• 대한토목학회논문집
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• 제9권2호
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• pp.135-141
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• 1989

고로(高爐) 슬래그는 미생물(微生物) 부착이 쉬운 거친 표면(表面)과 pH를 중화(中和)시킬 수 있는 칼슘과 마그네슘을 다량 함유하고 있으며, 반응조내(反應槽內)의 미생물(微生物)을 응집(凝集)시킬 수 있는 알루미늄이나 철염을 비롯한 미생물(微生物)의 영양소를 함유하고 있어, 혐기성(嫌氣性) 생물막(生物膜) 공법(工法)의 여재(濾材)로서의 사용가능성(使用可能性)을 검토(檢討)하여 보았다. 유가공(乳加工)의 탄수화물(炭水化物), 폐기물(廢棄物) 침출수(浸出水) 및 당밀폐수와 같은 산성폐수(酸性廢水)를 슬래그를 여재(濾材)로 사용(使用)한 실험실(實驗室) 혐기성(嫌氣性) 반응조(反應槽)에 주입(注入)하였는데 예측한 대로 pH를 중화(中和)시키며 미생물(微生物)을 확보시키는데 효과적(效果的)인 것으로 나타났다. 특히 푸라스틱을 사용한 경우의 유가공폐수(乳加工廢水)의 운전결과(運轉結果)와 비교할때에 고부하(高負荷)에서 슬래그를 사용한 경우의 COD 제거효율(除去效率)이 높았다.

• Journal of Applied Biological Chemistry
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• 제42권1호
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• pp.25-28
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• 1999

For investigating the effectiveness of Korean natural zeolite for removal of $NH_4{^+}$ in waste waters containing $NH_4{^+}$ and $Cu^{2+}$, the adsorption of $NH_4{^+}$ and $Cu^{2+}$ by three Korean natural zeolite samples, which contained mordenite and/or clinoptilolite, was measured by adding solutions containing $NH_4{^+}$ and $Cu^{2+}$ or both at a concentration range from 1 to 7 mmol(+)/L of each cation. In the solutions, the zeolite samples adsorbed more amounts of $NH_4{^+}$ than $Cu^{2+}$. By seven successive equilibrations, Korean natural zeolites adsorbed $NH_4{^+}$ corresponding to 23~33% of those cation exchange capacity from the solution containing both $NH_4{^+}$ and $Cu^{2+}$ at 3 mmol(+)/L of each cation. Whereas, the corresponding adsorption of $Cu^{2+}$ was 17-27% of the CEC. Korean natural zeolite exhibited selectivity for $NH_4{^+}$ but not for $Cu^{2+}$. Nevertheless, it using as a soil amendment after removing of $NH_4{^+}$ in waste waters should be carefully controlled on the application rate.

• 한국해양환경ㆍ에너지학회지
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• 제5권2호
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• pp.35-40
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• 2002

어구용 폐스티로폼을 자원으로 활용할 수 있도록 하기 위하여 세정과 건조공정을 도입하여 감용하는 장치를 자체 개발하였으며, 시스템을 폐스티로폼 발생 지자체에 설치하여 설비의 운전 신뢰성을 확인하였다. 굴피 및 홍합피 등의 이물질을 완벽하게 제거하고 해수에 포함된 염분을 육상에서 발생되는 스티로폼 수준까지 낮춤으로써 어구용 폐스티로폼은 플라스틱의 원료로 탈바꿈할 수 있었으며, 종래의 처리 방법에 비해 1/10수준에 불과한 비용으로 어구용 폐스티로폼의 처리가 가능하도록 함으로써 설비의 설치나 운영에 따르는 경제성 문제를 해결하고자 하였다.

• Nuclear Engineering and Technology
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• 제42권2호
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• pp.131-144
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• 2010

The Korea Atomic Energy Research Institute (KAERI) has been developing pyroprocessing technology for recycling useful resources from spent fuel since 1997. The process includes pretreatment, electroreduction, electrorefining, electrowinning, and a waste salt treatment system. This paper briefly addresses unit processes and related innovative technologies. As for the electroreduction step, a stainless steel mesh basket was applied for adaption of granules of uranium oxide. This basket was designed for ready handling and transfer of feed material. A graphite cathode was used for the continuous collection of uranium dendrite in the electrorefining system. This enhances the throughput of the electrorefiner. A particular mesh type stirrer was designed to inhibit uranium spill-over at the liquid Cd crucible. A residual actinide recovery system was also tested to recover TRU tracer. In order to reduce the waste volume, a crystallization method is employed for Cs and Sr removal. Experiments on the unit processes were tested successfully, and based on the results, engineering-scale equipment has been designed for the PRIDE (PyRoprocess Integrated inactive DEmonstration facility).

• 상하수도학회지
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• 제21권5호
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• pp.551-558
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• 2007

From the view point of biological wastewater treatment, C/N ratio is one of the most important factor in biological nutrient removal process. However, municipal sewage in Korea is characterized by extremely low content of carbon source and relatively higher portion of N source. Accordingly, it is necessary to dose external carbon source in order to obtain higher degree of carbon source within the process. In this study, the effects of pH pretreatment as an alternative plan for increasing carbon source on the cell disruption and COD solubility of waste activated sludge were conducted under well defined experimental conditions. During 5 hours, the value of COD solubilization rate ($S_R$) at pH 11.5 is approximately 4.4 times higher than the value of $S_R$ at pH 9.5. It is expected that the level of SCOD increased due to the result from cell disruption. However, VSS/TSS ratio was not significantly changed after 5 hours. As Alkalinity changes gradually from less than 15, 30 and 60 meq NaOH/L, average RBCOD/SCOD fraction showed 34, 36 and 45%,respectively.

• 한국환경과학회지
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• 제29권8호
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• pp.827-835
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• 2020

Zeolite material having XRD peaks of Na-A zeolite in the 2θ range of 7.18 to 34.18 can be synthesized from the waste catalyst using a fusion/hydrothermal method. The adsorption rate of Mn ions by a commercial Na-A zeolite and the synthesized zeolitic material increased as the adsorption temperature increased in the range of 10 ~ 40℃. The adsorption of Mn ion were very rapid in the first 30 min and then reached to the equilibrium state after approximately 60 min. The adsorption kinetics of Mn ions by the commercial Na-A zeolite and the zeolitic material were found to be well fitted to the pseudo-2^nd order kinetic model. Equilibrium data by the commercial Na-A zeolite and the zeolitic material fit the Langmuir, Koble-Corrigan, and Redlich-Peterson isotherm models well rather than Freundlich isotherm model. The removal capacity of the Mn ions by the commercial Na-A zeolite and the zeolitic material obtained from the Langmuir model was 135.2 mg/g and 128.9 mg/g at 30℃, respectively. The adsorption capacity of Mn ions by the synthesized zeolitic material was almost similar to that of commercial Na-A zeolite. The synthesized zeolitic material could be applied as an economically feasible commercial adsorbent.

• Asian-Australasian Journal of Animal Sciences
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• 제6권2호
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• pp.205-209
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• 1993

A new treatment system for animal waste water has been developed as an alternative to the activated sludge process. It consists of two treatments; one is operated with 7 tanks, and the other is soil and plant cultivation bed. Aerobic microorganisms are added to the influent water in the tanks where the water is aerated so that the microbes utilize the pollutants, while sedimentation removes the indigestible solids. In the secondary treatment the water, which has already received a primary treatment, is filtered through soil where it also receives treatment by soil organisms. In addition there is transpiration of water and absorption of minerals by plants. In the primary treatment BOD, SS, coliforms (E. coli), TP and total bacteria were removed 79-99%, but COD and TN were removed only 58% and 36%, respectively. In the secondary treatment removal of nutrients proceeded further, and 93-99% of pollutants were removed. The treated waters met the quality standard of discharge water in Japan except for TN, which was in too great a concentration to meet discharge standards. This problem requires further study.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.215-219
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• 2001

Impurities removal from waste carbon black was carried out to produce high-grade carbon black. A lot of hydrophilic carbon black is produced as a byproduct of the hydrogen production process by flame decomposition of water. Due to its impurity content such as sulphur, iron, ash and etc., it can only be used as low-grade carbon or burnt out. High-grade hydrophilic carbon black is 3-5 times more expensive than oil-based carbon black because of its process difficulties and requires pollutant treatment. Hydrophilic carbon is normally used far conductive materials for batteries, pigment for plastics, electric wire covering, additives for rubber, etc.. In these applications, hydrophilic carbon must maintain its high purity. In this study magnetic separation, froth flotation and ultrasonic treatment were employed to remove impurities from the low-grade hydrophilic carbon black. As results, the ash, iron and sulphur content of product decreased to less than 0.01wt.%, 0.0lwt.% and 0.3wt.% respectively, and the surface area of product was about 930 $m^2$/g.

• 한국세라믹학회지
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• 제45권11호
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• pp.667-674
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• 2008

In this study, we prepared Fe-activated carbon fiber(ACF)/$TiO_2$ composites with titanium (VI) n-butoxide (TNB) as the titanium source for ACF pre-treated with iron compounds through the impregnation method. In terms of textural surface properties, the composites demonstrate a slight decrease in the BET surface area of the samples and an increase in the amount of iron compounds treated. The surface morphology of the Fe-ACF/$TiO_2$ composites was characterized by means of SEM. The composites have a porous texture with homogenous compositions of Fe and titanium dioxide distributed on the sample surfaces. The phase formation and structural transition of the iron compounds and titanium dioxide were observed in X-ray diffraction patterns of the Fe-ACF/$TiO_2$ composites. The chemical composition of the Fe-ACF/$TiO_2$ composites, which was investigated with EDX shows strong peaks for the C, O, Fe and Ti elements. The photo degradation results confirm that the Fe-ACF/$TiO_2$ composites show excellent removal activity for the COD in piggery waste due to photocatalysis of the supported $TiO_2$, radical reaction by Fe species, and the adsorptivity and absorptivity of ACF.

• Environmental Engineering Research
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• 제17권2호
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• pp.59-63
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• 2012

This paper proposes a modified Ludzack-Ettinger (MLE) type membrane bioreactor (MBR) as a method of treatment for wastewater from food waste disposer. Micro-membrane filtration allows for an extremely low concentration of suspended solids in the effluent. The effluent of the reactor in question is characterized by a relatively high level of non-biodegradable organics, containing a substantial amount of soluble microbial products and biomass. Results obtained in this paper by measurement of membrane fouling are consistent with biomass concentration in the reactor, as opposed to chemical oxygen demand (COD). The MLE process is shown to be effective for the treatment of wastewater with a high COD/N ratio of 20, resulting in are markedly high total nitrogen removal efficiency. Denitrification could be improved at a higher internal recycle ratio. Despite the low concentration of influent phosphorus, the phosphorus concentration of the outflow is seen to be relatively high. This is because outflow phosphorous concentration is related to COD consumption, and the process operates at along solids retention time.