• Journal of Environmental Science International
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• v.5 no.1
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• pp.61-69
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• 1996

The combined wastewater of municipal landfill leachate and municipal sewage was treated using several sets of bench-scale aerated circulating system including porous media. Investigated items in this experiment were the dominant protozoa and metazoa in this system, the variation of microfauna relationship between operating condition and dominant genera. Also considered the factors determining dominant genera and their role. The outcome of this research is as follows; 1. Aspidisca, Vorticella, Truhellophyllum, Lecane, Philodina, Cyclops were mainly appeared prior to combinding leachate, while Trachelocerca, Bodo, Glaucoma were the dominant genera after combinding leachate. 2. As to metazoa, Nematode and Philodina were not influenced by 5oA leachate mixing ratio, meanwhile Crustacea has high sensitivity for increased leachate mixing ratio and it was not appeared in 5% leachate mixing ratio. 3. The appropriate treatability could'nt be expected at the above 10% leachate mixing ratio. Especially, in the condition of 20% leachate mixing ratio, all of the microfauna were affected damage seriously on their existence. Meanwhile hydraulic retention time, substrate loading rate and slut자e production rate didn't give notable influence on increasing the number of microfauna. 4. As to protozoa, saprozoic and holozoic species were appeared commonly and polysaprobic species were dominent. 5. Filamentous organsms were nearly not affected by leachate mixing. It seems that they could live without any trouble at the 10% leachate mixing ratio, if the substrate is sufficient. 6. Diversity of microfauna had a reducing trernd as the sewage was mixed with leachate.

• Environmental Analysis Health and Toxicology
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• v.11 no.1_2
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• pp.31-39
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• 1996

Leachate from municipal solid waste (MSW) landfill, effluent from leachate treatment plant, and ground water sample from a monitoring well near landfill site were tested for an acute toxicity. Microtox toxicity test was used for testing the acute toxicity of leachate and other samples. EC$_{50}$ values which a concentration of pollutant for reducing 50% light output from luminescent bacteria, Photobacterium phosphoreum were determined to assess the toxicity of pollutants as well as the relative toxicity. In addition, characteristics of leachate were studied and compared to those of phenol and pentachlorophenol (PCP) which are typical aquatic toxic pollutants. For leachate, EC$_{50}$ for 30 min incubation was 10.8%, while for phenol and PCP, 46 ppm and 1.2 ppm, respectively. the relative toxicity of treated leachate by in situ aeration with activated sludge was reduced to more than 75% of toxicity of the untreated leachate. Microtox toxicity test was failed to figure out EC$_{50}$ values for groundwater from a monitoring well since the relative toxicity of the unconcentrated sample was too low to estimate EC$_{50}$. Addition of activated carbon to leachate was reduced the relative toxicity. The reduction Pattern of the relative toxicity of leachate by mechanical aeration was similar to that of PCP, but different from that of phenol. These findings suggest that the toxicity of leachate may come from PCP-like toxic compounds rather than phenol-like one. In conclusion, the process of aeration with activated sludge might be very important to reduce the environmental toxicity of leachate. And Microtox test could be a reasonable bioassay for screening and monitoring the environmental toxicity of leachate from municipal solid waste landfill as well as for determining the reduction efficiency of the leachate toxicity by various treatment processes in leachate treatment plant.

• The Korean Journal of Ecology
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• v.22 no.6
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• pp.343-348
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• 1999

Populus euramericana has been identified as a possible species for use for phytoremediation of landfills. To identify the effects of waste leachate on the growth and physiological characteristics of Populus euramericana. four different treatments were applied to Populus euramericana seedlings: leachate solution (100% leachate). 25% dilution (75% leachate: 25% water. v/v), 50% dilution (50% leachate: 50% water. v/v) and control (100% tab water) were applied to Populus euramericana. Treatment with waste leachate significantly stimulated Populus euramericana height. diameter at root collar and biomass production relative to the water control. Chlorophyll contents. photosynthesis and transpiration of leachate irrigated-trees were significantly higher than those of water control. These results suggested that poplar could be a suitable species for phytoremediation in landfills because these species showed good growth performance and were capable of taking up waste leachate.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.269-276
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• 1995

An experimental research was conducted in order to study the treatability of municipal landfill leachate using a combined physio-chemical and biological treatment. The leachate was obtained from Nanjido landfill site in Seoul. Several sets of bench-scale sequencing batch reactor(SBR) and physic-chemical reactors were used as experimental apparatus. This experiment lasted for about 2 years. The results are as follows: 1. The characteristics of Nanjido landfill leachate were pH 7.4~8.2, BOD 79~450mg/L, COD 998~1460mg/L, $NH_3-N$ 1380~3412mg/L, 7-P 2.6~7.0mg/L, color 890~1992 unit, and heavy metals are a very small amount. 2. Either physio-chemical or biological treatment of Landfill leachate alone did not work well. So for the adequate treatment of leachate, it was necessary to deal with the physio-chemical pretreatment before biological treatment. And it was found that both electrolysis and ozone treatment are better pretreatments of leachate than others. 3. In this study, landfill leachate was effectively processed by two step : first by electrolysis pretreatment, and secondly by SBR treatment. Thus, the study showed considerable substrate removal of raw leachate, even though the rate of COD removal depended on HRT.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.117-117
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• 1995

An experimental research was conducted in order to study the treatability of municipal landfill leachate using a combined physio-chemical and biological treatment. The leachate was obtained from Nanjido landfill site in Seoul. Several sets of bench-scale sequencing batch reactor(SBR) and physic-chemical reactors were used as experimental apparatus. This experiment lasted for about 2 years. The results are as follows: 1. The characteristics of Nanjido landfill leachate were pH 7.4~8.2, BOD 79~450mg/L, COD 998~1460mg/L, $NH_3-N$ 1380~3412mg/L, 7-P 2.6~7.0mg/L, color 890~1992 unit, and heavy metals are a very small amount. 2. Either physio-chemical or biological treatment of Landfill leachate alone did not work well. So for the adequate treatment of leachate, it was necessary to deal with the physio-chemical pretreatment before biological treatment. And it was found that both electrolysis and ozone treatment are better pretreatments of leachate than others. 3. In this study, landfill leachate was effectively processed by two step : first by electrolysis pretreatment, and secondly by SBR treatment. Thus, the study showed considerable substrate removal of raw leachate, even though the rate of COD removal depended on HRT.

• Journal of Environmental Impact Assessment
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• v.12 no.3
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• pp.161-170
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• 2003

To investigate the characteristics of 17 solid waste landfills in the upper drainage basin of Lake Daechong, the landfill sites were surveyed, the leachate of these landfills were analyzed, and the analysis results were assessed from standpoint of water contamination. Sanitary landfills which are now being operated are relatively well equipped with facilities such as leachate collection, daily soil cover and landfill gas treatment devices. But a few of open-dumping landfills were leaking leachate apparently and were supervised improperly and neglectfully by local governments. Some of sanitary landfills exceeded the COD permission criteria of leachate effluent, and some of open-dumping landfills exceeded SS, T-P, Pb, As, Fe, Mn permission criteria of leachate effluent. To improve the water quality of Lake Daechong which is utilized for supplying drinking water, agricultural water, and industrial water to the great part of Chungchong area, the adequate and prompt measures for preventing Daechong Lake water contamination from landfills leachate is necessary.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.129-133
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• 2000

The objective of this study was to invetigate the coagulation effects of landfill leachate by using Acid Mine Drainage(AND). The coagulation efficiency was investigated by mixing landfill leachate with F $e^{+3}$ solution earned by oxidation of pyrite(AMD). In the results of this experiment, it was found that the amount of removed COD and SS was approximately 30% respectively by mixing at the ratio of AMD three to leachate one. And it showed highest turbidity removal efficiency at all mixing ratio. Concentration of Fe was decreased with increasing mixing ratio, however it was increased inversely at mixing ratio 4. Optimal mixing ratio was 3 at the results obtained by leachate coagulation experiments. Also removal efficiency at mixing ratio 3 corresponded to 500mg/$\ell$ of FeC $l_3$ dosage. it was suggested that pretreatment by mixing of AMD and leachate remove both suspended organic material of leachate and metal of AMD.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.2
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• pp.117-123
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• 1996

A bench-scale continuous activated sludge system was operated in order to study the effects of solid waste landfill leachate on municipal wastewater treatment. The leachate sample was collected from Nanjido landfill. During the 7 weeks of operational period, the leachate content in the influent fed to the system was increased stepwise from 3% to 5% and 7%. The solids retention time was the major process control parameter, and it was 10 days. With the municipal wastewater alone, COD removal was 75%. The removal percents, however, decreased to 60% and 45% when the leachate content was 3% and 7%, respectively. For the wastewater spiked with the leachate, the sludge production was higher than for the municipal wastewater alone. Sludge settleability determined by SVI deteriorated with the increase of leachate content. The specific oxygen uptake rate, however, was measured higher as leachate content increased.

• Journal of Animal Environmental Science
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• v.16 no.3
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• pp.215-226
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• 2010

The pig slurry leachate was dark brown-colored solution that leaches out of woodchip trickling filter. The purpose of this research was to investigate the effect of pig slurry leachate and byproduct on growth characteristics of leaf lettuce in hydroponics culture. The effects of addition of fish meal, bone meal and crab shell for the growth of leaf lettuce were investigated. Leaf lettuce were grown in each of six combination treatment solutions; slurry leachate, slurry leachate + fish meal, slurry leachate+bone meal, slurry leachate + crab shell and chemical hydroponic solution for lettuce based on EC content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of lettuce. The all of nutrient solution was adjusted 1.5 mS/cm in EC in hydroponics culture. 1. The pH level of leachate of trickling filter was increased and EC decreased gradually during treatment. Pig slurry leachate was low in suspended solids (SS), phosphorus (P), but rich in potassium (K). 2. The plot of slurry leachate (SL) was lowest in the growth characteristics of lettuce. The leaf length and width of lettuce treated with mixture plot of slurry leachate and fish meal (SL + FM) was higher compared with plot in slurry leachate. The chlorophyll reading was reduced in plot treated with slurry leachate, but that in plot of SL+FM was similar compared with control plot. 3. The fresh weight of lettuce showed lowest in the plot treated with slurry leachate. The addition of fish meal increased the yield of comparing plot of slurry leachate, but plots of bone meal and crab shell addition were not significantly difference. The fresh weight of leaf lettuce in plot of SL+FM was 87% as 400.0g compared with control. In conclusion, the mixture solution of pig slurry leachate and fish meal could be used as a nutrition solution of organic lettuce hydroponics.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.293-305
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• 2017

This experiment was conducted to evaluate the effect of leachate replacement frequency on solid state anaerobic digestion (SSAD) of dairy manure using 22 L volume lab-scale digesters at mesophilic temperature ($37^{\circ}C$) in batch mode. Three different leachate replacement strategies (no replacement, once every three days, and once every nine days) were applied and three digesters per each treatment were operated for 45 days. Results showed that leachate replacement test unit every nine days resulted in 1.6 times more methane production ($53.8N{\cdot}mL\;g^{-1}{\cdot}VS$) from SSAD compared to test unit every three days ($34.0N{\cdot}mL\;g^{-1}{\cdot}VS$). No leachate replacement strategy applied group showed slightly higher methane production ($56.3N{\cdot}mL\;g^{-1}{\cdot}VS$) than every nine days replaced one. When added the methane production potential of replaced leachate itself to the methane produced from digester, leachate replacement every nine days resulted in quite similar methane production ($56.5N{\cdot}mL\;g^{-1}{\cdot}VS$) to no leachate replacement group. Even though methane production potential of replaced leachate itself added to the methane produced from digester, every three days replacement showed only $34N{\cdot}mL$ methane production per gram of volatile solids. These results suggest that farmers do not need to replace leachate during SSAD of dairy manure and sawdust mixture in order to maximize methane production. If there are any concerns with accumulation of inhibiting substances in the digester, the 9-day cycle leachate replacement is appropriate.