Hybrid Clay: A New Highly Efficient Adsorbent for Water Treatment

Unuabonah, Emmanuel I.; Günter, Christina; Weber, Jens; Lubahn, Susanne; Taubert, Andreas

doi:10.1021/sc400051y

Cited by 131 publications

(125 citation statements)

References 42 publications

Supporting

Mentioning

110

Contrasting

Order By: Relevance

“…The second rapid mass loss stage around 110 to 400 °C is mainly attributed to the pyrogenic decomposition of cellulose and hemicellulose. The last stage (400 to 600 °C) of slight mass loss in fiberboards is accompanied by the calcination of charcoal (Chen et al 1993;Zeriouh and Belkbir 1995;Shen and Kawi 1999;Chen et al 2005;Chiranjeevi et al 2006;Unuabonah et al 2013). These results are in agreement with char yield and FTIR analysis.…”

supporting

confidence: 85%

Fire Performance of Ultra-Low Density Fiberboard (ULDF) with Complex Fire-Retardants

Liu¹,

Chen²,

Wei³

et al. 2016

BioResources

View full text Add to dashboard Cite

To clarify how the fire performance of ultra-low density fiberboard (ULDF) can be improved by complex fire-retardants, the limiting oxygen index (LOI) and microstructure of ULDFs with different additive amounts of complex fire-retardants was analyzed. The char yield, chemical bonding, and thermostability of ULDFs treated by different temperatures were also tested. Results showed that the LOI values and compactness of ULDFs were increased with increased amounts of fire-retardants. Three steps of char yield curves in control fiberboard (CF) and mixed fiberboard (MF) were apparent. The preliminary degradation in lignin and cellulose of CF occurred at 300 °C. The cellulose had completely decomposed at 400 °C, but in the case of MF, the lignin and cellulose were not completely decomposed at 400 °C. It was shown that there are different ways to improve the fire resistance of ULDF using boron, nitrogen-phosphorus, silica, and halogen-based fire-retardants. The fiberboard with silicium compounds had the lowest mass loss in three stages and total mass loss. Compared with CF, MF had a lower mass loss. Furthermore, the exothermic peak for MF at around 400.0 °C was decreased, indicating that the fire resistance of ULDF was improved by the complex fire-retardants.

show abstract

supporting

confidence: 85%

Fire Performance of Ultra-Low Density Fiberboard (ULDF) with Complex Fire-Retardants

Liu¹,

Chen²,

Wei³

et al. 2016

BioResources

View full text Add to dashboard Cite

show abstract

“…The strong preference for Pb 2? exhibited by GHA-modified kaolinite is possibly due to the ease of this metal ion to loose its hydration shell and be adsorbed as compared with other metal ions with higher hydration shell energies (Unuabonah et al 2013). The Jahn-Teller effect makes the adsorption capacity of the modified adsorbent for Cu 2? higher than that for Zn 2?…”

Section: Equilibrium Studiesmentioning

confidence: 99%

Competitive adsorption of metal ions onto goethite–humic acid-modified kaolinite clay

Unuabonah

Olu-Owolabi

Adebowale

2016

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

A binary mixture of humic acid and geothite was prepared and used to modify kaolinite to produce geothite-humic acid (GHA)-modified kaolinite adsorbent useful for the adsorption of Pb 2? , Cd 2? , Zn 2? , Ni 2? and Cu 2? from Single and Quinary (5) metal ion systems. The cation exchange capacity (CEC) and specific surface area of GHA-modified kaolinite clay adsorbent were found to be 40 meq/100 g and 13 m 2 /g, respectively, with the CEC being five times that of raw kaolinite clay (7.81 meq/ 100 g). The Langmuir-Freundlich equilibrium isotherm model gave better fit to experimental data as compared with other isotherm models. In Quinary metal ion system, the presence of Zn . The GHA-modified kaolinite showed strong preference for the adsorption of Pb 2? in both metal ion systems. BrouersWeron-Sotolongo (BWS) kinetic model gave better fit to kinetic data compared with other kinetic models used. Data from BWS kinetic model indicate that adsorption of metal ions onto GHA-modified adsorbent in both metal ion systems followed strictly, diffusion-controlled mechanism with adsorption reaction proceeding to 50 % equilibrium in\2 min in the Single metal ion system and\1 min in the Quinary metal ion system. Adsorption of metal ions onto GHA-modified kaolinite is fairly spontaneous and endothermic in nature in both metal ion systems although the rate of metal ion uptake and spontaneity of reaction are reduced in the Quinary metal ion system.

show abstract

“…Synergistic combinations of clays and biosorbents (both being low cost adsorbents) are beginning to receive attention [31] because these low cost sorbents are generally believed to increase the subsequent properties of the new adsorbents. This is achieved by combining individual characteristics of each composite to yield fewer final adsorbent limitations than the pure individual low cost adsorbents.…”

Section: Introductionmentioning

confidence: 99%

“…Such synergistic combinations may lead to better sorbent properties such as high cation exchange capacity (CEC), reduce/eliminate bleeding, enhanced mechanical strength, pore size and consequently higher adsorption efficiency, better stability and durability, re-usability, sometimes larger surface area and even comparatively lower cost for water treatment. Some of these goals have been achieved by the calcination of kaolinite clays with pulverized Carica papaya seeds [31]. However, some clay properties suggest that not all such synergistic combinations may yield composites of better adsorption efficiencies.…”

Section: Introductionmentioning

confidence: 99%

Calcined biomass-modified bentonite clay for removal of aqueous metal ions

Olu-Owolabi

Alabi

Unuabonah

et al. 2016

Journal of Environmental Chemical Engineering

Self Cite

View full text Add to dashboard Cite

A B S T R A C TRecent studies have shown that kaolinite clay modified with biosorbents are promising low cost adsorbents for the removal of metals from aqueous solution because the resultant composites have higher adsorption capacities, and hence a better aqueous metal ions removal efficiencies. However, some clay properties suggest that not all such modifications enhance adsorption capacity. In this study, bentonite (BEN) clay was calcined after modification with Carica papaya seeds or pine cone to obtain C. papaya-modified bentonite (CPB) and pine cone-modified bentonite (PCB). The efficiencies of these adsorbents for the removal of Pb(II), Cu(II) and Cd(II) ions from aqueous solutions were studied as a function of pH, time, sorbate concentration and temperature. X-ray diffraction results showed that CPB and PCB had lattice structure as BEN, but reductions in the surface areas of CPB and PCB were observed. Adsorption results showed that pH did not significantly affect removal of aqueous metal ions between pH 3 and 7. The adsorption fitted pseudo-second order (r 2 ! 0.966) and intra-particle diffusion models and indicated mainly surface phenomena involving sharing of electrons between the adsorbent surfaces and the metal ion species. Unlike Cu(II) and Cd(II), Pb(II) adsorption reduced in CPB and PCB indicating that not all calcined biomass-clay composites have enhanced aqueous metal adsorption efficiency. However, undesired properties such as adsorbent bleeding were removed and mechanical strength enhanced while easier separation of the adsorbents from solution as compared to the raw bentonite was observed.

show abstract

Hybrid Clay: A New Highly Efficient Adsorbent for Water Treatment

Cited by 131 publications

References 42 publications

Fire Performance of Ultra-Low Density Fiberboard (ULDF) with Complex Fire-Retardants

Fire Performance of Ultra-Low Density Fiberboard (ULDF) with Complex Fire-Retardants

Competitive adsorption of metal ions onto goethite–humic acid-modified kaolinite clay

Calcined biomass-modified bentonite clay for removal of aqueous metal ions

Contact Info

Product

Resources

About