김우일 Woo Il Kim , 정성경 Seong Kyeong Jeong , 이동진 Dong Jin Lee , 조윤아 Yoon A Cho , 신선경 Sun Kyeong Shin , 강영렬 Young Yeul Kang , 오길종 Gil Jong Oh

DOI:

Abstract

This study was performed to investigate the leaching and contents characteristics of hazardous wastes from the paint industry. In order to establish a hazardous waste list, samples discharged from paint industry have been analyzed for II regulated heavy metals (i.e., As, Cd, CN, Cr6+ Cu, Hg, T-Cr, and Pb). In more detail, hazardous waste samples from 64 workplaces, e.g. manufacture, formulation, supply and use (MFSU) of coatings, adhesives, sealants and printing inks processing, have been chosen and analyzed. Result of leaching and contents tests for inorganic metal species in samples shows that the regulated hazardous substances satisfy all the criteria, while quantitative analyses reveal that 4 samples exceeded the regulated level, In conclusion, we expect that the result of this study will help to align the waste catalogue of hazardous waste management in Korea with international legislations, and consequently contribute to reduce environmental pollution as well as health risk by hazardous wastes.

Key Words

Classification of hazardous waste, Absolute entry, Mirror entry, Leaching and contents analysis

오민아 Min Ah Oh , 문소영 So Young Moon , 현미 Min Hyun , 이재영 Jai Young Lee

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Abstract

Arsenic, one of endocrine disrupters, is vety toxic, so that contaminated soil with arsenic can cause many problems for human beings. However, standardized remediation process for the soil contaminated with arsenic is insufficient due to characteristics of its anion-mobility and speciation changed by Eh-pH of soil. One of the well-known efficient remediation processes is the modified soil washing that particle separation process by only water. However, it is required that the treatment plan for the fine soil what was discharged after modified soil washing. Therefore, this research suggests the treatment plan that the recycling method using arsenic immobilization by FeS-H2O2, The batch experiments results for the arsenic immobilization showed that the water content was at least 50%, the injection of FeS and H2O2 (assay-35%) were 8% (w/w at dry base) and 0.2mL/10g of fine soil respectively. Arsenic concentration with KSLT was decreased about 95.4%. The results indicated that the mixing of FeS-H2O2 was highly efficient on the immobilization of As-contaminated soil.

Key Words

Arsenic, Fine soil, FeS, H2O2, Immobilization

윤용수 Yong Soo Yoon

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Abstract

In this study, cylindrical Al electrode as anode was used to determine the feasibility of electrochemical treatment of T-P in sewage by electrolysis in continuous mode. Three kind of wastewater, i.e., synthesized wastewater, practical sewage and treated wastewater from pilot plant were used for electrolysis at 10 V. Remaining T-P concentrations of treated wastewater depend on the concentration of NaCl, flow rate and initial concentration of T-P. Most case of the results of experiments could be remove T-P below 0.2mg/L at appropriate conditions, Therefore, this study on electrochemical treatment of T-P in sewage provides new technology for T-P removal in sewage treatment plant and obtains the parameters for design and effective operating conditions.

Key Words

T-P removal, Electrolysis, Al electrode, Advanced treatment of sewage

강호 Ho Kang , 정지현 Ji Hyun Jeong , 박선옥 Sun Uk Park , 조상선 Sang Sun Cho

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Abstract

A methane enhancement system, which consists of mesophilic plug-flow maize digester coupled with a leachate recycle loop to an external intermittent CO2 stripper, was developed to upgrade digester offgas. Quantitative evaluation of the system variables defined the effect of intermittent stripping of CO2 at different sweep gas flow rates on offgas methane contents, biogas productivity and TVS removal efficiency. The results showed that the offgas methane Content over 95% was obtained at an intermittent stripping ratio upto 3 hours stripping (N2 sweep gas 700ml/mm) and 1 hour no-stripping. It thus resulted in a 25% reduction from the total energy and sweep gas consumption. At this condition, the TVS removal efficiency of the methane enhancement system was 85.7% which corresponds to 103% of the control reactor and the methane productivity appeared to be 082v/v-d. It is obvious that the biogas productivity increased as the sweep gas flow rate and the CO2 stripping length of time decreased. Consequently it led to increase in TVS removal efficiency however methane contents became lower.

Key Words

Methane enhancement, Anaerobic digestion, Intermittent CO2 stripping, Plug flow reactor, Leachate recycle

오아람 Ah Ram Oh , 이우근 Woo Keun Lee

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Abstract

We prepared geopolymeric foam block, using raw material as blast furnace slag, mine tailing and alkaline activator in this research. We especially discussed the effect of Si02/Na20 mole fraction on the physical properties of geopolymer foam block prepared. Geopolymer possesses excellent mechanical properties, such as fire and chemical resistance. And also toxic substitutents like heavy metals are de-toxificated by geopolymerization process, because of the dissolution and polymerization of Si and Al from mine tailing. The density of foam block prepared was ranged from 0.62 to 0.76 g/cm3 and the compressive strength was ranged from 0.9 to 5, 6 MPa, The compressive strength was increased and the density was decreased with the decrease of Si02/Na20 mole ratio, The maximum compressive strength was 5.64 MPa under the condition of Si02/Na20 mole ratio of 1.4 and 0.20% of Al powder. According to FT-IR and XRD results, geopolymer structure in foam block was found out.

Key Words

Mine tailing, Geopolymer, Foam block, Compressive strength, Density

박상우 Sang Woo Park , 장철현 Cheol Hyeon Jang

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Abstract

The combustion characteristics and kinetic parameters of thermal-treated sludge, coal, and sludge/coal blends were investigated, and the corresponding results are given as follows: In the case of the differential thermogravimetric (DTG) characteristics below 300°C, two peaks were observed, and therefore, over 300°C, only a single peak was observed. As for the parameters for the combustion characteristics, initial temperature (IT) was slightly high because of the high thermal treatment temperature of the sludge, and hence, even burnout temperature (BT) showed similar results. The sludge/coal blends had different proportions of IT and WI`, depending on the type of coal， The optimum reaction order values ranged from 4.0 to 4.2 for the devolatilization step, whereas the values for the char combustion step ranged from 1.4 to 2.3. These values were higher than that of coal, whose values ranged from 1.1 to 1.3. The activation energy of the sludge/ coal blend depended on the type of coal; however, the activation energy decreased as the of amount of sludge increased, Therefore, the pre-exponential factor (A) of combustion of the sludge/coal blend was lower than that of a single combustion of only coal. It was found that due to the low reaction rate constant (K) values, the combustion rate was low.

Key Words

Sewage sludge, Combustion characteristics, Kinetics parameters, Thermogravimetric analysis

한규성 Gyu Seong Han , 양인 In Yang , 사공문 Gong Moon Sa

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Abstract

The physiochemical properties and elemental analysis of agricultural residues (AR), such as pepper stalk, corn cob, corn stalk, tobacco stalk, rice husk, rice straw, barley straw and wheat straw, were investigated to evaluate the potential of the AR as a raw material for the production of agropellets. All ARs were high in holocellulose and lignin contents, and had a broad ash content ranging from 1.67% to 10.87%. In quantitative analysis of the ash, all ARs had high potassium and calcium contents following by magnesium and sodium content. In the elemental analysis, nitrogen contents of all AR were much higher than that of larch, and even exceeded the wood pellet standard (<0.30%) established by Korea Forest Research Institute. The heating values of the AR also were lower than that of larch. The results suggested that the AR used in this study might be appropriate as raw materials of low-grade pellets for cogeneration or large-scale plants, In addition, the AR outdoor-exposed for 2 and 7 weeks was used to fabricate agropellets, Ash, chlorine and nitrogen contents of the agropellets effectively reduced. The results of this study indicate that AR might be used as a raw material of high-grade pellets if agropellets are fabricated with outdoor-exposed AR or a certain amount of wood sawdust in manufacturing process of pellets.

Key Words

Agropellet, Agricultural residues, Outdoor-exposure, Heating values, Ash content

위환 Whan Wi , 정숙경 Suk Kyeong Jung , 송형명 Hyung Myung Song , 윤상훈 Sang Hoon Yoon , 강영주 Yeong Ju Kang , 김은선 Eun Sun Kim , 정경훈 Kyeong Hoon Jung

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Abstract

In this paper, the adsorption behavior of heavy metals such as Cd and Pb, and mechanism in aqueous solution was investigated using various leaves. Daimyo oak, ginkgo, platanus, ficus carica and persimmon leaves are used for metal removal in this study. The influence of various parameters such as leaves dosage, initial concentration of heavy metals and temperature on the adsorption of heavy metals on leaves has been studied. With 4 hour-time period from the initial reaction, the optimum removal efficiencies of the residual of Cd and Pb by persimmon leaves were highest as 94.0% and 97.8% respectively in comparation with other leaves, The amounts of Cd and Pb were 8.74-1.18mg and 8.54-1.10mg for lg of persimmon leaves, The adsorption energy of Cd and Pb obtained from the D-R model was ranged from 4.72 kJ/mol to 5.56 kJ/mol and physical adsorption processes as primary adsorption mechanism, Total tannin disappeared at the same incubation period. This suggests that heavy metals in the mixture are reduced with concomitant oxidation of the tannin. The major fractions of Cd forms in persimmon leaves were organically bound (32.8%), exchangable fraction (22.1%), and those of Pb forms were organically bound (30.7%) and exchangable fraction (25.5%).

Key Words

Heavy metals, Persimmon leave, Adsorption energy, Fractions

김기헌 Ki Heon Kim , 정해영 Hae Young Jung , 박재성 Jae Sung Park , 권오준 Oh Jun Kwon , 오길종 Gil Jong Oh , 차준석 Jun Seok Cha

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Abstract

High-temperature incineration experiment was performed for the treatment of transformer oil containing PCBs, Behaviors of dioxin emission according to the concentrations of transformer oil containing PCBs were investigated. Concentration ranges of PCBs were classified as by ordinary (Ord), ordinary-low (<50ppm) and ordinary-high (>50ppm), PCBs feeding was carried out under complete combustion condition, Since the calorific value of the transformer oil is known as 10,000 kcal/l, stable operation was possible. By these reasons, all facilities investigated were satisfied with the air pollutants emission standard, the concentrations of PCDD/Fs at facility A for ordinary, ord-low and ord-high conditions were 0.910ng I-FEQ/Sm3, 0.769ng I-ThQ/Sm3 and 0.598ng I-TEQ/Sm3, respectively. Concentrations of PCDD/Fs at facility B were 0.014ng 1-TEQ/5m3, 0.015ng I-TEQ/5m3 and 0.009ng l-`FEQ/Sm3, respectively. All of these concentrations satisfied with PCDD/Fs emission standard of 0.1ng 1-TEQ/Sm3 in waste incinerator.

Key Words

PCDD/Fs, PCBs, Incinerator, Transformer oil, POPs

이진석 Jin Seok Lee , 엄태규 Tae Kyu Eom

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Abstract

Recently, livestock wastewater treatment has a difficulty due to its rapid increase according to livestock farming what is becoming bigger and bigger. 43millions ton of livestock wastewater is produced in Korea for a year, 85% of it is converted to energy and the rest of it is dumped in ocean and purified, It will be prohibited to dump in the ocean since 2012, that have to treat all of them on the ground up to 2011. Even though production rate of livestock wastewater is 0.6% of total sewage and wastewater, it is getting serious because of loading rate of pollution amount to 25.8%. The purpose of this study is to research the possibility of fertilizer from the swine manure by SBR process and Bacillus sp. The result of an experiment for suitability and possibility as an organic feed, it was satisfied a fertilizer grade, water content salinity and odor level, it was especially effective in odor removal. The possibility for eco-friendly fertilizer was however not enough because heavy metal contents in fertilizer exceed the standard, The feed is in circulation in Korea includes high concentration heavy metal, therefore it has to be considered to remove the heavy metal for application of liquid-fertilizer from swine manure.

Key Words

Sequencing batch reactor, bacillus, sp., Swine manure, Liquefied fertilizer, Odor removal

김성천 Seong Cheon Kim , 지대원 Dae Won Ji , 정영남 Young Nam Chun

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Abstract

The pyrolysis and gasification of the biomass and waste resources produces gas including the tar component condensed in the low temperature. The tar component causes the problem in the gas utilization apparatus like the gas engine and turbine. The gliding arc plasma reformer and externally oscillated device was connected for the discharge area expansion of the plasma and tar conversion, the external oscillation gliding arc plasma reformer was designed. A simulation test was conducted using benzene, which is produced during the pyrolysis gasification of biomass and waste, as the representative tar substance. The parametric screening study performed about the electrode geometry, nozzle diameter electrode gap and the electrode length changes of the gliding arc plasma reformer. The experimental result showed on the removal efficiency of the benzene, energy efficiency, and reformed gas concentration, In the reference condition, the decomposition efficiency of the benzene and energy efficiency showed 90.7% and 22.95 g/kWh. And the higher heating value of the reformed gas generated by decomposition of the benzene was 9, 718 kJ/Nm3 (the N2 exclude) and the carbon balance was 82.7%. The reformed gas was composed the hydrogen, carbon monoxide, carbon dioxide, methane, ethylene, and ethane. The results showed gliding arc plasma reformer was effective the tar reforming and discharge area was increased by the external oscillation. The gliding arc plasma reformer of the best suited forming condition was presented.

Key Words

Gliding arc plasma, Tar, External oscillation, Reforming, Syngas

장용철 Yong Chul Jang , 김민철 Min Cheol Kim , 김건국 Geon Guk Kim

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Abstract

Waste electrical and electronic equipment (WEEE), also called electronic waste (in short e-waste), is one of the fast growing waste streams in Korea and around the world. This results partly from rapid technology development of electronic industiy and common replacements of the devices by consumers with newer ones, In order to more effectively recover and process the WEEE produced from consumers and to reduce its impact on the environment, Korea Ministiy of Environment (Korea MOE) promulgated an extended producer responsibility (EPR) regulation for a number of electronic equipment in 2003. In 2007, the Act of Waste Electrical and Electronic Equipment (WEEE) was enacted to avoid the disposal of end-of-life consumer devices and setting high recycling targets for the percentages of the products that have to be collected. The WEEE Act specifies 10 different types of electrical and electronic equipment, and each item has a defined recycling and recovery target rate annually. This paper discusses the estimation of proper recycling target rate of WEEE in Korea by using the Monte-Carlo simulation. The simulation was made, based on a number of considerations and input assumptions, including the increased recycling rates by producers, retailers, municipalities and improved recycling policy to be introduced by the government. This study was performed based on the review of recent recycling statistics, available WEEE-related literature, and the conversations with environmental authorities and Korea Association of Electronics and Environment. The Monte-Carlo simulation results with iterations of 100,000 showed that in 2017 on average approx. 5.15 kg/per capita of WEEE with 5% percentile 4.58 kg/per capita and 95% percentile 5.79 kg/per capita are expected to be recycled, while on average 3.69 kg/per capita of WEEE with 5% percentile 3.51 kg/per capita and 95% percentile 3.88 kg/per capita are predicted to be recycled in 2013. Large household appliances with on average approx. 3.72 kg/per capita in 2017 are estimated to be the largest category among the WEEE category, followed by audio and video equipment (0.80kg/per capita/yr) and IT telecommunication (0.45 kg/per capita/yr). In 2014, the national recycling rate of WEEE is expected to be about 4.0 kg/capita, which is the same as the EU average collection and recycling target rate by EU WEEE Directive. Not only electronic industry producers and retailers but local governments and consumers related to WEEE collection and recycling should take more collective actions to promote successful collection and recycling schemes as well as to nationally achieve recycling target rates predicted by this study.

Key Words

Waste electrical electronic equipment, Electronic waste, Recycling, Recycling target rate

전성환 Seong Hwan Jeon , 민경산 Kyung San Min , 소양섭 Yang Seob Soh

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Abstract

This study is an evaluation of a reaction between concrete and TFT-LCD glass during the recycling of TFT-LCD waste glass which is a waste generated from manufacturing TFT-LCD glass as a raw material for concrete pile. Currently, it is difficult to recycle TFT-LCD waste glass, so vast majority of the glass has been buried. Therefore, It is need to recycling technology of the TFT-LCI) waste glass powder, when WT-LCD waste glass powder was used as a raw material for concrete pile in order to develop the recycling technology of TFT-LCD waste glass, excellent physical properties appeared in that concrete pile compared with the existing concrete pile. As a result of analyzing the reason through XRD measurement, physical properties are deemed to have improved because much more C-S-H hydrate is created when added with TFT-LCD glass powder and an activator for reaction. Concerning the C-S-H phase, which is a hydrate, it showed the greatest reaction when added with an appropriate amount of the activator, and the C-S-H hydrate is thought to be created from a pozzolan reaction between Si in TFT-LCD glass and Ca in cement.

Key Words

Recycling, TFT-LCD glass, Concrete pile, Pozzolan reaction