• Journal of Korean Society of Environmental Engineers
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• v.30 no.3
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• pp.278-285
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• 2008

This research was performed to evaluate the landfilling method of organic sludge from mix of pre-treated organic sludge (OS) and municipal solid waste(MSW). Organic sludges were dried, composted, and solidified as pre-treatment and the OS and MSW were mixed in ratios of 2 to 8 and 4 to 6. Approximately 1,800$\sim$2,500 L of landfill gas(LFG) was generated in the lysimeter with solidified-OS, which was higher than 1,150$\sim$1,650 L of the dried- and composted- ones. Maximum H$_2$S concentration was found in the following order : Composted-20(80 ppmv) > Composted-40(55 ppmv) > Dried-20(30 ppmv) > Dried-40 $\fallingdotseq$ Solidified-20 $\fallingdotseq$ Solidified-40 (20 ppmv). BOD$_5$ at initial leachate generation period was 38,000 mg/L for Composted-40, 28,000 mg/L for Dried-40, 26,000 mg/L for Dried-20, 21,000 mg/L for Composted-20 and Solidified-40, and Solidified-20 for 17,000 mg/L. In the final period of experiment, BOD$_5$ was low as 300$\sim$500 mg/L in the lysimeter with solidified-OS and MSW and showed 2,000$\sim$3,500 mg/L in dried- and composted- ones. As the results, landfilling by mix of solidified-OS and MSW was evaluated as the most appropriate method for biodegradable organics. Direct landfilling of OS is permitted for landfill site with CDM facility. Therefore, mixed landfilling of solidified-OS and MSW should be considered for much more LFG generation as methane.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.470-477
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• 2007

This research was conducted to evaluate the effect of moisture content on direct landfilling prohibition of organic sludge. Organic sludges with moisture content (Me) of 75 and 85% were filled in two lysimeters. The lysimeters were named as Exp.75 and Exp.85, respectively. LFG of 2,064 l was generated greatly for Exp.85, compared to 1,500 l for Exp.75. LFG generations in Exp.75 and Exp.85 were 64.1 l/kg and 157.1 l/kg as dry TS basis, and 113.6 l/kg and 266.2 l/kg as dry VS basis. Total $CH_4$ generation in LFG for Exp.85 was 1,238 l, while 1,050 l for Exp.75. $H_2S$ of $3{\sim}150$ ppmv was generated from Exp.85, which was 5 times higher than $2{\sim}30$ppmv from Exp.75. Leachate was not generated from Exp.75 during operation time. However, 420 ml of leachate was generated from Exp.85. From the results of gas generation, composition, odorous compounds, and leachate generation, landfilling of organic sludge with high MC was more harmful to the environment in spite of great LFG generation. However, direct landfilling of organic sludges without great difference of MC made a severe odor problem. Therefore, it was thought that current direct landfilling prohibition law for all organic sludge was appropriate.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.102-113
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• 2000

This study was conducted to investigate the expandibility of sludge treatment by earthworm through real scale experiment and the optimum counter-plan for organic sludge treatment. For the purposes, sludge removal efficienciesof night-soil using earthworm and it's behavior according to the transplanting methods of the earthworm on non-cover worm bed or in the green house worm bed were compared. Sludge uptake rates on non-cover worm bed for 6 months were $0.27{\sim}0.33ton/m^2$ and the excrement of earthworm yields $0.15ton/m^2$(44.1~46.7% of raw night soil sludge dosage). These results were not much different from the worm bed in the green house. The average and maximum earthworm density were about $6.5kg/m^2$ and $7kg/m^2$ respectively on the non-cover worm bed. The density of the worm bed was comparatively higher in spring and fall terms but lower in summer. The amount of old earthworm was much plenty than young earthworm on the non-cover worm bed, resulting in reverse distribution type of pyramid. From the experiments on non-cover worm bed(7,000 pyeong)and in the green house worm bed(1,200 pyeong), it was concluded that landfill and transporting cost could be reduced when the earthworm was applied for the night-soil sludge treatment. Profits from the excrement sale of earthworm was 9,600,000 won. Through this study, it was founded that earthworm treatment method for organic sludge are much more environmentally sound than landfill treatment.