간행물
한국폐기물자원순환학회지 KCI 등재 Journal of Korea Society of Waste Management
- 발행기관 한국폐기물자원순환학회
- 자료유형 학술지
- 간기 연8회
- ISSN 2093-2332 (Print)2287-5638 (Online)
- 수록기간 1984 ~ 2018
- 주제분류 공학 > 환경공학 공학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제31권 제7호 (2014년 10월) 15건
2.
2014.10
서비스 종료(열람 제한)
This study investigated the optimal sequential hydrolysis conditions by comparing with reducing sugar yield ofsequential hydrolysis of Laminaria japonica processing residue. After acid-catalyzed hydrothermal hydrolysis, sequentialenzymatic hydrolysis was performed with single enzymes such as Celluclast® 1.5L, Saczyme, and Alginate Lyase, andtheir mixture. As a result, the yield of reducing sugar by sequential hydrolysis with the mixed enzymes was the highest,but there would be an economical problem with excessive enzyme loading. Therefore, considering the reducing sugaryield and economics, it is thought that hydrolysis by the mixed enzymes has no advantage, thus, using the Celluclast®1.5L in the sequential hydrolysis was practically more appropriate. The optimal sequential hydrolysis conditions ofLaminaria japonica processing residue were determined to be 8% v/w of enzyme injection, 42.6oC of reaction temperature,pH 4.1, and 26 hours of reaction time after acid-catalyzed hydrothermal hydrolysis (0.108 N-HCl, 144oC of reactiontemperature, and 22 minute of reaction time).
3.
2014.10
서비스 종료(열람 제한)
Anaerobic digestion is getting attention by its ability to degrade organic materials and produce energy at the same time.Even though most full-scale anaerobic digesters are operated as continuously fed reactors, laboratory-scale tests for designparameters would be conducted using batch or semi-batch reactors. The objective of this study was to investigate theeffect of different feeding patterns with an identical organic loading rate on the performance of laboratory-scale batchanaerobic digestion reactors. Laminaria japonica was applied as a substrate with 1.5g-VS/L.day of loading rate. Threedifferent types of feeding periods, i.e, 12, 24, and 48 hours, were applied. The reactors were operated at HRT 26.7 days,35±1oC mesophilic anaerobic condition. The methane production rates were 165.10±16.92, 120.74±40.25, and57.81±20.06mLCH4/gVS for feeding periods of 12, 24, and 48hours, respectively. Reactors fed more frequentlyproduced more methane gas and the coefficient of variation was lower. As substrate feeding period increased,concentrations of total volatile fatty acids (VFAs) increased and pH decreased. Finally, the reactor with 48 hours of feedingperiod was failed after 22 days of operation. Consequently, it was shown that feeding pattern may significantly affectperformances of laboratory-scale batch anaerobic digestion reactors and the results from laboratory tests may mislead thedesign of full-scale digesters.
4.
2014.10
서비스 종료(열람 제한)
Waste deposit & refund system was performed in order to recycle the waste since 1992, and this system developedinto the EPR (Extended Producer Responsibility) system since 2003 in Korea. Many products and packaging materialsare recycled by this system, and government published the ‘EPR Practical Manual (2007)’ to estimate the actual recyclingrate. According to styrofoam-buoy (SB) included EPR item in 2010, SB does not practical to estimate the recycling rate,EPS (Expanded Poly-Styrene) was recycled only. So in this study, SB recycling rate also includes ‘EPS+parts’ was toestimate through the field investigation. As a results, parts portion of SB are 3.49% when manufactured, and 2.03% whenrecycled. And process loss, contaminant content, parts portion and yield of EPS ingot are 0.00%, 64.28%, 0.71% and35.01% in SB recycling, respectively. In the future SB recycling rate is calculated by adding the EPS ingot productionand parts recovered.
5.
2014.10
서비스 종료(열람 제한)
This research investigated the feasibility of rice husk (RH) as a biosorbent for the removal of anions from aqueoussolution. RH-g-GMA-Am biosorbent, which possesses anionic exchangeable function, was prepared through graftpolymerization of glycidyl methacrylate (GMA) in the presence of N,N'-methylene-bis-acrylamide as a cross-linker usingpotassium peroxydisulphate as a redox initiator and subsequent amination reaction using ethylenediamine (EDA),diethylenetriamine (DETA), dimethylamine (DMA) and trimethylamine (TMA) as a amine source. Fourier transforminfrared (FTIR) and scanning electron microscopy (SEM) analysis as well as the sorption capacity for anions verifiedthe presence of grafted GMA polymers and amine groups on the RH surface. The zero point of surface potential ofaminated RH-g-GMA-Am sorbent was 6.4, which facilitated the sorption of anions on the positively charged sorbent atpH<6.4. The sorption capacity of RH-g-GMA-Am depending on the amination chemicals increased in the order:DETA≥EDA>DMA>TMA, i.e., primary amine>secondary amine>tertiary amine. The sorption selectivity of RH-g-GMA-Am sorbent aminated with DETA and EDA in the presence of equimolar anions and at pH 4.7 increased in theorder: SO4>PO4>NO3>F. Furthermore, their sorption capacities for PO4 were much higher than those of commercialanion-exchange resins. The results obtained suggest that the RH-g-GMA-Am biosorbent prepared by the GMA graftcopolymerization and subsequent amination can be used as an effective anion-exchanger comparable to commercial anion-exchange resins.
6.
2014.10
서비스 종료(열람 제한)
The objective of this study was to find optimum pretreatment conditions of ozone and microwave for solubilizationof thickened waste activated sludge (TWAS). Response surface analysis was applied to determine the combination of ozoneconcentration (0.03 to 0.1g O3/g total solid (TS)) and microwave temperature (100~170oC). The temperature significantlyaffected the solubilization degree of sludge (p<0.01). Within the design boundaries, the conditions predicted to maximizethe solubilization degree of 41.6% were determined to be 0.065g O3/g TS and 170oC. On the other hand, the solubilizationdegree with the ozone pretreatment alone was 2.7 to 12.2% at 0.03~0.1g O3/g TS. The results show that the combinationof ozone and microwave pretreatments is effective in solubilization of TWAS.
7.
2014.10
서비스 종료(열람 제한)
Wheel tracking test and ice pull-out test were performed in laboratory on dense grade asphalt mixture and asphaltmixture including 2.5% of 19mm PE aggregates. Meanwhile, temperature change, thermal conductivity, and snow meltingspeed were measured for both dense grade asphalt and PE aggregate mixed asphalt pavement via field testing on a testroad. Laboratory test results show that dynamic stability was improved and ice was removed easily by mixing PEaggregates in an asphalt mixture. Moreover, the existence of PE aggregates enhances heat insulation and snow meltingspeed due to the lower thermal conductivity compared to ordinary dense grade asphalt mixtures.
8.
2014.10
서비스 종료(열람 제한)
At present red mud didn't recognized as recyclable resources because of large generation and some problems such asimpermeability, high pH value, aluminium leachate, and causing red water in Korea. In order to recognized as recyclableresources, therefore, we suggest the policy proposals were suggested by reducing the above mentioned problems. In 'WasteManagement Act' similar inorganic sludge which has similar characteristics with red mud is regulated land treatment bymixing with general soil, so red mud should be treated in the same method in order to promote the permeability. Redmud should be neutralized because its pH is very high. It should be careful in neutralized operation because of red watergenerated from red mud. It may be suspected that the red water is contaminated un aesthetic point. To reduce the strengthof red water, red mud is treated to a magnetic process in order to recover the magnetic ferrous material. Through thismagnetic process, ferrous material could be recovered 20 thousand ton per year, and the color intensity reduced to 77.3%.
9.
2014.10
서비스 종료(열람 제한)
The objectives of this research was to evaluate the anaerobic digestibility of waste activated sludge (herein after WAS)and waste beverages (herein after WB) in beverages manufacturing industry using actual plant under various conditions.In this study, anaerobic digestion with WAS and WB were evaluated according to different operating conditions. As thebasis operating conditions for anaerobic digestion, the reaction temperature was controlled at 35 and hydraulic retentiontime 30 days. WAS and WB were mixed at the ratio of 1:0, 9:1, 8:2, 7:3, 5:5, Respectively. The organic loadingrate (herein after OLR) was maintained less than 0.5kgVS/m3·day. Biogas productivity in accordance with VS was fedat the each mixing ratio with WAS and WB was increased from 0.92Nm3/kg VSfeed to 1.28Nm3/kg VSfeed, except mixingratio 5:5 (0.19Nm3/kg VSfeed). Also Biogas productivity in accordance with VS was removed at the each mixing ratiowith WAS and WB was increased from 1.13Nm3/kg VSrem to 1.81Nm3/kg VSrem, except mixing ratio 5:5 (0.35Nm3/kg VSrem). It was judged that pH was reduced with WB addition. From the results, it was judged that anaerobic digestionusing WAS and WB could be feasible.
10.
2014.10
서비스 종료(열람 제한)
In this study the effects of co-digestion of sewage sludge and food waste leachate on the anaerobic digestion efficiencyfrom sewage treatment facilities in S. Korea were investigated. For this study 15 facilities were selected including 9facilities treating sewage sludge only (S-Only) and 6 facilities treating sewage sludge and food waste leachate (S-MIX).The average volatile solid (VS) removal rate of S-Only was 30.7% and that of S-MIX was 45.2%. The COD removalrate of S-MIX (61.3%) was higher than that of S-Only (48.6%). It has been observed that the anaerobic digestion efficiencyof S-MIX was superior to that of S-Only because S-MIX contained more sufficient nutrient with higher VS contents andtotal solid (TS) contents emerging from food waste leachate. Therefore food waste leachate addition in sewage sludgeanaerobic digestion would be the preferred option to treat only sewage sludge.
11.
2014.10
서비스 종료(열람 제한)
Carbon dioxide generated from construction materials and construction material industry among the fields ofconstruction is approximately 67million tons. It is about 30% of the carbon dioxide generated in the fields of construction.In order to reduce carbon dioxide in the fields of construction, it is necessary to control the use of fossil fuel consumedand decrease carbon emission by reducing the secondary and tertiary curing generating carbon dioxide in constructionmaterial industry. Therefore, this study produced an extrusion panel by using cement as the base materials and substitutingbinding materials up to 40% to analyze strength characteristics. According to the results of strength characteristics bythe replacement binder (Low energy curing Admixture) showed an apparent active strength improvement. In particular,specimens substituting binder as 45% indicated the greatest strength improvement. When binding materials was used withsubstitution, it showed strength characteristics similar or higher than specimens made from tertiary autoclave curing assecondary steam curing.
12.
2014.10
서비스 종료(열람 제한)
In this research, chemical vapor deposition equipment built in the semiconductor·CVD (Chemical Vapor Deposition)process was introduced. Through polysulfone hollow fiber membranes under similar conditions to those of the actualprocess, conditions such as flow and pressure were used to observe the influence in order to separate and collect the SF6and CF4 substances. Results showed that as the retentate flow rate of the discharge unit increased and the residence timeto penetrate the membrane decreased, the emission concentration increased. As the pressure of the discharge unit increasedand the exhaust flow decreased, when the retentate flow rate was 10L/min, CF4 was shown to have a density of 4,963ppm, and it was 4,028ppm for SF6 the gas mixture had a concentration effect of three to four ratio. In addition, throughthe separation factor of fluorinated gases that arise in the actual process, the collection and concentration of SF6 and CF4were possible each gas’s recovery rate was higher than 99%.
13.
2014.10
서비스 종료(열람 제한)
Generator’s direct weighing method was applied for investigation of household waste generation. At least 28 days, eachhousehold member measured and recorded the weight of garbage discharged with plastic garbage bag, food waste, andrecyclable waste. Collected garbage record books were used as input data in Microsoft Excel, and statistical analysis weredone with Minitab 16 software. By generator’s direct weighing method for household waste generation, garbage dischargedby plastic bag, food waste, and recyclable waste were 130.5, 98.2, and 187.9g/capita/day, respectively. Difference inaverages of per capita garbage discharge between Seoul, Gyeonggi, Incheon, and Chungbuk were no statisticallysignificant. And as the number of house member decrease, per capita garbage discharge increase numerically, but therewas no statistically significant.
14.
2014.10
서비스 종료(열람 제한)
Hydrochlorofluorocarbon (HCFC) is an ozone-depleting substance that is subject to environmental regulations based onthe Montreal Protocol, and in Republic of Korea, which is regarded as a developing country, its use will be restricted inphase starting in 2013 until finally being prohibited in 2030. HCFC is regulated Based on the Tokyo Protocol, HCFC isa regulated construction material for carbon dioxide reduction with GWP of 1,700~2,400 times that of CO2, with a GWPof 1. Using the CO2 in the heat insulating material in the extrusion process conditions are the first extruder, the polystyreneresin (melting point) and the blowing agent (CO2:Ethanol:HCFC) as interval (Mixing zone) which is the combinedpressure 11.0MPa, temperature 200oC, second within the extruder discharge pressure 6.5 MPa, and determines that it isdesirable to set the temperature of 115oC, the blowing agent mixing ratio (CO2:Ethanol:HCFC), taking into account thestability of the thermal conductivity of 30:20:50%, 25:25:50% is expected to be utilized in the foaming agent.
15.
2014.10
서비스 종료(열람 제한)
Agriculture is not only sources, but also sinks of GHGs through removal or sequestration of carbon and methane. Therehave been many efforts around the world to improve agriculture’s ability to sequester GHGs and to seek ways for economicbenefits through the emissions reduction project. Specially, animal waste management system and biogas plants have beenuseful to environmental policies in agriculture sector. The objectives of this study were to analyze the CDM project currentsituation in agriculture sector and draw a implications from its analysis. As a result of the investigation, strategies andprocedures are suggested to link agricultural policies to the CDM projects to create economics opportunities for the koreanagriculture. So it will be useful, a strategy to raise the economic feasibility of a rural area’s animal waste managementsystem and biogas plant project should consider to develop domestic technologies of biogas digester. Also, localgovernment, local college, rural communities should agree to closely work together to resolve the national’s greenhousegas reduction issue.
