Aluminium ions at polyelectrolyte interfaces. II. Role in the surface-area-exclusion chromatography of humic acid

2001 ◽  
Vol 279 (5) ◽  
pp. 493-497 ◽  
Author(s):  
E. Pefferkorn ◽  
J. Widmaier ◽  
F. Elfarissi
Keyword(s):  
Humic Acid ◽  
Surface Area ◽  
Exclusion Chromatography

Photocatalytic Degradation of Humic Acid Using Ti/Anodized TiO2 Metal Plate with Fe-Doping

2012 ◽  
Vol 724 ◽  
pp. 33-36 ◽  
Author(s):  
Jong Oh Kim ◽  
Seung Pil Choi ◽  
Geon Tae Kim ◽  
Yong Hak Kim
Keyword(s):  
Humic Acid ◽  
Photocatalytic Degradation ◽  
Surface Area ◽  
Acid Concentration ◽  
Uv Irradiation ◽  
Metal Plate ◽  
Fe Doping ◽  
Treatment Efficiency ◽  
Acid Degradation ◽  
Hypochromic Effect

We evaluated the treatment efficiency of humic acid using Ti and anodized TiO2metal plate with/without Fe-doping. Variation of humic acid concentration after 60 minutes of UV irradiation in the case of Ti only, Fe-Ti, TiO2only and Fe-TiO2was about 3.0%, 5.5%, 9.8% and 9.2%, respectively. . It is found that hypochromic effect was revealed in all cases with respect to doping time. Fe doping method is considered to be effective for humic acid degradation in spite of relatively low surface area of Ti and anodized TiO2metal plate.

Examination of Penetrable Volumes ("Pores") in A High-Performance Size-Exclusion Chromatography Matrix

1985 ◽  
Vol 43 ◽  
pp. 386-387
Author(s):  
W. E. Rigsby ◽  
W. L. Lingle ◽  
D. J. O Kane ◽  
J. Lee
Keyword(s):  
Surface Area ◽  
Size Exclusion Chromatography ◽  
High Performance ◽  
Matrix Material ◽  
Total Surface Area ◽  
Size Exclusion ◽  
Prediction Errors ◽  
The Matrix ◽  
Exclusion Chromatography ◽  
Separation Of Proteins

The separation of proteins by high performance size exclusion chromatography (HPSEC) is based upon the interaction of a protein, having an effective hydrodynamic radius, A, with "pores" in the HPSEC matrix material. Two different theoretical treatments (1, 2) yield widely different estimates of the mean "pore" radius, Ao, and have different prediction errors for A. A given "pore" can be characterized by the radius of the largest molecule that it can accomodate, Ai If A > Ai, the protein is excluded from the "pore".The "pore" diameter value quoted for TSK G3000 SW is 24.0nm (3). This is at variance with A0 calculated by either treatment using the same HPSEC data: 28.4 ± 6.3nm (1) and 0.89 ± 5.4nm (2). From a knowledge of the "pore" volume it was calculated that approximately 50% of the total surface area of the HPSEC matrix corresponded to "pore". If Ae = 28.4nm, then ≥ 25% of the total surface area of the matrix should be occupied by "pores" with radii ≥ 28.4nm. These results prompted an investigation of the structure and size of "pores" in the HPSEC matrix material TSK G3000 SW.

Chlorsulfuron Adsorption by Humic Acid, Iron Oxides, and Montmorillonite

Weed Science ◽  
1988 ◽  
Vol 36 (4) ◽  
pp. 530-534 ◽  
Author(s):  
Ole K. Borggaard ◽  
Jens C. Streibig
Keyword(s):  
Humic Acid ◽  
Surface Charge ◽  
Surface Area ◽  
Iron Oxides ◽  
Acidic Solution ◽  
Background Electrolyte ◽  
Acid Base ◽  
Weakly Acidic Solution ◽  
Ph Conditions ◽  
Soil Constituents

An investigation of the adsorption of chlorsulfuron by four selected soil constituents, i.e. humic acid, two iron oxides, and montmorillonite, was carried out under concentration and pH conditions similar to those in most natural soils. CaCl2(0.01 M) was used as background electrolyte to suppress nonspecific adsorption. Negligible amounts of chlorsulfuron were adsorbed by montmorillonite, whereas humic acid and the iron oxides were found to be important adsorbents. For these adsorbents, chlorsulfuron adsorption decreased when pH increased from 4 to 8, with little adsorption occurring at pH 8. Adsorption by iron oxides was a function of their surface area. Chlorsulfuron adsorption was found to be closely related to the surface charge of the adsorbents, but in weakly acidic solution, also to the acid-base properties of chlorsulfuron itself.

Evaluation of photocatalytic degradation of a commercial humic acid in water using a simulated solar UV irradiation and monitoring the changes by size exclusion chromatography

2011 ◽  
Vol 11 (6) ◽  
pp. 692-698 ◽  
Author(s):  
S. Valencia ◽  
J. Marín ◽  
G. Restrepo ◽  
F. H. Frimmel
Keyword(s):  
Humic Acid ◽  
Photocatalytic Degradation ◽  
Size Exclusion Chromatography ◽  
Uv Irradiation ◽  
Molecular Size ◽  
Size Exclusion ◽  
Size Fractions ◽  
Preferential Adsorption ◽  
Exclusion Chromatography ◽  
Solar Uv

Much research has been undertaken on the photocatalytic degradation of humic substances with titanium dioxide using commercial humic acids (HA), which are extracts from either peat or coal. Most of the research has been focused on the changes in dissolved organic carbon (DOC) and UV254 absorption. These parameters only give a general assessment. This work studies the changes in the physical and structural properties of a commercial humic acid by size exclusion chromatography with DOC and UV254 absorption detection (SEC-DOC, SEC-UV254), and the evolution of halogenated organic compounds (AOX) and trihalomethanes (THMs) during the photocatalytic degradation with simulated solar UV irradiation and Degussa P-25 TiO2. These changes are compared with those reported for natural organic matter (NOM). The photodegradation of commercial HA and NOM proceeds in a similar and sequential manner, initially with the preferential adsorption of larger molecules, then the degradation of these larger molecular size fractions and proceeding towards smaller molecular size fractions, while decreasing THMs and AOX formation potential.

scholarly journals Structural Characterization and Adsorption Capability of Carbonaceous Matters Extracted from Carbonaceous Gold Concentrate

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Huiqun Niu ◽  
Hongying Yang ◽  
Linlin Tong
Keyword(s):  
Particle Size ◽  
Humic Acid ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Mesoporous Structure ◽  
Average Pore Diameter ◽  
Average Pore ◽  
Complex Organic Compound

In this paper, the structures of element carbon and humic acid extracted from carbonaceous gold concentrate were characterized employing a variety of analytical methods. The extracted amounts of ECE (elemental carbon extract) and HAE (humic acid extract) were 14.84–38.50 and 11.55–28.05 mg g−1, respectively. SEM and porosity analysis indicated that ECE occurred mostly as irregular blocky particles with a mesoporous surface with the average pore diameter being 31.42 nm. The particle size of ECE was mainly ranged from 5.5 to 42 μm and the specific surface area was 20.35 m2 g−1. The physicochemical features and structure of ECE were close to activated carbon, and the crystallinity was slightly lower than graphite. The particle size distribution of HAE varied from 40 to 400 nm with the specific surface area of 42.84 m2 g−1, whereas the average pore diameter of HAE was 2.97 nm. FTIR and UV–VIS analyses indicated that HAE was a complex organic compound containing the enrichment of oxygen-containing structure. The results showed that the adsorption amounts of ECE and HAE under the acidic conditions were 470.46 and 357.60 mg g−1, respectively. In an alkaline environment, the amount of ECE was 449.02 mg g−1 and the value of HAE was 294.72 mg g−1. ECE mainly utilized the outer surface and mesoporous structure to adsorb gold, while the functional groups’ complexation or surface site adsorption was the leading approach for HAE to adsorb gold.

Surface Area Exclusion Chromatography of Diblock Copolymers from Micellar Solutions

1994 ◽  
Vol 27 (19) ◽  
pp. 5277-5284 ◽  
Author(s):  
Clarisse Huguenard ◽  
A. Elaissari ◽  
E. Pefferkorn
Keyword(s):  
Surface Area ◽  
Diblock Copolymers ◽  
Micellar Solutions ◽  
Exclusion Chromatography
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