• 한국막학회:학술대회논문집
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• 한국막학회 1995년도 제3회 하계분리막 Workshop (환경과 막분리 공정의 역할)
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• pp.27-38
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• 1995

Based on innovative membrane module concepts reverse osmosis and nanofiltration are going to become important instruments in environmental engineering. One example is the Disc-Tube-module and its application for the purification of landfill leachate. Currently over 45 different landfills are using this ROCHEM DT-module, in some cases combined with the high pressure reverse osmosis versions of this module, operating at up to 120 bar and 200 bar. This state of the art membrane technology and the DTF-module for nanofiltration, developed by ROCHEM on the basis of the DT-module and RO-systems for the purification of landfill leachate, make possible in hybrid processes permeate recovery rates of more than 97 % with concentration factors up to 40.

• Environmental Engineering Research
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• 제24권1호
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• pp.38-44
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• 2019

The Biochemical Methane Potential (BMP) of fresh leachate and domestic wastewaters codigestion was determined by laboratory Bach Tests at $35^{\circ}C$ over a period of 90 d using a wide range of leachates volumetric ratios from 0% to 100%. To simulate wastewaters plant treatment step, all the ratios were first air stripped for 48 h before anaerobic incubation. The kinetic of biogas production was assessed using modified Gompertz model and exponential equation. The results obtained showed that cumulative biogas production was insignificant in the case of wastewaters monodigestion while the codigestion significantly improves the BMP. Air stripping pretreatment had positive effect on both ammonium concentration and volatiles fatty acids with reduction up to 75% and 42%, respectively. According to the Modified Gompertz model, the optimal anaerobic co-digestion conditions both in terms of maximal biogas potential, start-up period and maximum daily biogas production rate, could be achieved within large leachate volumetric ratios from 25% to 75% with a maximum BMP value of 438.42 mL/g volatile solid at 50% leachate ratio. The positive effect of codigestion was attributed to a dilution effect of chemical oxygen demand and volatile fatty acid concentrations to optimal range that was between 11.7 to $32.3gO_2/L$ and 2.1 to 7.4 g/L, respectively. These results suggested that the treatment of fresh leachate by their dilution and co digestion at wastewaters treatment plants could be a promising alternative for both energetic and treatment purposes.

• 대한본초학회지
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• 제22권4호
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• pp.177-185
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• 2007

Objectives : The present study purposed to compare the anti-oxidative effect of Fructificatio Inonoti Obliqui aqueous extract according to extraction temperature. Methods : We measured the total phenol content and anti-oxidative activity of Fructificatio Inonoti Obliqui total extract and $50^{\circ}C$ low-temperature leachate. Results : Anti-oxidative activity of Fructificatio Inonoti Obliqui total extract and $50^{\circ}C$ low-temperature leachate was different according to extraction temperature, concentration, and antioxidant effect measuring method. In all experiments, the total extract showed higher antioxidant than n-BuOH fraction. The total phenol content was higher in Fructificatio Inonoti Obliqui total extract than $50^{\circ}C$ low-temperature leachate. Conclusions : Both Fructificatio Inonoti Obliqui total extract and Fructificatio Inonoti Obliqui $50^{\circ}C$ low-temperature leachate have significant anti-oxidative effect.

• 환경위생공학
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• 제20권1호
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• pp.32-39
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• 2005

Recently, sanitary landfill was one of the most widely used for disposal of waste in Korea. With increasing of use and public awareness of this method for disposal. there is an increased concern with respect to the pollution potential by the landfill leachate. Especially, an aged landfill leachate contained relatively large amount of the nonbiodegradable substances which could not be removed by biological treatment processes. So, this study was conducted to the removal of nonbiodegradable substances, such as Humic acid and Fulvic acid with the electrolysis. In this study, electrode materials, electrolyte concentration, electrode distance, current density, and pH value were found to have significant effect on both pollutant removal efficiency and current efficiency in electrochemical oxidation process.

• 한국응용과학기술학회지
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• 제22권3호
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• pp.250-256
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• 2005

This study was aimed to investigate treatment feasibility of leachate from D landfill that is located in gyr대ungbuk. From the analytical results of leachate, organic and nonbiodegradable matters were contained in high concentration. Thus chemical treatment was introduced to degrade nonbiodegradable matters in pre or post biological process. Two types of Fenton oxidation were adapted in this study. The first one is pre treatment process before biological treatment. The second one is post treatment process after biological treatment. The optimal conditions of both treatment methods were investigated as follows. In case of pre treatment process, the optimal conditions appeared in $Fe^{+2}/H_2O_2$(mmol/mmol): 0.1, $H_2O_2/CODcr$(mg/mg): 27.0, pH: 3 and reaction time: 2hrs. On the other hand, in case of post treatment process, the optimal conditions appeared in $Fe^{2+}$(mmol/mmol): 0.14, $H_2O_2/COD_{cr}$(mg/mg): 57.4, pH: 3 and reaction time: 1.25hrs. In the above optimal conditions, high COD removal was obtained in pre and post treatment process. Also it can expect that Fenton oxidation converted nonbiodegradable matters into biodegradable matters.

• 한국물환경학회지
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• 제23권2호
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• pp.244-250
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• 2007

This study was carried out to obtain the optimum design factors for an eletrolytric flotation reactor. When the effluent of the leachate treatment facility was treated under the condition of 10 volts, 30 minutes, at the Al-Al electrode system; COD removal efficiency was 45%, and total phosphorus removal efficiency was 98%. The high removal efficiency was caused by the fact that phosphate was removed by leaching $Al^{3+}$ from two electrodes. The leachate containing high ammonium nitrogen concentration was treated by a batch test under the condition of 60 minutes reaction time and added chloride ion; ammonium nitrogen removal efficiency was 89%. This high efficiency was affected by added chloride ion to wastewater. To find the optimum current density and voltage of the leachate containing chloride ion (ratio of $Cl^-/NH_4-N$ is 11) a electrochemical polarization curve was used. These values were found to be $4.5mA/cm^2$ and about 2.1 V, respectively. When C-Al electrode system was used at a batch test, the total nitrogen removal efficiency was increased by 1.8 to 3.3 times, compared to Al-Al electrode system due to high $Cl_2$ gas production.

• 한국토양비료학회지
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• 제48권5호
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• pp.326-331
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• 2015

High salinity and sodicity of soils play a negative role in producing crops in reclaimed tidal lands. To evaluate the effects of soil ameliorants on salt removal in a highly saline and sodic soil of reclaimed tidal land, we conducted a column experiment with treating gypsum, compost, and phosphate at 0-2 cm depth and measured the salt concentration of leachate and soil. Electrical conductivity of leachate was $45-48dSm^{-1}$ at 1 pore volume (PV) of water and decreased to less than $3dSm^{-1}$ at 3 PV of water. Gypsum significantly decreased SAR (sodium adsorption ratio) of leachate below 3 at 3 PV of water and soil ESP (exchangeable sodium percentage) below 3% for the whole profile of soil column. Compost significantly decreased ESP of soil at 0-5 cm depth to 5% compared with the control (20%). However, compost affected little the composition of cations below a depth of 5 cm and in leachate compared with control treatment. It was concluded that gypsum was effective in ameliorating reclaimed tidal lands at and below a soil layer receiving gypsum while compost worked only at a soil layer where compost was treated.

• 상하수도학회지
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• 제29권2호
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• pp.183-192
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• 2015

Response surface methodology (RSM) based on a Box-Behnken Design (BBD) was applied to optimize the thermal-alkaline pre-treatment operating conditions for anaerobic digestion of flotation scum in food waste leachate. Three independent variables such as thermal temperature, NaOH concentration and reaction time were evaluated. The maximum methane production of 369.2 mL $CH_4/g$ VS was estimated under the optimum conditions at $62.0^{\circ}C$, 10.1% NaOH and 35.4 min reaction time. A confirmation test of the predicted optimum conditions verified the validity of the BBD with RSM. The analysis of variance indicated that methane production was more sensitive to both NaOH concentration and thermal temperature than reaction time. Thermal-alkaline pretreatment enhanced the improvement of 40% in methane production compared to the control experiment due to the effective hydrolysis and/or solubilization of organic matters. The fractions with molecular weight cut-off of scum in food waste leachate were conducted before and after pre-treatment to estimate the behaviors of organic matters. The experiment results found that thermal-alkaline pre-treatment could reduce the organic matters more than 10kD with increase the organic matters less than 1kD.

• 한국토양비료학회지
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• 제48권1호
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• pp.64-71
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• 2015

Soil contamination with arsenic and heavy metals is a worldwide problem. Main objective of this research was to evaluated effects of reducing heavy metal leaching under reduced soil condition amended with industrial by-products. The contaminated soil was amended with 3% (w/w) of limestone (Ls), steel slag (SS) and acid mine drainage sludge (AMDS). Synthetic acid rain ($H_2SO_4:HNO_3=6:4$, pH 5.5 fixed) was used for feeding solution with flow rate of $0.78{\sim}0.88mL\;min^{-1}$. Results showed that similar pH and EC of leachate was observed in all treatments regardless of applied industrial by-products. However, arsenic concentration of leachate increased when industrial by-products were mixed. Meanwhile, concentration of heavy metal in the leachate decreased from 11.3 to 4.59 mg for Cd, from 92.3 to 7.93 mg for Pb, and from 11,716 to 1,788 mg for Zn via immobilization in soil with AMDS amended, respectively. Overall, application of industrial by-products can be an environmentally-friendly way to remediate soil and(or) leachate contaminated with metal(loid)s in metal mine site.

• Journal of Radiation Protection and Research
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• 제36권4호
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• pp.223-229
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• 2011

일반적으로 사용되는 액체섬광계수기를 이용한 $^{226}Ra$ 분석에는 Ba 공침법을 통해 얻어진 $Ba(Ra)SO_4$ 침전물을 이용하게 된다. 그러나, 인산석고 침출수의 경우 ${SO_4}^{2-}$, $Ca^{2+}$등의 이온이 다량 존재하여 순수한 $Ba(Ra)SO_4$ 침전물을 얻기가 힘들기 때문에 정확한 분석이 매우 어렵다. 본 연구에서는 분석화학에서 금속이온의 분리에 일반적으로 많이 활용되는 Ethylenediaminetetraacetic acid (EDTA)를 이용하여 인산석고 침출수에서의 Ba 공침법을 개발하였고 실제 인산석고 야적장 주변 침출수의 분석에 적용하였다. 또한 개발된 분석 방법은 침출수와 유사한 매질의 $^{226}Ra$ 모의표준시료을 제조하여 확인하였고 IAEA-434 인증표준물질을 통해 분석 신뢰성을 검증하였다. 실제 인산석고 야적장 침출수를 분석한 결과 0.102 $Bq{\cdot}kg^{-1}$의 농도를 보였고 검출하한치는 3.4 $mBq{\cdot}kg^{-1}$였다. $^{226}Ra$ 모의표준시료 분석을 통한 측정농도는 첨가한 농도와 1% 내외로 잘 일치하며 좋은 상관관계($R^2$=0.99)를 보였다. 인증표준물질의 분석 결과 인증값과 비교하여 5.8% (k=1)이내로 잘 일치하였다.