• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1331-1337
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• 2006

A mathematical model has been proposed for the batch culture of Agaricus blazei with mixed carbon sources of glucose and dextrin. In the proposed model, the metabolism of A. blazei was divided into three parts: cell growth, exopolysaccharides (EPS) production, and another EPS production pathway activated by dextrin hydrolysis. Each pathway was described mathematically and incorporated into the mechanistic model structure. Batch cultures were carried out with six different carbon source compositions. Although parameters were estimated by using the experimental data from the two extreme cases such as glucose only and dextrin only, the model represented well the profiles of glucose, cell mass, and EPS concentrations for all the six different carbon source mixtures, showing a good interpolation capability. Of note, the lag in EPS production could be quite precisely predicted by assuming that the glucose-to-cell mass ratio was the governing factor for EPS production.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2753-2759
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• 2013

The aim of the present study is to explore the possibility of utilizing fly ash and loess, as alternative to activated carbon, for the adsorption of diazinon in water. Batch adsorption experiment was performed to evaluate the influences of various factors like initial concentration, contact time and temperature on the adsorption of diazinon. The adsorption data shows that fly ash is not effective for the adsorption of diazinon. The equilibrium data for both activated carbon and loess were fitted well to the Freundlich isotherm model. The pseudo-second-order kinetic model appeared to be the better-fitting model because it has higher $R^2$ compared to the pseudo-first-order kinetic model. The thermodynamic parameters such as free energy (${\Delta}G$), the enthalpy (${\Delta}H$) and the entropy (${\Delta}S$) were calculated. Contrary to loess, the ${\Delta}G$ values of activated carbon were negative at the studied temperatures. It indicates that the adsorption of diazinon by activated carbon is a favorable and spontaneous process. The positive ${\Delta}H$ values of activated carbon and loess suggest that the diazinon adsorption process is endothermic in nature. In addition, the positive ${\Delta}S$ values show that increased randomness occurs at the solid/solution surface during the adsorption of diazinon.

• KSBB Journal
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• v.11 no.3
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• pp.276-287
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• 1996

Batch suspension cultures of hybridoma cell were performed with various initial glutamine concentrations to investigate the effects of glutamine on cell growth and death, monoclonal antibody production, glucose and glutamine consumption, and the production of lactate and ammonium ion. An mathematical kinetic model was formulated to describe the kinetics of cell growth, the consumption of nutrients (glucose and glutamine), and the production of monoclonal antibody and waste metabolites (lactate and ammonium ion) based on experimental data. An equation for the specific growth rate was developed such that superimposed Monod equation in glucose and glutamine, with non-competitive type inhibition relations in ammonium ion and lactate. The inhibition constant for lactate was inversely proportional to the lactate concentration. The specific death rate was considered to be a function of glucose, glutamine, ammonium ion and lactate concentration.

• Journal of Environmental Science International
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• v.22 no.12
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• pp.1651-1660
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• 2013

The adsorption of lithium ion onto zeolite was investigated depending on contact time, initial concentration, cation forms, pH, and adsorption isotherms by employing batch adsorption experiment. The zeolite was converted into different forms such $K^+$, $Na^+$, $Mg^{2+}$, $Ca^{2+}$, and $Al^{3+}$. The zeolite had the higher adsorption capacity of lithium ion in $K^+$ form followed by $Na^+$, $Ca^{2+}$, $Mg^{2+}$, and $Al^{3+}$ forms, which was in accordance with their elctronegativities. The lithium ion adsorption was explained using the Langmuir, Freundlich, and Dubinin-Radushkevich adsorption isotherms and kinetic models. Adsorption rate of lithium ion by zeolite modified in $K^+$ form was controlled by pseudo-second-order and particle diffusion kinetic models. The maximum adsorption capacity obtained from Langmuir isotherm was 17.0 mg/g for zeolite modified in $K^+$ form. The solution pH influenced significantly the lithium ions adsorption capacity and best results were obtained at pH 5-10.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.296-300
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• 2003

A large equilibrium and kinetic data set for multi-component cation exchanges was obtained and tested with mass action law and surface complexation model. The systematic batch equilibrium and column experiments of cation adsorption were conducted for binary, ternary, quaternary, and quinary cation exchanges involving $ H^{+}, Li^ {+}, Na^{+}, NH$_4$^{+}, Mg^{2+} $ on a strongly acidic cation exchange resin IRN 77. The mass action law and surface complexation model were tested against both data set to investigate the consistency of ion selectivity and their predictability for competitive cation exchanges. Surface complexation model provided more accurate predictions for both equilibrium and kinetic experimental data than mass action model.

• Environmental Engineering Research
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• v.17 no.3
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• pp.125-132
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• 2012

The removal of Cd(II) and Cu(II) from aqueous solution by an agricultural solid waste biomass prepared from Moringa oleifera bark (MOB) was investigated. The biosorbent was characterized by Fourier transform infrared spectroscopy and elemental analysis. Furthermore, the effect of initial pH, contact time, biosorbent dosage, initial metal ion concentration and temperature on the biosorption of Cd(II) and Cu(II) were studied using the batch sorption technique. Kinetic studies indicated that the biosorption process of the metal ions followed the pseudo-second order model. The biosorption data was analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models. Based on the Langmuir isotherm, the maximum biosorption capacities for Cd(II) and Cu(II) onto MOB were 39.41 and 36.59 mg/g at 323 K, respectively. The thermodynamic parameters, Gibbs free energy (${\Delta}G^o$), enthalpy (${\Delta}H^o$), and entropy (${\Delta}S^o$) changes, were also calculated, and the values indicated that the biosorption process was endothermic, spontaneous and feasible in the temperature range of 303-323 K. It was concluded that MOB powder can be used as an effective, low cost, and environmentally friendly biosorbent for the removal of Cd(II) and Cu(II) ions from aqueous solution.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.1
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• pp.49-57
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• 2013

The present study was conducted to investigate phosphate removal from aqueous solution using industrial wastes, red mud (RM), acid treated red mud (ATRM) and converter furnace steel slag (CFSS). The chemical composition of adsorbents was analyzed using X-ray fluorescence (XRF). Batch experiments and elution experiments using water tank were performed to examine environmental factors that influences on phosphate removal. Kinetic sorption data of RM, ATRM, and CFSS were described well by the pseudo second-order kinetic sorption model, and equilibrium sorption data of all adsorbents obeyed Freundlich isotherm model. The adsorption capacities of adsorbents followed order: ATRM (7.06 mg/g)>RM (4.34 mg/g)>CFSS (1.88 mg/g). Increasing pH from 3 to 11, the amount of adsorbed phosphate on all RM, ATRM, and CFSS were decreased. The presence of sulfate and carbonate decreased the phosphate removal of RM and ATRM but did not influence on the performance of CFSS. The phosphate removal of RM, ATRM, and CFSS was greater in seawater than deionized water, resulting from the presence of cations in seawater. The water tank elution experiments showed that RM capping blocked the elution of phosphate effectively. It was concluded that the adsorbents can be successfully used for the removal of the phosphate from the aqueous solutions.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.234-238
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• 1998

Anaerobic degradation characteristics of dewatered liquid of household food waste including methane conversion efficiency and degradation kinetics were studied in an anaerobic batch reactor of 5 L volume. The ultimate methane production for dewatered liquid of household food waste tested was over 0.31L $CH_4/L{\cdot}dewatered$ liquid of household food waste. The kinetic constant of dewatered liquid of household food waste tested was $0.223d^{-1}/L$. The kinetic behavior of anaerobic degradation was described as a first order series reaction. The determinant of rate-limiting step(DR) that is balanced out from the rates of reaction steps was defined by the logarithmic difference of the maximum acidification rate and the maximum methanation rate. Anaerobic degradation characteristics of organic materials were evaluated by the value of DR. The DR of dewatered liquid of household food waste tested was 1.17.

• Advances in environmental research
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• v.7 no.1
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• pp.53-71
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• 2018

Waste glass disposal causes environmental problems in the cities. To find a suitable green environmental solution for this problem low cost adsorbent in this study was prepared from waste glass. An effective new green adsorbent was synthesized by hydrothermal treatment of waste glass (WG), followed by acidic activation of its surface by HCl (WGP). The prepared adsorbent was characterized by scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), and BET surface measurement. The developed adsorbent was used for the removal of heavy metals (Cd, Cu, Fe, Pb and Zn) from well water. Batch experiments were conducted to test the ability of the prepared adsorbent for the removal of Cd, Cu, Fe, Pb and Zn from well water. The experiments of the heavy metals adsorption by adsorbent (WGP) were performed at different metal ion concentrations, solution pH, adsorbent dosage and contact time. The Langmuir and Freundlich adsorption isotherms and kinetic models were used to verify the adsorption performance. The results indicated high removal efficiencies (99-100%) for all the studied heavy metals at pH 7 at constant contact time of 2 h. The data obtained from adsorption isotherms of metal ions at different time fitted well to linear form of the Langmuir sorption equation, and pseudo-second-order kinetic model. Application of the resulted conditions on well water demonstrated that the modified waste glass adsorbent successfully adsorbed heavy metals (Cd, Cu, Fe, Pb and Zn) from well water.

• Carbon letters
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• v.14 no.4
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• pp.234-242
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• 2013

Potassium hydroxide-activated carbons (CK21, CK11, and CK12) were prepared from pistachio nutshells. Physicochemical properties of activated carbons were characterized by TGA, $pH_{pzc}$, Fourier transform infrared spectroscopy, scanning electron microscopy, and $N_2$-adsorption at $-196^{\circ}C$. The examinations showed that activated carbons have high surface area ranging between 695-1218 $m^2/g$, total pore volume ranging between 0.527-0.772 mL/g, and a pore radius around 1.4 nm. The presence of acidic and basic surface C-O groups was confirmed. Batch adsorption experiments were carried out to study the effects of adsorbent dosage, temperature, initial concentration of adsorbate, and contact time on deltamethrin adsorption by activated carbons. The kinetic studies showed that the adsorption data followed a pseudo-second order kinetic model. The Langmuir model showed a maximum adsorption capacity of 162.6 mg/g at $35^{\circ}C$ on CK12. Thermodynamic studies indicated that adsorption was spontaneous and increased with temperature, suggesting an endothermic process.