• KSBB Journal
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• 제16권1호
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• pp.61-65
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• 2001

BTX를 배출하는 지역에서 얻어진 슬러지를 적절한 배지에 3개월 간 적응시킨 결과, benzene과 toluene을 빠르게 분해하는 MY컨소시엄와 p-, m-, o-xylene을 빠르게 분해하는 MA컨소시엄을 획득하였다. 균주의 동정결과 MA 및 MA컨소시엄의 주된 균주는 Rhodococcus ruber DSM 43338T과 Rhodococcus sp.로 밝혀졌다. BTX 단일성분의 분해속도 측정결과 benzene > toluene > o-xylene > p-xylene > m-xylene의 순으로 분해가 일어났다. MY 및 MY컨소시엄으 동시배양을 이용한 2-5종의 복합 BTX의 분해실험결과 대부분의 경우 108시간내에 완전히 분해되었으며, 각 혼합물의 조성에 따라 촉진 및 방해작용을 나타내었다. 분 연구에서 획득한 2종의 미생물컨소시엄은 BTX의 생물학적 처리에 매우 유용하게 사용될 수 있을 것으로 사료된다.

• 한국가구학회지
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• 제10권1호
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• pp.51-56
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• 1999

This research was carried out to investigate the Hanji sludge(black color)-wood fiber and wood particle composited applied by waste sludges arising from the making process of Hanji (Korea paper). In experimental design, four levels of the mixed ratio of Hanji sludge to wood fiber or wood particle(10:90, 20:80, 30:70 and 40:60), three kinds of the resin(PMDI, urea and phenol resin)and three kinds of the specific gravity(0.6, 0.75 and 0.9) were designed to determine the tensile strength of Hanji sludge-wood fiber and wood particle composites. From the results and discussion, it may be concluded as follows: In Hanji sludge-wood fiber and wood particle composites, tensile strengths showed decreasing tendency absolutely by increasing Hanji sludge additive, but clearly increase with the increase of specific gravity. In Hanji sludge-wood fiber composites, there were no differences between PMDI and urea resin-bonded composites, but phenol resin-boned composites were made possibly until the addition of 30% Hanji sludge. On the other hand, Hnji sludge-wood particle composites(SpGr=0.6) have very low tensile strength values. But they were made favorably until the addition of 20% Hanji sludge in Hanji sludge-wood particle composites(SpGr=0.9).

• 한국분말재료학회지
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• 제23권1호
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• pp.43-48
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• 2016

Waste SiC powders obtained from silicon wafer sludge have very low density and a narrow particle size distribution of $10-20{\mu}m$. A scarce yield of C and Si is expected when SiC powders are incorporated into the Fe melt without briquetting. Here, the briquetting variables of the SiC powders are studied as a function of the sintering temperature, pressure, and type and contents of the binders to improve the yield. It is experimentally confirmed that Si and C from the sintered briquette can be incorporated effectively into the Fe melt when the waste SiC powders milled for 30 min with 20 wt.% Fe binder are sintered at $1100^{\circ}C$ upon compaction using a pressure of 250 MPa. XRF-WDS analysis shows that an yield of about 90% is obtained when the SiC briquette is kept in the Fe melt at $1650^{\circ}C$ for more than 1 h.

• 한국농공학회지
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• 제40권4호
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• pp.77-84
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• 1998

Adsorption and leaching characteristics of the artificial soils produced from water and wastewater treatment sludges were examined. The batch adsorption test and TCLP leaching test were used, and constituents of interest were heavy metals and nutrients. As, Cr, Cu, Pb, and Cd were analyzed for metals, and nitrogen and phosphorus were analyzed for nutrients. All the artificial soils showed strong adsorption and low leaching for the heavy metals, which implies that the artificial soils may not be hazardous to the environment due to heavy metals and even they can be utilized effectively to remove metals in solution like mine and industrial wastewaters. This is quite promising result because in most case heavy metals are the most concern in the application of sludge product to the farmland. For the nutrients, generally, artificial soils showed high adsorption and low leaching except artificial soil from wastewater sludge produced by low temperature firing. The artificial soils produced from water treatment sludge were active in adsorbing nutrients and showed low leaching that they can be practically used to remove nutrients in advanced treatment process of the wastewater. The artificial soils produced from wastewater treatment sludge were less active in adsorbing nutrients and showed high teaching. However, they could be used usefully if applied properly to the plant growing because of their fertilizing effect. Based on the test results, overall, the artificial soils were thought to be not hazardous to the environment and they could be more useful if applied properly.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.238-244
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• 2005

This study performs the pilot-plant experiments to evaluate the effect of the oxygen enrichment on the co-incineration of municipal solid waste and organic sludge from a wastewater treatment facility. The design capacity of the stoker-type incinerator pilot-plant is 150 kg/h. Combustion chamber temperatures were measured as well as the stack gas concentrations, i.e., NOx, CO, and the residual oxygen. The maximum ratio of organic sludge waste to the total waste input is 30%. Also the oxygen-enriched air with 23% of oxygen in supplied air is used for stable combustion. As the co-incineration ratio of the sludge increased up to 30% of the total waste input, the primary and the secondary combustion chamber temperature was decreased $to900^{\circ}C$ (primary combustion chamber), $750^{\circ}C$(secondary combustion chamber), respectively, approximately $200^{\circ}C$ below the incineration temperature of the domestic waste only (primary: $1,100^{\circ}C$, secondary: $950^{\circ}C$). However, if the supplied air was enriched to 22% oxygen content in air, the incinerator temperature was high enough to burn the waste mixture with 30% sludge, which has the heating value of 1,600 kcal/kg.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1183-1190
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• 2007

A metabolic uncoupler, 3,3',4',5-tetrachlorosalicylanilide (TCS), was used to reduce excess sludge production in biological wastewater treatment processes. Batch experiments confirmed that 0.4 mg/l of TCS reduced the aerobic growth yield of activated sludge by over 60%. However, the growth yield remained virtually constant even at the increased concentrations of TCS when cultivations were carried out under the anoxic condition. Reduction of sludge production yield was confirmed in a laboratory-scale anoxic-oxic process operated for 6 months. However, it was found that ammonia oxidation efficiency was reduced by as much as 77% in the presence of 0.8 mg/l of TCS in the batch culture. Similar results were also obtained through batch inhibition tests with activated sludges and by bioluminescence assays using a recombinant Nitrosomonas europaea (pMJ217). Because of this inhibitory effect of TCS on nitrification, the TCS-fed continuous system failed to remove ammonia in the influent. When TCS feeding was stopped, the nitrification yield of the process was resumed. Therefore, it seems to be necessary to assess the nitrogen content of wastewater if TCS is used for reducing sludge generation.

• 상하수도학회지
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• 제23권1호
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• pp.121-128
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• 2009

Objectives of this study were to investigate influencing factors of detention time, particle size distribution, and filter medium characteristics for waterworks sludge dewatering. The stepped pressure filtration was carried out with lab scale apparatus and the filter press pilot test for dewatering was conducted at the water treatment plant. Effects of filter medium and polymer dose were examined through observing water content and dewatering velocity and cyclic dewatering rate with filter press pilot test. Relationships among detention time, particle size distribution and filtration resistance were analyzed. Prolongation of sludge detention time was found to cause blinding phenomenon in cake and filter medium and to decrease dewatering process efficiency. The average specific resistance increased according to detention time. In pilot test of dewatering for thickened sludge with Nylon Multi-NY840D and Nylon Mono-100% filter media, dewatering velocities were 0.92 and $0.93kg\;DS/m^2{\cdot}hr$ according to 0.1% polymer dose of dried solids weight base. And cyclic dewatering rates were 2.45 and $2.50kg\;DS/m^2{\cdot}cycle$ cycle for the Nylon Multi-NY840D and Nylon Mono-100% media. Dewatering velocity of polymer dosed sludge was observed to be higher than that of non-polymer sludge.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.526-531
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• 2000

Application of electrodewatering (EDW) to mechanical dewatering system was studied to decrease water content in the sludge generated from waste water treatment process. Experiments realized the reduction of water content in the sewage sludge. EDW enhancing the conventional filtration by an electric field is an emerging technology with the potential to improve dewatering. In this study, a piston filter press was constructed, the digested sludges were dewatered by EDW under conditions of DC electric field and constant pressure in the piston filter press. Constant electric field from $0{\sim}120\;V/cm$ and constant pressure $98.1{\sim}392.4\;kPa$ were used. The results showed that as electric field was increased the dewatering rates increased and as pressure was increased the dewatering rates decreased. Also as polymer was added the dewatering rates increased. This experiments produced final sludge cake with water content of 60 wt% using EDW, compared with 80 wt% using pressure filtration alone.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.701-710
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• 1996

Composting has gained rapid acceptance as a method of recyling relatively dry organic materials such as leaves and brush and , when alternative disposal costs are high, even moist materials such as grass clippings and dewatered sewage sludges. However, as moisture contents rise above 60% , the need for a dry bulking amendment increase the costs of composting , both by direct purchases of amendment and though increased reactor capacity and materials handling requirements. High moisture materials also present increased risks of anaerobic odor formation through reduced oxygen transport (Miller , 1991) . These costs and operational challengers often constrain the opportunities to compost high moisture materials such as agricultural manures. During the last several decades economies of scale in livestock production have been increasing livestock densities and creating manure management challenges throughout the world. This issue is particularly pressing in Korea, where livestock arms typically manage little or no cropland, and the nutrients and boichemical oxygen demand in manure pose a serious threat to water quality. Composting has recently become popular as a means of recycling manure into products for sale off the farm, but bulking amendments (usually sawdust) are expensive designed to minimize bulking agent requirements by using the energy liberated by decompostion. In this context the composting reactor is used as a biological dryer, allowing the repeated use of bulking amendment with several batches of manure.

• 한국물환경학회지
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• 제20권4호
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• pp.346-351
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• 2004

Because of being produced a great deal of excess sludges from biological wastewater treatment process, the subject regarding treatment and disposal of them has been significantly handled in real plants. It should be considered the alternative treatment with easy operating and cost effective process in rural areas. For the thickening of wasted activated sludge from small scale wastewater treatment facilities, thus, the provisional sludge thickening system was developed by the application of mesh filter module. Three meshes with different pore size(100, 150, $200{\mu}m$) were prepared for filter modules that were used to withdraw effluent from thickening system. A filter module with $100{\mu}m$ mesh was chosen as the most effective thickening material in the viewpoint of volume reduction and effluent quality: the volume reductions of initially injected sludge with 3,600 mg/L and 9,100 mg/L were 95% and 85%, respectively, and the filtered effluents were enough good to be shown below 1.0 mg/L of SS and 1.0 NTU of turbidity. Since the filtration of thickening was influenced by the cake layer formed on mesh filter module and this system was operated in the combination of sludge thickening with gravity settling, the filter modules with smaller pore size and the larger floc size were required for long term operation safely.