본 연구는 해양배출폐기물의 해양환경공정시험기준 생태독성시험 관련 시료전처리방법 개선 및 폐기물 업종별 독성 판정기준 적합여부 파악을 목적으로 실시하였다. 해양성 발광박테리아 독성시험은 시료26점에 대하여 46%(12점)의 ‘독성 없음’ (상대발광저해율 30%이하 적용) 판정이 나왔으며, 저성성 단각류시험은 염수추출 전처리 시료7점 중 섬유오니 1점만 ‘독성 없 음’(상대평균생존율 30%이하 적용) 판정이 나왔다. 시험결과로 업종별 독성 크기를 살펴보면 발광박테리아시험 상대발광저해율 은 축산분뇨>식품제조>음식물폐수>섬유․염색>방지시설 순서로 독성이 나타나고, 저서성 단각류시험은 섬유오니 시료의 결과 가 독성이 낮게 나왔으나, 시험대상 시료수가 많지 않은 관계로 업종별 독성 크기 파악은 생략했다. 다만 동일 폐기물 시료7점에 대한 두 가지 독성시험 결과로 판단할 때 발광박테리아시험의 기준만족(독성 없음) 확률이 저서성 단각류시험에 비하여 높게 나 타날 것으로 판단된다.

Depending on the steam pressure and temperature balance, it is possible to increase the power generation efficiency of the steam turbine by increasing the heat loss of the turbine by increasing the temperature and pressure. As the high temperature and high pressure increase, the boiler main steam amount is reduced by about 10%, but the increase rate of the heat drop is larger than the decrease rate of the steam flow rate, leading to improvement of power generation efficiency. Utilizing the US Department of Energy Steam Turbine Calculator, we calculated the electricity produced by steam temperature and pressure changes. In this study, the steam temperature was increased from 50℃ to 500℃ at the steam temperature of 20 kg/cm²×300℃, and increased by 10 kg/cm² at the pressure of 20 kg/cm² at the pressure of 60 kg/cm² to investigate the changes in electricity production. Electricity production increased with increasing temperature and pressure. The electricity production was increased by 40.11% at 40 kg/cm²×400℃ and 75.56% at 60 kg/cm²×500℃ compared to the standard condition of 20 kg/cm²×300℃ for comparison.

Energy can be reduced by reducing the exhaust gas temperature at the catalyst inlet and reducing or not using the amount of steam to reheat the exhaust gas. At this time, it is a method to improve the power generation efficiency by using the saved energy for power generation. When the exhaust gas temperature at the inlet of the catalytic reaction tower is operated at about 210℃, it is necessary to increase the temperature of the flue gas downstream of the bag filter at 165℃ to 45℃ to 210℃ required for the catalytic reaction. In the case of low temperature catalyst application, the temperature required for the catalytic reaction tower may be 185℃ and the temperature may be raised only 20℃. Therefore, the amount of steam for heating can be reduced. If the exhaust gas temperature of the bag filter inlet can be increased to 190℃, it can be combined with the low-temperature catalyst to reduce the energy consumed by removing exhaust gas ash. On the other hand, since the high-pressure steam is used as the heat source for reheating the exhaust gas, the reheating temperature is limited. According to such conditions, the exhaust gas temperature at the inlet of the catalytic reaction tower is often designed at about 200 to 220℃.

Even if the amount of exhaust gas is the same, it is possible to reduce the exhaust gas exit heat at the outlet of the boiler facility by lowering the outlet temperature of the economizer, so that it is possible to increase the heat quantity recovered from the boiler facility. There are many cases where the existing facility adopts 220~250℃ as the design value of the exhaust gas temperature at the exit of the economizer. However, in recent years, there has been a case of cooling and recovering heat to 200℃ or less from the viewpoint of active heat recovery. The amount of combustion exhaust gas is reduced by reducing the amount of combustion air supplied to the incinerator, and the amount of heat exhausted from the boiler facility is reduced, thereby improving the boiler efficiency. The holding energy of the combustion exhaust gas is the product of the exhaust gas amount and the specific heat and the temperature. In order to recover more heat from the combustion exhaust gas, not only the heat loss in the boiler facility is reduced, but also the heat radiated from the boiler facility is reduced. It is effective to reduce the exhaust gas temperature at the outlet of the heat recovery equipment and reduce the amount of exhaust gas in order to reduce the amount of exhaust heat of the exhaust gas. Even if the exhaust gas temperature at the outlet of the economizer is the same, the amount of exhaust gas discharged at the boiler facility outlet is reduced by reducing the amount of exhaust gas, and an increase in the recovered heat quantity at the boiler is expected.

Persistent organic pollutants are highly toxic, stay in the environment for a long time, accumulate in the body according to the food chain, and cause damage not only to the area where they occur but also to other areas beyond the border. Parties to the Convention, as well as Korea, are obliged to carry out various efforts to control, reduce or eliminate sources of POPs in accordance with the national implementation plan. In addition, national efforts to limit the production, distribution and use of persistent organic pollutants and the current state of domestic pollution and emissions should be submitted every five years. A flame retardant is a polymeric material with a property that is easy to burn, and it lowers the ignition point by adding a compound having a large flame retarding effect such as halogen, phosphorus, and a nitrogen metal compound. Among them, chlorine-based flame retardants classified as halogen-based are used for suppressing ignition of combustible organic materials including plastics, furniture, textiles, clothing, and electronic products. It is also used as an alternative to brominated flame retardants, causing mutations in carcinogenic substances, hormone destruction, and nervous system damage. In the case of waste containing chlorine-based flame retardants in Korea, the methods and standards for disposal of waste are not specified. The highest SCCP values were 4,253.09 mg/kg for polyurethane foam, 628.29 mg/kg for mobile phone case and 341.91 mg/kg for flame retardant rubber sheet. In the case of car seats no SCCPs were detected, and TCEP was detected at 512. 66 mg/kg, exceeding the EU limit of 5 mg/kg. However, other chlorinated flame retardants TDCP and TDCPP were not detected in all samples.

Annex A and Annex B of the Stockholm Convention define POPs as unintentional releases to Annex C, as well as organochlorine pesticides, polychlorinated biphenyls and hexachlorobenzen which are intentionally produced and used. These pesticides are very stable in the atmosphere due to insecticides, fungicides, herbicides, etc., and are likely to accumulate in living organisms due to residues in crops. There are 15 substances listed in POPs. These materials are widely used due to their high chemical stability, low solubility in water, high volatility, strong insecticidal effect and relatively low production costs. Aldrin-containing pesticides are known to have a combustion method for incineration in a chemical incinerator equipped with a reheat-burner device and a gas scrubber, and a solidification isolation method for solidifying and filling with cement mixed with a combustible material in waste treatment. In the case of solid-phase pesticides, HCB was 421.8 ng/g, Endosolfan-2 73.044 ng/g, PeCB 53.972 ng/g and Endosolfan-1 43.649 ng/g. In the case of liquid pesticides, HCB concentration was the highest at 167.489 ng/g similar to that of the solid phase, followed by PeCB at 23.462 ng/g. B-HCH, g-HCH, d-HCH and the like were detected as a small amount of other substances. It is judged that it is not necessary to set separate operating conditions or preventive facility standards since the material is decomposed sufficiently at 850℃ or more. However, considering the possibility of dioxin or unintentional persistent organic pollutants, it is considered appropriate to operate at above 1,100℃.

Elemental analysis, calorific value, etc. were measured to obtain basic information such as decomposition temperature and required oxygen amount for thermal treatment of waste containing chlorine-based flame retardant. Moisture, flammability and ash content of polyurethane foam were high in water, flammable rubber sheet in case of ash and flame retardant rubber sheet in case of ash. As a result of thermogravimetric analysis, the weight change in the range of 300 ~ 600 ℃ was large. The content of chlorinated flame retardant agent was analyzed to be higher than that of polyurethane foam (4,253.09 mg/kg), cell phone case (cloth, leather) 628.29 mg/kg and flame retardant rubber sheet 341.91 mg/kg. Chlorinated flame retardant materials, TDCP and TDCPP, were not detected in all samples. As a result of the decomposition tests for chlorine-based flame retardants at 850 ℃ and 1,100 ℃, chlorine-based flame retardant components were not detected in exhaust gas at all at 1,100 ℃ as well as at 850 ℃ in all samples including mobile phone cases, flame retardant rubber sheets and car seats. As a result of calculating the conversion rate for total chlorine value, it showed more than 99% even at 850 ℃ as well as at 1,100 ℃. Considering the decomposition rate in laboratory experiments of chlorine-based flame retardant-containing wastes, it is considered possible to incinerate at a scale of 2 ton/hour or more, which is the existing incineration facility. It is judged that it is not necessary to set separate operating conditions or preventive facility standards since the material is decomposed sufficiently at 850 ℃ or more. However, considering the possibility of dioxin or unintentional persistent organic pollutants, it is considered appropriate to operate at above 1,100 ℃.

As a result of analyzing the contents of organic chlorine pesticide-containing wastes, HCB 421.8 ng/g, Endosolfan- 2 73.044 ng/g, PeCB 53.972 ng/g, Endosolphan-1 43.649 ng/g respectively. In the case of liquid pesticides, the HCB concentration was the highest at 167.489 ng/g, similar to that of the solid phase, followed by PeCB at 23.462 ng/g. As a result of decomposition experiments on total OCPs among the pesticide liquid and solid phase components, initial concentrations were 597.384 ng/L for liquid pesticides and 198.176 ng/L for solid pesticides. However, the final effluent gas after decomposition showed a decomposition rate of more than 99.99% at a minimum of 0.005 ng/L and a maximum of 0.055 ng/L. Degradation test results for 25 species of OCPs such as PeCB, HCB, and Endosolfan for pesticide solid phase and liquid phase at reaction temperatures of 850℃ and 1,100℃. Of the 25 OCPs in the exhaust gas, trace amounts of PeCB and HCB were detected in the range of 0.006 to 1.025 ng/L at 1,100 ℃ and 850 ℃, and 23 OCPs were not detected. In the case of pesticides, the method of high temperature incineration and high temperature melting is proposed as the designated waste, but detailed methods of treatment conditions such as incineration conditions are not presented. Organochlorine pesticides were decomposed smoothly at 850 ℃ as well as incineration temperature of 1,100 ℃. However, since the dioxin concentration in exhaust gas exceeds 850 ℃, it is safe to operate at more than 1,100 ℃ in order to prevent the possibility of dioxin in advance.

WtE of MSW plays a crucial role in renewable energy production in Korea. Municipal solid waste (MSW) is an important energy resource for combined heat and power (CHP) production. This study investigated an increasing method to the power generation efficiency by MSW to energy (WtE) plants in South Korea and discussed the issues related to energy efficiency improvement. To achieve energy efficiency improvement is used to lower temperature for emission gas at catalyst inlet, or to reduce/stop using steam to reheat emission gas. Saved energy from this process can be used as power source in order to increase generation efficiency. It is possible to increase denitrification efficiency by maintaining the temperature of emission gas for catalyst denitrification. The temperature of emission gas of which moisture is increased to saturation point (relative humidity of 100%) at the exit of wet scrubber is between 50 and 60℃. This means there should be reheating of emission gas with the approximate temperature of 150℃. Dry emission gas treatment, on the other hand, is the technology to increase generation efficiency by using highly efficient desalination materials including highly-responsive slaked lime and sodium type chemicals in order to comply with air pollution standards and reduce used steam volume for reheating emission gas. If dry emission gas is available, reheating is possible only with the temperature of 45℃ in order to expect generation efficiency by reducing steam volume for reheating.

When adopting drain close system, the temperature of emission gas at the boiler exit is set high by spraying and evaporating drained water on quencher tower. According to applying drain close system boiler and power generation efficiency were decreased. In case of the water close system is not applied to treat the wastewater from incineration facility, the economizer outlet temperature can be reduced to 190∼220℃. And this leads to the increased ability of boiler's heat recovery. However, the temperature of emission gas at economizer exit should be set at 250℃ or higher if applying drain close system (minor conditions can affect as well). Boiler efficiency and generation efficiency can be improved by comparing the temperature of emission gas at economizer exit at 190℃ without the introduction of drain close system and 250℃ with drain close system. There are three types of white plume reduction equipment: one is offline type to blow air into chimney through heat source and exchange points after heating the air by using steam from equipment like boiler; another is in-line type to blow air into chimney through heat exchanger of combustion emission gas (mainly boiler exit); and the other is to blow air into chimney through hot wind burner by using fuels including kerosene. At a facility with white plume reduction equipment equipped with 5℃ of outdoor temperature and 60% of humidity, power generation volume and generation efficiency can be improved by using leftover steam for steam turbine from suspension of using white plume reduction equipment.

The Stockholm Convention is an agreement to reduce POPs use, production and emissions. POPs are highly toxic substances and can not be decomposed in their natural state. It has the characteristic of long distance movement. In this study, we calculated the theoretical air volume based on the result of element analysis. Considering that the inside of the reactor is small, more than 10 times of the air ratio was injected. Also, the retention time was set to 4 seconds or longer by giving a margin. The incineration temperature was 850℃ and 1,100℃ degrees. As a result of thermogravimetric method analysis, the weight of chlorine-based flame retardant-containing wastes was 300∼600℃, and that of organic chlorine-based pesticides was 200∼400℃. On the basis of this, it was experimentally investigated whether the environmentally stable incineration is achieved when the sample is thermally treated using lab-scale, 1 kg/hr. As a result of analyzing five kinds of exhaust gas, the concentration of O2 was high, but the amount of CO was decreased. It is considered that complete combustion is difficult because of the small size of the furnace due to the nature of lab-scale. The chlorinated flame retardants had a decomposition rate of 100 % and the average organochlorine pesticides were 99.9935%. Considering the decomposition rates of chlorinated flame retardants and organochlorine containing pesticide derived wastes derived from this study, incineration treatment at over 2 tons/hour, which is a conventional incinerator, is considered to be possible. Considering the occurrence of dioxins and unintentional persistent organic pollutants, it is considered possible to operate at more than 1,100℃.