Oxidized fulvic acid adsorption on activated carbon

2013 ◽  
Vol 14 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Ivan Kozyatnyk ◽  
Joanna Świetlik ◽  
Ursula Raczyk-Stanisławiak ◽  
Nataliya Klymenko ◽  
Jacek Nawrocki
Keyword(s):  
Free Energy ◽  
Activated Carbon ◽  
Organic Carbon ◽  
Gibbs Free Energy ◽  
Chlorine Dioxide ◽  
Fulvic Acids ◽  
Ozone Treatment ◽  
Free Energy Of Adsorption ◽  
Biodegradable Dissolved Organic Carbon ◽  
Oxidative Effect

This study evaluates and compares the parameters of equilibrium adsorption from aqueous solutions of river fulvic acids (FA) and peat fulvic acids. Compared to peat FA, the river FA had lower biodegradable dissolved organic carbon (BDOC). We observed a tendency for correlation between change of Gibbs free energy of adsorption and BDOC value. A chlorination dose of 1.4 mg L−1 did not change FA biodegradability and adsorbability. ClO2 treatment produced similar results; ClO2 had a stronger oxidizing influence on FA with low BDOC than on FA with high BDOC. In general, the oxidative effect of O3 was greater than Cl2 or ClO2 and the oxidative effect of ClO2 was greater than Cl2. Qi–Schideman and modified Freundlich equations well described all isotherms of FA on activated carbon F300. The content of low-adsorbed substances in peat FA decreased in the sequence: initial solution – Cl2 – ClO2 – O3. A similar difference was also seen with BDOC content in FA solutions. For peat FA with high BDOC content, the low-adsorbed fraction transformed to a strong-adsorbed fraction. Chlorination and chlorine dioxide treatment decreased low-adsorbed fraction absorbability, although ozone treatment increased it, which corresponded with a change in BDOC and a change in Gibbs free energy of adsorption. Chlorination and ClO2 treatment increased the non-adsorbable fraction, and ozonation substantially decreased the non-adsorbable part of the FA. Treatment by chlorine and ozone increased the concentration range of the strong-adsorbed fraction; chlorine dioxide did not significantly influence this fraction.

Dissolved Organic Carbon Removal from a Prairie Water Supply Using Ozonation and Biological Activated Carbon

1999 ◽  
Vol 34 (4) ◽  
pp. 615-632 ◽  
Author(s):  
Joanne Sketchell ◽  
Hans G. Peterson ◽  
Nick Christofi
Keyword(s):  
Activated Carbon ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Source ◽  
Drinking Water Source ◽  
Biological Activated Carbon ◽  
Chlorine Demand ◽  
Biodegradable Dissolved Organic Carbon ◽  
Carbon Filtration ◽  
By Products

Abstract Large quantities of dissolved organic carbon in prairie surface water reservoirs make sustainable treatment quite challenging. Organic material is a precursor for the formation of disinfection by-products. Here, ozonation and biological activated carbon filtration were used as methods for removing dissolved organic carbon from the water of a small prairie reservoir used as a drinking water source. Biofiltration alone yielded significant reductions in dissolved organic carbon, colour, total trihalomethanes and chlorine demand. When ozonation preceded biofiltration, the increased proportion of biodegradable dissolved organic carbon allowed for significantly greater (p<0.05

scholarly journals Platinum Nanoparticles Loaded on Activated Carbon as Novel Adsorbent for the Removal of Congo Red

2012 ◽  
Vol 9 (1) ◽  
pp. 63-74 ◽  
Author(s):  
M. Ghaedi ◽  
S. J. Hossaini ◽  
S. Ramezani
Keyword(s):  
Free Energy ◽  
Activated Carbon ◽  
Platinum Nanoparticles ◽  
Congo Red ◽  
Adsorption Process ◽  
Second Order ◽  
Particle Diffusion ◽  
Free Energy Of Adsorption ◽  
Pseudo Second Order ◽  
Enthalpy And Entropy

Platinum nanoparticles loaded on activated carbon as novel adsorbent was successfully applied for efficient removal of congo red. The influences of effective parameters including contact time, pH and temperature, amount of adsorbents and concentration of initial dye on the efficiency of removal of congo red from aqueous solution were investigated. Adsorption experiments indicate that the extent of adsorption is strongly dependent on pH of solution. Thermodynamic parameters like Free energy of adsorption, enthalpy and entropy changes were calculated to know the nature of adsorption. The calculated values of free energy of adsorption (negative value) indicate that the adsorption process is spontaneous. The estimated values of enthalpy and entropy both show the positive sign, which indicate that the adsorption process is endothermic and the dye molecules are organized on the adsorbent surface in more randomly fashion than in solution. Fitting experimental data to different kinetic models including first order, pseudo second order and Elovich and intra-particle diffusion models shows that the rate of dye adsorption follows pseudo second order model and involvement of intera- particle diffusion mechanism.

Toward Accurate and Efficient Predictions of Entropy and Gibbs Free Energy of Adsorption of High Nitrogen Compounds on Carbonaceous Materials

2014 ◽  
Vol 118 (9) ◽  
pp. 4774-4783 ◽  
Author(s):  
Andrea Michalkova Scott ◽  
Leonid Gorb ◽  
Elizabeth A. Burns ◽  
Sergey N. Yashkin ◽  
Frances C. Hill ◽  
...  
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Nitrogen Compounds ◽  
Carbonaceous Materials ◽  
High Nitrogen ◽  
Free Energy Of Adsorption

scholarly journals Hysteresis and thermodynamic properties of water sorption in ‘Malagueta’ pepper seeds

2018 ◽  
Vol 22 (9) ◽  
pp. 658-663
Author(s):  
Hellismar W. da Silva ◽  
Renato S. Rodovalho ◽  
Isneider L. Silva
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Gibbs Free Energy ◽  
Water Sorption ◽  
Water Adsorption ◽  
Gravimetric Method ◽  
Free Energy Of Adsorption ◽  
Adsorption And Desorption ◽  
Moisture Contents ◽  
Compensation Theory

ABSTRACT The objective of this study was to determine hysteresis, enthalpy, entropy, enthalpy-entropy compensation theory and Gibbs free energy for water adsorption and desorption in ‘Malagueta’ pepper seeds. Hygroscopic equilibrium moisture contents were determined by the static gravimetric method, with water activity in the range from 0.29 to 0.90 and temperatures of 30, 40 and 50 °C. The hysteresis of the ‘Malagueta’ pepper seeds reduces with the increase of temperature. Enthalpy, entropy and Gibbs free energy of adsorption and desorption increase with the reduction of the moisture content of the seeds. The enthalpy-entropy compensation theory is valid for the sorption processes. The sorption of water between seeds and the surrounding air is a non-spontaneous process.

scholarly journals Adsorption Efficiency of Activated Carbon Produced from Corn Cob for the Removal of Cadmium Ions from Aqueous Solution

2019 ◽  
pp. 12-20
Author(s):  
Ezeh Ernest ◽  
Okeke Onyeka ◽  
Aburu C. M. ◽  
Aniobi C. C. ◽  
Ndubuisi J. O
Keyword(s):  
Aqueous Solution ◽  
Free Energy ◽  
Activated Carbon ◽  
Adsorption Process ◽  
Adsorption Efficiency ◽  
Corn Cob ◽  
Free Energy Of Adsorption ◽  
Cadmium Ions ◽  
Gibb’S Free Energy ◽  
Peak Value

Studies were carried out to evaluate the adsorption efficiency of activated carbon produced from corn cob for the removal of Cd II ions from aqueous solution. The studies were carried out with due consideration of standard analytical procedures and instrumentation. Increase in the Cd II ions concentration from 90 to 180mg/l decreased the adsorption capacity of the adsorbent from 89.273 to 65.770%. Increase in the adsorbent’s dosage from 0.5 to 2.0g increased the adsorption of Cd II ions from 81.522 to 91.980%. At pH of 5.0, the adsorption process attained equilibrium with a peak adsorption of Cd II ion at 93.628%. At a contact of time of 30mins between the adsorbate (Cd II ions) at the adsorbent; the adsorption of Cd II ions reached a peak value of 92.410%. The adsorption of Cd II ions on the surface of the activated carbon increased from 90.436 to 93.210% with increase in temperature from 40o to 160oC. The decrease in Gibb’s free energy of adsorption of Cd II ions on the surface of the activated carbon revealed that the adsorption was favourable at high temperatures. The positive values of ∆H and ∆S shows that the adsorption process was endothermic.

Sign in / Sign up

Export Citation Format

Share Document