• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.201-204
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• 2004

The purpose of this study is recycling of sewage sludge and fly-ash. In this experiment, green aggregates, which is a mixture of sewage sludge and clay and fly-ash, with different content of sewage sludge (up to $80wt\%$). Then they were burned in different soak temperatures from $1190^{\circ}C\;to\;1290^{\circ}C$ with changed soak time and heating rate at 5, 7, 10 minutes and $20^{\circ}C/min$, $30^{\circ}C/min$ respectively in order to produce lightweight aggregate (LWA). Data of both experiment series were generated to evaluate the quality of LWA as well as the relationship between burning condition and product's quality.

• 한국물환경학회지
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• 제31권5호
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• pp.476-481
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• 2015

Water permeable block was manufactured using waste sewage sludge, loess and clay for the purpose of recycling waste sludge due to the prohibition of waste sludge ocean dumping. Experiments for determining optimum mixing ratio was conducted by changing sludge content in water permeable block as 5~20%. In respect of compressive strength, $1,600N/cm^2$ ($163.3kg/cm^2$) was obtained when the mixing ratio of sludge : loess : clay were maintained by 5% : 65% : 30%, 10% : 65% : 25% and 15% : 65% : 20%, respectively. These mean that relatively high compressive strength can be obtained when the sludge content is maintained 5, 10, 15% at the 65% of loess content. In terms of water permeability and absorption rate, the higher values can be obtained as the sludge content increases. The optimum mixing ratio of sludge : loess : clay came out to be 15% : 65% : 20% when water permeability, absorption and strength were considered altogether, which matches the result observed by an electron microscope. The heavy metal leaching test result of the prepared permeable block appeared to satisfy the environmental standard in the content of Cd, Cu, Pb and As.

• 한국토양환경학회지
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• 제1권1호
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• pp.11-17
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• 1996

본 실험은 산업 현장에서 광범위하게 사용하고 있는 유기용제인 Trichloroethylene (TCE)이 저장탱크누출, 작업장에서의 취급 부주의, 매립지 침출수 유출 등을 통해 토양과 지하수를 오염시킬 우려가 있는 물질이므로 토양내에서의 TCE의 흡착성향을 파악하기 위하여 본 연구를 수행하였다. 이를위해 토양의 유기물 함량과 석회 시용량을 달리하여 TCE에 대한 Freundlich 등온흡착식 상수 k와 n을 결정하였다. 유기물함량은 sewage sludge cake을 0ton/ha, 50ton/ha, 100ton/ha 수준으로 처리하고 S1, S2, S3라 명명하였다. 석회는 2ton/ha, 4ton/ha, 6ton/ha, 10ton/ha. 수준으로 처리하였다. sewage sludge cake을 수준별로 처리한 실험에서 구한 Freundlich 등온흡착식은 다음과 같다. (단, TCE 처리 농도범위가 0.5~2.5ng/g soil 일 경우임) S1 : x/m = 0.393 $C^2$, S2 : x/m = 0.436 $C^2$, S3 : x/m = 0.636 $C^2$위 식에서 보듯이 k값이 sewage sludge cake 처리수준이 증가할수록 0.393, 0.436, 0.636으로 증가하므로 TCE 처리농도가 같다면 sewage sludge cake 처리수준이 높은 토양일수록 TCE에 대한 흡착효율이 좋았다. 반면 석회시용 수준이 증가할수록 토양의 pH는 증가하였고 TCE 흡착능력은 감소하였다.

• 한국미생물·생명공학회지
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• 제28권6호
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• pp.361-366
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• 2000

Genera and number of protozoa were investigated in the conventional activated sludge pilot plant used for the treatment of municipal sewage and pre-treated night soil-containing sewage. In both case, the predominant protozoa was ciliates and among them Vorticella was the most common. In the pilot plant where pre-treated night soil was mixed with municipal sewage, genera of free-swimming ciliates, flagellates and amoeba was higher than in those withour night soil. Correlation analysis on the quality of effluent and protozoa indicates that municipal sewage has positive correlation with protozoa. However in the pilot plan 샐 sewage contatinin pre-treated night coil soil more samples show negative correlation. Followed equations were derived by the regression analysis of BOD in both the pilot plants. In case of pilot plant A of municipal sewage, the analysis B of munici-pal and pre-treated night soil-containing sewage, the analysis of BOD was $6.731$\times$10_{-2}$ $\times$Bodo+0.306(Adjusted $R^2$=0.864). At low temperature, number of protozoa was decreased to 35% and among therm, Aspidisca was the most common genus. Therefore, protozoa can be used as indicator of quality of the effluent in sewage treatment plants.

• 유기물자원화
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• 제4권1호
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• pp.53-60
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• 1996

혐기적으로 1차 분해된 하수슬러지를 건물 중 기준으로 0, 1, 3, 그리고 5톤/10a 비율로 포장에 시용한 후, 대두 및 당근의 수량과 무기성분 흡수 등 몇가지 화학적 특성에 미치는 영향을 검토하였다. 슬러지 시용의 결과는 토양의 몇가지 화학적 특성을 증진시킨 반면, 작물에서의 Pb, Cd, Cr, As 및 Hg과 같은 유해 중금속의 흡수는 나타나지 않았다. 슬러지 시용은 작물의 N, P, K 및 Ca 등의 무기성분 흡수를 증가시켰고, 슬러지중 과량의 Al은 작물의 Al흡수에 별다른 영향을 주지 않았다. 또한 슬러지는 두 작물의 수량을 증가시킨 반면, 슬러지 미부숙으로 인해 당근의 외관적 품질을 저하시켰다. 결론적으로 하수슬러지의 작물 생육효과가 긍정적으로 평가된 반면, 농업적으로 이용할 때는 반드시 퇴비화와 같은 슬러지의 안정화가 선행되어야 한다.

• 상하수도학회지
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• 제11권1호
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• pp.64-73
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• 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.

• 상하수도학회지
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• 제29권1호
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• pp.57-63
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• 2015

Recently, Korea's municipal wastewater treatment plants generated amount of wastewater sludge per day. However, ocean dumping of sewage sludge has been prohibited since 2012 by the London dumping convention and protocol and thus removal or treatment of wastewater sludge from field sites is an important issue on the ground site. The hydrothermal carbonization is one of attractive thermo-chemical method to upgrade sewage sludge to produce solid fuel with benefit method from the use of no chemical catalytic. Hydrothermal carbonization improved that the upgrading fuel properties and increased materials and energy recovery, which is conducted at temperatures ranging from 200 to $350^{\circ}C$ with a reaction time of 30 min. Hydrothermal carbonization increased the heating value though the increase of the carbon and fixed carbon content of solid fuel due to dehydration and decarboxylation reaction. Therefore, after the hydrothermal carbonization, the H/C and O/C ratios decreased because of the chemical conversion. Energy retention efficiency suggest that the optimum temperature of hydrothermal carbonization to produce more energy-rich solid fuel is approximately $200^{\circ}C$.

• Journal of Applied Biological Chemistry
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• 제44권2호
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• pp.95-97
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• 2001

• 한국응용과학기술학회지
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• 제30권4호
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• pp.688-700
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• 2013

하수 슬러지로부터 추출된 유지를 이용하여 바이오디젤 생산에 대해 고찰하였다. 바이오디젤 생산의 밝은 전망에도 불구하고, 이를 상용화하기 위한 노력은 매우 제한되어 있다. 주요 장애물 중 하나는 전체 생산비용의 약 70~75%를 구성하는 정제 유지의 공급 원료와 연관된 높은 가격이다. 따라서 이를 극복하기 위하여 폐유나 낮은 품질 유지 등의 저가 원료를 사용하여 바이오디젤의 생산 비용을 낮추는 기술이 제안되어 왔다. 이런 측면에서 하수 슬러지로부터 추출된 유지는 비교적 저렴하여 유망한 원료로 평가받고 있다. 본 연구에서는 하수 슬러지로부터 추출된 유지를 이용한 바이오디젤의 생산기술을 검토하였다. 하수 슬러지로부터 유지 추출공정 및 에스테르화 전환공정 및 무촉매 열화학 전환공정을 살펴보았다.

• 유기물자원화
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• 제13권2호
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• pp.74-84
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• 2005

본 연구의 목적은 열풍건조를 이용하여 슬러지를 감량화하는 과정에서 발생되는 열적거동을 조사하는데 있다. 실험에서 중요한 운전매개변수는 공급되는 건조온도가 $130{\sim}170^{\circ}C$와 증발속도 WD를 변화시켜 실행하였다. 슬러지내 수분을 증발하는 과정에서 열적거동의 변화에 미치는 영향인 주요매개 변수는 공급되는 온도변화에 따른 건조시간, 슬러지내 수분함량, 슬러지의 고형물량에 따른 결과를 조사하였다. WD=0.95m/s의 조건에서 $170^{\circ}C$의 건조온도에서 수분이 증발되는 포화점은 95분과 $130^{\circ}C$에서 120분에서 조사되었다. 열풍의 의한 증발속도가 1.0 m/s로 일정할 때 건조온도가 130와 $150^{\circ}C$일 때 보다 $170^{\circ}C$인 경우가 증발율이 더 높게 나타났고, 건조기 온도가 $130^{\circ}C$인 경우는 WD=1.0 m/s일 때 WD=0.5 m/s 보다 증발율이 높게 나타남을 볼 수 있었다.