Selective adsorption of soil humic acid on binary systems containing kaolinite and goethite: Assessment of sorbent interactions

Author(s):  
Hongfeng Chen ◽  
Luuk K. Koopal ◽  
Jinling Xu ◽  
Mingxia Wang ◽  
Wenfeng Tan
2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4066
Author(s):  
Xianyuan Fan ◽  
Hong Liu ◽  
Emmanuella Anang ◽  
Dajun Ren

The adsorption capacity of synthetic NaX zeolite for Pb2+, Cd2+, Cu2+ and Zn2+ in single and multi-component systems were investigated. The effects of electronegativity and hydration energy on the selective adsorption, as well as potential selective adsorption mechanism of the NaX zeolite for Pb2+, Cd2+, Cu2+ and Zn2+ were also discussed. The maximum adsorption capacity order of the heavy metals in the single system was Pb2+ > Cd2+ > Cu2+ > Zn2+, and this could be related to their hydration energy and electronegativity. The values of the separation factors (α) and affinity constant (KEL) in different binary systems indicated that Pb2+ was preferentially adsorbed, and Zn2+ presented the lowest affinity for NaX zeolite. The selective adsorption capacities of the metals were in the order, Pb2+ > Cd2+ ≈ Cu2+ > Zn2+. The trend for the selective adsorption of NaX zeolite in ternary and quaternary systems was consistent with that in the binary systems. Pb2+ and Cu2+ reduced the stability of the Si-O-Al bonds and the double six-membered rings in the NaX framework, due to the high electronegativity of Pb2+ and Cu2+ than that of Al3+. The selective adsorption mechanism of NaX zeolite for the high electronegative metal ions could mainly result from the negatively charged O in the Si-O-Al structure of the NaX zeolite, hence heavy metal ions with high electronegativity display a strong affinity for the electron cloud of the oxygen atoms in the Si-O-Al. This study could evaluate the application and efficiency of zeolite in separating and recovering certain metal ions from industrial wastewater.


2000 ◽  
Vol 88 (2) ◽  
Author(s):  
D. Rößler ◽  
K. Franke ◽  
R. Süß ◽  
E. Becker ◽  
H. Kupsch

A natural moor soil humic acid (HA) was labeled with Tc-99m via reduction of pertechnetate with stannous chloride. The humic acid species obtained were characterized by thin layer chromatography (TLC), gel permeation chromatography (GPC), sequential chromatographic analysis (SCA), paper electrophoresis and micropore filtration. Labeling was found to take place in all ranges of molecular weight. Due to the complex humic acid composition and the formation of hydroxo species the labeling yields strongly depend on the separation conditions, ranging from 42% to 80%. The pH-dependent distribution of mobile and immobile species was determined by SCA for HTcO


RSC Advances ◽  
2014 ◽  
Vol 4 (45) ◽  
pp. 23658-23665 ◽  
Author(s):  
A. Nebbioso ◽  
A. Piccolo ◽  
M. Lamshöft ◽  
M. Spiteller

Humeomics encompasses step-wise chemical fractionation and instrumental determination to fully characterize the heterogeneous molecular composition of natural organic matter.


1997 ◽  
Vol 28 (9-10) ◽  
pp. 787-796 ◽  
Author(s):  
J. C. Lobartini ◽  
G. A. Orioli ◽  
K. H. Tan
Keyword(s):  

1962 ◽  
Vol 27 (1) ◽  
pp. 170-174 ◽  
Author(s):  
GISELE GREENE ◽  
CORNELIUS STEELINK

2010 ◽  
Vol 29 (2) ◽  
pp. 215 ◽  
Author(s):  
Tatjana Anđelković ◽  
Ružica Nikolić ◽  
Aleksandar Bojić ◽  
Darko Anđelković ◽  
Goran Nikolić

The binding of Cd(II) to soil humic acid (HA) at pH 6.5 and in 0.1 mol/L KNO3 ionic medium, was studied by potentiometric titration with a cadmium ion selective electrode. The influence of carboxyl groups in cation-humic interactions was investigated by selective blocking of humic acid carboxyl groups with thionyl chloride and methanol. Infrared spectroscopic analysis confirmed that esterification took place. Differences between underivatized and derivatized HA complexation properties are ascribed to carboxyl groups. The Scatchard plots and incremental formation constants were used to obtain values for Cd-binding constants, for both HAs. The derivatization decreased the number of HA complexing sites by approximately 60 %, which correlates with acid-base properties of both HAs, studied by barium hydroxide and calcium acetate exchange methods. The stability constants for binding at the strongest sites (logKINT) was larger for underivatized HA (5.40) than for derivatized HA (4.92), indicating greater stability in the case when carboxyl groups are involved in complexation reaction.


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