Average removal efficiencies 93.5% and 72.7% were achieved in the EGSB reactors under volumetric loading rates of $1.0-15kg-COD/m^3/day$ and terephtalate and p-toluate of 351-526 mg/L, respectively. Gas production reached total methane production rate of 0.30 L/g-COD under these conditions in the sequential EGSB reactor system. Higher strength influent COD concentration above 4.8 g-COD/L related to field conditions was fed to observe the disturbance of the EGSB reactors.

• 환경위생공학
• /
• 제13권2호
• /
• pp.47-56
• /
• 1998

Effects of sulfate on the anaerobic substrate utilization were evaluated using UASB (Upflow Anaerobic Sludge Blanket) reactor. Effect of sulfate on the organic removal rate was dependent on the relative amount of microorganisms in the reactor, the operational condition, and the characteristics of sludge. When the sulfate shock was applied to 0.0 - 3.0g SO$_{4}$$^{2-}$/d, more than 95% of COD removal efficiency was achieved. Therefore, if F/M ratio was kept to low sufficiently with recirculation, it is shown that operation of the reactor was not affected significantly, though sulfate shock load was doubled compared to the normal operation. Provided that it is shocked by high strength of sulfate or temporary shock load is applied frequently the efficiency of reactor may be disadvantageous as well as the wash-out of sludge will be increased by decreasing the size to the accumulated frequency of granular sludge and the size with maximum frequency.

• 한국초전도ㆍ저온공학회논문지
• /
• 제23권3호
• /
• pp.32-36
• /
• 2021

Milking parlor wastewater contains not only high concentrations of organic compounds, but often animal antibiotics. To discharge the antibiotics to public water area cause problem of antibiotics resistant bacteria. Magnetic separation was applied into improvement of milking parlor wastewater treatment process. A new process, composed of a magnetic activated sludge (MAS) process and a contact oxidation (CO) process, was proposed in this study. This process was evaluated by the simulated milking parlor wastewater (4500 mg/L COD_Cr and 10 mg/L tetracycline) using a bench scale experimental setup. As a result, the process was able to removed 97% COD_Cr as well as 94% tetracycline. The MLVSS (mixed liquor volatile suspended solids) concentration of MAS was maintained at 12000 mg/L without excess sludge drawing. This process was considered to be useful as treatment process for milking parlor wastewater in which waste-milk including antibiotics is often discharged.

• 대한화학회지
• /
• 제55권5호
• /
• pp.842-845
• /
• 2011

Wet air oxidation (WAO) of oily sludge was carried out using $Fe^{3+}$ as catalyst, placed in a 0.5 L batch autoclave in the temperature range of $250-330^{\circ}C$. Experiments were conducted to investigate the effects of temperature, the initial COD, reaction time, concentration of catalyst and $O_2$ excess (OE) on the oxidation of the oily sludge. The results showed that in the WAO 88.4% COD was achieved after 9 min reaction at temperature of $330^{\circ}C$, OE of 0.8 and the initial COD of 20000 mg/L. Temperature was found to have a significant impact on the oxidation of oily sludge. Adding a catalyst significantly improved the COD removal. Homogenous catalyst, $Fe^{3+}$, showed effective removal for pollutants. COD removal was 99.7% in the catalytic wet air oxidation (CWAO) over $Fe^{3+}$ catalyst. The results proved that the CWAO was an effective pretreatment method for the oily sludge.

• 한국물환경학회지
• /
• 제16권4호
• /
• pp.513-521
• /
• 2000

Intermittently aerated activated sludge process was applied as a water reuse process of $70m^3/day$ for the upgrade of organic, nitrogen and phosphorus removal efficiency and clarifier performance. After application of the intermittently aeration, removal efficiency of BOD, SS, T-N and T-P were achieved 95%, 90%, 80% and 60%, respectively. Removal efficiencies in intermittently aerated process were considerably increased. comparing to those of continuously aerated activated sludge process. Also sludge rising problem in clarifier was improved. Average concentration of supplied reusing water were BOD 5 mg/L, turbidity 4 NTU and after chlorination, residual chlorine 0.4 mg/L, coliform 0 MPN/100mL. Intermittently aerated activated sludge process could be one of the best alternative process for the retrofit of conventional activated sludge process for the removal of nutrient in water reuse system.

• 상하수도학회지
• /
• 제11권1호
• /
• pp.64-73
• /
• 1997

Most of the municipal wastewater treatment plants operated in Korea are designed for high concentrations municipal sewage. However, activated sludge process employed by municipal wastewater treatment plant is operated at low organic loading. The objective of this study was to determine optimum operating condition of activated sludge process for treatment of low concentration municipal sewage. Three bench scale activated sludge reactors were operated to investigate the effect of HRT and SRT on the COD and TSS removal efficiency. The average concentration of TSS, SCOD, SBOD and TKN in influent were 118mg/l, 61mg/l, 21mg/l, and 12mg/l, respectively. The activated sludge reactors operated with various HRT and SRT showed about 89-93% TSS removal efficiency. HRT and SRT does not affect the TSS removal efficiency of actvatied sludge process significantly. However, HRT affected the SCOD removal efficiency slightly. As the HRT decreases from 13hours to 3hours, the SCOD removal efficiency decreases from 67% to 56%. The average effluent TCOD concentration of the reactor operated with 3hours of HRT was approximatly 40-45mg/l. Kinetic coefficient yield (Yt) and decay coefficients(Kd) were 0.594-0.954 mgMLVSS/mgCOD and $0.0197-0.0317day^{-1}$, respectively. Low concentration municipal sewage can be treated with 3 hours of HRT without effluent quality deterioration and SRT does not affect the substrate removal efficiency at this operation condition.

• 한국토양환경학회지
• /
• 제4권2호
• /
• pp.149-161
• /
• 1999

본 연구에서는 위생매립지 차수재로써 부산석회의 이용방안을 검토하기 위하여 1) 부산석회의 지반 공학적 특성, 2) 오염물질 거동특성, 그리고 3) 용출특성을 살펴보았다. 연구결과 부산석회의 투수계수는 차수재의 허용 최대 투수계수($10^{-7}$ cm/s)보다 약 10배정도 낮은 투수계수를 보였다. 유기물(페놀)과 중금속(Cu, Pb)에 대한 지연효과는 부산석회의 높은 pH(> 11)로 인해 중금속에 대한 지연효과가 더 큰 것으로 나타났다. 용출실험 결과 비록 규제치를 상회하지는 않았지만, Pb과 Cd이 제한 기준치에 근접한 농도를 나타내어 지속적인 관찰이 요구되는 물질로 나타났다.

• 자원리싸이클링
• /
• 제8권4호
• /
• pp.39-44
• /
• 1999

높은 유기성분을 가지고 있으나 주로 매립에 의존하고 있는 맥주폐수 슬러지와 분뇨처리슬러지의 재자원화를 위한 이들 혼합물의 퇴비화에 관한 연구를 수행하였다. 분뇨슬러지와 맥주폐수 슬러지의 적정 혼합비는 1:1로 나타났으며 초기 시료의 pH는 퇴비내 미생물의 활동을 위한 온도상승에 큰 영향을 미치지 않았다. 또한 혼합비가 1:1인 시료의 퇴비화시 C/N 비는 10-15를 유지하여 약간 낮게 나타났으나 pH의 상승없이 퇴비화가 잘 이루어짐을 알 수 있었고 주 1회 뒤집기를 수행하는 것이 가장 효율적인 것으로 나타났다.