• Korean Journal of Environmental Agriculture
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• v.11 no.3
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• pp.195-200
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• 1992

Heavy metal adsorption on peat was studied to examine the utilization of abundant natural resouces as pollution control. The smaller the peat particle size, the more the heavy metals studied were adsorbed. Adsorption of heavy metals on peat was greater in single metal solutions than in mixed solutions, and the order of adsorption amount on peat was Cu > Cd > Zn. The most effective pH range of the adsorption of Cd, Zn, and Cu was between 4 and 6. With increasing the concentration of heavy metals the amount of adsorption on peat was increased, but the adsorption ratio was decreased. The adsorption of heavy metals on peat was fitted to the Freundlich isotherm and peat was appeared to be an effective adsorbent of the heavy metals. The treatment of polyethyleneimine(PEI) on the peat surface effectively increased adsorption capacity of the heavy metals. Because of its higher energy content, the heavy metal adsorbed peat could be utilized as a energy source. After burning the peat, the reduced peat volume could be save the expenses for waste disposal.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.996-1003
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• 2006

The absorption characteristics of powdered activated carbon doped by transition-metal nanoparticles were investigated to enhance the remove efficiencies of $TCOD_{Mn}$ and Color from the flexo-inks wastewater. According to the adsorption dynamics of PAC and MPAC, the optimal dosage of activated-carbon adsorbents was 3 g/L under the reaction conditions of pH6.0, 30 mill of reaction time, 240 rpm of mixing intensity. The removal efficiencies by the optimal dosages were maximized as 19% $TCOD_{Mn}$, 57% Color for PAC and 88% $TCOD_{Mn}$, 95% Color for MPAC. Freundlich indexes of isotherm absorption were estimated as follows: i) For PAC, k=-8.11, 1/n=2.98, r=0.91 in the raw water, and k=0.14, b/n=0.75, r=0.96 in the biological treatment water, ii) For MPAC, k=2.69, 1/n=0.21, r=0.80 in the raw water, and k=0.74, 1/n=1.17, r=0.95 in the biological treatment water. MPAC (Powdered activated carbon doped by transition-metal nanoaprticles) was very effective in the removal of organics from the raw water and biological treatment water, as Freundlich indexes of 1/n for both types of water were estimated less than 2.0.

• Membrane and Water Treatment
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• v.11 no.1
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• pp.41-48
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• 2020

Lead is a highly toxic heavy metal that causes serious health problems. Nonetheless, it is increasingly being used for industrial applications and is often discharged into the environment without adequate purification. In this study, Pb(II) was removed by powdered waste sludge (PWS) based on the biosorption mechanism. Different PWSs were collected from a submerged moving media intermittent aeration reactor (SMMIAR) and modified Ludzack-Ettinger (MLE) processes. The contents of extracellular polymeric substances were similar, but the surface area of MLE-PWS (2.07 ㎡/g) was higher than that of SMMIAR-PWS (0.82 ㎡/g); this is expected to be the main parameter determining Pb(II) biosorption capacity. The Bacillaceae family was dominant in both PWSs and may serve as the major responsible bacterial group for Pb(II) biosorption. Pb(II) biosorption using PWS was evaluated for reaction time, salinity effect, and isotherm equilibrium. For all experiments, MLE-PWS showed higher removal efficiency. At a fixed initial Pb(II) concentration of 20 mg/L and a reaction time of 180 minutes, the biosorption capacities (q_e) for SMMIAR- and MLE-PWSs were 2.86 and 3.07 mg/g, respectively. Pb(II) biosorption using PWS was rapid; over 80% of the maximum biosorption capacity was achieved within 10 minutes. Interestingly, MLE-PWS showed enhanced Pb(II) biosorption with salinity values of up to 30 g NaCl/L. Linear regression of the Freundlich isotherm revealed high regression coefficients (R² > 0.968). The fundamental Pb(II) biosorption capacity, represented by the K_F value, was consistently higher for MLE-PWS than SMMIAR-PWS.

• Journal of Navigation and Port Research
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• v.38 no.3
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• pp.269-275
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• 2014

In this study, the adsorption efficiency of mixed heavy metals in aqueous solution was investigated using steel slag. Moreover, heavy-metal stabilization treatment of contaminated marine sediment was achieved using steel slag as stabilizing agents. Heavy metal adsorption was characterized using Freundlich and Langmuir equations. The equilibrium adsorption data were fitted well to the Langmuir model in steel slag. The adsorption uptake of heavy metals were higher in the order of $Pb^{2+}$ > $Cd^{2+}$ > $Cu^{2+}$ > $Zn^{2+}$ > $Ni^{2+}$. The steel slage was applied for a wet-curing duration of 150 days. From the sequential extraction results, the exchangeable, carbonate, and oxides fractions of Ni, Zn, Cu, Pb, and Cd in sediment decreased by 13.0%, 6.0%, 1.3%, 17.0%, and 50.0%, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.344-349
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• 2001

The removal of chlorine from aqueous solutions on dried Chlorella vulgaris(DCV) and green tea powder(GTP) were investigated as a function of contact time, pH and initial chlorine concentration. Removal by DCV and GTP reached equilibrium after 3hrs and 0.5hr, respectively. Optimum removal pH values of DCV and GTP were determined as above 10. Both Langmuir and Freundlich adsorption models were suitable for describing the short-term removal of chlorine by DCV and GTP. According to Langmuir adsorption isotherms the maximum removal capacity of DCV (2.75mg $Cl_2/mg$) was nearly two times greater than those of GTP (1.53mg $Cl_2/mg$) and activated carbon (1.47mg $Cl_2/mg$). These results suggested that Chlorella vulgaris biomass might potentially be used as an alternative to traditional water treatment materials for removal of residual chlorine in drinking water or process waste-water.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.1
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• pp.73-79
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• 1983

Activated carbon has been widely used in water and wastewater treatment for removal of trace organics. The objective of this study was to define adsorption characteristics of trihalomethane(THM) on granular activated carbon(GAC) surfaces by laboratory experiments. Synthetic samples were prepared by adding chloroform into distilled and deionized water. The experiments conducted were a batch run and isotherm studies with five different temperature-pH levels. Adsorption of THM on GAC at an equilibrium condition was well described by the Freundlich isotherm equation. Lower temperature favored the adsorption, but the effect of pH was negligible. Utilizing the results of a batch run and the isotherm results, three parameters, mass transfer coefficient, pore diffusion coefficient, and surface diffusion coefficient, were evaluated by comparing with simulation results of an adsorption model. The results also showed that the pore diffusion was much greater than the surface diffusion.

• Environmental Engineering Research
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• v.15 no.4
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• pp.207-213
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• 2010

This study investigated the potential of using bottom ash to be used as an adsorbent for the removal of lead (Pb) from aqueous solutions. The physical and chemical characteristics of bottom ash were determined, with a series of leaching and adsorption experiments performed to evaluate the suitability of bottom ash as an adsorbent material. Trace elements were present, such as silicon and aluminum, indicating that the material had a good adsorption capacity. All heavy metals leached during the Korea standard leaching test (KSLT) passed the regulatory limits for safe disposal, while batch adsorption experiments showed that bottom ash was capable of adsorbing Pb (experimental $q_e$ = 0.05 mg/g), wherein the adsorption rate increased with decreasing particle size. The adsorption data were then fitted to kinetic models, including Lagergren first-order and Pseudo-second order, as well as the Elovich equation, and isotherm models, including the Langmuir, Freundlich and Dubinin-Radushkevich isotherms. The results showed that pseudo-second order kinetics was the most suitable model for describing the kinetic adsorption, while the Freundlich isotherm best represented the equilibrium sorption onto bottom ash. The maximum sorption capacity and energy of adsorption of bottom ash were 0.315 mg/g and 7.01 KJ/mol, respectively.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.381-385
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• 2003

We investigated possible application of waste ferrite in treating Cd and Pb in wastewater. Adsorption of Cd and Pb on Mn-Ferrite are influenced by several controlling factors such as contact time, heavy metal concentrations, pH and temperature. Both Cd and Pb achieved adsorption equilibrium within 5 minutes. Based upon this kinetic data, 24 hours of contact time was allowed for other experiment. The adsorption of Cd and Pb was high at high pH and high ion concentrations. The reaction was also affected by temperature. Adsorption isotherms fits well with the Freundlich isotherm equation. pH is the main controlling factor in Cd, Pb adsorption on the Mn-ferrite. Cd showed S type adsorption curve while Pb showed sorption edges, depending on the Pb concentrations.

• Analytical Science and Technology
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• v.15 no.2
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• pp.163-171
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• 2002

The adsorption characteristics of Cd(II) and Pb(II) ions has been studied by using chitin as an adsorbent. The pure chitin was obtained from the extraction of red-crab shell dumped by fish factory. Adsorption kinetics of Cd(II) and Pb(II) ions on the chitin reached at the maximum adsorption within two minutes. Adsorbed amounts of heavy metals were pH 7.0>10.5>3.5 in the following order. Adsorption ratio by chitin was 21${\sim}$99% for Cd(II) ion and 24${\sim}$95% for Pb(II) ion. Recovery ratio of Cd(II) ion on the chitin was 22${\sim}$53%, and that of Pb(II) ion was 22${\sim}$73%. The adsorption behavior of these heavy metals was explained well by Freundlich adsorption isotherm.

• The Journal of Engineering Geology
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• v.5 no.1
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• pp.75-93
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• 1995

This study investigates the adsorption capacity of the gibbsite and the clay on the development of admixed liner. The gibbsite is produced as a by-product in the pretreatment process for cleaning and coloring of Alurninurn sash. From the study, following conclusions were obtained: 1) The adsorption of metals such as Cu(II), Cd(II), and Ni(II) and phenol on gibbsite and l:entonite was equilibrated rather quickly(12 ~48 hrs ). 2) The rate and extent of adsorption is a function of surface area the adsorbent having. 3) The Larigmuir isotherm is found to be more suitable than Freundlich isotherm for the adsorption analysis of heavy metals on gibbsite and bentonite. 4) In case of phenol, Freundlich isotherm, whose N value is close to 1, i.e., close to linear isotherm, is more fit to describe the adsorption on gibbsite and bentonite. 5) The amount of metals and phenol adsorbed is found to be in the following order : Adsorbent : $2{\mu}m-Al(OH)_3$ > Mixed Solid > $12{\mu}m-Al(OH)_3$ > Na-Bentonite > $30{\mu}m-Al(OH)_3$