Intercalation of cations into niobyl-vanadyl phosphate by redox reactions

1990 ◽  
Vol 68 (9) ◽  
pp. 1616-1620 ◽  
Author(s):  
A. Jimenez-Lopez ◽  
A. L. Garcia-Ponce ◽  
L. Moreno-Real
Keyword(s):  
Transition Metal ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Redox Reactions ◽  
Alkaline Earth ◽  
Exchange Capacity ◽  
Layered Compounds ◽  
Degree Of Hydrolysis ◽  
Vanadyl Phosphate ◽  
Hydrolysis Of

Mixed niobyl-vanadyl phosphate, Nb0.86V0.14OPO4•2.7H2O, intercalates various alkali, NH4+ alkaline earth, Zn2+, Cd2+, transition metal, and H+ cations by topotactic redox reactions. All the intercalates thus obtained are tetragonal (a = b = 6.44 Å, c lower than in the precursor solid). The degree of hydrolysis of the mixed phosphate in the intercalate in the redox reactions is always lower than 1%. Upon reduction, the cation exchange capacity (CEC) of the intercalates is 71 mequiv. per 100 g of solid calcined at 1000 °C. Keywords: mixed niobyl-vanadyl phosphate, layered compounds, redox intercalation.

The Use of Some Ion-Exchange Sorbing Tracer Cations in Insitu Experiments in High Saline Groundwaters

1994 ◽  
Vol 353 ◽  
Author(s):  
J. Byegård ◽  
G. Skarnemark ◽  
M. Skålberg
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Alkali Metals ◽  
Alkaline Earth ◽  
Exchange Capacity ◽  
Alkaline Earth Metals ◽  
Crushed Granite ◽  
The Difference

AbstractThe possibility to use alkali metals and alkaline earth metals as slightly sorbing tracers in in-situ sorption experiments in high saline groundwaters has been investigated. The cation exchange characteristics of granite and some fracture minerals (chlorite and calcite) have been studied using the proposed cations as tracers. The results show low Kd’s for Na, Ca and Sr (∽0.1 ml/g), while the sorption is higher for the more electropositive cations (Rb, Cs and Ba). A higher contribution of irreversible sorption can also be observed for the latter group of cations. For calcite the sorption of all the tracers, except Ca, is lower compared to the corresponding sorption to granite and chlorite. Differences in selectivity coefficients and cation exchange capacity are obtained when using different size fractions of crushed granite. The difference is even more pronounced when comparing crushed granite to intact granite.

Role of a Labile Terpene Compound in the Assessment of the Age of a Fossil Wood from Siena (Tuscany, Italy)

Holzforschung ◽  
2000 ◽  
Vol 54 (6) ◽  
pp. 591-596 ◽  
Author(s):  
G. Staccioli ◽  
A. Meli ◽  
G. Menchi ◽  
U. Matteoli ◽  
G. Ricottini
Keyword(s):  
Pinus Sylvestris ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Partial Loss ◽  
Wood Component ◽  
First Time ◽  
Geological Formations ◽  
Hydrolysis Of

Summary Fossil samples of Pinus sylvestris found near Siena (Tuscany, Italy) in geological formations 2–3 million years old were chemically examined in order to solve the problem of the contrast between the age of geological formations and their good degree of preservation. Comparison with a living Pinus sylvestris was carried out on standard wood component analyses, cation exchange capacity and residual terpene content. The analyses of wood components were close to those of the reference pine, whilst the cation exchange capacity values showed remarkable changes. The increase of salt carboxyls suggested the hydrolysis of ester carboxyls originally present, whilst the reduction of total carboxyls revealed a partial loss of hemicelluloses. Both changes were attributed to the percolation of salt-bearing water through the wood, thus causing ester hydrolysis, carboxyl salification and hemicellulose solubilisation. Residual terpene analysis showed, for the first time in a terrestrial fossil, tetrahydroabietic acid which forms by disproportion of the abietic acid. The 14C dating assigned the fossil to an age of about 18,000 years and suggested a landslide of Wurmian interglacial age occurred inside the geological formations of 2–3 million years old. Transient terpene compounds, formed in incipient diagenesis, are proposed as tracers for the assessment of particular ranges of fossil age, as previously suggested by the analyses of both a Larix decidua 14,500 years old and a Picea abies 100,000 years

EVALUASI PERUBAHAN KUALITAS TANAH PADA LAHAN BEKAS PENAMBANGAN NIKEL DI PULAU GEBE

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Mardi Wibowo
Keyword(s):  
Organic Carbon ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Mining Activity ◽  
Evaluation Activity ◽  
Land Quality ◽  
Environment Quality

Since year 1977 until 2005, PT. ANTAM has been exploited nickel ore resources at Gebe Island – Center ofHalmahera District – North Maluku Province. Mining activity, beside give economically advantages also causedegradation of environment quality espicially land quality. Therefore, it need evaluation activity for change ofland quality at Gebe Island after mining activity.From chemical rehabilitation aspect, post mining land and rehabilitation land indacate very lack and lackfertility (base saturated 45,87 – 99,6%; cation exchange capacity 9,43 – 12,43%; Organic Carbon 1,12 –2,31%). From availability of nutrirnt element aspect, post mining land and rehabilitation land indicate verylack and lack fertility (nitrogen 0,1 – 1,19%). Base on that data, it can be concluded that land reclamationactivity not yet achieve standart condition of chemical land.Key words : land quality, post mining lan

scholarly journals Attributes of the soil fertilized with sewage sludge and calcium and magnesium silicate

2015 ◽  
Vol 19 (11) ◽  
pp. 1107-1113 ◽  
Author(s):  
Geraldo R. Zuba Junio ◽  
Regynaldo A. Sampaio ◽  
Altina L. Nascimento ◽  
Luiz A. Fernandes ◽  
Natália N. de Lima ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Ricinus Communis ◽  
Block Design ◽  
Magnesium Silicate ◽  
Exchange Capacity ◽  
Sludge Compost ◽  
Sewage Sludge Compost ◽  
Randomized Block Design

ABSTRACTThis study aimed to evaluate the chemical attributes of an Inceptisol cultivated with castor bean (Ricinus communis L.), variety ‘BRS Energia’, fertilized with sewage sludge compost and calcium (Ca) and magnesium (Mg) silicate. The experiment was conducted at the ICA/UFMG, in a randomized block design, using a 2 x 4 factorial scheme with three replicates, and the treatments consisted of two doses of Ca-Mg silicate (0 and 1 t ha-1) and four doses of sewage sludge compost (0, 23.81, 47.62 and 71.43 t ha-1, on dry basis). Soil organic matter (OM), pH, sum of bases (SB), effective cation exchange capacity (CEC(t)), total cation exchange capacity (CEC(T)), base saturation (V%) and potential acidity (H + Al) were evaluated. There were no significant interactions between doses of sewage sludge compost and doses of Ca-Mg silicate on soil attributes, and no effect of silicate fertilization on these attributes. However, fertilization with sewage sludge compost promoted reduction in pH and increase in H + Al, OM and CEC. The dose of 71.43 t ha-1 of sewage sludge compost promoted the best soil chemical conditions.

scholarly journals Effect of Low Zeolite Doses on Plants and Soil Physicochemical Properties

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2617
Author(s):  
Alicja Szatanik-Kloc ◽  
Justyna Szerement ◽  
Agnieszka Adamczuk ◽  
Grzegorz Józefaciuk
Keyword(s):  
Plant Growth ◽  
Physicochemical Properties ◽  
Cation Exchange ◽  
Surface Area ◽  
Cation Exchange Capacity ◽  
N Fertilization ◽  
Exchange Capacity ◽  
First Year ◽  
Soil Physicochemical Properties ◽  
Water Holding

Thousands of tons of zeolitic materials are used yearly as soil conditioners and components of slow-release fertilizers. A positive influence of application of zeolites on plant growth has been frequently observed. Because zeolites have extremely large cation exchange capacity, surface area, porosity and water holding capacity, a paradigm has aroused that increasing plant growth is caused by a long-lasting improvement of soil physicochemical properties by zeolites. In the first year of our field experiment performed on a poor soil with zeolite rates from 1 to 8 t/ha and N fertilization, an increase in spring wheat yield was observed. Any effect on soil cation exchange capacity (CEC), surface area (S), pH-dependent surface charge (Qv), mesoporosity, water holding capacity and plant available water (PAW) was noted. This positive effect of zeolite on plants could be due to extra nutrients supplied by the mineral (primarily potassium—1 ton of the studied zeolite contained around 15 kg of exchangeable potassium). In the second year of the experiment (NPK treatment on previously zeolitized soil), the zeolite presence did not impact plant yield. No long-term effect of the zeolite on plants was observed in the third year after soil zeolitization, when, as in the first year, only N fertilization was applied. That there were no significant changes in the above-mentioned physicochemical properties of the field soil after the addition of zeolite was most likely due to high dilution of the mineral in the soil (8 t/ha zeolite is only ~0.35% of the soil mass in the root zone). To determine how much zeolite is needed to improve soil physicochemical properties, much higher zeolite rates than those applied in the field were studied in the laboratory. The latter studies showed that CEC and S increased proportionally to the zeolite percentage in the soil. The Qv of the zeolite was lower than that of the soil, so a decrease in soil variable charge was observed due to zeolite addition. Surprisingly, a slight increase in PAW, even at the largest zeolite dose (from 9.5% for the control soil to 13% for a mixture of 40 g zeolite and 100 g soil), was observed. It resulted from small alterations of the soil macrostructure: although the input of small zeolite pores was seen in pore size distributions, the larger pores responsible for the storage of PAW were almost not affected by the zeolite addition.

Effects of pH and ionic strength on the cation exchange capacity of soils with variable charge

Soil Research ◽  
1981 ◽  
Vol 19 (1) ◽  
pp. 93 ◽  
Author(s):  
GP Gillman
Keyword(s):  
Ionic Strength ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Surface Soils ◽  
Ph Values ◽  
Variable Charge ◽  
Effects Of Ph ◽  
Variable Charge Soils

The cation exchange capacity of six surface soils from north Queensland and Hawaii has been measured over a range of pH values (4-6) and ionic strength values (0.003-0.05). The results show that for variable charge soils, modest changes in electrolyte ionic strength are as important in their effect on caton exchange capacity as are changes in pH values.

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