• Applied Chemistry for Engineering
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• v.20 no.2
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• pp.223-226
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• 2009

In this study, we investigated the recovery of copper and synthetic fuel from the waste wire by low temperature pyrolysis which can overcome problems of the recent incineration methods. Through thermal decomposition process of waste wire, we achieved the big advantage of getting usable resources as the forms of copper and fuel with a very high value. The TG/DTA and small-scale reaction experiments were carried out to determine an optimum temperature for waste wire pyrolysis. And the pyrolysis was done at 350, 450, and $550^{\circ}C$, respectively, and heating rate of the TG/DTA was $5^{\circ}C/min$ untill $700^{\circ}C$. The result shows that the optimum temperature range for dehydrochlorination of PVC was $280{\sim}350^{\circ}C$, as a lower temperature range than $400{\sim}550^{\circ}C$ of PE and PP. Practically over 95% of copper metal and synthetic fuel, which has the 8027 kcal/kg as a calorific value, were recovered from the waste wire samples.

• Journal of Environmental Science International
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• v.5 no.6
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• pp.785-799
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• 1996

The incineration tests of mixed industrial wastes using the stoker type incinerator are carried out to investigate the partitioning characteristics of heavy metals during incineration. The results obtained from this study are as follow. The partitioning characteristics of heavy metals throughout this incinerator are found that, at given condition of $700^{\circ}C$, the elements with the relatively high boiling point such as Cr, Cu and Pb are partitioned into a bottom ash, a fry ash captured tv cyclone, and a flue gas stream, 67~88%, 2~19% and 6~16% of initial amount entering the incinerator, respectively, but the Cd and Hg of 75~81% is vaporized into the flue gas. It appears that the partitioning characteristics according to the particle size of ash is different between the bottom ash and the fly ash. For bottom ash, the fraction of partitioning into 75${\mu}{\textrm}{m}$ oversized particles is reatively high. For fly ash, the characteristics of distributions with the particle size can not be clearly shown.

• Solar Energy
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• v.18 no.3
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• pp.169-175
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• 1998

Metal hydrides can be used for the purpose of heat storage and transportation from the industrial complex which own recoverable waste heats to the neighboring cities by the medium of hydrogen. The properties of metal hydrides, some problems of heat transportation using metal hydrides, and the example of heat transportation system were discussed.

• Economic and Environmental Geology
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• v.28 no.5
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• pp.469-480
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• 1995

Gravity and magnetic surveys were carried out to investigate the three-dimensional configuration and characteristics of the landfills at Nanjido waste disposal site. For terrain correction and three-dimensional density inversion of gravity data an algorithm, which calculates the gravity effect of a three-dimensional body by using the solid angle method, is developed. This algorithm has been proved to give more accurate terrain correction values for the small survey area having varied topography like Nanjido site as compared with widely used methods such as Hammer's method and multiquadric equation method. Density inversion of gravity anomaly data gives very useful information about the lateral and vertical variation of the landfills, which can be used to discriminate the kinds of wastes. The average density of filled materials appears to be $1.7\;g/cm^3$ which is much higher than the value $(0.8\;g/cm^3)$ estimated by Seoul City. The lateral variation of density shows high correlation with the pattern of ongoing depression of the landfills. The northern region of the landfill no. 1, which shows low density and high depression, is closely associated with the industrial waste and sludge filled area. The magnetic anomaly data provide information about relative concentration of magnetic materials, which is also very useful to investigate characteristics of the fills. Several high positive anomaly regions on the reduced-to-pole magnetic anomaly map are appeared to be associated with the industrial waste fills, but certain industrial waste fills show low negative anomalies. This kind of magnetic information can be used in selecting drilling locations over landfills away from buried metal products during the stabilization process.

• Journal of Microbiology and Biotechnology
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• v.23 no.7
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• pp.1004-1014
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• 2013

Six nonpathogenic fungal strains isolated from alkaline soils of Buenos Aires Province, Argentina (Acremonium murorum, Aspergillus sidowii, Cladosporium cladosporoides, Neurospora tetrasperma, Purpureocillium lilacinum (formerly Paecilomyces lilacinus), and Westerdikella dispersa) were tested for their ability to produce keratinolytic enzymes. Strains were grown on feather meal agar as well as in solid-state and submerged cultures, using a basal mineral medium and "hair waste" as sole sources of carbon and nitrogen. All the tested fungi grew on feather meal agar, but only three of them were capable of hydrolyzing keratin, producing clear zones. Among these strains, P. lilacinum produced the highest proteolytic and keratinolytic activities, both in solid-state and submerged fermentations. The medium composition and culture conditions for the keratinases production by P. lilacinum were optimized. Addition of glucose (5 g/l) and yeast extract (2.23 g/l) to the basal hair medium increased keratinases production. The optimum temperature and initial pH for the enzyme production were $28^{\circ}C$ and 6.0, respectively. A beneficial effect was observed when the original concentration of four metal ions, present in the basal mineral medium, was reduced up to 1:10. The maximum yield of the enzyme was 15.96 $U_c/ml$ in the optimal hair medium; this value was about 6.5-fold higher than the yield in the basal hair medium. These results suggest that keratinases from P. lilacinum can be useful for biotechnological purposes such as biodegradation (or bioconversion) of hair waste, leading to a reduction of the environmental pollution caused by leather technology with the concomitant production of proteolytic enzymes and protein hydrolyzates.

• Journal of Powder Materials
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• v.23 no.4
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• pp.325-330
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• 2016

Owing to increasing demand of rare metals present in ICT products, it is necessary to promote the rare metal recycling industry from an environmental viewpoint and to prevent climate change. Despite the fact that information for toxic substances is partly indicated, a legal basis and an international standard indicating usage of rare metals is insufficient. In order to address this issue, a newly created study group of environment and climate change at the ITU (International Telecommunication Union) is doing research to develop methodologies for recycling rare metals from ICT products in an eco-friendly way. Under this group, the Republic of Korea has established two international standards related to rare metals present in ICT products. The first is 'Release of rare metal information for ICT products (ITU-T L.1100)' and the other is 'Quantitative and qualitative analysis methods for rare metals (ITU-T L.1101)'. A new proposal for recommending the provision of rare metal information through a label by manufacturers and consumer/recycling businesses has been approved recently and is supposed to be published later in 2016. Moreover, these recommendations are also being extended to IEC, ISO and other standardization organizations and a strategy to reinforce the ability for domestic standardization is being established in accordance with industrial requirements. This will promote efficient recycling of rare metals from ICT products and will help improve the domestic supply of rare metals.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.4
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• pp.51-58
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• 2008

This paper presents the effect of acid treatment on the removal of metals and the brightness of pulp. The bleached kraft pulps, metal-absorbed pulps and recycled pulps((ONP, OCC, MOW, and SC) were treated with the acidic solutions. Among metals in the bleached kraft pulps, Cu, Ca and Mg were removed easily by the acid washing, whereas Fe, Al and Si were not removed. The acid washing also removed distinctly metals from the metal-absorbed pulps. The metals absorbed in pulps reduced the brightness (%, ISO). Especially, Fe was the most detrimental metal. However, the brightness which was decreased by metals was restored to the status quo by the acid washing. The level of metals in recycled pulps was gradually reduced after the first flotation and acid treatment. Hence, the degree of metal removal by the acid washing was mainly dependent upon the kinds of waste pulps and metal ions.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.56-64
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• 2019

Various approaches have been attempted to develop recycling technologies related to industrial waste resources containing metals. Among them, glass is not decomposed into microorganisms, so landfill is not suitable, and interest in the recycling of waste glass is increasing. In this paper, by incorporating chelate resin to suppress the elution of heavy metals in waste glass and using waste glass as a fine aggregate and we want to evaluate the strength, drying shrinkage, alkali-silica reaction and heavy metal leaching of shielded filler materials and to provide basic data for utilizing waste glass as an economical and environmentally friendly shielding filler. As a result of the test, it was found that the use of waste glass as a fine aggregate was effective in the development of strength, but the incorporation of chelate resin had an influence on the strength development. In addition, the addition of chelate resin was effective in improving drying shrinkage but it was found to affect the alkali - silica reaction. As a result of the heavy metal leaching test, the KSLP test method satisfies all the criteria for heavy metal leaching. However, in case of lead, the limit of US ANSI 67-2007a was exceeded and further study should be done.

• Journal of Animal Environmental Science
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• v.15 no.1
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• pp.59-68
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• 2009

This study investigated the evaluation of maturity, stability, nutrient and heavy metal from rotating drum composter of food waste amended with poultry manure composting inoculated with effective microorganisms(EM). Composting were performed for the first, drying reactor($15m^3$) 3 hours and the second, composting reactor($30m^3$) 24 hours, and parameters monitored this period included moisture content, NaCl, pH, electrical conductivity(EC), C/N ratio, organic matter(OM), nutrient content and heavy metal. Changes in compost temperature during composting were maintained constantly in the range of $60{\sim}80^{\circ}C$ using firewood boiler(450 MJ/h). We examined physicochemical parameters and heavy metals in order to assess their effectiveness as stability and maturity, nutrient and harmful indicators such as seed germination rate<60%, potassium 1>%, dm and NaCl>1%, dm at the end of the final compost. The finished compost obtained after decomposition phase at the end of the 2nd composter could not be utilized for land improvement or reclamation.

• Ocean and Polar Research
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• v.25 no.4
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• pp.447-457
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• 2003

In order to understand the distribution of changes of geochemical characteristics in surface sediments according to various environmental changes around the artificial Lake Shihwa, surface sediments were sampled at $13{\sim}15$ sites form 1997 to 1999 and analyzed by C/S analyzer, ICP/MS and AAS. The average $S/C_{org}$ ratio was 0.35 in the surface sediments, which is similar to 0.36, the characteristic ratio of marine sediments. Heavy metal contents and enrichment factors in the surface sediments tended to be decreasing from the head to the mouth of the Lake Shihwa. With the deposition of fine-grained sediments in the central part of lake, anoxic water column induced the sulfides compounds with Cu, Cd and Zn. Metals such as Al, Fe, Cr, Co, Ni, Cu, Zn and Cd except for Mn and Pb showed relatively high correlation coefficients among them. The contents of Cr, Co, Ni, Cu, Zn and Cd in the surface sediments of the lake were two to five times higher than those in the lake before dike construction and also in outer part of the dike. These are mainly due to the Input of untreated industrial and municipal waste-waters into the lake, and the accumulation of heavy metals by limitation of physical mixing. Although metal contents of the surface sediments at the sites near the water-gate due to outer seawater inflow tended to be lower than those during the desalination, heavy metals were deposited in areas around the new industrial complex in the evidence of spatial distribution of heavy metals in the sediments. This is mainly due to the input of untreated waste-waters from tributaries.