A Comparative Study of Surface Acid–Base Characteristics of Natural Illites from Different Origins

Liu, Wenxin; Sun, Zhong-Xi; Forsling, Willis; Du, Qing; Tang, Hongxiao

doi:10.1006/jcis.1999.6448

Cited by 49 publications

(38 citation statements)

References 43 publications

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“…The total surface sites concentration (Hs, mol/l) of the nanoparticles can be calculated by the formulas shown by Liu et al [27]. The total concentration of reacted protons (TOTH, mol/l) in each titration point was calculated by the following formulas:…”

Section: Characterization Of Nanoparticles and Their Complexesmentioning

confidence: 99%

Sorption of atrazine onto humic acids (HAs) coated nanoparticles

Yan

et al. 2009

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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a b s t r a c tWith the development of nanotechnologies, a large number of nano-materials with novel properties are being released into the environment. However, little is known about their fate, transport, toxicity and interactions with organic matters in aqueous environment. In this study, nano-SiO 2 or kaolinite, coated with soil humic acid (SHA) and peat humic acid (PHA), were used as sorbents. The original and HA-coated nanoparticles were characterized for particle size, TEM and electrophoretic mobility. Sequential ultrafiltration (UF) was used to characterize the molecular size fractionations of dissolved HAs. Sorption data of atrazine (AT) under various solution concentration, ionic strength and pH were well fitted with Freundlich model. Sorption amount of AT on HA-coated nanoparticles was significantly lower than that on original particles. The sorption maximum appeared at I = 0.001 mol/l (NaNO 3 ), pH 3. Size of nanoparticle aggregates, conformation of HA and specific surface area were factors affecting the sorption process. The compressed conformation of HA was more favorable for HA sorption than expanded one. Size of aggregation was not a determinant factor for the sorption process, while the specific surface areas of nano-sorbent was an important one. Results indicated that HA plays an important role in the transport and toxicity of nanoparticles and AT in aqueous environment.

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Section: Characterization Of Nanoparticles and Their Complexesmentioning

confidence: 99%

Sorption of atrazine onto humic acids (HAs) coated nanoparticles

Yan

et al. 2009

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…In certain previous studies (Stadler and Schindler, 1993;Chorover and Sposito, 1995;Ludwig and Schindler, 1995;Du et al, 1997;Liu et al, 1999), in-situ Gran plots were utilized to determine the standard electrode potential and the volume of titrant added at the equivalence point for the potentiometric titration of suspension systems. In this study, the Gran plots for B. cereus biomass suspension system, as shown in Fig.4, were adopted to ascertain the specific volume of the titrant added at the equivalence point (V e ), furthermore, to calibrate zero titration point and to calculate the total surface site concentration.…”

Section: Determination Of Total Surface Site Concentrationmentioning

confidence: 99%

Surface reaction of Bacillus cereus biomass and its biosorption for lead and copper ions

Pan

Liu

Tang

2007

Journal of Environmental Sciences

105

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In this study, the surface chemical functional groups of Bacillus cereus biomass were identified by Fourier transform infrared (FTIR) analytical technique. It had been shown that the B. cereus cells mainly contained carboxyl, hydroxyl, phosphate, amino and amide functional groups. The potentiometric titration was conducted to explain the surface acid-base properties of aqueous B. cereus biomass. The computer program FITEQL 4.0 was used to perform the model calculations. The optimization results indicated that three sitesthree pK a s model, which assumed the cell surface to have three distinct types of surface organic functional groups based on the IR analysis results, simulated the experimental results very well. Moreover, batch adsorption experiments were performed to investigate biosorption behavior of Cu(II) and Pb(II) ions onto the biomass. Obviously, the adsorption equilibrium data for the two ions were reasonably described by typical Langmuir isotherm.

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“…H S is an index of the surface reactive site concentration of the solid particles. The sorbent presents larger H S value produces the higher sorption capacity for ion chemicals [36,37]. The acid-base titration experiments show that H S values are higher for sediment samples and lower for soil samples, and increases when decreasing the particle size (Table 4).…”

Section: Physicochemical Characteristics Of Sample and Subsample Partmentioning

confidence: 97%

“…Potentiometric titration can be used to determine the sequential binding of the proton by the surface functional groups of solid particles [35][36][37][38]. An automatic potentiometric titration system (665 Dosimat, Metrohn Co., Greece) equipped with a glass electrode in conjunction with a double-junction Ag/AgCl reference electrode was utilized here to carry out the back-titration process.…”

Section: Acid-base Titrationmentioning

confidence: 99%

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Sorption interaction of phenanthrene with soil and sediment of different particle sizes and in various CaCl2 solutions

Zhou

Liu

Tang

2004

Journal of Colloid and Interface Science

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The objective of this investigation is to evaluate the influences of natural sorbent particle size and system Ca 2+ concentration on sorption of low-polarity organic chemicals. The physicochemical properties of the different particle size soil and sediment subsamples and the surface characters of the soil and sediment samples in various CaCl 2 concentrations were determined. The sorption behavior of phenanthrene (PHN) on the subsamples of different particle size and to the samples in various CaCl 2 solutions was examined. Batch experiments demonstrate that the sorption capacities increase with decreased particle size for both soil and sediment. It is presumably due to the higher total organic carbon (TOC) content for the finer particles. But the enhancements in sorption coefficients are not met with the equal increases in TOC contents. The effect of Ca 2+ on PHN uptake is strong in short contact time but slight in long contact time. With increasing Ca 2+ concentration, the sorption capacities for Beizhai soil increase first in the low Ca 2+ concentration range, and then decline. Nevertheless, the increase of Ca 2+ concentration greatly reduces the uptake of phenanthrene on Guanting sediment over the overall measured range. The different physicochemical properties, such as dissolved organic carbon (DOC) content, mineral and element composition, and surface characters, between soil and sediment may result in this discrepancy.

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A Comparative Study of Surface Acid–Base Characteristics of Natural Illites from Different Origins

Cited by 49 publications

References 43 publications

Sorption of atrazine onto humic acids (HAs) coated nanoparticles

Sorption of atrazine onto humic acids (HAs) coated nanoparticles

Surface reaction of Bacillus cereus biomass and its biosorption for lead and copper ions

Sorption interaction of phenanthrene with soil and sediment of different particle sizes and in various CaCl2 solutions

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