Lead(II) Adsorption by Raw and Acid-Activated Vermiculite

2012 ◽  
Vol 557-559 ◽  
pp. 1127-1130 ◽  
Author(s):  
Wen Jun Xiang
Keyword(s):  
Specific Surface ◽  
Surface Charge ◽  
Langmuir Isotherm ◽  
Cation Exchange Capacity ◽  
Zero Point ◽  
Exchange Capacity ◽  
Zero Point Of Charge ◽  
Adsorption Capacities ◽  
Adsorption Data ◽  
Hcl Solution

Acid-activated vermiculite (AAV) was prepared by treating raw vermiculite (RV) at 80°C with HCl solution. The surface properties and Pb(II) adsorption characteristics of RV and AAV were studied. The specific surface area (SSA), cation exchange capacity (CEC), pH at zero point of charge (pHZPC), and surface charge at pH 5.8 of AAV were 287.62 m2/g, 24.85 cmol/kg, pH 3.06, and -0.361 mmol/g, respectively. Compared to RV, the SSA, CEC and surface charge of AAV increased, but the value of pHZPC decreased. At pH 5.8, the maximum adsorption capacities (qmax) for Pb(II) of RV and AAV were 10.72 and 18.53 mg/g, respectively. The adsorption data for Pb(II) by RV and AAV could be well fitted using Langmuir isotherm (R2 =0.990 and 0.995, respectively)

Adsorption Characteristics for Lead(II) by Fulvic Acid-Modified Vermiculite

2012 ◽  
Vol 253-255 ◽  
pp. 939-942
Author(s):  
Wen Jun Xiang
Keyword(s):  
Fulvic Acid ◽  
Cation Exchange Capacity ◽  
Negative Charge ◽  
Zero Point ◽  
Exchange Capacity ◽  
Freundlich Isotherms ◽  
Zero Point Of Charge ◽  
Adsorption Capacities ◽  
Adsorption Data ◽  
Xrd Patterns

Fulvic acid-modified vermiculite (FA-Ver) was prepared by mixing vermiculite and fulvic acid in a suspension. The XRD patterns showed that the vermiculite in FA-Ver possesses an irregular stacking of layers supported and non-supported by fulvic acid particles. The specific surface area (SSA), cation exchange capacity (CEC), pH at zero point of charge (pHZPC), and surface charge at pH 6.0 of FA-Ver was 379.35 m2/g, 52.17 cmol/kg, pH 2.36, and -0.442 mmol/g, respectively. The SSA, CEC and surface negative charge of FA-Ver increased and the pHZPC decreased compared to the corresponding values of vermiculite. Langmuir and Freundlich isotherms fitted the adsorption data for Pb(II) by HA-vermiculite well (R2=0.988 and 0.982, respectively). The Freundlich correlation coefficient of vermiculite was low (R2=0.954) and that of FA-Ver was slightly higher (R2=0.980). At pH 6.0, the Langmuir maximum adsorption capacities for Pb(II) of vermiculite and FA-Ver were 11.86 and 19.41 mg/g, respectively.

Coating Humic Acid on Vermiculite Surface for the Adsorption of Nickel(II)

2012 ◽  
Vol 557-559 ◽  
pp. 1989-1992
Author(s):  
Xu Hong Deng ◽  
Shi Yong Wei
Keyword(s):  
Fractal Dimension ◽  
Negative Charge ◽  
Freundlich Isotherm ◽  
Zero Point ◽  
Exchange Capacity ◽  
Surface Fractal Dimension ◽  
Zero Point Of Charge ◽  
Adsorption Capacities ◽  
Surface Fractal ◽  
Adsorption Data

Surface properties and Ni(II) adsorption characteristics of HA-vermiculite were investigated and compared with those of vermiculite. The cation exchange capacity (CEC), pH at zero point of charge (pHZPC), and surface charge at pH 6.5 and surface fractal dimension of HA-vermiculite were 44.69 cmol/kg, pH 2.57, -0.418 mmol/g, and 2.45, respectively. Compared to vermiculite, the CEC, surface negative charge and surface fractal dimension of HA-vermiculite increased, and the pHZPC of HA-vermiculite decreased. The adsorption data for Ni(II) by HA-vermiculite could be fitted by Langmuir isotherm (R2 =0.982) and also by Freundlich isotherm (R2 =0.987). At pH 6.5, the Langmuir maximum adsorption capacities for Ni(II) of vermiculite and HA-vermiculite were 11.86 and 19.41 mg/g, respectively.

scholarly journals Analysis of the sorption properties of different soils using water vapour adsorption and potentiometric titration methods

2016 ◽  
Vol 30 (3) ◽  
pp. 369-374 ◽  
Author(s):  
Kamil Skic ◽  
Patrycja Boguta ◽  
Zofia Sokołowska
Keyword(s):  
Specific Surface ◽  
Cation Exchange ◽  
Surface Charge ◽  
Surface Area ◽  
Water Vapour ◽  
Potentiometric Titration ◽  
Specific Surface Area ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Sorption Properties

Abstract Parameters of specific surface area as well as surface charge were used to determine and compare sorption properties of soils with different physicochemical characteristics. The gravimetric method was used to obtain water vapour isotherms and then specific surface areas, whereas surface charge was estimated from potentiometric titration curves. The specific surface area varied from 12.55 to 132.69 m2 g−1 for Haplic Cambisol and Mollic Gleysol soil, respectively, and generally decreased with pH (R=0.835; α = 0.05) and when bulk density (R=−0.736; α = 0.05) as well as ash content (R=−0.751; α = 0.05) increased. In the case of surface charge, the values ranged from 63.00 to 844.67 μmol g−1 Haplic Fluvisol and Mollic Gleysol, respecively. Organic matter gave significant contributions to the specific surface area and cation exchange capacity due to the large surface area and numerous surface functional groups, containing adsorption sites for water vapour molecules and for ions. The values of cation exchange capacity and specific surface area correlated linearly at the level of R=0.985; α = 0.05.

scholarly journals Low-temperature synthesis of zeolite from perlite waste — Part II: characteristics of the products

2014 ◽  
Vol 32 (4) ◽  
pp. 526-532 ◽  
Author(s):  
Magdalena Król ◽  
Justyna Morawska ◽  
Włodzimierz Mozgawa ◽  
Waldemar Pichór
Keyword(s):  
Phase Composition ◽  
Low Temperature ◽  
Specific Surface ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Synthesis Parameters ◽  
Autogenous Pressure

AbstractThe paper investigates the properties of sodium zeolites synthesized using the hydrothermal method under autogenous pressure at low temperature with NaOH solutions of varying concentrations. During this modification, zeolites X, Na-P1 and hydroxysodalite were synthesized. The synthesis parameters, and thus, phase composition of resulting samples, significantly affected the specific surface area (SSA) and cation exchange capacity (CEC). SSA increased from 2.9 m2/g to a maximum of 501.2 m2/g, while CEC rose from 16 meq/100 g to a maximum of 500 meq/100 g. The best properties for use as a sorbent were obtained for perlite waste modified with 4.0 M NaOH at 70 °C or 80 °C.

Mineralogical study of clays from Dobrodo, Serbia, for use in ceramics

Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 369-377 ◽  
Author(s):  
Maja Milošević ◽  
Predrag Dabić ◽  
Sabina Kovač ◽  
Lazar Kaluđerović ◽  
Mihovil Logar
Keyword(s):  
Specific Surface ◽  
Cation Exchange ◽  
Surface Area ◽  
Specific Surface Area ◽  
Cation Exchange Capacity ◽  
Mineralogical Composition ◽  
Exchange Capacity ◽  
Mineralogical Characterization ◽  
Mineralogical Study

AbstractThis study focuses on the mineralogical characterization of four raw clay samples from Dobrodo deposit, Serbia. Several analytical methods were applied to determine the chemical and mineralogical composition, morphology and physical properties (colour, plasticity, specific surface area, particle size and cation-exchange capacity) of the clay samples. Kaolinite, smectite and illite are the predominant phases in all of the samples studied that contain between 60.2 and 87.1 wt.% of clay. Quartz, feldspars, paragonite and Ti- and Fe-bearing phases were also identified. The relatively high SiO2/Al2O3 mass ratio indicates abundant quartz. The cation-exchange capacity of the samples varied between low and moderately charged clay minerals (12–52 mmol 100 g–1) with specific surface area values ranging from 94 to 410 m2 g–1. The plasticity index values (11–23%) suggest low to moderate plasticity. Preliminary results show that most of the raw clay from Dobrodo deposit might be suitable for use in ceramic applications.

Surface Properties and Selenate Adsorption of Hydroxyiron-Vermiculite Complexes

2012 ◽  
Vol 482-484 ◽  
pp. 1201-1204 ◽  
Author(s):  
Shi Yong Wei
Keyword(s):  
Fractal Dimension ◽  
Surface Properties ◽  
Langmuir Isotherm ◽  
Ph Value ◽  
Freundlich Isotherm ◽  
Point Of Zero Charge ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Capacities ◽  
Adsorption Data

Hydroxyiron-vermiculite complexes (Fe-Vermiculite) were prepared and identified using X-ray diffraction (XRD). The surface properties and selenate adsorption characteristics of Fe-Vermiculite were investigated. The specific surface area, surface fractal dimension D value and the pH value of the point of zero charge (pHPZC) of vermiculite were 287.19 m2/g, 2.14, and 2.87, respectively, and those of Fe-Vermiculite were 312.48 m2/g, 2.59, and 5.74, respectively. At pH 5.5, the maximum adsorption capacities (qmax) for selenate of vermiculite and Fe-Vermiculite were 4.36 and 9.12 mg/g, respectively. Langmuir isotherm was very suitable for describing the selenate adsorption of vermiculite (R2 =0.993), and Freundlich isotherm could fit the adsorption data for selenate by Fe-Vermiculite (R2 =0.981).

Sign in / Sign up

Export Citation Format

Share Document