• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.10
• /
• pp.767-773
• /
• 2011

The purpose of this study was to investigate the possibility of an alternative fuel resource by incinerating a mix of combustible MSW (municipal solid waste) and offals after separating recyclable material at the MRF (material recovery facilities) location. We analyzed the physical and chemical properties including the 3-contents, the calorific value, and chemical compositions of the separation rejects in MRF, and compared the results with combustible MSW. Moreover, we experimented the trend of combustible properties and the concentration change of air pollutants at mixed incineration in the MSW incinerator. According to the results of the experiment, the separation rejects showed higher heating value (5,865 kcal/kg), and lower moisture and ash content than combustible MSW. Since we have incinerated MSW in the MSW incinerator mixing the offals at 30% and 50% respectively, we know that the change of the concentration of dust, $SO_2$, $NO_2$, and CO did not appear significant, and not exceed the pollutants emission regulation. But, considering the enhancement of the HCl emission concentration (max. 33.7 ppm) at the co-incineration of the 50% offals, we believe that the proper mixing ratio of the separation rejects would become within 30%.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.25 no.2
• /
• pp.42-53
• /
• 2020

In this study, heavy metal in road-deposited sediments (RDS) and marine sediment around Gwangyang Bay area have been investigated to assess the pollution status of metals and to understand the environmental impact of RDS as a potential source of metal pollution. Zn concentration for <63 ㎛ size fraction was the highest (2,982 mg/kg), followed by Cr, Ni, Pb, Cu, As, Cd, and Hg. Metal concentrations in RDS increased with decreasing particle size and relatively higher concentrations were observed around the metal waste and recycling facilities. For particle size in RDS smaller than 125 ㎛, EF values indicated that Zn was very high enrichment and Cr, Cd, Pb were significant enrichment. The concentrations of metals in marine sediments were mostly below the TEL value of sediment quality guidelines of Korea. However, the Zn concentrations has increased by 30~40% compared to 2010 year. The amounts of Zn, Cd and Pb in less than 125 ㎛ fraction where heavy metals can be easily transported by stormwater runoff accounted for 54% of the total RDS. The study area was greatly affected by Zn pollution due to corrosion of Zn plating materials by traffic activity as well as artificial activities related to the container logistics at Gwangyang container terminal. The fine particles of RDS are not only easily resuspended by wind and vehicle movement, but are also transported to the surrounding environments by runoff. Therefore, further research is needed on the adverse effects on the environment and ecosystem.

• Journal of Animal Environmental Science
• /
• v.15 no.1
• /
• pp.69-74
• /
• 2009

A survey questionnaire that addressed the issues to manure compost producers and users was prepared. The questionnaire addressed three main topics as follows: 1) types of manure treatment and composting facilities are being operated, 2) quantity of manure compost produced and used, 3) problems experienced in producing and using manure compost. A total of 30 manure compost producers and 10 manure compost users were interviewed. Solid manure are applied to composting. Slurry and wastewater are simplified aeration method to produce liquid fertilizer. The open elongated type manure composting are generally used on manure compost centers jointly used by several farms. The amount of annually manure compost production was most common in the range of $5{\sim}10$ thousand tons per manure compost center. The manure compost utilization and cucumber yield were mostly $6{\sim}15$ tons and $20{\sim}27$ tons per 10a of cucumber farmland, respectively. Environmentally friendly use both of manure compost and chemical fertilizer are recommended for natural recycling agriculture.

• Plant Journal
• /
• v.14 no.3
• /
• pp.35-41
• /
• 2018

Considering the recent government policy toward North Korea and situation of power facilities in North Korea, it will be necessary to prepare for the consumption of the anthracite coal from Korea in coal-fired power plants. In this study, the anthracite co-fired tests in 500 MW thermal power plants were conducted with varying the main operation conditions, such as anthracite injection position in the boiler, coal fineness and combustion air flow, to investigate the effects on the generation of unburned carbon. It was confirmed that the generation of unburned carbon was remarkably reduced when the anthracite coal was injected into the boiler low burner with a relatively long residence time in the main combustion region, and that the increase of the coal fineness proportional to the combustion reaction surface area also reduces the generation of unburned carbon. An increase in the combustion air flow, which increase the combustion reactivity, also contributes to the reduction of unburned carbon. It is possible to maintain the unburned carbon generation below 5 % of the ash recycling quality by controlling the above operating conditions for the given mixing rate of anthracite, and the priority of changing the operating conditions within the test range is the highest for anthracite coal injection position.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.6
• /
• pp.660-665
• /
• 2002

In Korea, an olive flounder is very popular fish food item. However, due to the increasing human population, the present catches of the olive flounder may not be sufficient to satisfy the present demand. To increase the supply of the olive flounder, aquaculture has been begun. An interest in the aquaculture of the olive flounder has been increased recently because of its characteristics of good growth and high price in the market, However, the productivity of the olive flounder aquaculture depends on economic inputs such as fuels, facilities, and labor. The rapid growths of the olive flounder aquaculture and the concerns about economic and ecological sustainability have focused peoples attention on the aquaculture industry. In this study, an energy systems model was built to simulate the variation of sustainability on the aquaculture of olive flounder, The results of simulation based on calibration data in 1995 show that olive flounder production yield and asset slowly increase to steady state because of the law of supply and demand. The results of simulation based on the variation of oil price show that the more increase the oil price, the more decrease the olive flounder economic yield and asset. Energy sources required for systems determine the sustainability of systems. Conclusionally, the present systems of the olive flounder aquaculture should be transformed to ecological-recycling systems or ecological engineering systems which depend on renewable resources rather than aquaculture systems which depend on fossil fuels, and be harmonized with the fishing fisheries by the sustainable use of renewable resources in the carrying capacity.

• Journal of the Korean GEO-environmental Society
• /
• v.20 no.5
• /
• pp.23-29
• /
• 2019

In general, pipe laying works are performed by constructing underground facilities such as pipes and then refilling the rest of the area with sand or soil. However, there are many problems in the compaction process such as difficulties in tampering around the underground facility and low compaction efficiency. Such problems cause deformation and damage to the underground pipes during refilling work and ultimately cause road sinks. Construction methods using CLSM are one of the typical methods to solve these issues, and recently, studies on CLSM using coal ash, which has similar engineering properties as sand, have been actively performed to protect environment and recycle resources. While many studies have been conducted to recycle fly ash in many ways, the demand for recycling bottom ash is increasing as most of the bottom ash is not recycled and reclaimed at ash disposal sites. Therefore, in order to find bottom ash applications using eco-friendly soil binders that are environmentally beneficial and conform with CLSM standards, this study investigated flow characteristics and strength change characteristics of eco-friendly soil binders, weathered granite soil, a typical site-generated soil, bottom ash, and fly ash mixed soil and evaluated the soil pollution to present CLSM application methods using bottom ash.

• Journal of Soil and Groundwater Environment
• /
• v.27 no.4
• /
• pp.10-21
• /
• 2022

In the South Korea, 47% of abandoned mines are suffering from the mining hazards such as the mine drainage (MD), the mine tailings and the waste rocks. Among them the mine drainage which has a low pH and the high concentration of heavy metals can directly contaminate rivers or soil and cause serious damages to human health. The natural/artificial treatment facilities by using neutralizers and coagulants for the mine drainage have been operated in domestic and most of heavy metals in mind drainage are precipitated and removed in the form of metal hydroxide, alumino-silicate or carbonate, generating a large amount of mine drainage treated sludge ('MDS' hereafter) by-product. The MDS has a large surface area and many functional groups, showing high efficiency on the fixation of heavy metals. The purpose of this study is to develop a ingenious heavy metal stabilizer that can effectively stabilize arsenic (As) and heavy metals in soil by recycling the MDS (two types of MDS: the acid mine drainage treated sludge (MMDS) and the coal mine drainage treated sludge (CMDS)). Various analyses, toxicity evaluations, and leaching reduction batch experiments were performed to identify the characteristics of MDS as the stabilizer for soils contaminated with As and heavy metals. As a result of batch experiments, the Pb stabilization efficiency of both of MDSs for soil A was higher than 90% and their Zn stabilization efficiencies were higher than 70%. In the case of soil B and C, which were contaminated with As, their As stabilization efficiencies were higher than 80%. Experimental results suggested that both of MDSs could be successfully applied for the As and heavy metal contaminated soil as the soil stabilizer, because of their low unit price and high stabilization efficiency for As and hevry metals.

• Journal of Applied Biological Chemistry
• /
• v.66
• /
• pp.258-265
• /
• 2023

After application of veterinary antibiotics, they may be partially metabolized before they are excreted by feces or urine either as unaltered form or as metabolites. Residual antibiotics enter the adjacent agricultural environments by spraying manure-based compost and liquid fertilizer on farmlands and lead to secondary pollution. The objective of this study was to compare the residual concentrations of 6 veterinary antibiotics by different production stages of liquid fertilizer from livestock manure recycling facilities. The relationship between concentration change of the residual antibiotics and the amount of liquid fertilizer component was also assessed. Pre-treatment showed the recovery of 63.4-106.7% at ppb level and the limit of quantification of 0.009-0.037 ㎍/L.As the result of analyzing the relationship between the residual concentrations of antibiotics and the amount of N component in liquid fertilizer by different production stages, the residual concentrations of antibiotics and N tended to decrease as the stabilization period elapsed during the liquid fertilization process. Average concentrations of sulfamethazine in raw materials, middle and final products of liquid fertilizer were 40.85, 26.17, 3.54 ㎍/L, respectively. Those of chlortetracycline decreased from 2.32 to 1.25 ㎍/L. The other 4 antibiotics also showed a decreasing trend by different production stages of liquid fertilizer. The amount of liquid fertilizer component N decreased from 0.21 to 0.096% by production stages of liquid fertilizer. It is considered that the correlation between residual antibiotic concentrations and N content can be applied as basic data for setting antibiotic reduction indicators.

• Journal of Animal Environmental Science
• /
• v.17 no.sup
• /
• pp.61-68
• /
• 2011

To assess the total cost with all stages of facilities, the feasibility of Life Cycle Cost (LCC) analysis was examined in this study to estimate the livestock manure treatment system and optimal decision making process. For the economic evaluation, the plant/equipment investment and annual operation cost of four Public Livestock Recycling Facilities, whose treatment capacity is 100 ton piggery manure per day, was compared. The initial cost was in the range of 2,699 million won to 3,202 million won, where T and E methods were highest and lowest, respectively. The annual operation cost was in the level of 378 million to 498 million won, which decreased in the following order : T method > J method > E method > B method. For the LCC analysis, 4.7% of interest rate, 3.13% of inflation rate, and 1.52% of net discount rate was considered by the data received from Bank of Korea and Statics Korea in the period of 2000 to 2009. Also, for the calculation of present value factor, the durable years of civil engineering & construction, machinery and electric instrument was 30 years, 10 years and 15 years, respectively. Based on these consideration, operation cost was in the range of 17,570 won/ton to 20,661 won/ton, and E method (17,570 won/ton) was economical and B method (20,661 won/ton) was non-economical. Though initial cost of T method was higher than that of B method, LCC analysis of T method was lower than that of T method due to the lower operation cost. Therefore, LCC analysis, which considers both initial cost and operation cost, is more reasonable evaluation method than either initial cost or annual operation cost. For the change of LCC analysis according to the uncertainty, the sensitivity analysis was carried out using fluctuation magnitude of discount rate in the period of 2000 to 2009. As a result, LCC analysis evaluated by discount rate was stable for the uncertain factors since the cost leadership did not change even though the sensitivity analysis varied. In summary, the economic evaluation using LCC analysis could be an efficient reference to choose the suitable livestock manure treatment plants. Furthermore, standardization of statement calculation for the actual cost analysis should be conducted and more detailed study is necessary to validate this summary. Therefore, the application of comprehensive technology evaluation, which considers LCC analysis, should contribute in obtaining objectivity and enhancing reliability for the 'Evaluation of Livestock Manure Treatment System and its Technology'.

• Journal of Environmental Health Sciences
• /
• v.30 no.4
• /
• pp.329-343
• /
• 2004

We conducted to investigate citizen's attitude to the treatment of food waste in Yongin city. The respondent of $41.81\%$ throws the food waste eliminate from home and store less than 1l in Yongin. When they dump the food waste, they speak out the inconvenience of damaged envelope by animals in case of home and store. This caused troubles for reason of sanitary. So a local autonomous entity must carefully consider of expand use specially designed container as like apartment house. They give an answer that the collecting time of food waste is suitable form dawn till morning. This answer shows the satisfaction of the period time to collect the food waste. They prefer to be appointed the exclusive place to collect food waste. The service interval of collect is suitable 1 time a day. They want to increase the number of washing of the collecting container. This is good method for sanitary condition, but the care of the period time to collect the food waste is more efficient than the care of the number of washing the collecting container. The care of the period time minimizes to incur the enmity of the people and to pollute in environment. The major of respondent handled the food waste after keeping the basket or a kit. This fact shows to us almost citizen doesn't feel the seriousness to remove the moisture of the food waste. Recently, many solutions which can be disposal efficiently are getting magnified and improved owing to increase utilities channel to loss in quantities and dry the food waste. We expect the reduction of food waste is solved getting easily step by step. The results of the awareness about the facility of food waste show citizen prefer recycling facility to the other facilities. If recycle facility and incineration facility are constructed, they were worried about bed smell. When some facility of the food waste is constructed, they have to maintain and to handle not to incur the enmity of the people. The spread rate of specially designed container already increased, the citizen set a high value on the use of specially designed container more than amount-rate vinyl envelope that people have used for several years. In the cost treatment about food waste, the major respondent answered the use cost of specially designed container is suitable price. So we can know the use charge is proper level. The majority of citizen more prefer autonomous plan which voluntary atmosphere creation and public information by mass media than levy system and rising treatment cost which forced plan. The citizens have pretty positive thinking of incineration, so the government needs more efforts for a public notice, which includes the incineration is no more than abandoned thing. Each of local self government has to sort the food waste and make kind of resource system related to collecting and carrying, constructing a suitable facility, proper disposal of the food waste and producing harmless in our surrounding in order to solve the invisible problems. To do above mentioned things, we have to analyze referred several problems till now. Also, to minimize the side effect, the government will have to improve through enforce the system.