• Journal of the Korea Organic Resources Recycling Association
• /
• v.13 no.3
• /
• pp.97-104
• /
• 2005

In this study, the change of water content, pH, and combustion weight on the decomposition of poly ester vinyl and high density poly ethylene were examined. The poly ester vinyl was degraded by microorganism in food wastes for 30 days, while high density poly ethylene vinyl was not degraded. Also, the poly ester vinyl was rapidly degraded after the 10 days of operation and its weight was decreased. In the combustion reaction between $300^{\circ}C$ and $600^{\circ}C$, complete combustion was performed. Due to the degradation of poly ester vinyl by microorganism in food waste, the pH was increased from 4.26 to 7.6. During of 60 days operation, poly ester vinyl was degraded over 90%.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.11 no.2
• /
• pp.66-73
• /
• 2003

To investigate the availability of solidified wastes as resource, wastewater sludge, waste gypsum and fly ash were mixed and the results with various mixing ratios are as follows. Compressive strength turned out to be increasing as the amount of waste gypsum increases, keeps longer curing inhibition, and higher forming Pressure under the conditions of waste gypsum/sludge ratio 0.31-0.45, and 0.9kg cement as 15% and 1.2kg cement as 20% of total amount. Solidified agent under the fly ash/sludge ratio 0.45, 0.6, compressive strength seemed to be higher than standard one which means solidified wastes with these conditions could be applicable in real life. These results inform that concentrations of the leachate $Cr^{+6}$, Cu, Zn, Cd, Pb solidified matrix, containing low concentration of heavy metal, were cured with/without enough time it still will cause adverse effect on nature environment and application of heavy metal sequester must be needed to reuse industrial wastes from incineration plant solidified matrix. Total cost price, when considering manufacturing capability of the facilities for resourcerizing as 18,000ton was presented 678,664,000 won, as it were, manufacturing cost price was 37,704 won per ton. The results as above has shown that it's possible to use the mixture of waste gypsum/sludge, fly ash/sludge, cement, additions, and solidification matter as substitute of materials like brick, block, interlocking which has proper compressive strength of KS L 5201 and KS F 4004.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.8 no.1
• /
• pp.97-102
• /
• 2000

This study was carried out to investigate the effects of operating temperatures on decomposition and physicho-chemical properties of household food wastes in a fermentation dryer, which was manufactured by Samwoo Co. Ltd. The household food wastes of 100 kg can be put and dried in this dryer at once. The experiments were performed at each temperature of $35^{\circ}C$, $45^{\circ}C$, $55^{\circ}C$ and $70^{\circ}C$ for two days respectively. The samples taken at the fixed time were dried at $105^{\circ}C$ and analyzed to find the decomposition rate and the concentration of each substance. The results obtained were as follows: The decomposition rate at 35 and $70^{\circ}C$ was the highest and showed the similar tendency during the experimental period. The higher the operating temperature was, the faster the water content of the composting material reduced. pH value increased at the operating temperature of 55 and $70^{\circ}C$ and was higher than at the other operating temperatures. Nitrogen content did not show any tendency during the experimental period. $P_2O_5$ and CaO content increased during the experimental period but MgO, $K_2O$ and NaCl were not accumulated. Cu content based on dry matter was in the range of ND~100.4 mg/kg and Cd, Pb and Cr were not detected.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.11 no.1
• /
• pp.101-101
• /
• 2003

본 연구는 남은 음식물을 유산균을 이용하여 발효 사료화 하기 위해 실시하였다. 발효를 촉진시키기 위한 균주로는 Lactobacillus acidophilus를 사용하였고 최적의 발효조건을 갖는 공기 주입량을 알아보기 위해 시료의 발효 조건을 각각 달리 하였다. 시료는 교반하지 않고 공기주입 또한 없는 혐기적 조건의 것과 50rpm의 속도로 교반하면서 0.25v.v.m의 공기를 주입한군, 70rpm의 속도로 교반하면서 0.5v.v.m의 공기를 주입한 군으로 나누었다. 시료는 모두 $37^{\circ}C$로 유지하면서 48시간 발효 시키며 12시간 단위로 시료를 채취하였다. p.H와 유기산함량, 환원당함량과 유산균수를 측정하여 남은 음식물을 발효시키기 위한 최적의 공기 주입량을 알아보았다. 실험결과 50rpm 0.25v.v.m에서 가장 낮은 p.H를 보여주었고 유기산 함량과 환원당 함량은 70rpm 0.5v.v.m에서 가장 높은 함량을 보였다. 유산균은 50rpm 0.25v.v.m에서 가장 많은 증식되었음을 보여주어 적절한 공기의 주입이 남은 음식물의 발효를 촉진하는 것으로 보여진다.

• Resources Recycling
• /
• v.21 no.3
• /
• pp.65-73
• /
• 2012

There are several kinds of displays such as liquid crystal display (LCD), cathode ray tube (CRT), plasma display panel(PDP), light emitting diode (LED), organic light emitting diode (OLED), etc. Nowadays, recycling technologies of waste displays have been widely studied from economy and efficiency points of view. In this paper, patents and literature on the recycling technologies of the waste displays have been comprehensively analyzed. The search was limited to the open patents of USA (US), European Union (EU), Japan (JP), and Korea (KR) and SCI journals published from 1980 to 2011. Patents and journals were systematically compiled and collected using key-words search and filtered by pre-set filtering criteria. The trends of the patents and journals were thus analyzed according to the years, countries, companies, and technologies.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.20 no.1
• /
• pp.31-40
• /
• 2012

In order to making resources for the organic wastes, it is very important to understand for the life cycle of wastes before the physicochemical analysis and engineering technology. Therefore we try to fine the solution through the interdisciplinary consilience between natural science and social science for the management of refuge in summer resort. Summer visitors of beach answered that fly tipping of refuse was 65.56% and insufficient separation was 17.78% about the survey. But insufficient separation was 42.5% and fly tipping was 37.5% in valley. The survey for the effective methods at reducing refuse was represented that campaign and teaching was 47.78%, fine was 23.33% and using the standard bags was 18.89% in beach. Campaign and teaching was 37.5%, using the standard bags was 37.5% and fine was 15% in valley. Bulk density of refuse in gyeongpo beach was measured in $74kg/m^{3}$. This value was three times as much low than municipal solid wastes. Moreover, the composition of refuses in beach showed that combustible materials was 81.1% and incombustible materials was 18.9%. Moisture, ash and combustibles were analyzed 19.0%, 9.2% and 91.8% respectively.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.28 no.1
• /
• pp.15-25
• /
• 2020

Biogas production potential was experimentally estimated for mono- and co-digestion of cow manure and waste grass. The two organic wastes were mixed at five different ratios (100:0, 75:25, 50:50, 25:75, 0:100) on the volatile solids basis, and were assessed using biochemical methane potential (BMP) test. Thee reaction temperatures, 25℃, 30℃ and 35℃, were applied as well, resulting in 15 different combinations for the test. The results showed that both higher temperature and waste grass mixing ratio resulted in higher methane yield and maximum methane production rate. Based on the experimental results, a theoretical farm- or community-scale (240 or 2400 ㎥) anaerobic digester was designed to evaluate the energy balance associated with mono- and co-digestion of the wastes at different temperatures. Although the energy production increased as the temperature and the waste grass mixing ratio increased, the net energy gain, energy production subtracted by energy consumption for heating and maintenance, was estimated to be the highest at 30℃, followed by at 35℃ and 25℃. Therefore, it is advised that both the experimental methane production and the detailed design parameters must be considered for the optimization of the net energy gain from these wastes.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.7 no.1
• /
• pp.13-21
• /
• 1999

The purposes of this research were to evaluate the character of laboratory wastewater, and to examine the utilization of waste egg shells for neutralization and removal of heavy metals. Waste egg shells are excellent at neutralizing acidic wastewater, because they have alkaline minerals such as calcium. It must be seemed that removal rate of heavy metals were very influenced by adsobent dosage and adsorbate concentrations, because waste egg shells acted as precipitation and adsorption. If we reflected the adsorption capacity(k) and adsorption(1/n) of Freundlich isotherm, we couldn't consider waste egg shells as a good adsorbent. In view of these results, it showed that wastes containing the similar compositions as waste egg shells could utilize the neutralization, precipitation and adsorption of heavy metals in laboratory wastewater.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.25 no.3
• /
• pp.63-71
• /
• 2017

In this study, washing parameters such as washing time, agitation velocity, and cycles were optimized for high surface area of the activated carbon (AC) by KOH activation. Even though AC with high surface area showed at higher washing efficiency, over 90% on washing efficiency was regulated by the intra-particle diffusion due to high tortuosity of the pore structures on AC. In addition, we can obtain $K_2CO_3$ through the evaporation from the wastewater and use it for chemical activation of AC. The AC with $K_2CO_3$ activation has specific surface area values of $2,219m^2/g$ equally that of KOH activation. Considering that $K_2CO_3$ is an effective alternative as a KOH, our results demonstrated that the process by recycling wastewater on AC production could be applicable for near-zero wastes.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.3 no.2
• /
• pp.47-57
• /
• 1995

The purpose of this study was to investigate the effect of mechanical mixing intensity on composting. The major parameters investigated were the mixing intensity and initial moisture content. Laboratory scale composting reactors with mixing equipment were used in this study. Wastes used for the study were raw nightsoil sludge, nightsoil sludge after vacuum evaporation treatment and pig manure. When moisture contents were 60% and 63%, amount of organic material degraded in the continuous mixing reactors was higher than that in the intermittent mixing reactors. Compost produced from reactors with continuous mixing had better texture than that obtained from reactors with intermittent mixing. When moisture content was 68%, organic waste was kneaded rather than mixed in the continuous mixing reactors. Amount of organic material degraded in the continuous mixing reactors also was lower than that in the intermittent mixing reactors.