• IE interfaces
• /
• v.20 no.2
• /
• pp.154-161
• /
• 2007

When the electrical appliances such as TVs and refrigerators become obsolete, they must be collected to the recycling centers to avoid environmental damages. The obsolete home appliances are first moved to the regional collection point; and then transported to one of the recycling centers. Each recycling center has a limited capacity; and some recycling centers can process only certain types of products. For given locations of the existing collection points and recycling centers, optimally assigning the obsolete home appliances of each type from each collection point to the recycling centers can significantly reduce the total transportation cost. We formulate this problem as an LP problem. We also present an approach to determine the locations of additional recycling centers in order to alleviate the over-utilization of the current recycling centers.

• Resources Recycling
• /
• v.20 no.1
• /
• pp.3-13
• /
• 2011

Taiwan's annual steel production reached 21.29 million tons. EAF accounted for about half of this total, or 11.2 million tons in 2008. The other 10.09 million tons came from blast furnace and converter process methods. The annual EAF carbon steel production is about 9.76 million tons, and the quantity of dust generated from the EAF process is 160 thousand tons, or about 16kg of dust per ton of steel was produced. In 2009, there is Walez process for carbon steel EAF dust recycling, and the capacity is about 70,000 tons per year; and there is RHF/SAF process for stainless steel EAF dust, the capacity is 60,000 tons per year which is enough to treat stainless steel EAF dust in Taiwan. There are many new treatment facilities processes will be that introduced to recycle the EAF dust in the near future, these processes will perform smoothly and successfully in Taiwan. The estimation of recycled crude ZnO is about 90,000 tons each year. The recycling and upgrading crude zinc oxide will be the next important issue in Taiwn zinc and steel industry.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.24 no.3
• /
• pp.15-21
• /
• 2016

This experiment was conducted to test desorption and recycling characteristics for silver ion adsorbed into waste coffee grounds by using various desorbing agents such as nitric acid, ethylene diamine triacetic acid (EDTA) and nitrilo triacetic acid (NTA). It is appeared that the highest desorption efficiency for silver ions was obtained as about 97.8 % by 1.0 M of nitric acid solution. Also, in the case of less than 1.0 of the ratio of solid and liquid (S/L) (g/L), silver ions adsorbed onto coffee grounds was desorbed as about 98~100 %, and most of desorption process was completed within 60min. In addition, adsorption capacity of reused waste coffee grounds for silver ions was highly maintained as about 43.9 mg/g until the $2^{nd}$ cycle, as compared with the adsorption capacity with 45.9 mg/g of the adsorption capacity for virgin waste coffee grounds.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.04a
• /
• pp.206-209
• /
• 2001

This study presents the leaching characterization of heavy metals according to changes of pH by ANC test on slag produced in electric arc furnace, bottom ash produced in coal-fired plants and their recycling products. Availability test was performed to assess the fraction of the total concentration that under worst environmental conditions could become available for leaching. TCLP, KLT(Korea Leaching Test) and KLTS(Korea Leaching Test of Soil contamination) were carried out to compare the leaching capacity and to estimate the adequacy of regulatory leaching test. Results from regulatory leaching tests could be misleading because the variable ANC of wastes can lead to very different final leachate pHs. The final pH of the regulatory test is not the ambient pH in the disposal environment, the actual solubilities of contaminants in the field may be entirely different from those predicted by these regulatory tests. Leaching behaviour of by-products was changed by recycling processes, therefore acid neutralization capacity and availability of new products, not leaching concentration by one batch regulatory test, are necessary to determine the method of recycling.

• Journal of the Korea Safety Management & Science
• /
• v.13 no.4
• /
• pp.193-199
• /
• 2011

In the past annual recycling obligation rate calculation of Extended Producer Responsibility (EPR) system, it was difficult to operate the system efficiently, because responsible producers passively participated in the scheme only bent on achieving annual obligation without long-term plan. Thus, a new scheme of long-term recycling obligation rate began to be established every five year from 2008 in order to give the basis for the notice of annual specific operation standard and recycling obligation, thereby helping responsible producers to make a preparation with a plan and giving expectation of active operation of the scheme. However, in the operation of long-term recycling target program, while the development of prediction models and the evaluation for existing items has been conducted in various ways, applications for a new target items and the evaluation are quite insufficient. Therefore, in this study, problems in implementing long-term recycling goal of new target items will be examined, and more objective and rational long-term recycling rate calculation and the operation standard will be proposed. Thus, the long-term recycling target will play a role as a pacemaker to steadily improve the recycling performance of target items, and responsible producers will be expected to increase the achievement with the realistic capacity.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.31 no.2
• /
• pp.34-41
• /
• 1999

Adsorption of cationic polyacrylamide dry strength resins onto the surface of papermaking fibers and fines is critical for their effective utilization. Since dry strength resins are frequently employed when recycled fibers containing a great deal of fines are used as a raw material, their adsorption characteristic onto the recycled fiber fines is of great importance. In this study, effects of recycling on adsorption characteristics of cationic polyacrylamide onto primary and secondary fines were examined. Never dried bleached hardwood kraft pulp was beaten and dried for recycling. In each recycling step the adsorption characteristic of a cationic PAM onto primary and secondary fines was evaluated by kjeldahl nitrogen analysis method. The influence of recycling on water retention value and carboxyl content along with the sheet density and tensile strength was examined. Secondary fines of never dried pulp adsorbed twice as much of C-PAM as the primary fines, however, the adsorption capacity of the secondary fines decreased rapidly during the course of recycling and showed lower adsorption capacily than primary fines.

• Journal of the Korean Society of Safety
• /
• v.20 no.2 s.70
• /
• pp.105-112
• /
• 2005

This is to find out that cement mortar mixed with waste tie particle can be applied for recycling it and enhanced to have shock absorption capacity. Therefore, architectural material specification and its related references for the disposal of it are based on for the study. Test has been performed with procedure, based on the Korea Standard insulation mortar and Compressive Strength Test has been done at K remicon factory approved by Korea Government in Korea, in order to decrease any possible error in mixing procedure. Test molds far insulation capacity and cohesive strength have been delivered to the expert agency for having more exact results. The result from the above test shows that waste tyre mixed with cement mortar has almost equal to the common concrete. This means that the recycling of the waste t)re will be demanded more and more in case of having continued development for this recycling area. And also waste t)to-using construction material can be more applied for construction area than existing material. Thus, this recycling method can be very usefully applied for solving environmental problem and for establishing economic aspect.

• Journal of the Korean Society for Railway
• /
• v.12 no.4
• /
• pp.481-487
• /
• 2009

On the paved track, the railway ballast is used as aggregate for the filling layer using the pre-packed concrete method. The condition of ballast as the paved track aggregate ensure that the compressive strength, particle distribution size for the pouring and surface clearance to increase the adhesive strength with mortar. It is profitable to recycle the existing railway ballast as a economical supply. In order to increase recycling characteristic, it is necessary to apply the similar criterion which does not exceed the conventional railway ballast criterion. Consequently, this paper was to investigate physical characteristics of existing ballast, particle size distribution, compressive and flexural strength, bearing capacity and filling capacity to prepare the aggregate's recycling. As a result, optimized aggregate criterion is suggested.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.24 no.2
• /
• pp.31-39
• /
• 2016

Due to the temporal variation of inflow/outflow, the water tank is needed. For the calculation of water tank capacity, the absolute difference between cumulative amounts of supply(e.g., rainfall) and demand(e.g.,watering) is used. No matter the (-) and (+) the absolute maximum capacity of the subtraction is calculated as the capacity. In this paper, using rainfall and watering of greenhouse facilities, it is proved that the non-linear supply or demand can be applied, and it is proved also that the greater non-linear variation case. And as the time interval for monitoring is decreased, the basin or tank volume are increased, with approximately 10 days as the critical monitoring interval for the annual natural rainfall event.

• Journal of Environmental Impact Assessment
• /
• v.17 no.5
• /
• pp.311-320
• /
• 2008

Reusing livestock manure have various advantages in securing soil organic resources, and since the costs needed for converting them into liquefied fertilizers are relatively moderate compared to normal treatment, such methods are necessary. In this study, the Recycling Capacity Assessment of Gyeonggi-do was carried out by comparing between the fertilizer demands for specific crops based on the cultivation areas and the amount of fertilizer resources that are generated from livestock manure. From this assessment, the possibility of obtaining resources by converting livestock manure into fertilizers were evaluated. The amount generated of Livestock Manure in Gyeonggi-do were evaluated by applying the emission units to the number of livestock manure. And from the amount generated of Livestock Manure, the amount of fertilizer produced from Livestock Manure were calculated by using the fertilizer a component rate. When considering the amount of fertilizer produced from Livestock Manure based on the type of livestock, N 6,626 ton/year, $P_2O_5$ 1,824 ton/year, $K_2O$ 4,480 ton/year were produced from milk cow manure, while N 5,247 ton/year, $P_2O_5$ 2,772 ton/year, $K_2O$ 2,879 ton/year, were produced from beef cattle manure. N 14,924 ton/year, $P_2O_5$ 7,205 ton/year, $K_2O$ 6,750 ton/year were produced from pigs and N 12,651 ton/year, $P_2O_5$ 4,458 ton/year, $K_2O$ 5,542 ton/year were produced by chickens. So the total amount of fertilizers that can be obtained from livestock manure were 3,668 ton/year Nitrogen, 16,259 ton/year phosphate and 19,651 ton/year kalium. And the total fertilizer demands in Gyeonggi-do were Nitrogen 27,200 ton/year, Phosphate 8,853 ton/year, and kalium 13,211 ton/year respectively. Nitrogen which had higher demands than production quantities were considered as limitation factors in crop growth. So the Recycling Capacity Assessment was carried out mainly based on Nitrogen. Since the Nitrogen quantities that can be provided by recycling livestock manure were 3,532 ton/year lesser than the Nitrogen demands, it is estimated that it would be desirable to convert livestock manure into resources. But in order to properly convert the entire livestock manure into organic resources, the seasonal situation that effects the nitrogen demands of crops along with the regional effects due to the industrial structures should be seriously analyzed. In addition, a system that can effectively produce and manage fertilizer should be established.