scholarly journals Lab Study on the Effect of Cation Exchange Capacity on Slurry Performance in Slurry Shields

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
By Pinghe Sun ◽  
Binkui Zhao ◽  
Han Cao ◽  
Jingyuan Wang ◽  
Dingqiang Mo ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Rheological Properties ◽  
Cation Exchange Capacity ◽  
Ph Value ◽  
Field Work ◽  
Exchange Capacity ◽  
Rheological Parameters ◽  
Flow Index ◽  
Linear Change ◽  
Design Requirements

Ion stabilizers can enhance the reinforcement slurry effect on the wall and stabilize the wall actively in slurry shields. This paper presents different cation exchange capacities obtained by changing the content of the ion stabilizer (1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, and 6.0%) in slurry associated with the basis of the existing slurry formula through the laboratory tests. In order to study the effect of the cation exchange capacity on the performance of slurry properties, the rheological properties of the slurry are analyzed and evaluated by the power law model. Results indicate that the cation exchange capacity of the slurry decreases first and then increases with the increase of the ion stabilizer content. When the content of the ion stabilizer is maintained at 3.50%, the cation exchange capacity reaches the minimum value of 2.92. The filtration volumes, pH values, and rheological parameters of the slurry also indicate an obvious linear change with the change of the cation exchange capacity. The minimum filtration volume is 9.70 mL/30 min when the ion stabilizer content reaches 3.50%. However, the pH value reaches the maximum, that is, 11.34 which is changed from 10, and the change could be considered as a constant value in the field work. When the cation exchange capacity increases, the continuity of polymer structure in the slurry decreases first and then increases, the flow index and consistency coefficient are located within a reasonable range, and the rheological properties of the slurry meet the design requirements of the standards.

scholarly journals Evaluation of the lime requirement of tropical soils in terms of other soil characteristics

1969 ◽  
Vol 36 (2) ◽  
pp. 155-160
Author(s):  
M. A. Lugo López ◽  
F. Abruña ◽  
J. Roldán
Keyword(s):  
Cation Exchange ◽  
Clay Mineral ◽  
Cation Exchange Capacity ◽  
Ph Value ◽  
Organic Matter Content ◽  
Clay Content ◽  
Tropical Soils ◽  
Exchange Capacity ◽  
Matter Content ◽  
Significant Regression

The quantity of limestone required to bring the pH of various acid Puerto Rican soils to 6.5 was investigated and found to vary from several hundred to several thousands pounds per acre. To investigate the relation of clay-mineral type, clay content, cation-exchange capacity, organic-matter content, and pH to lime requirement, these properties were determined for several soils. A highly significant regression of lime requirement on pH was obtained which can be expressed by the equation: Y = 18.39 — 3.196 X, where Y is the lime requirement and X is the pH value. Multiple regressions including other factors did not significantly increase the variability which could be explained on terms of the first regression. Further analysis were made by arranging the data according to the predominant clay mineral. For kaolinitic soils highly significant correlations were obtained between lime requirement and either pH or cation exchange capacity. The regressions were: (a) Y = 15.26 — 2.632 pH, and (b) Y = 3.048 + 0.5774 (cation-exchange capacity), where Y is the lime requirement. A regression of lime requirement on both factors did not significantly increase the variability explained by the second equation. No significant regressions were obtained for beidellitic soils.

Changes in effective cation exchange capacity and exchangeable aluminum with soil pH in lime-amended field soils

Soil Research ◽  
1992 ◽  
Vol 30 (2) ◽  
pp. 177 ◽  
Author(s):  
Z Hochman ◽  
DC Edmeades ◽  
E White
Keyword(s):  
Cation Exchange ◽  
Linear Relationship ◽  
Soil Ph ◽  
Cation Exchange Capacity ◽  
Ph Value ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Acidic Soils ◽  
Hydrogen Ion Concentration ◽  
Wide Range

Eleven acidic soils from northern N.S.W., having a wide range of values for ECEC, A1 and soil organic carbon (%C), were treated in the field with five rates of lime. The relationships between soil pH and the effective cation exchange capacity (ECEC), and between pH and exchangeable aluminium (Al), were investigated for the top 10 cm of these soils. Increases in the total exchangeable cations (TEC) calculated as ECEC-Al, were shown to be madelup almost entirely by increases in exchangeable calcium. There were no consistent changes in the amount of exchangeable magnesium, potassium or sodium due to liming these acidic soils. Formulae used to predict changes in A1 and ECEC with pH in the 'Lime-it' model were tested and modified on the 11 soils from northern N.S.W. A strong linear relationship was observed in each soil between Al and pH (transformed to hydrogen ion concentration x 103). The slope of this relationship (SALs) can be predicted from the pH and A1 values of unlimed soils. Strong linear relationships were also observed between pH and TEC, for each of the 11 soils. The SL, (the slope of the linear relationship TEC/pH for any soil 's') was shown by multiple regression analysis to be a function of TECi/pHi (where TECi is the sum of exchangeable cations of unlimed soil 's'; and pHi is the pH value of unlimed soil 's'), %C of the unlimed soil, and SALs. By using the measured values of pH, ECEC, Al and %C of unlimed soils, the values of Al, and TEB can be predicted for any pH value that may be measured (or predicted) after liming. The predictive relationships developed on N.S.W. soils were tested against independent data from New Zealand. The results confirmed the Al/pH predictions (R2 = 0.955), while the TEC/pH predictions were less well matched (R2= 0.62) possibly due to unusual clay mineralogy or organic matter fractions of 3 of the 18 soils tested.

Chemical and charge characteristics of kaolinitic soils of south-east Queensland

Soil Research ◽  
1983 ◽  
Vol 21 (3) ◽  
pp. 271 ◽  
Author(s):  
JO Skjemstad ◽  
AJ Koppi
Keyword(s):  
Cation Exchange ◽  
Surface Area ◽  
Cation Exchange Capacity ◽  
Negative Charge ◽  
Ph Value ◽  
Divalent Cations ◽  
Active Surface ◽  
Exchange Capacity ◽  
Oxide Surface ◽  
Oxalate Extraction

Cation exchange capacity at field pH and net negative charge at pH 8.5 of 39 kaolinitic soils were studied in relation to surface area and other soil characteristics. All soils exhibited an anion exchange capacity at field pH, but this was very low compared with cation exchange capacity. Little evidence could be found for the presence of amorphous aluminium or silica, or short-range order alumino-silicates on the basis of acid oxalate-extraction, in contrast to Tiron extraction. All samples had significant permanent negative charge as deduced using the method of Gillman and Uehara, in addition to pHdependent charge. The former was strongly related to the exchangeable divalent cations, and this may explain the great variation in base saturation observed. Most of the charge in these soils is derived from the small poorly crystalline kaolins, although at high pH oxalate-extractable iron contributes significantly to the negative charge. Based on the results for those soils containing less than 5% iron oxide, surface area determined by ethylene glycol is linearly related to the net negative charge at pH 8.5. The average surface charge density on the soils containing <5% hematite and goethite measured at this pH value is 0.9 nm2/charge. Hematite and goethite show much lower negative charge densities and effectively dilute the active surface.

Field amelioration of acidic soils in south-east Queensland. I. Effect of amendments on soil properties

1998 ◽  
Vol 49 (4) ◽  
pp. 627 ◽  
Author(s):  
R. L. Aitken ◽  
P. W. Moody ◽  
T. Dickson
Keyword(s):  
Organic Carbon ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Buffer Capacity ◽  
Ph Value ◽  
Field Trials ◽  
Exchange Capacity ◽  
Wide Range ◽  
Initial Ph ◽  
Ph Buffer

Replicated field trials with rates of lime ranging up to 8 t/ha were conducted at each of 27 sites in south-east Queensland. At 16 of these sites, single rates (2 t/ha) of gypsum or phosphogypsum were also applied. Soil samples (0-10 cm) were collected from each plot and analysed for pH in both water (pHw) and 0·01 M CaCl2 (pHCa), for electrical conductivity, exchangeable cations, and extractable Al and Mn. Gypsum application resulted in either a general trend for, or significant (P < 0·05), reductions in pHw but had no significant effect on pHCa. The relationship between rate of applied lime and soil pH at each site permitted the calculation of pH buffer capacity for a wide range of soil types and properties. The pH increase per t applied lime ranged from 0·14 to 0·82 and from 0·16 to 0·63 for pH measured in water and 0·01 M CaCl2, respectively, reflecting the range in pH buffer capacity which was significantly correlated with organic carbon. Multiple regression indicated that organic carbon and clay significantly contributed to the variation in pH buffer capacity but only around 40% of the variation could be accounted for. The pH values at which Al saturation was reduced to 10% ranged from 4·82 to 6·02 (pHw) and from 4·26 to 4·93 (pHCa) and indicated that if neutralising exchangeable Al is the basis for liming, then no single target pH value will be appropriate for all soils. However, the target pH at which Al saturation would be reduced to 10% could be predicted from the initial pH and initial Al saturation. The effective cation exchange capacity (ECEC) was increased by liming at all sites and the additional exchange capacity was occupied by Ca. This increased Ca saturation was not necessarily at the expense of exchangeable K and Mg, which were significantly (P < 0·05) reduced at only a few sites. The increase in ECEC for a unit increase in pH ranged from 0·5 to 9 cmol(+)/kg and at some sites represented a doubling of the soil"s cation exchange capacity.

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.

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