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MINERAL-ORGANIC COMPOUND OF SOILS: FORMATION MECHANISMS, PROPERTIES, FUNCTIONS INTRODUCTION Kurochkina G. N., Pinsky D.L. The adsorption of organic substances on an aluminosilicate matrix with high energy is an essential problem of pedogenesis, primerely, of the formation of highly dispersed mineraloorganic (MO) derivatives of the soil adsorbing complex (SAC) [Gorb, Orl ]. Greenland believes that 50 to 80% of soil organic matter is bound to clay mineral [Greenland]. The composition, degree of accumulation, and migration of mineraloorganic derivatives determine the adsorbing capacity, the type and fertility of soils and their resistance to anthropogenic impact [Malin Orl]. Many authors reveled that adsorbed MO form no continuous film on the surface of a mineral; they are immobilized on a minor part of its surface, on so-called adsorption sites [ Mal Theng]. The energy of interaction between these sites and organic molecules affects the conformation of adsorbed molecules, the strength of surface adsorption compounds, and finally, the degree of humus immobilization and its resistanse. The aim of this work was to study the mechanism of adsorption interaction between organic molecules and soil’s aluminosilicate in controlled conditions. EXPERIMENTAL The experimental subjects were synthetic gels with various contents of silica and alumina, which ware used as analogs of soil’s aluminosilicate (Table 1). Table 1. Basic physicochamical characteristics of the adsorbents Sample SiO 2 /Al 2 O 3 S, m 2 /g V, cm 3 /g Surface Charge S AS-1 AS-2 AS-5 A 100% SiO 2 4/1 2/1 1/2 100% Al 2 O 3 750 167 248 194 244 1.01 1.71 0.75 0.53 0.51 ─ ─ + + + Note: S, silica gel; AS, aluminosilicate gel; A, alumina gel; s, the specific surface area as measured with argon; and v, total pore volume. 102
The sorptives were high-molecular-weight aliphatic polyelectrolytes (PE) containing various polar groups. These compounds are surfactants; their physicochemical characteristics are summarized in Table 2. Table 2. Composition of the functional groups and molecular mass of the polyelectrolytes Polyelectrolyte Functional groups, % M×10 ─5 , g/mol PVA PAA PAAM PAA–1 K–4 OH (100) COOH (100) CONH 2 (100) CONH 2 (25-30), OC-NH-CO (13.3), COOH (50-60) COOH, COONa, CONH 2 0.22 18.8 5.0 52.7 2.4 Note: PVA, polyvinyl alcohol; PAA, polyacrylic acid; PAAM, polyacrilamide; PAA-1, a copolymer of the derivatives of acrylic acid; K-4, an incompletely hydrolyzed polyacrylonitrile; and M, molecular mass. The adsorption of the PE from dilute aqueous solutions on the aluminosilicates was measured by viscosimetry as a function of the time and temperature over a concentration range from 1×10 ─5 to 1×10 ─1 wt %. The kinetics of the adsorption of the PE in 1% suspensions at ~20 o C was studied by adding a weighted portion of an adsorbent to a polymer solution of desired composition. The suspention was stirred in a closed vessel with a mixer for 1 to 2 min and allowed to stand for 15, 30 or 60 and so min, after which it was separated on a centrifuge into liquid and solid part. The centrifugates were extracted and kept at 20 o C for 15 min, after which the concentration of the PE was measured. The effect of temperature on the kinetics and equilibrium of adsorption were studied in a thermostat at 25, 50, and 90 o C for 15, 30, 60 and so min, and then centrifuged them. After kept in a thermostat at 20 o C for 30 min the physicochemical characteristics of the PE (viscosity, refractive index, etc) were measured. The adsorption was calculated by the formula G (mg/g) = (C 0 – C t ) V×10/m and G 1 (mg/g) = (C 0 – C t ) V×10/(mS), where G and G 1 are the adsorption values (mg/g), C 0 and C t are the initial and current concentrations of PE in solution at time t, g/100ml; m is the weight of the adsorption sample, g; and S is the specific surface area, m 2 /g. 103
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PHYSICS, CHEMISTRY AND BIOGEOCHEMIS
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IN MEMORIAM Dr Ludmila Petrovna Kor
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magnetic (ferrimagnetic) oxides, ma
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educed water activity, would favour
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In this paper AT sorption by surfac
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were obtained with clay content, pH
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In present investigation the quartz
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Hence, the micromorphology suggests
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As the indicators of soil aeration
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Stomatal diffusive resistance of th
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indicators of soil aeration conditi
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REFERENCES 1. 2. 3. 4. 5. 6. 7. 8.
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Table 1. Breakdown of numbers and t
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MORPHOLOGICAL AND PHYSICOCHEMICAL P
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conditions, existing at the first p
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INFLUENCE OF TEMPERATURE ON WATER P
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moisture % 100 90 80 70 60 50 40 so
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STATE OF MICROBIAL COMMUNITIES IN M
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million cells/g soil 25 20 15 10 5
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THE INFLUENCE OF COMPOSITION AND PR
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days grew faster than on substrate
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SOIL SALINITY AND CLIMATE CHANGES I
Page 46 and 47: POROUS STRUCTURE OF NATURAL BODIES
Page 48 and 49: These nonuniform classification sys
Page 50 and 51: Mercury intrusion data are plotted
Page 52 and 53: METHOD AND MATERIALS The shear stre
Page 54 and 55: wheat flour NaCl salt fine milk Fig
Page 56 and 57: The shear experiments revealed two
Page 58 and 59: Variable charge of mineral surfaces
Page 60 and 61: 3. Huffaker RC and Wallace A 1958 P
Page 62 and 63: Q V (pH)/N t = α(pH) = n ∑ i= 1
Page 64 and 65: REFERENCES 1. De Wit, J.C.M, Van Ri
Page 66 and 67: BM - biomass; NM - necromass; MM -
Page 68 and 69: thousand times at the absence of co
Page 70 and 71: . m 131.5 131.0 I Height above sea
Page 72 and 73: SEASONAL VARIABILITY OF SOIL WATER
Page 74 and 75: The mean difference (MD) and the ro
Page 76 and 77: Acknowledgement This paper presents
Page 78 and 79: 1992; Selim 1999). The relative imp
Page 80 and 81: 1.0 C rel 0.5 0.0 v=0.7 D=3.28 v=0.
Page 82 and 83: 1.0 a b C rel 0.5 0.0 0 1 2 3 0 1 2
Page 84 and 85: Comparison of before- and after-pul
Page 86 and 87: provides the accessibility of catio
Page 88 and 89: MODEL RESEARCH ON FORMATION OF SYNT
Page 90 and 91: The analysis of the specific surfac
Page 92 and 93: PHOSPHATE-INDUCED CHANGES IN THE SP
Page 94 and 95: According to the data of Table 1, t
Page 98 and 99: RESULTS AND DISCUSSION An analysis
Page 100 and 101: INTRODUCTION CHEMICAL DEGRADATION O
Page 102 and 103: of organic particles and their elec
Page 104 and 105: HNO 3 -extractable form is very clo
Page 106 and 107: Results demonstrated that Pb and Cd
Page 108 and 109: tion was measured using the Tjurina
Page 110 and 111: OUTPUT FLUXES OF LEAD IN FOREST ECO
Page 112 and 113: Regional data on Pb concentrations
Page 114 and 115: DEVICE FOR EVALUATION OF THE RAPE P
Page 116 and 117: SPECTROSCOPIC COMPARISON OF HUMIC A
Page 118 and 119: ehavior of sequentially extracted H
Page 120 and 121: MODERN MONITORING SYSTEMS FOR THE M
Page 122 and 123: The control of the measurement syst
Page 124 and 125: ASORPTION AND SURFACE AREA OF SOILS
Page 126 and 127: Nm xCBET N = ( 1− x BET − )[ 1+
Page 128 and 129: According to this, when x/N (1-x) i
Page 130 and 131: POTENTIAL OF AZOLLA CAROLINIANA TO
Page 132 and 133: The decrease of Pb(II) and of Cd(II
Page 134 and 135: 12. 13. 14. 15. 16. Piechalak, A.,
Page 136 and 137: Kloc, 2001]. Nitrogen adsorption is
Page 138 and 139: This is worth noting that the lower
Page 140 and 141: N ( h) 1 2 γ ( h) = [ ( ) ( )] ( )
Page 142 and 143: Exemplary spatial distributions (sa
Page 144 and 145: This is worth noting that significa
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adsorbed chemicals to microorganism
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were detected in the untreated soil
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0.4 1000 Moisture [Vol.] 0.3 0.2 0.
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NITROUS OXIDE EMISSION FROM SOILS W
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N2O-N [mg kg -1 ] 100 80 60 40 20 0
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LITERATURE 1. 2. 3. 4. 5. 6. 7. 8.
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where v(t) - CO 2 production rate;
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carbon was involved mainly into mic
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Demkin Vitaliiy DrSc Dmitrakov Leon
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Priputina Irina PhD Rudko Tadeusz P
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