• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.628-632
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• 2001

The removal rate of Cl from municipal solid waste incineration(MSWI) ash(bottom ash and fly ash) by washing was investigated. The Cl contents in the bottom ash and fly ash were 2.6-3.0% and 25-30% respectively, and KCl, NaCl, CaCIOH and friedel's salt were main components. From the results on the effects of washing time and temperature, the Cl contents in the bottom ash and fly ash were decreased up to 0.3% and 2.0% respectively by using of water as a solvent within 30 min at 2$0^{\circ}C$, 300 rpm of agitation speed and 10 of liquid/solid ratio. It is expected that the removal of Cl from the incineration ash by washing could make use of the ash for a cement raw material and so on.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.494-499
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• 2001

The present work investigates the possible use of fly ash for the removal of heavy metal ions from aqueous solutions. Batch experiments were conducted and the influences of metal concentration, pH, and fly ash concentration were investigated. Heavy metals used in these studies were zinc, lead and cadmium. Adsorption studies were done over a range of pH values (3-10) at $25^{\circ}C$ and heavy metal concentrations of 10-400 mg/L using fly ash concentrations of 10, 20 and 40 g/L. Experiments were also conducted without fly ash to determine the extent of heavy metal removal by precipitation. Kinetic and equilibrium experiments were performed and adsorption data were correlated with both Langmuir and Freundlich adsorption models. The results indicate that fly ash can be used as an adsorbent for heavy metals in the aqueous solutions, yet the degree of removal depends on the pH.

• Resources Recycling
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• v.10 no.4
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• pp.10-17
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• 2001

The present work investigates the possible use of fly ash for the removal of heavy metal ions from aqueous solutions. Batch experiments were conducted and the influences of metal concentration, pH, and fly ash concentration were investigated. Heavy metals used in these studies were lead and zinc. Adsorption studies were done over a range of pH values (3~10) at $25^{\circ}C$ and heavy metal concentrations of 10~400 mg/L using fly ash concentrations of 10 and 20 g/L. Experiments were also conducted without fly ash to determine the extent of heavy metal removal by precipitation. Kinetic and equilibrium experiments were performed and adsorption data were correlated with both Langmuir and Freundlich adsorption models. The results of these studies indicate that 리y ash can be used as an adsorbent for heavy metals in the aqueous solutions, yet the degree of removal depends on the pH.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.142-146
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• 2001

This research was undertaken on the use of bottom ash as a fine aggregate in Controlled. Low-strength Material(CLSM). The mixtures contained constant fly ash. And four different level of bottom ash with fly ash contents, 25%, 50%, 75%, 100% are investigated. Mixture proportions were developed for producing CLSM at three 28-day strength levels: removal with tools (less than $7kgf/cm^{2}$), removal by mechanical means (less than $200kgf/cm^{2}$), and removal with power equipment (less than $83kgf/cm^{2}$). To obtain these strengths, cement contents of 30, 60, and $120kg/cm^{3}$ were utilized. The compressive strength properties support the concept that by-product bottom ash can be successfully used in CLSM.

• Journal of Environmental Science International
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• v.15 no.2
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• pp.185-191
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• 2006

In this paper, removal time of side form from concrete using OPC(ordinary Portland cement) and FAC(fly ash cement) are proposed by appling logistic model, which evaluates the strength development of concrete with maturity. W/B, types of cement and curing temperatures are adapted as test parameters. The estimation of strength development by logistic model has a good agreement between calculated values and measured ones. As for the removal times of form works suggested in this paper, as W/8 increases, curing temperature decreases and fly ash is used, removal time of side form is prolonged. Removal time of form from concrete using OPC suggested in this paper is shorter $2.5\~3.5$ days than those of KASS-5 (Korean Architectural Standard Specifications-5) in the range of over $20^{\circ}C$. And in the range of $10\~20^{\circ}C$ removal time of form is shorter than that of KASS-5 by as much as $4\~4.5$ days. The use of FAC results in an increase in removal time of form compared to that of OPC by about 1 day.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.3
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• pp.359-366
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• 2011

The feasibility of using volcanic ash for lead ion removal from wastewater was evaluated. The adsorption experiments were carried out in batch tests using volcanic ash that was treated with either NaOH or HCl prior to the use. Volcanic ash dose, temperature and initial Pb(II) concentration were chosen as 3 operational variables for a $2^3$ factorial design. Ash dose and concentration were found to be significant factors affecting Pb(II) adsorption. The removal of Pb(II) was enhanced with increasing volcanic ash dose and with decreasing the initial Pb(II) concentration. Pb(II) adsorption on the volcanic ash surface was spontaneous reaction and favored at high temperatures. Calculation of Gibb's free energy indicated that the adsorption was endothermic reaction. The equilibrium parameters were determined by fitting the Langmuir and Freundlich isotherms, and Langmuir model better fitted to the data than Freundlich model. BTV(base-treated volcanic ash) showed the maximum adsorption capacity($Q_{max}$) of 47.39mg/g. A pseudo second-order kinetic model was fitted to the data and the calculated $q_e$ values from the kinetic model were found close to the values obtained from the equilibrium experiments. The results of this study provided useful information about the adsorption characteristics of volcanic ash for Pb(II) removal from aqueous solution.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.489-493
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• 2001

Big cities in Japan have serious problems due to the shortage of new reclaimed land for municipal wastes. If harmful heavy metals such as cadmium, lead, copper and etc. are contained in the municipal waste combustion residues, they are not able to fill up according to the environmental law in Japan. In this study, the removal of heavy metals in the fly ash (EP ash) was dealt with chloridizing vaporization method. EP ash as a non-hazardous materials is utilized as covering materials, road bed, and building materials.

• Tribology and Lubricants
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• v.34 no.5
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• pp.175-182
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• 2018

Accumulation of coal ash at the boiler wall reduces combustion and fuel efficiency. The design of a wall blower is important to effectively remove coal ash. We present numerical results for the removal of coal ash from boiler walls of domestic coal-fired power plants, associated with the computational fluid dynamics for the flow from spray nozzle to boiler wall. The numerical model simulates an erosion process in which the multiphase fluid comprising saturated vapor and fluid water is sprayed from the nozzle, and the water particles impact the boiler wall. We adopt the Finnie erosion model for water particles. We obtain the erosion rate density as a function of nozzle angle and its injection angle. As excessive coal ash removal usually induces damage to the boiler wall, the removal operation typically focuses on a large area with uniform depth rather than the maximum removal of coal ash at a specific location. In order to estimate the removal performance of the wall blower nozzle considering several functionality and reliability factors, we evaluate the optimal injection and nozzle angles with respect to the biggest cumulative and highest erosion rates, as well as the widest range and lowest standard deviation of the erosion rate distribution.

• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.40-45
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• 1999

This study deals with an investigation on low cost adsorbents locally available n dyeing wastewater treatment of color removal. Peat, bentonite, slag and fly ash were utilized for this study. Considering that low cost adsorbents contained in $SiO_2$, $Fe_2O_3$ and $Al_2O_3$ compositions, and coagulants were mainly used aluminate and ferrate in color removal. Color of dyeing wastewater was high removed in peat, berntonite and slag except for fly ash with passed time. It could be known that color removal of peat and slag were increased to pH 4, but was hardly changed with advancing to alkaline. Color intended to be high removed with increasing of agitation speed but to be almost slow after 150rpm. As a result on the experiment of Freundlich adsorption isotherms, adsorption intensity(l/n) appeared to be peat>fly ash>slag>bentonite and adsorption capacity(k) came out peat>bentonite>slag>fly ash. Therefore, if low cost adsorbents substituted for existing adsorbents, peat, bentonite and slag could look forward to an expected economical effect.

• Carbon letters
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• v.11 no.1
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• pp.1-8
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• 2010

The adsorption of Acid Blue 92 onto three low cost and ecofriendly biosorbents viz., cow dung ash, mango stone ash and parthenium leaves ash and commercial activated carbon have discussed in this work. The ash of all the mentioned bio-wastes was prepared in the muffle furnace at $500^{\circ}C$ and all the adsorbents were stored in an air thermostat. Experiments at total dye concentrations of 10~100 mg/L were carried out with a synthetic effluent prepared in the laboratory. The parameters such as pH and dye concentration were varied. Equilibrium adsorption data followed both Langmuir and Freundlich isotherms. The results indicate that cow dung ash, mango stone ash and parthenium leaves ash could be employed as low-cost alternatives to commercial activated carbon in wastewater treatment for the removal of dye.