• 한국환경보건학회지
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• 제40권4호
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• pp.322-329
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• 2014

Objectives: The purpose of this study was to investigate the effect of BIO-CLOD on advanced wastewater treatment for enhanced removal efficiency and meeting the stringent discharge water requirements of wastewater treatment plants. Methods: Two experimental apparatuses consisting of anaerobic, anoxic and aeration tanks were operated. One included a BIO-CLOD cultivation tank. Organic and nutrient parameters and removal efficiency were analyzed by pH, BOD, CODcr, SS, T-N and T-P. Results: The average removal efficiencies of BOD, COD and SS from the apparatus with BIO-CLOD tank installation were 95.5%, 88.6% and 92.9%, respectively, and these were higher than the results from the apparatus without BIO-CLOD. The average TP removal efficiency with BIO-CLOD tank marked 56.0%, higher than the 47.3% from the apparatus without one. BIO-CLOD showed a higher performance for TN removal at 49.6%, compared to the result without BIO-CLOD of 34.3% Conclusion: By reaction with BIO-CLOD, ammonia removal was effective in the aeration tank, as was phosphorus release in the anaerobic tank. Phosphorus luxury uptake and nitrification in aeration tank proceeded smoothly. The application of BIO-CLOD can improve the decrease of odor and settleability of activated sludge in a wastewater treatment plant, as well as increase the removal efficiency of organic and nutrient materials in water.

• 한국산학기술학회논문지
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• 제16권12호
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• pp.8665-8672
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• 2015

본 연구에서는 하수처리장의 소화슬러지(digest sludge)를 대상으로 악취제거 및 유기물제거에 대한 타당성을 검토하고자 BIO-CLOD를 넣은 반응조와 넣지 않은 반응조에 대하여 24시간, 48시간, 72시간 후 ammonia, methyl mercaptan(MMC) 및 $H_2S$에 대해서 측정하였다. BIO-CLOD를 침적시킨 반응조(BIO-CLOD)에서 24시간 내에 ammonia는 48%인 것에 비해 $H_2S$와 MMC는 98%이상의 높은 제거율을 보인 반면에 BIO-CLOD를 침적시키지 않은 반응조(Non BIO-CLOD)에서는 24시간 내에 ammonia가 45%, $H_2S$는 71%, MMC는 84%로서 악취제거 가능성을 보였다. 암모니아 농도는 시간이 지남에 따라 감소하면서 질산성질소농도는 증가하는 질산화 현상을 보였으며, 소화슬러지내의 유황계 악취성분들이 호기성 미생물들에 의해 산화 분해되어 용액 중의 황산염농도를 증가시키는 데는 BIO-CLOD효과가 있었음을 알 수 있었으며, 황산염농도증가와 대기중의 $H_2S$ 제거율간에는 상관관계가 있음을 알수 있었다. 반응조 유출수에서 유기물의 감소는 짧은 시간 내에서는 BIO-CLOD가 영향을 주지 않았으며, HRT 12시간과 HRT 24시간으로 운전하였을 때 경제적인 면에서 HRT 12시간을 고려해야 할 것으로 판단되었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.46-56
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• 2013

Laboratory scale experiments to remove benzene in solution by using the bio-carrier composed of dead biomass have been performed. The immobilized bio-carrier with dead Bacillus drentensis sp. and polysulfone was manufactured as the biosorbent. Batch sorption experiments were performed with bio-carriers having various quantities of biomass and then, their removal efficiencies and uptake capacities were calculated. From results of batch experiments, 98.0% of the initial benzene (1 mg/L) in 1 liter of solution was removed by using 40 g of immobilized bio-carrier containing 5% biomass within 1 hour and the biosorption reaction reached in equilibrium within 2 hours. Benzene removal efficiency slightly increased (99.0 to $99.4%{\pm}0.05$) as the temperature increased from 15 to $35^{\circ}C$, suggesting that the temperature rarely affects on the removal efficiency of the bio-carrier. The removal efficiency changed under the different initial benzene concentration in solution and benzene removal efficiency of the bio-carrier increased with the increase of the initial benzene concentration (0.001 to 10 mg/L). More than 99.0% of benzene was removed from solution when the initial benzene concentration ranged from 1 to 10 mg/L. From results of fitting process for batch experimental data to Langmuir and Freundlich isotherms, the removal isotherms of benzene were more well fitted to Freundlich model ($r^2$=0.9242) rather than Langmuir model ($r^2$=0.7453). From the column experiment, the benzene removal efficiency maintained over 99.0% until 420 pore volumes of benzene solution (initial benzene concentration: 1 mg/L) were injected in the column packed with bio-carriers, investigating that the immobilized carrier containing Bacillus drentensis sp. and polysulfone is the outstanding biosorbent to remove benzene in solution.

• 한국물환경학회지
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• 제32권3호
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• pp.303-309
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• 2016

This study aimed to assay the biological removal of TDS (total dissolved solids) from RO (reverse osmosis) rejected water. Following bio-sorption of TDS with AGS (aerobic granular sludge), the effects of TDS on biological nitrogen removal were examined. The bio-sorption of TDS after AGS treatment was confirmed by checking for TDS removal efficiency and surface analysis of microorganisms with SEM and EDS. Then, the effects of TDS on biological nitrogen removal and the denitrification efficiency were evaluated using the MBR reactor. According to the results, the bio-sorption of TDS with AGS was 0.1 mg TDS/mg AGS, and we confirmed that the microorganism surfaces had adsorbed the TDS. Biological nitrogen removal efficiency was measured at inhibiting denitrification at 4,000 mg/L of TDS-injected material. Based on this study, it is necessary to pretreat TDS-containing RO rejected water and to maintain TDS concentration lower than a specific value (≤4,000 mg/L), when considering biological nitrogen removal.

• 한국물환경학회지
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• 제37권5호
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• pp.363-368
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• 2021

On the assessment results of the non-point source pollutant removability of bio-block using waste sewage sludge, at the reactor's initial operation stage, the removal efficiency of COD was slightly unstable. However, after the reactor was stabilized, the COD removal efficiency was higher in the reactor filled with bio-blocks compared to the reactor filled with broken stones. In terms of nitrogen and phosphorus, their removal efficiency was unstable at the initial stage of the reactor operation. This phenomenon was investigated through the bio-block elution experiments. Results indicated that nitrogen and phosphorus were eluted from the bio-blocks affecting their removal at the initial operation. Furthermore, based on elution tests conducted after the dry ashing of the waste sewage sludge, part of the nitrogen and phosphorus was eluted similar to the bio-block elution test results, although considerable amounts of nitrogen and phosphorus were reduced compared to the sludge cake. Prior to the use of the waste sewage sludge bio-blocks as a filter medium to remove non-point source pollutants, a stabilization period of 10 days was required. After the stabilization process, results showed similar characteristics as general aggregates. Moreover, to use the bio-block as a filter medium for the non-point pollutant removal, the filling ratio of 75% was the most suitable as it resulted in the highest nitrogen removal efficiency after the stabilization. The results of this study suggested that waste sewage sludge can be suitably recycled as a mixed raw material for the bio-blocks, with satisfactory application as a filter medium in artificial wetlands, stormwater runoff problems, stream water pollutants to eliminate non-point source pollutants.

• 한국환경과학회지
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• 제17권11호
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• pp.1265-1271
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• 2008

Aerated submerged bio-film (ASBF) pilot plant has been developed. The presented studies optimized an inexpensive method of enhanced wastewater treatment. The objectives of this research were to describe pilot scale experiments for efficient removal of dissolved organic and nitrogen compounds by using ASBF reactor in plug-flow reactor (PFR) and improve understanding of dissolved organic matter and nitrogen compounds removal rates with dynamic relationships between heterotrophs and autotrophs in the fixed-film reactor. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. This direct gas-phase contact should increase the oxygen transfer rate into the bio-film, as well as increase the micro-climate mixing of water, nutrients, and waste products into and out of the bio-film. This research also investigated the efficiency of dissolved organic matter and ammonia nitrogen removals in the ASBF. As it was anticipated, nitrification activity was highest during periods when the flow rate was lower, but it seemed to decline during times when the flow rate was highest. And ammonia nitrogen removal rates were more sensitive than dissolved organic matter removal rates when flow rates exceeded 2.2 L/min.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.260-263
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• 2008

KEPCO(Korea Electric Power Corporation) is performing the nation's first biogas-MGT project as an effort to encourage the utilization of wasted biogas which contains useful CH4. The goals of this project are to develop the Pretreatment system of Livestock bio-gas and set up the biogas-MGT co-generation system. The project will not only utilze flared biogas as precious energy but also improve the economics of the plant a lot. The pretreatment system mainly consists of sulfur removal tower, biogas compressor and many filtering systems. A computational fluid dynamics study in the bio gas sulfur removal tower and sulfur absorption filter was carried out. Understanding of the flow in the sulfur removal tower and sulfur adsorption filter obtained by this study can be used to identify the problems in the sulfur removal tower and to improve the sulfur removal efficiency of the sulfur removal tower. Resistance material modeling is used to simulate the sulfur adsorption filter, and the resistance coefficient was adjusted to reflect the experimental pressure loss value. And the pressure loss change with the flowrate is predicted

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.414-422
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• 2006

Before applying PVA bio-beads to practical biological treatment of nitrate-containing wastewater, their characteristics were examined. PVA bio-beads could steadily produce nitrogen gas from nitrate for 28 batches with 0.04 ml/l/h of the maximum gas production rate; however, the maximum gas production rate dropped remarkably thereafter with apparent deformation of beads. Addition of 2.2% solution containing 1% casamino acid, 1% yeast extract, 0.1% mineral solution, and 0.1% vitamin solution to the culture medium resulted in not only recovery of activity of deactivated beads, but also a higher rate of gas production. Calculation of economic benefit for the use of bio-beads in a long-run operation indicated that reactivation of bio-beads by chemicals had economical advantages over packing new bio-beads in the system. The continuously stirred bioreactor exhibited a satisfactory performance at HRT of 20.0 h. With a 9.5 mg $NO_{3}^{-}N/l/h$ nitrate removal rate, nitrate could completely be removed without nitrite accumulation. The use of PVA bio-beads in nitrate removal appears very promising.

• 유기물자원화
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• 제30권4호
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• pp.15-25
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• 2022

수본 연구에서는 Bio-drying 공법 활용한 공기 송풍량 및 예열에 따른 음식물류 폐기물의 수분 및 유기물의 처리 효율에 대해 분석하였으며, 음식물류 폐기물 처리 시 온도, CO2의 평가를 통해 공기 송풍량 및 공기 예열이 Bio-drying 공법의 미치는 영향에 대해 평가하였다. 그 결과 공기 송풍량의 증가는 수분 제거율 및 제거 속도가 증가하는 결과를 미쳤지만, Bio-drying 내부 온도를 저하 시켜 미생물 활성도의 감소를 야기시켰다. 미생물의 활성도 유지를 위해서는 음식물류 폐기물의 성상에 따른 적정 공기 송풍량을 주입하는 것이 필요할 것으로 판단되었으며, 본 연구에서는 15L/min으로 주입하였을 때가 최적이었다. 공기 예열 유무에 따른 유기물 및 수분 제거율을 평가한 결과 공기 예열을 하였을 때가 하지 않았을 때에 비해 유기물 제거율 및 수분 제거율이 3~5% 가량 증가하는 결과를 보였다. 또한 Bio-drying 내부에 응축수 발생에 의한 내부 뭉침 현상도 발견되지 않았다. 따라서, 음식물류 폐기물의 효과적인 Bio-drying을 위해서는 미생물 활성도 유지를 위한 적정 송풍량을 유지 해야 하며, 공기 예열을 통한 주입이 필요할 것으로 사료된다.

• Environmental Engineering Research
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• 제11권2호
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• pp.106-125
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• 2006

Cesium and strontium are two important fission products and the removal/speciation of these two cations with several inorganic/bio-materials is an interesting topic to discuss. It is to be noted that inorganic materials are found to be fairly effective and efficient in the removal/speciation of these cations. Moreover, these solids are to be found promising as they show fairly good radiation and temperature stability. Hence, they play an important role in the radioactive waste management studies. However, various studies reveal that in addition to inorganic materials various biosorbents can also be employed in the removal/speciation of these ions. But the radiation and temperature stability of these bio-sorbents and dead biomasses are still the topic lying among the researchers to be investigated.