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Palm kernel shells (PKS), empty fruit bunches (EFB), and trunks are by-products of the palm oil industry and form approximately 50 wt % of fresh fruit bunch (FFB). In particular, EFB accounts for approximately 20 wt % of FFB. Although large amounts of EFB are generated from palm oil mills every year in Indonesia and Malaysia, EFB is treated as waste because commercial technologies for thermo-chemical conversion of EFB into renewable energy are still under development. A robust conversion method can transform EFB into an appealing renewable energy source. In order to secure this renewable energy source, Korea can import EFB as biomass. This paper investigates literature on the status of utilization of EFB, by-products from palm oil mills in order to identify the best available technological process to use EFB as bio-solid refuse fuels (SRF). Meanwhile, physico-chemical analyses (proximate, elemental, and calorific value analyses), biomass and heavy metal content were measured in order to assess whether EFB would be suitable for use as a bio-SRF, in accordance with the Korean quality standard for SRF. According to the analysis results, EFB showed applicability to use as bio-SRF; main analysis results - moisture (9.63 wt %), ash (5.94 wt %), biomass content (97.82 wt %) and calorific value (3668 kcal kg).

We mix food waste leachate and sewage sludge by the proportion of 1:9, 3:7 and 5:5. It turns out that they produced 233, 298 and 344 CH4⋅mL/g⋅VS of methane gas. The result suggests that as the mixing rate of food waste leachate rises, the methane gas productions increases as well. And more methane gas is made when co-digesting sewage sludge and food waste leachate based on the mixing ratio, rather than digesting only sewage sludge alone. Modified Gompertz and Exponential Model describe the BMP test results that show how methane gas are produced from organic waste. According to the test, higher the mixing rate of food waste leachate is, higher the methane gas productions is. The mixing ratio of food waste leachate that produces the largest volume of methane gas is 3:7. Modified Gompertz model and Exponential model describe the test results very well. The correlation values(R 2 ) that show how the results of model prediction and experiment are close is 0.92 to 0.98.

PURPOSES : This study is to investigate the fundamental properties of limestone added cement concrete for application of pavement. METHODS : As the production of Portland cement causes environmental problems, engineers have sought more environment-friendly concrete construction materials. Limestone powder can be used for concrete as a partial replacement of Portland cement. One of the great applications of limestone powder added cement concrete might be a cement concrete pavement since the concrete pavement consumes massive quantity of Portland cement. Experimental variables were different replacement level of limestone powder by 0% to 25% with 5% increment. Before hardening of fresh concrete, setting time and plastic shrinkage characteristics were investigated in addition to other basic properties. Properties of hardened concrete included compressive, tensile and flexural strength as well as drying shrinkage. RESULTS : The addition of limestone powder did not significantly affect the properties of fresh concrete. Strength deceased as the replacement ratio increased and when the replacement ratio was greater than 10% decrease rate increased. CONCLUSIONS : It was found that the partial replacement of the limestone powder to cement in pavement materials can be positively considered as its mechanical properties show comparable performance to those normal concrete.

Human keratinocytes are generally cultured in media containing bovine pituitary extract (BPE), an animal product that can be a source of infectious contaminants. We investigated whether a safer plant product could replace BPE in the culture medium. Medium containing both BPE and soy protein hydrolysates (Bacto Soytone and Soy Hydrolysate) produced the largest number of viable cells, followed in descending order by medium supplemented only with BPE, only with the hydrolysates, and without supplementation (basal medium only). Soybean protein is thus an excellent source of nutrients for the growth of adherent keratinocytes, although they do not fully substitute for BPE.

End-of-life vehicles are dismantled to recover reusable parts and then sent to a shredding facility for steel material recovery. The residue generated from the shredding process, so-called automobile shredder residue, is now being mostly disposed in landfill, however landfill will be prohibited in the near future. More recycling and energy recovery must be made by the regulation. The most appropriate method is the thermal treatment that will produce various forms of fuels and less volume of vitrified residue. In this research, an automobile shredder residue was simulated with considering the residue from a shredding factory based on the new vehicle and thermally treated by pyrolysis or gasification to observe the yields of gas, oil and char. In the temperature range of 400-800 degrees C, the yields of gas, oil, and char were 38.7-45.8%, 12.3-18.2%, and 36.0-49.0%, respectively. The optimum pyrolyzing temperature for more oil production was around 600 degrees C. Emission characteristics of the byproducts, PCDDs, PCDFs and dioxin-like PCBs were studied at the temperature of 600 degrees C. The analysis on the concentration and distribution of the isomers in various forms of the products were completed with and without oxygen, PVC, and catalytic metals, in order to observe how the existence of oxygen, PVC, and catalytic metals affect the formation of PCDDs, PCDFs, and dioxin-like PCBs from pyrolysis or gasification process. Without PVC, no PCDDs, PCDFs and dioxin-like PCBs were found in any products. PCDFs were predominant in any conditions. Catalyst and oxygen were found to affect to form more PCDDs, PCDFs, and dioxin-like PCBs. Effects of catalyst and oxygen on the byproduct formation seemed to be similar in oil and gas while that was different in char.

This study presents the Mid-Lateglacial vegetation history of southwestern Korea. From the result of AMS dating and pollen analysis, four local pollen assemblage zones(BS) were recognized. The four local pollen assemblage zones are BS 1. 12,222cal BC9,160cal BC: cool-temperate northern/altimontane mixed coniferous & deciduous broad-leaved forest, BS 2. 9,160cal BC 4,210cal BC: cool-temperate central/montane deciduous broad-leaved forest, BS 3. 4,210cal BC125cal BC: cool-Temperate southern/submontane mixed coniferous & deciduous broad-leaved forest. BS 4. BC125cal present: warm-temperate/cool-temperate southern/submontane coniferous forest. Pine forest expanded since 4,210cal BC and full-scale rice cultivation might started since 2,120cal BC. A radical expansion of Pinus densiflora forest after postglacial stage might be caused by human impacts including full-scale agriculture.

The characteristics of particulate matter (PM) emission such as the estimation of emission factors, size distributions and of heavy metal emission from small-size incinerators and boilers have been investigated. In PM-10 emission, a fine mode was found in the formation of sub-micron PM by growth of nucleated aerosol of metal vapor, having a bimodal particle size distribution in overall size range. The emission ratios of PM-10 to TPM (total PM) from boilers and incinerators ranged from 29% to 62% and 10% to 84%, respectively, which resulted in more and larger sized PM emission due to poorer combustion from solid waste incinerators than boilers. The targeted metals were copper, cadmium, manganese, chromium, magnesium, lead, zinc and copper, and their contents in bottom ash, fly ash and dust (PM) were compared. More volatile metals such as cadmium, lead and zinc showed higher enrichment in PM emitted through stack than bottom ashes. Cadmium, copper, lead and zinc on the fine PM under 2.5 μm accounted for approximately 90% of the total mass of each metal in PM-10. The effects of chlorine concentration and temperature on such metals emission were also observed due to their volatility changes.

This study was carried out to examine the formation and the emission status of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) in the flue gases of commercial-scale municipal solid waste (MSW) incinerators, and thus to provide the engineering data for the reduction of PCDDs/PCDFs emitted from MSW incinerators. The formation concentrations of the PCDDs/PCDFs generated at the outlet of waste heat boilers (WHB) were in the range of 1.18–29.61 ng-TEQ/N m3 (average 5.75 ng-TEQ/ N m 3 ), while the emission concentrations at the stacks were in the range of 0.026–4.548 ng-TEQ/ N m 3 (average 0.924 ng-TEQ/ N m 3 ). Two major 2,3,7,8-substituted congeners were 2,3,4,7,8-PeCDF and 2,3,4,6,7,8-HxCDF, and their concentrations were up to 50% and 64% of total TEQ values at the outlet of WHB and the stack, respectively. From the results of multi-regression analysis, the formation concentration of PCDDs/PCDFs could be predicted as follows with the correlation factor of r2=0.962: PCDDs/PCDFs ( ng-TEQ / N m 3 )=3.036 ( Cl )+0.094 (T 1 )−0.472 ( Combustibles )+0.059 ( CO )−0.039 ( THC )−3.366 ( H )+22.157 , where T 1 (° C ) is the temperature at the outlet of the WHB. Cl, Combustibles and H are given as percentages and the others are in parts per million.

The present investigation is dealing with the communition of the cement particle to the ultrafine level (~220 nm) utilizing the bead milling process, which is considered as a top-down nanotechnology. During the grinding of the cement particle, the effect of various parameters such as grinding time (1–6 h) and grinding agent (methanol and ethanol) on the production of the ultrafine cement has also been investigated. Performance of newly produced ultrafine cement is elucidated by the chemical composition, particle size distribution, and SEM and XRD analyses. Based on the particle size distribution of the newly produced ultrafine cement, it was assessed that the size of the cement particle decreases efficiently with increase in grinding time. Additionally, it is optimized that the bead milling process is able to produce 90% of the cement particle<350 nm and 50% of the cement particle<220 nm, respectively, after 6.3 h milling without affecting the chemical phases. Production of the ultrafine cement utilizing this method will promote the construction industries towards the development of smart and sustainable construction materials.

This study strives to estimate the emission of dioxin and furthermore attempts to find the best technological control methods available for waste incinerators by investigating the emission status thereof. In order to incorporate the Stockholm Convention, a particular stringent law was promulgated in Korea and in recent years incinerators were forced to utilize better technological control. After the enforcement of special dioxin emission regulation in 2003, the average concentration of dioxin emitted from municipal and industrial waste incinerators decreased from 15.25 and 12.86 ng TEQ Nm−3 to 5.53 and 4.96 ng TEQ Nm−3 in 2001 and 2004, respectively. Based on test results at commercial plants, several best arranged sets of air pollution control devices (APCDs) were suggested in order to provide guidelines to help operators. These sets included combinations of spray dry absorbers, bag type filters, wet scrubbers, selective catalytic reductions and electrostatic precipitators. Different suggestions and real installations of APCD arrangement were investigated during the years around the regulation in effective. The results were presented depending on the capacity of the incinerators and different waste streams to observe the efforts to reduce dioxin emission by operators of incineration plants. The annual amount of dioxin emission from the incinerators is expected to be 212.5 g-TEQ in 2011 and 234.3 g-TEQ in 2015, respectively, compared to 891.6 g-TEQ recorded in 2001. The enforcement of new regulation and the installation of better APCDs showed the significant effect on such reduction. This reduction in dioxin emission from incinerators confirmed the nation’s commitment to the regulatory requirement set by the Stockholm Convention.