• 생태와환경
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• 제35권3호통권99호
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• pp.213-219
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• 2002

녹조 제어를 위하여 수중의 인 제거에 관여하는 CellCaSi의 여러 가지 조건별 인 제거효과를 조사하였다. CellCaSi의 입도에 따른 인 제거효과는 직경 1, 2 그리고 4mm 이하의 3가지 중 1mm 이하의 작은 입자를 사용했을 때 가장 우수하였다. CellCaSi의 인 제거효과는 처리량의 증가에 비례하였다. 수중의 pH 5, 7, 9에서 초기 인 농도 0.20mg/l는 각각 0.09, 0.08및 0.08mg/l로 감소되어 상이한 pH조건에 따른 CellCaSi의 인 제거효과는 큰 차이를 보이지 않았다. CellCaSi에서 용출되는 양이온은 Ca이며, Al과 Fe양이온은 검출되지 않았다. 초기에 급격히 용출된 Ca양이온은 수중의 인과 반응하는 것으로 확인되었다. 초기 인 농도 0.10, 1.0mg/1는 CellCaSi와 Ca, Fe 화합물을 첨가한 처리구에서 8일 후 각각 0.03,0.47mg/l를 기록하며 가장 많이 감소하였다. 이에 따라 인 제거효과는 CellCaSi와 Ca, Fe 화합물을 동시에 처리하였을 때 가장 좋은 것으로 조사되었다. CellCaSi의 처리에 따라 pH가 약간 증가하였고, 전기전도도도 증가되지만 상수원수 기준 허용치 (500${\mu}$S/cm) 이내였다.

• 대한환경공학회지
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• 제22권2호
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• pp.291-302
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• 2000

연료가스로부터 황화수소를 제거하기 위해 망간계 탈황제를 개발하여, 대기압하 고정층반응기에서 황화/재생 반복실험을 통하여 탈황제의 효용성, breakthrough times, 그리고 평형농도를 구하였다. 황화수소 제거능에 영향을 미치는 입자크기, 황화반응 온도, 재생온도 그리고 재생 특성에 관해 살펴보았다. 황화수소 제거를 위한 적정 조업온도는 $800^{\circ}C$였으며 입자크기가 감소할수록 탈황능은 증가하였으나 입경 0.214~0.631mm에서는 큰 차이를 보이지 않았다. 실험으로부터 구한 황화수소 평형관계식은 log(K)=3.396/T-1.1105이고 탈황제 이용효율은 $800^{\circ}C$에서 92%를 나타냈다. 공기를 사용해서 재생할 때 $SO_2$ 배출농도는 $800^{\circ}C$에서 8.5% 이상, $850^{\circ}C$에서 8.4% 이상, 그리고 $900^{\circ}C$에서 8.8% 이상을 보여 황산제조에 사용될 수 있을 것으로 판단된다.

• 아시안잔디학회지
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• 제10권2호
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• pp.151-157
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• 1996

Samples from the L, F, H and $A_1$ horizons of the Phragmites communis, Miscanthus sacchariflorus, Scirpus tabernaemontani and Typha angustata grassland were collected in Paldangho and the removal rates of ritrogen were investigated. The removal rates of nitrogen of the litters were 0.85 in P.communis, 0.56 in M sacchariflorus, 0.45 in T. angustata and 0.31 in S. tabernaemontani The time required to decay 50, 95, 99 percent of the steady state levels and turnover values of nitrogen on the grassland floor were 0.81, 3.53, 5.89 years in the P. communis, 1.23, 5.32, 8.86 years in the M sacchariflorus, 1.54, 6.68, 11.13 years in the S. tabernaemontani and 2.22, 9.63, 16.04 years in the T. angustata Key words: Removal rate, Accumulation, Paldangho, Nitrogen, Phragmites communis, Miscanthus sacchariflorus, Scirpus tabernaemontani, Typha angustata.

• 상하수도학회지
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• 제28권2호
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• pp.207-215
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• 2014

Wastewater containing heavy metals such as copper (Cu) and nickel (Ni) is harmful to humans and the environment due to its high toxicity. Crystallization in a fluidized bed reactor (FBR) has recently received significant attention for heavy metal removal and recovery. It is necessary to find optimum reaction conditions to enhance crystallization efficacy. In this study, the effects of crystallization reagent and pH were investigated to maximize crystallization efficacy of Cu-S and Ni-S in a FBR. CaS and $Na_2S{\cdot}9H_2O$ were used as crystallization reagent, and pH were varied in the range of 1 to 7. Additionally, each optimum crystallization condition for Cu and Ni were sequentially employed in two FBRs for their selective removal from the mixture of Cu and Ni. As major results, the crystallization of Cu was most effective in the range of pH 1-2 for both CaS and $Na_2S{\cdot}9H_2O$ reagents. At pH 1, Cu was completely removed within five minutes. Ni showed a superior reactivity with S in $Na_2S{\cdot}9H_2O$ compared to that in CaS at pH 7. When applying each optimum crystallization condition sequentially, only Cu was firstly crystallized at pH 1 with CaS, and then, in the second FBR, the residual Ni was completely removed at pH 7 with $Na_2S{\cdot}9H_2O$. Each crystal recovered from two different FBRs was mainly composed of CuxSy and NiS, respectively. Our results revealed that Cu and Ni can be selectively recovered as reusable resources from the mixture by controlling pH and choosing crystallization reagent accordingly.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.720-725
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• 2000

To remove harmful gases from combustion exhaust gases. fundamental study on NOx removal using pulse corona discharge has been performed through experiments and simulations. The energy consumption should be decreased in order to apply non-thermal plasma technology to industry process. This work summarized the effects of $H_2O$ and Hydrocarbon additive in NOx removal efficiency. The Radical program is used to simulate high voltage discharge and the process of NOx removal. At last, experimental results were compared with simulation results to verify the reliability of this program.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권7호
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• pp.103-111
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• 2015

Soil washing with ethylenediaminetetraacetic acid (EDTA) is highly effective in the remediation of soils contaminated with heavy metals. The EDTA recycling process is a requisite for reducing the operating cost. The applicability of Na₂S addition on the precipitation of heavy metals from the spent soil washing solution and thereby recycling of EDTA was investigated. Addition of Na₂S into the single metal-EDTA and the mixed metal-EDTA solutions ([Na₂S]/[metal-EDTA] ratio = 30, reaction time = 30 min and pH = 7~9) was highly effective in the separation of Cu and Pb from metal-EDTA complexes, but not for Ni. The Zn removal efficiency varied with pH and slightly increased upto 40% as the reaction time increased from 0 to 240 min which was longer than those for Cu and Pb. Ca(OH)₂ was subsequently added to induce further precipitation of Zn and Ni and to reduce the Na₂S dose. At the [Na₂S]/[metal-EDTA] ratio of 10, the removal efficiencies of all heavy metals excluding Ni were above 98% with the dose of Ca(OH)₂ at 0.002, 0.006 and 0.008 g into 100 mL of Cu-, Pb- and Zn-EDTA solutions, respectively. However, Ca(OH)₂ addition was not effective for Ni-EDTA solution. A further research is needed to improve metal removal efficiency and subsequent EDTA recycling for the real application in field-contaminated soils.

• 한국건설순환자원학회논문집
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• 제12권2호
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• pp.229-238
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• 2024

이 연구에서는 박테리아 기반 악취저감 키트의 악취제거 성능을 평가하였다. 박테리아는 악취오염원인 암모니아(NH₃), 황화수소(H₂S), 총질소(T-P) 및 총인(T-N)을 제거할 수 있는 Rhodobacter capsulatus, Paracoccus limosus 및 Brevibacterium hankyongi를 사용하였다. 사용된 소재들은 박테리아와 다공성골재(팽창질석, 제올라이트 비드, 활성탄)이며, 제거 메커니즘에 따라 소재들의 융합을 달리하였다. 물리적 흡착 메커니즘을 갖는 소재들(제올라이트 비드 및 활성탄)은 악취오염원(NH₃, H₂S, T-P 및 T-N)의 농도 저감율이 점차 둔화되어 48시간 이후부터 더 이상의 악취오염원의 농도의 저감 효과가 없었다. 생물학적 흡착 메커니즘으로 악취를 제거하는 박테리아가 고정화된 팽창질석은 지속적인 농도 저감으로 108시간 이후에 악취오염원의 농도가 0 ppm에 도달하였다. 결과적으로 실제 하천수에서 물리적 흡착 메커니즘을 갖는 소재들의 악취제거 성능은 환경부에서 제시하고 있는 악취 배출허용 기준을 만족하지 못한 반면, 박테리아가 고정화된 팽창질석은 악취 배출허용 기준을 만족하였으며, 수질도 1등급으로 평가되었다.

• Environmental Engineering Research
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• 제24권2호
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• pp.318-323
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• 2019

Paper focuses on comparison between two different orifice plate configurations (plate number 1 and plate number 2) used as cavitating device in the hydrodynamic cavitation reactor for improving pollutant removal efficiencies. Effect of four different parameters such as hydraulic characteristics (in terms of range of flow rates, orifice velocities, cavitation number at different inlet pressures); cavitation number (in range of 5.76-0.35 for plate number 1 and 1.20-0.35 for plate number 2); inlet pressure (2-8 bars) and reaction time (0 to 60 min) in terms of chemical oxygen demand (COD) removal and chlorpyrifos degradation has been studied and compared. Optimum inlet pressure of 5 bars exists for degradation of pollutants for both the plates. It is found that geometry of orifice plate plays important role in removal efficiencies of pollutant. Results obtained confirmed that orifice plate 1 with configuration of 1.5 mm 17 holes; cavitational number of 1.54 performed better with around 60% COD and 98% chlorpyrifos removal as compared to orifice plate 2 having configuration of 2 mm single hole; cavitational number of 0.53 with 40% COD and 96% chlorpyrifos in 2 h duration time.

• Korean Membrane Journal
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• 제8권1호
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• pp.1-12
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• 2006

In semiconductor industries, dissolved oxygen is one of the most undesirable contaminants of ultrapure water. A method for dissolved oxygen removal (DOR) consists in the use of polymeric hollow fibres, loaded with a catalyst and fed with a reducing agent such as hydrogen. In this work, PVDF hollow fibres loaded with Pd were characterized by means of perporometry, scanning electron microscopy (SEM), energy dispersive X-ray (EDX). The hollow fibre analyzed shows a five-layer structure with remarkable morphological differences. An estimation of pore diameters and their distribution was performed giving a mean pore diameter of 100 nm. The permeance and selectivity of the fibres were measured using $H_2,\;N_2,\;O_2$ as single gases, at different operating conditions. An $H_2$ permeance of $37 mmol/m^2s$ was measured and $H_2/O_2$ and $H_2/N_2$ selectivities of ca. 3 were obtained. $H_2$ permeance was 1/3 when a water stream flows in the shell side. Catalytic fibrebehaviour was simulated using a mathematical model for a loop membrane reactor, considering only $O_2$ and $H_2$ diffusive transport inside the membrane and their catalytic reaction. Dimensionless parameters such as the Thiele modulus are employed to describe the system behaviour. The model agrees well with the experimental reaction data.

• 한국환경과학회지
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• 제4권2호
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• pp.215-222
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• 1995

Thiokncillus neapolitanus R-10 isolated from sludge of night soil, showed an oxidizing activity on several malodorous sulfur compounds. The microbe successfully utilized hydrogen sulfide(H2S), methy mercaptan(MM), dimethyl sulfide(DMS) and dimethyldisulfide(DMDS) during the batch culture reaction, of which H2S was rather rapidly oxidized. To examine the ability for removal of malodorous sulfur compounds, various concentrations of sulfide substrates were supplemented separately to basal medium and their responses were investigated. As the concentration of sulfide was increased, growth was accelerated within three days of cultivation. 2.5mM was the most favorable substrate concentration of sulfide added for all cases tested. However, when the concentration of sulfur compounds were raised over 4M, they behaved as a growth inhibitor.