• Applied Chemistry for Engineering
• /
• v.33 no.2
• /
• pp.151-158
• /
• 2022

In this paper, parameter characteristics such as pH effect, isotherm, kinetic and thermodynamic parameters and competitive adsorption of dyes including malachite green (MG), direct red 81 (DR 81) and thioflavin S (TS), which have different functional groups, being adsorbed onto activated carbon were investigated. Langmuir, Freundlich and Temkin isotherm models were employed to find the adsorption mechanism. Effectiveness of adsorption treatment of three dyes by activated carbon were confirmed by the Langmuir dimensionless separation factor. The mechanism was found to be a physical adsorption which can be verified through the adsorption heat calculated by Temkin equation. The adsorption kinetics followed the pseudo second order and the rate limiting step was intra-particle diffusion. The positive enthalpy and entropy changes showed an endothermic reaction and increased disorder via adsorption at the S-L interface, respectively. For each dye molecule, negative Gibbs free energy increased with the temperature, which means that the process is spontaneous. In the binary component system, it was found that the same functional groups of the dye could interfere with the mutual adsorption, and different functional groups did not significantly affect the adsorption. In the ternary component system, the adsorption for MG lowered a bit, likely to be disturbed by the other dyes meanwhile DR 81 and TS were to be positively affected by the presence of MG, thus resulting in much higher adsorption.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.9
• /
• pp.1423-1428
• /
• 2006

In this study, we have prepared pitch binded AC (activated carbon)/$AC/TiO_2$ composites photocatalysts through carbon tetrachloride solvent method. The developed samples were characterized with surface properties, structural crystallinity between AC and $AC/TiO_2$, elemental identification and photocatalytic activity. The results of the textural surface properties demonstrate that there are slight increases in the BET surface area and adsorbed volume from adsorption isotherm of composite samples with increasing of the amount of AC. The SEM results present to the characterization of porous texture on the pitch/AC/$AC/TiO_2$ composites and homogenous compositions in the particle for all the materials used. From XRD data, a weak and broad carbon peak of graphene remained rutile peaks kept with anatase structure were observed in the X-ray diffraction patterns for the pitch/AC/$AC/TiO_2$ composites. The EDX spectra show the presence of C, O and S with strong Ti peaks. Most of these samples are richer in carbon and major Ti metal than any other elements. Finally, the excellent photocatalytic activity of the pitch/AC/$AC/TiO_2$ composites between relative concentration ($c/c_o$) of MB and UV irradiation time could be attributed to the both effects between photocatalysis of the supported $AC/TiO_2$ and adsorptivity of the two kinds of carbons.

• Journal of Soil and Groundwater Environment
• /
• v.11 no.2
• /
• pp.13-21
• /
• 2006

Polycyclic aromatic hydrocarbons (PAHs) are widespread soil contaminants and major environmental concerns. PAHs have extremely low water solubility and are strongly sorbed to soil. A potential technology for remediation of PAHcontaminated soils is a soil washing with surfactant solutions. While the use of surfactants significantly enhances the performance of soil remediation, operation costs are increased. Selective adsorption of PAHs by activated carbons is proposed to reuse the surfactants in the soil-washing process. The adsorption isotherms of pure chemicals (Triton X-100 and phenanthrene) onto three granular activated carbons were obtained. The selective adsorption of phenanthrene in mixed solution was examined at various concentrations of phenanthrene and Triton X-100. The selectivity results were discussed with pore size distribution of activated carbons and molecular sizes of phenanthrene and the Triton X-100 monomer. The selectivity for phenanthrene was much larger than 1 regardless of the particle size of activated carbons. The selective adsorption using activated carbons with proper pore size distribution would greatly reduce the material cost for the soil washing process by the reuse of the surfactants.

• Korean Journal of Environmental Agriculture
• /
• v.6 no.2
• /
• pp.46-52
• /
• 1987

This study of adsorption and column percolation was conducted to examine the utilization of natural zeolite for the removal of heavy metals from waste water to compare with that of absorption activated carbon. The adsorption of heavy metals by natural zeolite was conformed to the Freundlich isotherm (1/n values: $0.12{\sim}0.45$, K values: $18.77{\sim}59.48$) and natural zeolite was turned out to be an effective adsorbent of heavy metals. At the same particle size and percolation velocity, zeolite adsorbed a greater amount of heavy metals was adsorbed on natural zeolite than activated carbon. The smaller the particle size, the more heavy metals that were adsorbed. It was postulated that the most effective size as an adsorbent of heavy metals from waste water ranged from 0.5 to 2.0mm. The slower the percolation velocity that of the heavy metal solution in column, the more heavy metals were adsorbed. Natural zeolite in a single solution adsorbed more heavy metals than that in mixed solution, and the order of the adsorption amount on natural zeolite was Cu>Zn>Cd.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.11
• /
• pp.1141-1147
• /
• 2006

In order to applicate a newly method for powdered activated carbon(PAC) selection based on economic efficiency, PAC adsorption tests were performed for removal of MIB and dissolved organic carbon(DOC) in drinking water supplies. The removal rate of MIB increased when the PAC dose increased. The Coal-based PACs were superior for adsorption of MIB compared to wood-based PACs. PAC adsorption of DOC and $UV_{254}$ were a little different for different PACs and types of raw water, but both were lower than adsorption of MIB. Among the tested PACs, the one called P-1000 was most effective for removal of MIB, DOC and $UV_{254}$. Most of the organics in the tested samples were proven by excitation emission matrix(EEM) results to be fulvic-like materials. Especially, fulvic-like materials, humic-like materials, and soluble microbial byproduct(SMP)-like materials decreased after contact with PAC. P-1000 which had the lowest MIB cost index(MCI) was selected as the optimum PAC for the target water. PAC efficiency and treatability, particle size and distribution, and the cost associated with PAC dosing for MIB removal according to DOC concentration should all be considered before making the final selection of the best PAC for the target water.

• Journal of environmental and Sanitary engineering
• /
• v.22 no.1 s.63
• /
• pp.17-27
• /
• 2007

This study was conducted the adsorption experiment way of organic wastewater (BOD, COD, TOC, T-N, T-P) by changing the carbonization temperature and the size of adsorbent to examine the adsorption capacity of Korean traditional charcoal which has similar characteristics to activated carbon of organic pollutants. Also, it was performed the basic experiment for pH and inorganic materials. As a result of observing Korean traditional charcoal with has the greatest inorganic contents which are the important factor of chemical adsorption. As the carbonization temperature was better high temperature charcoal than law temperature charcoal to adsorption capacity of pollutant and as the particle was minute (D size : $3.35mm{\sim}2.0mm$), it was most effective. The result of adsorption experiment of organic wastewater show that the elimination ratio of pollutants by bamboo high temperature charcoal was found as BOD(82.1%), COD(91.7%), TOC(52.4%), T-N(66.6%), T-P(83.2%) and it has most excellent adsorption capacity of organic pollutants.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.09a
• /
• pp.302-305
• /
• 2002

Scoria is a bomb-sized, generally vesicular pyroclast that is red or black in color and light in weight. In this study, scoria from Cheju was examined for the use as a sorbent. It is composed of plagioclase, olivine, hornblende, pyroxene, and glass, with an average composition of 49.84% SiO$_2$, 14.07% A1$_2$O$_3$, End 9.14% Fe$_2$O$_3$. Studies on kinetic isotherm sorption of Zn(II) onto scoria under various parameters such as initial zinc concentration, particle size, and adsorbent/adsorbate ratio were carried out using an agitated batch. The results suggest that the smaller scoria size and the larger adsorbent/adsorbate ratio produce the higher degree of Zn(II) removal. More effective removal also appears at lower initial Zn concentration. The sorption behavior of Zn(II) onto scoria seems to be mainly controlled by cation exchange. Studies on equilibrium isotherm sorption of other heavy metals (Pb, Cu, Cd) onto scoria were also conducted and compared with those onto powdered activated carbon (PAC) and non-organic matter scoria (NOS), The results suggest that the Cheju scoria has the slightly higher sorption capability than PAC and NOS, and the order of the effective sorption onto scoria and PAC is Pb > Cu > Zn > Cd. The monometal sorption onto scoria is more stronger than the competitive sorption.

• Journal of environmental and Sanitary engineering
• /
• v.13 no.3
• /
• pp.102-112
• /
• 1998

The fate of polynuclear aromatic hydrocarbons(PAMs) in soil has drawn increasing concern due to their toxic, carcinogenic, and mutagenic effects. These compounds have been most commonly carried into the soil in solvent, as in a coal tar or cresote. This study has been focused on the applicability of microwave treatment of soils contaminated by PAHs. Studies have been conducted with soil(particle diameter $150~500{\mu}m$), which was spiked with naphthalene, acenaphthene, fluorene, anthracene and pyrene, with different moisture contents. According to the results of the research, up to 95% removal efficiency of naphthalene was observed in 10% moisturized soil for five minutes microwave inducing And the removal efficiency of acenaphthene and fluorene were observed to be 88.9%, 67.2% in 30% moisturized soil, respectively. Due to the low vapor pressure, anthracene and pyrene showed the low removal efficiency. In case the powdered activated carbon was added to the soil as a sensitizer, anthracene and pyrene were decomposed into a various by-products. Decomposition rates of anthracene and pyrene were increased with incresing addition of a PAC to the soil. It is concluded that the developement of a microwave process to remediate soils contaminated with PAHs is foreseeable. But additional studies are also needed regarding continuous microwave heating process.

• Journal of Soil and Groundwater Environment
• /
• v.17 no.6
• /
• pp.102-111
• /
• 2012

Fine suspended solids generated effluence from treatment process of mine drainage could destroy environment as the aesthetic landscapes, and depreciate water quality. Therefore, the purpose of this research is focused on process development applied the actual field for controlling fine suspended solids and heavy metals, and so lab-scale test was performed for inducement of basic data. The mine drainage used in this research was sampled in H mine located Jeongseon-gun, Gangwon-do. Concentration of suspended solid, arsenic, iron and manganese was exceeded the standard of contaminant limitation for the clean water, and particle size of suspended solid was less than 10 m as fine particle. Although hydraulic retention time of mine drainage for effective settling was required more than 6 hours, hydraulic retention time would be increased in winter season when the settling efficiency could be reduced because of viscosity decreasing. Moreover, installed inclination plate helped to increase settling efficiency of suspended solid about 48 %. Filtering media that was the most effective removal of suspended solids and heavy metal was decided granular activated carbon of 1~2 mm was the optimal size.

• Particle and aerosol research
• /
• v.12 no.4
• /
• pp.161-168
• /
• 2016

The purpose of this study is to determine the performance characteristics of the paint particulate and volatile organic compounds(VOCs) simultaneous removal from the spraying paint booth in the laboratory and real site by sticky paint particulate and VOCs simultaneous removal demonstration unit. The sticky paint particulate and VOCs simultaneous removal unit is composed of the horizontal type pleated filter modules and the zig-zag type granular activated carbon packing modules. The test conditions at the laboratory are $50.15g/m^3$ of average paint aerosol concentration and 300 ppm of VOCs concentration which were same as the working conditions of spraying paint booth in the real site. But, the demonstration conditions at the real site are varied according to the working condition of spraying paint booth for the kind of passenger car bodies. The test results at the laboratory obtained that 99% of total particulate collection efficiency at 0.62 m/min of filtration velocity and 84% at 1.77 m/min of filtration velocity. The VOCs removal efficiencies are 97% at $3500hr^{-1}$ of gas hour space velocity and 59% at $10,000hr^{-1}$ of gas hour space velocity. In the real site test, the average removal efficiency of PM10 was measured to be 99.65%, the average removal efficiency of PM2.5 was 99.38%, the average removal efficiency of PM1 was 98.52%, and the average removal efficiency of VOCs was 89%.