• Membrane Journal
• /
• v.25 no.4
• /
• pp.358-366
• /
• 2015

Flat membrane with $0.4{\mu}m$ pore size was prepared with PVdF (polyvinylidene fluoride) nanofiber, which has the advantages such as excellent strength, chemical resistance, nontoxic, non-combustibility. After that, spiral wound module was manufactured with it including a woven paper. Effect of pH was studied by comparing permeate fluxes and rejection rates of the spiral wound module using simulation solution including kaolin and humic acid. The recovery rate and filtration resistance were calculated after water back-washing at the end of filtration experiment. In addition, after the water filtrated by the spiral wound module was passed through a column filled with GAC (granular activated carbon), adsorption effect of GAC was investigated by measuring the turbidity and $UV_{254}$ absorbance.

• Applied Chemistry for Engineering
• /
• v.27 no.6
• /
• pp.590-598
• /
• 2016

In this study, the adsorption behavior from aqueous solution as well as kinetic and thermodynamic parameters of Acid Black 1 were investigated through batch reaction using coconut shell based granular steam activated carbon. The effects of various adsorption parameters such as pH, initial concentration, contact time, temperature were studied. To confirm the effect of pH, pHpzc measurements were analyzed followed by measuring removal efficiencies of Acid Black 1 at the pH range from 3 to 11. Experimental equilibrium adsorption data were fitted using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich adsorption isotherm. The conformity of adsorption reaction for pseudo first and second order model were evaluated through kinetic analysis. Values of enthalpy change and activation energy were also investigated through thermodynamic analysis and it was confirmed that the adsorption process was endothermic. The spontaneity of adsorption process was evaluated using the values of entropy and Gibbs free energy changes.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.7
• /
• pp.499-504
• /
• 2009

Erythrosine is used a food coloring, ink and dye, etc. but erithrosine is rarely used in United States due to its known hazards. The adsorption characteristics of erythrosine by granular activated carbon were investigated in the batch adsorber and the packed column. The adsorptivity of activated carbon for erythrosine were largely improved by pH control. When the pH was 11 in the sample, the erythrosine could be removed 98% of initial concentration. It was estabilished that the adsorption equilibrium of erythrosine on granular activated carbon was successfully fitted by Freundlich isotherm equation in the concentration range from 10mg/L to 1,000mg/L. The characteristics of breakthrough curve of activated carbon packed column depend on the design variables such as initial concentration, bed height, and flow rate.

• Applied Chemistry for Engineering
• /
• v.27 no.2
• /
• pp.199-204
• /
• 2016

The adsorption of Rhodamine-B dye using granular activated carbon from aqueous solution was investigated. Adsorption experiments were carried out as a function of the adsorbent dose, pH initial concentration, contact time and temperature. The equilibrium adsorption data showed a good fit to Langmuir isotherm model. Based on the estimated Langmuir separation factor ($R_L$ = 0.0164~0.0314), our adsorption process could be employed as an effective treatment method. The kinetics of adsorption followed the pseudo first order model. Also, the negative values of Gibbs free energy (-4.51~-13.44 kJ/mol) and positive enthalpy (128.97 kJ/mol) indicated that the adsorption was spontaneous and endothermic process. The isosteric heat of adsorption increased with increase in the surface loading indicating lateral interactions between the adsorbed dye molecules.

• Analytical Science and Technology
• /
• v.13 no.5
• /
• pp.573-583
• /
• 2000

Activated carbon fibers (ACFs) were prepared from various precursors of plantic, synthetic, and mixed fabrics of viscous rayon and cotton. Their adsorption performances of phenol and methylene blue in aqueous phase were evaluated through their adsorption isotherms, adsorption rates and breakthrough curves. The two adsorbates showed type I adsorption isotherm on ACFs. Adsorption rates to ACFs were 100 fold faster than to GAC. The effective diffusion coefficients of the adsorbates in ACFs were twenty fold greater than in GAC. The ACFs removed completely ten organic pollutants from a prepared water specimens through the 2nd column of a natural filtration method where 50 L of the water samples were treated.

• Korean Chemical Engineering Research
• /
• v.51 no.1
• /
• pp.127-135
• /
• 2013

In this study, both pressure drop and microbe-population-distribution were observed while running a novel biofilter system with improved design in which the biofilter system is composed of two, upper and lower biofilters with both equal feed-rates of up-flow and down-flow, respectively. Then they were compared with the pressure drop and microbe-population-distribution observed in a conventional biofilter of the same effective volume with unidirectional flow. The pressure drop-value of biofilter system with improved design turned out to be less at the incipient stage of run or steady-state long term operation by more than 40~80% of that of the conventional biofilter. The microbe-population-distribution was observed to be lower and higher at higher and lower column of biofilter, respectively, for both the conventional biofilter and the biofilter system with improved design. The microbe-media of waste-tire crumb showed much greater CFU counts than GAC. In the biofilter system with improved design, the $bottom{\rightarrow}up$ feeding of waste air showed greater microbe-population growth than the $top{\rightarrow}down$ feeding for both the microbe-media of waste-tire crumb and GAC. However, it was more prominent for the former than the latter. Comparing the microbe-population-distributions of both of the conventional biofilter and the biofilter system with improved design, the microbe-population of latter was distributed ca. 15 and 2.5 times more evenly for GAC and the media of waste-tire crumb, respectively, than that of former.

• Applied Chemistry for Engineering
• /
• v.8 no.2
• /
• pp.204-210
• /
• 1997

Zeolite 4A-impregnated complex molecular sieve was prepared by hydrothermal reaction after aluminosilicate gel was penetrated into the pore of activated carbon granule. The crystals of zeolite 4A mainly were formed in the macropore of activated carbon, and their average diameter is $0.8{\mu}m$. The pore volume of activated carbon granule is $0.67m{\ell}/g$, and the pore volume of the sample including 21.6wt% of zeolite 4A crystal is $0.41m{\ell}/g$ decreasing the pore volume by 40% due to the crystallization of zeolite 4A crystals on the internal surface of activated carbon. The calcium ion exchange capacity of zeolite 4A-impregnated sample is 320mg $CaCO_3/g$ zeolite, and this value is almost the same as that of zeolite 4A powder. The crystal of zeolite 4A was not separated from the support of activated carbon granule in the course of ultrasonic dispersion. The adsorption isotherm of water on zeolite 4A-impregnated sample shows the intermediate shape between types, I and III. In addition, zeolite 4A-impregnated sample shows the hydrophilic and hydrophobic properties simultaneously.

• Korean Chemical Engineering Research
• /
• v.46 no.5
• /
• pp.994-1001
• /
• 2008

Freundlich isothermal adsorption parameters, applicable to such biofilter-model as process-lumping model(Lim's model), for sterilized granular activated carbon(GAC), sterilized compost and sterilized equal volume mixture of GAC and compost were obtained and were compared each other, assuming that adsorbents are enclosed by water layer, in order to construct robust process-lumping biofilter model effective for wide-range of hydrophilic volatile organic compounds(VOC). In this investigation 0.04, 0.08, 0.12, 0.16, 0.2, 0.4, 0.8 and 1.0ml of ethanol were added to three kinds of adsorbent-media and were placed at $30^{\circ}{\cdots}$ under the wet condition of the media, which was the same as biofilter operating condition, until the adsorption reached the condition of equilibrium before each adsorbed amount of ethanol was obtained. Then adsorption capacity parameters(K) and adsorption exponents of Freundlich adsorption isotherm equation, which simulates the adsorbed amount of ethanol equilibrated with the ethanol concentration of the condensed water in the pore of the media, were constructed for sterilized granular activated carbon(GAC), sterilized compost and sterilized equal volume mixture of GAC and compost as (0.7566 and $5.070{\times}10^{-7}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.7566}$), (0.8827 and $1.000{\times}10^{-8}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.8827}$) and (0.5688 and $5.243{\times}10^{-6}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.5688}$), respectively. These Freundlich isothermal adsorption parameters were applicable to the adsorption characteristics of biofilter media enclosed with bio-layer. The order of magnitude of the ratio of ethanol-air/water partition coefficient and toluene-air/water partition coefficient was almost consistent to that of ethanol-adsorbed amounts in this experiment with compost and in the investigation of Delhomenie et al. on toluene-adsorption to wet compost.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.2
• /
• pp.475-483
• /
• 2017

Geosmin and 2-methylisoborneol (2-MIB) produced by cyanobacteria during algal blooming in surface water are the major taste-and-odor-causing compounds in drinking water and need to be removed. Activated carbon is often used in treatment plants for the mitigation of odor problem. However, there is a lack of information on the effect of pore size distribution and particle size of activated carbon for adsorption of both odor compounds. Therefore, we studied the effect of pore size distribution and particle size of activated carbon on the adsorption of geosmin and 2-MIB. When comparing the adsorption of geosmin and 2-MIB between activated carbon fiber (ACF), powdered activated carbon (PAC) and granular activated carbon (GAC), the order of removal efficiency was PAC > ACF > GAC. As a result of comparing PACs with various pore distribution characteristics, well-developed micropores on activated carbon were found to be favorable for adsorption of geosmin and 2-MIB. For particle size, smaller was more effective for adsorption of geosmin and 2-MIB.

• Korean Chemical Engineering Research
• /
• v.40 no.6
• /
• pp.694-702
• /
• 2002

Activated carbons have been used as adsorbents in various industrial application, such as solvent recovery, gas separation, deodorization, and catalysts. In this study, the effects of residual water on the activated carbon adsorbent surface on the adsorption capacity of $CCl_4$ were investigated. Adsorption behavior in a fixed bed was studied in terms of feed concentration, flow rate, breakthrough curve and adsorption capacity for $CCl_4$. Desorption characteristics of residual water on activated carbon were also studied. The water contents of the activated carbon were varied in the range of 0-20%(w/w) and all experiments were performed at 298.15 K. The adsorption equilibrium data $CCl_4$ on the activated carbon were well expressed by Langmuir isotherm. The adsorption capacity of $CCl_4$ decreased with increasing residual water content. Desorption of residual water in activated carbon decreased expotentially with $CCl_4$ adsorption. The obtained breakthrough curves using LDF(linear driving force) model represented our experimental data.