During the decay process of food waste, odor and leachate are generally produced because food is easily decomposed due to its high organic and moisture contents. In this study, various food waste samples, including samples artificially prepared and collected from actual waste containers, were tested to determine odor and leachate production as the samples were decomposed at a constant temperature of 35°C. In the air phase, total volatile organic compounds (TVOCs), acetaldehyde (AA), methyl mercaptan (MM), hydrogen sulfide (H2S), and dimethyl sulfide (DMS) were measured as a function of the decay period for four days. The results of the experiment showed that TVOC and AA were produced at higher concentrations in the actual food waste than in all artificial wastes. The AA concentration accounted for about 90% of the TVOC in all of the waste samples except for the food waste containing meat and fish only. The concentrations of volatile sulfur compounds (VSCs) were generally lower than 100 μg/kg, and the concentration of DMS was the highest among the VSCs. In the waste sample containing meat and fish only; however, the concentration of VSCs increased up to 1,700 μg/kg, and mostly consisted of MM and DMS. Complex odor concentrations were found to be the highest after a decay period of 12-48 hours. In addition, the complex odor was mostly related to VSCs with low odor thresholds rather than the TVOC. The pH values mostly decreased from 5 to 3.5 as the waste samples were in the decomposition periods, while the pH value increased to 6 in the food waste containing meat and fish only. Consequently, odor intensity and leachate production were the highest in the 12-48 hour range as the decomposition started, and thus an appropriate control strategy needs to be implemented based on the waste composition and the decay period.

In this study, we investigated influent and effluent water pollutants in 53 Public Sewage Treatment Works (PSTWs) where industrial wastewater or landfill leachate is combined four times for two years from 2014 to 2015. Also, we analyzed the characteristics of heavy metals and volatile organic carbons at influent and effluent of these PSTWs caused by sewage treatment combined with industrial wastewater or landfill leachate. As a result, six heavy metals such as barium, copper, iron, manganese, nickel and zinc, and four volatile organic carbons (VOCs) including phenols, di(2-)ethylhexyl phthalate (DEHP), formaldehyde and toluene were observed above detection limits in most of PSTWs. Also, it was revealed that six heavy metals such as hexavalent chromium, mercury, cadmium, chromium, nickel and selenium, and four VOCs including 1,1-dichloroethylene, vinyl chloride, naphthalene, and epichlorohydrin were observed more frequently according to precipitation. As a result of reviewing the monitoring data on “Water Quality Monitoring Networks” in lower watersheds of PSTWs, both heavy metals and VOCs were below detection limits, indicating that the effluent water had little influence on the watershed. Nevertheless for the better management of influent and effluent pollutants in PSTWs, it is necessary to establish the advanced management plans for water pollutants in PSTWs, which include a list of priority substances management, monitoring plans, and guidelines for industrial wastewater and landfill leachate combined in PSTWs.

Herein , the effect of changes in the organic loading rate in anaerobic digestion was evaluated. The experiment was carried out by a laboratory -scale semi-continuous stirred tank reactor, and feedstock was food-waste leached. The organic loading rate was increased by 0.5 kgVS/m3 in each phase from 1.0 kgVS/m3 to 4.0 kgVS/m3. At the end of the operation, to check the failure of the reactor, the organic loading rate was increased by 1.0 kgVS/m3 in each phase and reached 6.0 kgVS/m3. This shows that the biogas yield decreased as organic loading rate increased. Biogas production seemed to be unstable at 3.5–6.0 kgVS/m3. Moreover, biogas production dramatically fell to approximately 0 mL at 6.0 kgVS/m3, which was decided as the operation failure on the 16th day of the las tphase. The result of the reactor analysis shows that the cumulation of volatile fatty acid increased as the organic loading rate increased. This seems to occur due to the decreasein pH in the reactor and led to extinction of anaerobic bacteria, which were the biogas products. Although the buffer compound (alkalinity) could prevent the decline in pH, the concentration of alkalinity was found to be lacking at a high organic loading rate

음식물류 폐기물은 함수율과 유기물 함량이 높은 것으로 알려져 있으며, 유기물의 분해과정에서 CO2와 H2O가 생성되어 침출수가 발생하는 것으로 알려져 있다. 이로 인해 음식물류 폐기물의 수거 및 처리과정에서 침출수에 의한 오염과 침출수 처리에 관한 문제가 증가하는 경향을 보이고 있다. 그러므로 배출지에 따라 변화하는 음식물류 폐기물의 조성과 부패기간에 따른 침출수의 발생 특성을 확인하고 그에 따른 침출수 처리방안에 대한 연구가 필요한 실정이다. 음식물류 폐기물의 경우 조성이 다양하며 그로인해 침출수의 누적발생량과 pH 변화량 또한 배출지별로 많은 차이가 생길 것으로 판단되었다. 본 연구에서는 침출수의 발생특성을 확인하기 위하여 인위적으로 조성비율이 다른 음식물류 폐기물을 제조하였으며, 환경부에서 고시한 “음식물 찌꺼기 표준시료”를 참고하여 제조한 환경부 고시 참고 시료와 단백질이 주성분인 어육류로만 제조한 어육류 단일시료, 단백질 함유량이 적은 채소와 곡류로만 제조한 채소･곡류 혼합시료를 제조하여 실험을 진행하였다. 제조 음식물류 폐기물은 곡류, 채소류, 과일류, 어육류로 구성되었으며, 함수율(80%)과 염분(4%)을 조절하여 제조하였다. 각자 비율에 맞게 제조를 완료한 시료는 일정한 온도에서 부패를 진행하였으며, 부패기간에 따른 침출수의 누적발생량과 pH 변화를 측정하였다. 부패가 진행되는 과정에서 24시간 간격으로 침출수의 누적발생량과 pH 변화량을 관찰하였다. 실험결과 표준적인 조성비율을 가진 환경부 고시 참고 시료의 경우 보다 극단적인 조성비율을 가지는 시료의 경우 부패가 빠르게 진행되는 것을 확인하였다. 어육류 단일시료의 경우 4일 후 120 mL/kg의 침출수가 발생하였으며, 환경부 고시 참고 시료의 경우 –20 mL/kg으로 오히려 처음에 비해 감소하는 경향을 보였다. 또한 pH 측정결과 환경부 고시 참고 시료와 채소･곡류 혼합시료의 경우 5.0에서 3.5까지 감소하는 경향을 보였지만 어육류 단일시료의 경우 5.8에서 6.5까지 증가하였다. 위 결과를 통해 배출지의 음식물류 폐기물의 조성 및 부패기간에 따른 침출수 처리장치 및 관리방안의 기초설계 인자를 도출하고자 하였다.

경도 E129˚ 03' 40", 위도 N36˚ 51' 19"에 위치한 장군광산은 과거에 갱도채굴을 하였으며 현재에는 갱구와 광미로부터 갱내수와 침출수가 유출되고 있다. 갱내수와 침출수의 pH 값의 범위는 6.81-9.59로 중성내지 약염기성을 나타낸다. 주요 양이온과 음이온의 농도 범위는 Mg (6.70-129.80 mg/L), Ca (289.29-661.02 mg/L), Mn (4.74-14.38 mg/L), SO42- (1205.00-2448.69 mg/L) 등이다. 하천바닥에 침전된 황갈색의 침전물은 결정도가 아주 낮은 2-line 페리하이드라이트(Fe2O3˙0.5H2O로 구성되어 있다. 주사전자현미경 관찰결과 0.1μm 정도의 구형의 미세입자로 구성되어 있으며 에너지분산분광분석에 의한 반정량 결과 주 구성원소는 Fe이며 그 외 소량의 Mn, Ca, Si, As 등을 포함하고 있다.

Six lab scale reactors were designed having the height of 1/20 scale of real burial site and each reactors contained aleachate collecting system. Cattle and pigs were buried in these reactors, and leachate was collected to determine theconcentration of antibiotics. Leachate samples were collected periodically over a period of 24 weeks along with the trendof temperature and decomposition degree. Sulfachloropyridazine was detected in the initial leachate (4 and 8 weekssamples) from the cattle 1 and cattle 2 reactors, as 56µg/L and 312µg/L respectively and thereafter it was not detectedin leachate (16~24 weeks samples). Most of the antibiotics concentration were detected higher in leachate released inbetween 4~8 weeks. However, sulfadimidine was detected throughout 24 weeks in cattle 1 reactor, with the range of2.2~17.5µg/L. As a result of comparison with different aqueous environment, improper management of carcass burialsites may result in both surface water and groundwater contamination. To protect public health and to prevent/minimizethe negative impacts of contamination by antibiotics, proper environmental monitoring of leachate before and after carcassdisposal is necessary.

This study analyzed concentration and characteristics of hazardous substances in treatment of leachate from carcass burial areas by using high temperature thermal desorption (HTTD). Concentrations of pollutants emitted from HTTD treatment of leachate contaminated soil of carcass burial sites satisfied the emission standards for 11 pollutants from domestic waste incineration facilities. Dioxin concentration was 0.0060 ng I-TEQ/Sm3 and 0.0061 (0.0055-0.0070) ng ITEQ/ Sm3 in the normal operation condition and the experimental condition, respectively, which are much lower than the MSWI Standard of 0.1ng I-TEQ/Sm3. As a result, it was considered that leachate from carcass burial areas could be treated by high temperature thermal desorption (HTTD).

A field research at Sudokwon landfill was carried to analyse the effect of leachate and organic waste water injection on decomposition characteristics of landfill waste. The moisture content after leachate (79,783 m3) addition into block 3A for 1 year increased from 27.4% to 34.1%. As a result of moisture increasement, Cellulose and Lignin proportions as indicators of waste degradability changed from 1.45 to 1.18. It is also illustrated that TOC as an indicator of CH4 production potential reduced from 22.0% to 19.5%. Comparison results of TOC after 4 months of each leachate, digested waste water, food waste water injection into block 4A shows reduction of 3.5%, 4.7% and 3.7%, respectively. Hence, it is indicated that injection of leachate and organic waste water into landfill enhances the rate of CH4 production as well as the speed of landfill stabilization.

Landfill gas (LFG) has received considerable attention to produce a renewable energy source from waste because LFG contains about 45 ~ 55% methane. In order to improve LFG, the concept of bioreactor landfill is applied to Sudokown Landfill site. In landfill field test, the research area 3A (300 m × 300 m) and reference area 2A (300 m × 300) are prepared to compare the effect of leachate recirculation. Using injection wells, leachate is injected into the research area in the 2nd Landfill site and the distribution of moisture content in the research area is homogeneously saturated by the injected leachate. Leachate characteristics such as Alkalinity, BOD, COD, TKN, and TOC are increased with the input of the injected leachate because wastes are decomposed by the injected leachate but pH of leachate is almost not affected by the injected leachate. The production of LFG in the reseach area is improved by about 40% comparing with that in the reference area and the content of CH4 in LFG is consistently higher than 50%. Hence, it can be summarized that the production and the quality of LFG can be improved by the injection of leachate into landfill site.

Animal manure and manure compost produced from livestock farms are widely applied in crop lands. Leachate and runoff water from them are presumed to be one of the major sources of water quality deterioration in rural streams. Laboratory experiments were conducted to investigate water quality characteristics and loading of leachate obtained under rainfall simulation. Manure composts for the experiments were collected from beef cattle farms, dairy farms, and pig farms. Water quality parameters include SS, COD, TN, and TP. Most parameters of leachate from pig manure compost was higher than others. Both TN and TP concentrations were reflecting the composition of manure itself. It is recommended, therefore that the leachate from the manure composts should be controlled not to be discharged into streams.

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.