• Journal of Soil and Groundwater Environment
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• v.6 no.2
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• pp.57-67
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• 2001

The purpose of this study is to predict appropriate leachate rates and leachate transport velocity through weathered zone and basement rock on the transient condition at Nanji waste landfill. The leachate transport in the Nanji waste landfill is analyzed using MODFLOW(A Modular 3-D Finite Different Groundwater Flow Model) model which simulates three dimension groundwater flow and MT3D(A Modular Three Dimentional Transport Model) model which describes three dimensional transport for advection, dispersion and chemical reaction of dissolved constituents in groundwater system on the transient condition. Leachate production rates are estimated by HELP(Hydraulical Evaluation of Landfill Performance) model and used weather records for recent 10 years. Leachate transport is predicted by a change of leachate level to after/before established HDPE, established slurry wall and wells.

• 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.

• Journal of Environmental Health Sciences
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• v.23 no.3
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• pp.27-39
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• 1997

This study, collaborated Gifu University, Japan, was performed to analyze chemical pollutants and microorganism and to clarify the distribution of sulfate-reducing bacteria and their insolubilization of heavy metal ions in leachates sampled seasonally between 1994 and 1996 from Nanjido waste landfill site, sampled 4 times between 1995 and 1996 from Pusan and Daejeon waste landfill site, and sampled 1 time between 1992 and 1994 from Hokkaido, Nagoya, Osaka and Hukuoka waste landfill site in Japan. The results were as follows: 1. The temperatures of internal leachate and leachate effluent were 40$\circ$C and 30$\circ$C, respectively, and the pH values of both leachates were about 8.0 at Nanjido waste landfill site. The concentration of SO$_4^{-2}$ gradually increased with the degree of stabilization and that of NO$_3$-N was detected in a part of sampling sites at one and half years, and in all sampling sites at 3 years after completion of landfill. 2. The organic substances in leachate of Nanjido waste landfill site decreased with the degree of stabilization and they were very fluctuated with measuring point and time. The concentration of organic substance and heavy metals in internal leachate were higher than in leachate effluent and those of Cd, Hg, and Pb were lower than detection limit except a part of samples in 1996. 3. APCs in internal leachate and leachate effluent were not much different and the minimum of APCs in internal leachate and leachate effluent were $1.0\times 10^4$/ml and $4.0\times 10^1$/ml, respectively. 4. The maximums of SRBs in Nanjido, Pusan, and Daejeon waste landfill site were 9180 MPN/ml, 24000 MPN/ml, and 348 MPN/ml, respectively and the maximum of SRBs in Japan waste landfill site was 9300 MPN/ml. 5. During 2-week-SRB culture, the values of MPN were high at 50$\circ$C for initial culture period and at 30$\circ$C for last culture period. MPN started to appear at first day and rapidly increased between 7th day and 9th day. 6. Cadmium and copper were insolubilized by SRB within 6 hr and iron and zinc were done within 48 hr. The rates of insolubilization of Cd, Cu, Fe, Zn, T-Cr were 100%, 99.5%, 95.0%, 99.8%, 16.1% after 48 hr treatment with SRB, respectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.36-42
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• 2003

To identify the rapacity of waste leachate absorption in Populus euramericana and Betula platyphylla var, japonica, four different treatments were applied to seedlings: leachate solution (100% leachate), 50% dilution (50% leachate: 50% water, v/v) and 25% dilution, (25% leachate: 75% water, v/v) were applied to these two species. After the experiment, concentrations of heavy metals in tree parts were analyzed by an Inductively Coupled Plasma emission spectrometer (ICP). treatment with waste leachate significantly stimulated both Populus euramericana and Betula platyphylla var. japonica biomass production relative to the water control. In addition, these species showed good absorption capacity of As, Co, Hg and Ni elements. The results of this study suggested that these two species can absorb the toxic materials through their roots and transport them to stems or leaves.

• Journal of Environmental Impact Assessment
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• v.13 no.3
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• pp.115-124
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• 2004

To utilize a closed municipal solid waste landfill site in environmentally secure conditions, it is necessary to verify the stabilization level of landfill leachate. To assess leachate stabilization of an open-dumping municipal solid waste landfill (Noeun Landfill) which is located at the upper drainage basin of Namhan River which flows into Lake Paldang utilized for Seoul Metropolitan water supplies, the surrounding characteristics of the landfill site was surveyed. After then, leachate, groundwater and soil samples from this landfill were chemically analyzed, and the analysis results were evaluated by "The Criteria of Landfill Waste Stabilization(CLWS)", "Discharge Criteria of Landfill Leachate", "The Criteria of Domestic Use in Groundwater Quality", and "Soil Contamination Criteria" promulgated by Korean Ministry of Environment. The closed open-dumping landfill was equipped with the final soil cover, 3 groundwater monitoring wells and poor landfill gas extraction devices for the post-closure management of the landfill. BOD/CODcr ratios in leachate were less than or slightly higher than 1/10. This results seemed to imply that the leachate stabilization level of this landfill based on the CLWS was almost completed. Qualities of groundwater sampled from monitoring wells located at outside of landfill were adequate for "The Criteria of Domestic Use in Groundwater Quality". Finally, concentrations of soil contaminants that were likely to be influenced by this landfill site were adequate to "Soil Contamination Criteria".

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.50-61
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• 2013

In order to generate a renewable energy-Methane, anaerobic systems fed with source separated food waste from university cafeteria were studied. At first, four reactors were evaluated with same feed components; content non-mixing anaerobic reactor without leachate withdrawal/recirculation, content mixing anaerobic reactor without leachate withdrawal/recirculation, content non-mixing anaerobic reactor with leachate withdrawal/recirculation and content mixing anaerobic reactor with leachate withdrawal/recirculation. From the first study, content non-mixing anaerobic reactor with leachate withdrawal/recirculation showed the highest gas production. From further study with this system, it was observed that leachate permeation rate within anaerobic reactor was very important factor for gas generation. The higher permeation rate, the more gas production was observed. It is assumed that 1kg of gas collector weight and C/N ration above 10 in food waste may cause gas consumption in the anaerobic reactor. The gas consumption was estimated by negative pressure build-up at gas collector. The negative pressure build-up must be explained to produce Methane from Food Waste.

• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.461-466
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• 2011

The feasibility of utilizing food waste leachate as an external carbon source was tested to enhance biological nutrient removal from an industrial wastewater with an average flow rate of $164,800m^3/d$ and a low carbon/nitrogen ratio of 2.8. A considerable improvement in the removal of nitrogen and phosphorus was observed when a certain amount of the leachate, ranging from 70 to $142m^3/d$, was supplemented to the biological industrial wastewater treatment process. The addition of the leachate led to an increase in the BOD/N ratio (4.5) and the removal efficiency of nutritents from 29.7% to 71.7% for nitrogen and from 34.8% to 65.6% for phosphorus. However, an excessive dose of the leachate that significantly exceeded $120m^3/d$ caused serious operational problems, like oil-layer formation in the grit chamber and scum layer in the primary clarifier. Thus, an supplement of food waste leachate at a dose acceptable to an existing facilities can be a practical and effective means to enhance the nutrient removal from industrial wastewater and to dispose of the food waste leachate.

• Environmental Engineering Research
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• v.20 no.4
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• pp.363-369
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• 2015

This study aims to characterize solid household waste and to present physicochemical characteristics of fresh leachate before landfilling in Kasba Tadla city, Morocco. Obtained results show that household waste produced in 2013 were about 11,787 tons, or 0.27 tons/capita/year. These wastes were composed essentially of organic materials (74%), paper (8%), plastics (9%), metals (1%), and glass (0.5%). However, monthly produced leachate ranges from a maximum of $130.92m^3$ during summer and a minimum of $21.88m^3$ in winter. Moreover, leachate treatment using Upflow Anaerobic Sludge Blanket technique was accompanied by a decrease in electrical conductivity, certainly related to leachate-sediment chemical exchanges. Otherwise, the same acidity reduction phenomenon occurs when pH value increased from 4.49 to 6.17 after 24 hours, confirming the system response since the early stages of treatment. In addition, temporal evolution of the treatment efficiency in terms of COD highlighted a very important reduction which reached 94% after 5 days with an average temperature of $25^{\circ}C$.

• 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.

• Environmental Engineering Research
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• v.19 no.1
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• pp.67-73
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• 2014

In India, disposal of vegetable market waste along with municipal solid waste in landfills or dumpsites is creating much nuisance in terms of odor nuisance, leachate production, and greenhouse gas emission into the atmosphere. Therefore, vegetable waste with high biodegradable and nutrient content is composted in a 550-L batch scale rotary drum composter to study the degradation process and its compost properties for its potential reuse as high quality compost. A total 150 kg of working volume was fixed for composting studies with two different ratios, trial A (6:3:1) of C/N 24 and trial B (8:1:1) of C/N 30, respectively. A maximum of $63.5^{\circ}C$ and $61.2^{\circ}C$ was observed in trials A and B; an average of $55^{\circ}C$ for more than 5 days, which helped in the degradation of organic matter and reduction of total and fecal coliform. The temperature dropped suddenly after the thermophilic stage in trial B, and leachate was observed due to insufficient amount of bulking agent. Mesophilic bacteria dominated during the initial stages of composting, and reduced considerably during the thermophilic stage. During the thermophilic stage, the rise in spore-forming organisms, including spore-forming bacteria, fungi, actinomycetes and streptomycetes, increased and these were predominant until the end of the composting process. By examination, it was observed that moisture and leachate production had adverse effects on the compost parameters with higher loss of micronutrients and heavy metals.