• Title/Summary/Keyword: equilibrium isotherm

Search Result 366, Processing Time 0.022 seconds

Characteristics of arsenic sorption on furnace slag in groundwater

  • S. R. Kanel;Saurabh Sharma;Park, Hechul
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • 2002.09a
    • /
    • pp.96-98
    • /
    • 2002
  • Furnace slag, a steel industry waste, has been converted into an inexpensive and efficient adsorbent. The product obtained has been utilized for the removal of arsenic from ground water. Kinetic studies have bepn described with the mechanism of adsorption The results from batch studies showed that the As(III) can be removed from the ground water within the pH range 3-7 However the maximum removal was experienced at pH 7.0. Equilibrium was attained within 24 hours. Adsorption data of arsenic correlate well with the Freundlich and Langmuir adsorption models. The maximum sorption capacity as calculated using Freundlich adsorption isotherm was found to be of 0.004 mg g-1 at pH 7 and $25^{\circ}C$.

  • PDF

Adsorption mechanism of copper ions on porous chitosan membranes: Equilibrium and XPS study

  • Ghaee, Azadeh;Zerafat, Mohammad Mahdi
    • Membrane and Water Treatment
    • /
    • v.7 no.6
    • /
    • pp.555-571
    • /
    • 2016
  • Heavy metal contamination has attracted considerable attention during recent decades due to the potential risk brought about for human beings and the environment. Several adsorbent materials are utilized for the purification of contaminated water resources among which chitosan is considered as an appropriate alternative. Copper is a heavy metal contaminants found in several industrial wastewaters and its adsorption on porous and macroporous chitosan membranes is investigated in this study. Membranes are prepared by phase inversion and particulate leaching method and their morphology is characterized using SEM analysis. Batch adsorption experiments are performed and it is found that copper adsorption on macroporous chitosan membrane is higher than porous membrane. The iso-steric heat of adsorption was determined by analyzing the variations of temperature to investigate its effect on adsorption characteristics of macroporous chitosan membranes. Furthermore, desorption experiments were studied using NaCl and EDTA as eluants. The mechanism of copper adsorption was also investigated using XPS spectroscopy which confirms simultaneous occurrence of chelation and electrostatic adsorption mechanisms.

A Study on Natural Dyeing (5) - Adsorption Properties of Berberine for Silk Fabrics - (천연염색에 관한 연구(5) - 황벽색소 베르베린의 견에 대한 염착특성 -)

  • Kim, Hye In;Park, Su Min
    • Textile Coloration and Finishing
    • /
    • v.14 no.2
    • /
    • pp.85-85
    • /
    • 2002
  • The interaction between berberine and tannin in aqueous solution was investigated spectrophotometerically. The dyeing mechanism of silk fabrics (control and tannin treated silk fabrics) with berberine was based on thermodynamic parameters obtained from equilibrium adsorption experiments. In adsorption spectra of aqueous solution of berberine and tannin mixture two isosbestic points (328nm, 357nm) were found and the mole fraction of reaction of components was 1:1. Initial dyeing rates were increased and the diffusion of dye was more effective by tannin treatment. Without regard to tannin treatment the adsorption isotherm of berberine was the langmuir type except high temperature, 80℃. By tannin treatment the saturation dye uptake was increased, the increase of dye uptake appeared to be a result of entropy change rather than enthalpy change. All these results can be interpreted by the hydrophobic interaction between berberine and silk treated with tannin and it is reasonable to conclude that not only the ionic force, but also the hydrophobic interaction contributes to the binding of berberine and tannin treated silk treated with tannin.

A Study on Natural Dyeing (5) - Adsorption Properties of Berberine for Silk Fabrics - (천연염색에 관한 연구(5) -황벽색소 베르베린의 견에 대한 염착특성 -)

  • 박수민;김혜인
    • Textile Coloration and Finishing
    • /
    • v.14 no.2
    • /
    • pp.9-17
    • /
    • 2002
  • The interaction between berberine and tannin in aqueous solution was investigated spectrophotometerically. The dyeing mechanism of silk fabrics (control and tannin treated silk fabrics) with berberine was based on thermodynamic parameters obtained from equilibrium adsorption experiments. In adsorption spectra of aqueous solution of berberine and tannin mixture two isosbestic points (328nm, 357nm) were found and the mole fraction of reaction of components was 1:1. Initial dyeing rates were increased and the diffusion of dye was more effective by tannin treatment. Without regard to tannin treatment the adsorption isotherm of berberine was the langmuir type except high temperature, $80^\circ{C}$. By tannin treatment the saturation dye uptake was increased, the increase of dye uptake appeared to be a result of entropy change rather than enthalpy change. All these results can be interpreted by the hydrophobic interaction between berberine and silk treated with tannin and it is reasonable to conclude that not only the ionic force, but also the hydrophobic interaction contributes to the binding of berberine and tannin treated silk treated with tannin.

Adsorption Charateristics of Tartrazine by Activated Carbon (활성탄에 의한 Tartrazine의 흡착 특성)

  • Yoon, Sung Wook;Lee, Jong-Jib
    • Journal of Korean Society on Water Environment
    • /
    • v.25 no.4
    • /
    • pp.568-572
    • /
    • 2009
  • The adsorption characteristics of tartrazine by granular activated carbon were experimentaly investigated in the batch adsorber and the packed column. The adsorptivity of activated carbon for tartrazine was largely improved by pH control, and 98 percent of initial concentration could be removed at pH 3. It was estabilished that the adsorption equilibrium of tartrazine on granular activated carbon was sucessfully fitted by Freundlich isotherm equation in the concentration range from 50 mg/L to 1,000 mg/L. The characteristics of breakthrough curve of activated carbon packed column, which depend on the design variables such as initial concentration, bed height, and flow rate, were studied.

Prediction of the Dynamic Adsorption Behaviors of Uranium and Cobalt in a Fixed Bed by Surface Modified Activated Carbon

  • Park, Geun-Il;Lee, Jung-Won;Song, Kee-Chan;Kim, In-Tae;Kim, Kwang-Wook;Yang, Myung-Seung
    • Proceedings of the Korean Radioactive Waste Society Conference
    • /
    • 2003.11a
    • /
    • pp.73-77
    • /
    • 2003
  • In order to predict the dynamic behaviors of uranium and cobalt in a fixed bed at various influent pH values of liquid waste, the adsorption system was regarded as multi-component adsorption between each ionic species in a solution. Langmuir isotherm parameters of each species were extracted by incorporating equilibrium data with the solution chemistry of uranium and cobalt using IAST. Prediction results were in good agreement with the experimental data, except for a high concentration and pH. Although there was some limitations in predicting the cobalt adsorption, this method may be useful in analyzing a complex adsorption system where various kinds of ionic species exist in a solution.

  • PDF

Studies on Silk Fibroin Membranes(II) -Adsorption of Acid Dyes in Silk Fibroin Memberane- (Silk Fibroin 막에 관한 연구 (II) -Silk Fibroin 막에 대한 산성염료의 흡착-)

  • 최해욱;박수민;김경환
    • Textile Coloration and Finishing
    • /
    • v.6 no.3
    • /
    • pp.60-66
    • /
    • 1994
  • With the view of studying on the dual adsorption mechanism of acid dyes in connection with the structural difference of silk fibroin, silk fiber and silk fibroin memberane were used for equilibrium dyeing at $60^{\circ}C$, $70^{\circ}C$, $80^{\circ}C$ and pH 3.2, pH 5.0. The dyes used were C.I.Acid Orange 7 and C.I.Acid Red 88 introduced aromatic hydrocabon into Acid Orange 7. From the adsorption isotherm experiment, the total uptake of dyes can be described by Langmuir sorption and Nernst partition. Nernst partition. Nernst partition coefficient $K_1$ decrease of crystalline regions and orientation. The saturation value S of Acid Red 88 were large than total amino group contents and it was attributed it hydrophobic bond. On the other hand, the standard afficity and enthalpy were increased with the in crease of hydrophobic part of dyes. Both $k_1$ and $K_2$ were decreased with the increase of pH, but $k_2$ were more effected than $K_1$.

  • PDF

Adsoption Removal of PCBs by Activated Carbon (활성탄에 의한 PCBs의 흡착제거)

  • Yu, Yong-Ho;Lee, Jong-Jig
    • Journal of the Korean Society of Safety
    • /
    • v.21 no.1 s.73
    • /
    • pp.59-64
    • /
    • 2006
  • In this study, adsorption characteristics of PCBs on granular activated carbon were experimentally investigated in a batch reactor and in a fixed bed reactor. Granular activated carbon removed above 98.4% of initial concentration, 1000mg/L, of PCBs. It was estabilished that the adsorption equilibrium of PCBs on granular activated carbon was more successfully fitted by Freundlich isotherm equation in the concentration range from 1 to 1000mg/L. Because Freundlich parameter, ${\beta}$ is 0.346, removall treatment of PCBs by activated carbon accounts for the fact that toxicity reduction can be achieved through this process. Appearance time of breakthrough curve is faster with the increase flow rate and inflow concentration of liquid. The utility of granular activated carbon is enhanced with the increase of bed height and with the decrease of inflow rate.

Phosphate removal in water by mesostructure based on titanium and silica (티타늄과 실리콘 기반의 메조구조체를 이용한 수중의 인 제거)

  • Lee, Seung-Yeon;Choi, Jae-Woo;Lee, Sang-Hyup;Lee, Ki-Bong;Hong, Seok-Won
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.25 no.5
    • /
    • pp.725-730
    • /
    • 2011
  • In this study, it was investigated that the feasibility of utilizing inorganic mesostructures for removal of phosphate in water. The comparison of the efficiency for phosphate adsorption between inorganic mesostructures was conducted. X-ray diffraction(XRD) and Brunauer-Emmett-Teller(BET) methods were used to characterize these mesostructures. The efficiencies of silica and titanium mesostructures for the removal of phosphate from aqueous solution were investigated. Equilibrium data were analyzed using the Langmuir isotherm. The maximum adsorption capacities of mesostructure adsorbents were found to be 49.3 and 19.5 mg $g^{-1}$ for the titanium and silica mesostructures, respectively. The adsorption kinetics was described by a pseudo third-order kinetic model. The results from this study indicated that the titanium mesostructure has the potential to be utilized for the cost-effective removal of phosphate from wastewater.

Removal of Amaranth by Activated Carbon Adsorption (활성탄 흡착에 의한 Amaranth의 제거)

  • Lee, Jong-Jib;Yoon, Sung-Wook
    • Journal of the Korean Society of Safety
    • /
    • v.24 no.4
    • /
    • pp.34-39
    • /
    • 2009
  • The adsorption characteristics of amatanth by granular activated carbon were experimently investigated in the batch adsorber and the packed column. The adsorptivity of activated carbon for amaranth were largely improved by pH control, and 94 percent of initial concentration(100mg/L) could be removed at pH 9. It was estabilished that the adsorption equilibrium of amaranth on granular activated carbon was sucessfully fitted by Freundlich isotherm equation in the concentration range from 1mg/L to 100mg/L. The characteristics of breakthrough curve of activated carbon packed column, which depend on the design variables such as initial concentration, bed height, and flow rate, were studied.