• Food Science and Preservation
• /
• v.24 no.8
• /
• pp.1088-1093
• /
• 2017

This study was conducted to investigate the effects of drying methods for Citrus junos peels on quality characteristics of the hot-water leachate from teabags containing those peels. Fresh peels were hot-air ($50^{\circ}C$), cold-air ($30^{\circ}C$), or freeze-dried ($-45^{\circ}C$), powdered to a size of 40 mesh, packaged with a paper sachet, and then the packaged teabags were leached for 10 min with hot-water ($70^{\circ}C$). $L^*$ value (lightness) and $-a^*$ value (greenness) of the peel powder were the highest in the freeze-dried samples. Soluble solids and titratable acidity of the teabag leachate were in the following order; cold-air, freeze, and hot-air dried samples. Among free sugar contents in all samples, fructose content was the highest, followed by glucose and sucrose. Fructose and glucose contents were not affected by drying methods. There was no significant difference in the flavonoid content among the peels dried using three drying methods. DPPH radical-scavenging activity of the leachate was the highest in the cold-air dried sample. These results suggest that cold-air drying would be an effective method to enhance the quality of hot-water leachate of teabags prepared from C. junos peels.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.26 no.2
• /
• pp.19-32
• /
• 2018

This study has been carried out to analyze the effects of leachate recirculation on methane gas concentration in the Landfill. The monthly average on precipitation of the landfill area during the period from 2010 to 2016 has been recorded at 130.9 mm and the total precipitation was recorded at 73.7 mm for the month of June in 2017. And based on the Korea meterological administration data obtained, the water content has been anticipated to be at low level. And for the control environment testing on the effects of leachate recirculation, the reading has been carried out in relation to the methane gas concentration with the landfill site tested with average reading of 30.14%. Once the reading has been established 5 tones of leachate has been injected and the readings carried out respectively with the first reading recorded at 24.66% on June with subsequent readings carried out, 31.51 (6/24), 36.88% (7/1) and final reading carried out on 7/25 registered at 52.47%. Based on the leachate recirculation, the test showed increase of methanate concentrations with the concentration percentage showing between 50~65%.

• Journal of Korea Soil Environment Society
• /
• v.5 no.3
• /
• pp.35-54
• /
• 2001

It is difficult to accurately predict each flow rate of landfill gas and leachate extracted from many of wells, which have been completed into a waste landfill containing gas and water. However it may be approximately predicted if we can define only relative fluid permeability of gas and leachate flowing through landfill porous media. Therefore numerical simulation using multi-phase flow equations makes use of ei s input data of the relative permeability which is measured and calculated in laboratory environment like in-situ, and consequently we can quantitatively obtain each flow rate of gas and leachate from collection wells. These series of technologies can provide with the important informations to determine the success or failure of landfill gas energy and landfill stabilization. This paper analyses the characteristics of landfill gas collection by six classes of case studies for none described landfill.

• Journal of Korean Society of Water and Wastewater
• /
• v.26 no.1
• /
• pp.21-27
• /
• 2012

This study evaluated the performance of a thermophilic two-phase anaerobic digestion (TTPAD) coupled with membrane process treating garbage leachate. The pilot-scale treatment system is consisted of thermophilic acidogenic reactor (TAR) and thermophilic methanogenic reactor (TMR) coupled with an ultrafiltration (UF) membrane unit. The hydraulic retention time of TAR and TMR were 4 and 20 days, respectively. Effluent TCOD and SCOD of the TTPAD were $25\;{\pm}\;6\;and\;12\;{\pm}\;3$ g/L, respectively, and the corresponding TCOD and SCOD removal efficiencies were 77% and 81%, respectively. Propionate was major acids as 75% in the effluent. Scum formation was not observed in TTPAD, which might be resulted from complete lipid degradation. However, TTPAD was appeared to be sensitive to free ammonia toxicity. The UF membrane was operated with constant pressure filtration at average TMP 1.3 atm. Permeate flux had a range of 15-30 $L/m^2/hr$. With UF membrane, TCOD removal increased from 77% to 93%, and this SS free effluent would be beneficial to subsequent processes such as ammonia stripping.

• Journal of Korean Society of Water and Wastewater
• /
• v.28 no.1
• /
• pp.55-60
• /
• 2014

Food waste leachate (FWL) is a serious pollutant waste coming from the food waste recycling facilities in Korea. FWL has a high organic matter content and high COD to nitrogen (COD/N) ratio, which can disturb efficient methane production in the anaerobic digestion of FWL. In the present study a microalga, Clorella vulgaris (C.V), was used as co-substrate for the FWL anaerobic digestion in order to supply nutrients, decrease the COD/N ratio and increase its methane yield. Different co-digestion mixtures (COD/N ratios) were studied by using biochemical methane potential test and modified Gompertz equation for kinetic study. Mixed substrate of FWL and C. vulgaris in the co-digestion clearly showed more the biomethane yield than the sole substrates. The maximum methane production, 827.7 mL-$CH_4$/g-VS added, was obtained for COD/N ratio of 24/1, whereas the highest improvement of methane yield was found for COD/N ratio of 15/1.

• Journal of Korean Society on Water Environment
• /
• v.30 no.5
• /
• pp.559-567
• /
• 2014

Since the ocean dumping of organic wastes is prohibited under the London Convention, the need for land treatment of food waste leachate (FWL) has significantly been growing in recent years. This study was conducted to use thermal solubilization to turn FWL into a form that can easily be degraded during the anaerobic digestion process, thereby reducing the percentage of solids and increasing the production of methane. To derive the optimal operating conditions of thermal solubilization, a laboratory-scale reactor was built and operated. The optimal reaction temperature and time turned out to be $190^{\circ}C$ and 90 min, respectively. The BMP test showed a methane production of 465 mL $CH_4/g$ $COD_{Cr}$ and a biodegradation rate of 90.1%. The production of methane rose by about 15%, compared with no the application of thermal solubilization. To reduce the solid content of FWL and improve the methane production, therefore, it may be helpful to apply thermal solubilization to pre-treatment facilities for anaerobic digestion.

• Journal of Korean Society on Water Environment
• /
• v.28 no.5
• /
• pp.663-668
• /
• 2012

The feasibility of enhancing biological nutrient removal from an industrial wastewater was tested with food waste leachate and sugar liquid waste as external carbon sources. Long term influences of adding external carbon sources were investigated to see how the biological nutrient removal process worked in terms of the removal efficiency. The addition of the external carbons led to a significant improvement in the removal efficiency of nutrients: from 49% to approximately 76% for nitrogen and from 64% to around 80% for phosphorus. Approximately, 20% of the removal nitrogen was synthesized into biomass, while the remaining 80% was denitrified. Though the addition of external carbon sources improved nutrient removal, it also increased the waste sludge production substantially. The optimal observed BOD/TN ratio, based on nitrogen removal and sludge production, was around 4.0 in this study.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 1998.10a
• /
• pp.388-394
• /
• 1998

In this study, the influence of soil contaminant on the cement solidification treatment was considered. Unconfined compression strength(UCS) test was carried out for solidificated specimen, Setting time was measured for cement slurry that was mixed with leachate and wastewater. It was appeared that treatment effect were affected by the the kind of soil, organic content, component of pore water and its concentration. And UCS of samples which were cured in the leachate were decrease about l/5. Especially for the marine clay, UCS of samples which were cured in leachate during 180 days were smaller than 90 days cured samples in the case of cement mixing ratio 5%, 10%.

• Environmental Analysis Health and Toxicology
• /
• v.7 no.3_4
• /
• pp.81-84
• /
• 1992

Physical compositions of solid waste in Wonju, shopping area were investigated with combustibles 78.13% (papers 35.89%, foods 14.41% etc.) incombustibles 21.87% (glass and ceramics 11.02%, metals 6.0% etc.) in 1991, solid waste in apartment area were investigated with combustibles 84.27% (foods 34.29%, papers 22.58% etc.), incombustibles 15.73% (glass and ceramics 8.77%, metals 4.85% etc.) and residence area were characterised with combustibles 70.37% (foods 33.55% , papers 10.53% etc.) and incombustibles 29.63% (ash of briquet 17.29%, glass and ceramics 7.49% etc.). Water qualities of a leachate from municipal landfill of Wonju city were analysed pH 8.0~8.4, total suspended solid 102~140 mg/1, CN￣ 0.003~ 0.008 mg/1, NO$_2$-N 0.108~0.294 mg/1 and phenols 0.46~1.12 mg/1. Volume of the leachate for 20% methemoglobin formation were 0.2~0.4 mg/ml in Octever, 0.3~0.4 ml/ml in December sampling, 0.2~0.3 ml/ml in St.1 and 0.4 ml/ml in St.3.

• Journal of Wetlands Research
• /
• v.2 no.2
• /
• pp.109-116
• /
• 2000

The equipment of a landfill need whole cut off facilities so that leachate generated from the landfill primarily do not leak to the ocean. Also, the whole collected leachate need a consecutive clarification treatment to discharge. A method is considered the best among the three alternatives. The merits of this method are as follows; have no secondary pollution. can cut down the expense of treatment, have good effects on preventing external leakage, don't need a leachate well, reliable quality control and easy post management. The weaknesses of this method are as follows; need a thorough survey about underground water and quality of the soil, need a special process to use as the land.