The odor removal of landfill site leachate was carried out using pyroligenous liquid. The constituent elements of pyroligenous liquid and leachate were also analysed, employing Atomic Absorption Spectroscopy(AAS). Before order removal, the heavy metal ions such as Pb, Zn, Cu, Mn, Fe and Ni, in pyroligenous liquid were detected with ultra trace level. However, in this liquid, other metal ions such as As, Hg and Cd were not observed. The optimum condition for removing odor from the leachate was observed in 15 times dilution of pyroligenous liquid. Also, the degree of outlet odor was 1. Furthermore, the concentration of odor constituent compounds, e.g. H2S, NH3, NH2 and CO2 in the leachate was remarkably reduced. Finally, water quality of the leachate was improved,

This study estimate the degree of contamination in the streamwater around the Sudokwon landfill site. It was sampled at 10 sites in Jan., Apr., Jul. and Oct., 1996. There were analyzed five kinds of toxic chemical material-CN, ABS, PCB, As, Org-P, and four kinds of heavy metal-Pb, Hg, Cd, C_r^+6. The result are 1)The COD was generally increased to compare before landfill, 2)The Org-P and PCB were not detected at all points, 3)The concentrations of Pb, C_r^+6 and As were lower than the environmental criteria values, 4)The CN, Hg and Cd were over envirommental criteria values, and so emergent regulation is needed, 5)The effects of the streamwater contamination were not only the leachate of the landfill, but also the small factories and agricultural land around the landfill.

Pollution characteristics of leachate and underground soil of the two landfill sites were investigated. Domestic wastes were dumped in the two adjacent landfill sites. Only small portion of S landfill site was filled with domestic wastes at the first stage of dumping, and most portion of the site was filled with construction wastes. However Y landfill site was filled with mostly domestic wastes. Higher concentrations of organic pollutants including VOCs were measured in Y landfill site leachate than in S landfill site. Underground soils of the two landfill sites were analyzed by the two kinds of leaching methods, KEP (Korean Extraction process) and Acid Digestion. Underground soils of the both landfill sites were not polluted by leachates. Underground soils of the two were composed of fine silty material. Thus it is found that fine silty soil layer of the sea shore may be used as a landfill site.

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, Trachellophyllum, 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 5% 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 sludge 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 affeced 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.

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 physio-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∼450㎎/L, COD 998∼1460㎎/L, NH_3-N 1380∼3412㎎/L, T-P 2.6∼7.O㎎/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.

Leachate from municipal landfill site is known to be hard to treat because it commonly contains various toxic material and heavy metals. In addition, portions of biodegradable organic substances in leachate are decreasing in the course of wastes stabilization, which is one of the critical reason for inefficient biological treatment at the end stage of landfill site operation. So this study was conducted to examine the feasibility of municipal landfill leachate pretreatment using electrolysis. The optimum electrode combination was made. The optimum electrode combination was found to be lead and graphite.

An experimental research was conducted in order to study the treatability of leachate and a combined wastewater of municipal landfill leachate and municipal sewage. The landfill leachate was that of Nanjido landfill site, and the municipal sewage was obtained from Chungnang municipal sewage treatment plant of Seoul. Several sets of bench-scale sequencing batch reactor(SBR) were used as experimental apparatus. Specially investigated items in this experiment were the removal efficiency of substrate and the influence of the hydraulic retention time(HRT). The experiment lasted for about 8 months. The result are as follows ; 1) The characteristics of leachate were pH 7.4∼8.1, BOD 280∼450 ㎎/1, COD 1300∼1350 ㎎/l, T-N 2021∼2110 ㎎/l, T-P 2.7∼3.2 ㎎/l, Cl- 3540∼4085 ㎎/l, and heavy metals are a very small amount. And the characteristics of sewage were pH 6.9∼7.3, BOD 78.4∼129.3 ㎎/l, COD 121.2∼305.0 ㎎/l, T-N 14.9∼36.4 ㎎/l, T-P 1.3∼5.9 ㎎/l. 2) The treatability of leachate alone was not treat well. So for the good treatment of leachate, it w;is necessary to deal with the pretreatment before biological treatment and a combined treatment of municipal sewage. 3) The various contents of the leachate were 5%, 10%, 30%, and 50%, and the removal efficiency of COD was 86.0%, 82.8%, 60.6%, and 31.7%. The maximum content of the leachate which could be successfully treated by SBR in the combined treatment eas 10% of that of sewage.