Calcium Exchange Capacity Research Articles

Rice husk ash based complex sodium di silicate – An alternative detergent builder for sodium tripolyphosphate and Zeolite 4A

Detergent builder is an essential part of any detergent powder, as it softens the hard water which hinders the cleaning action of surfactants. Nowadays, sodium tripolyphosphate and Zeolite 4A are used as detergent builders extensively in detergent formulation. Though STPP has higher capacities to remove hardness from the water but has a detrimental impact on the environment like eutrophication and hence it has been banned for detergent application in various countries. Zeolite 4A is currently leading the detergent industry with moderate hardness removal, but it has certain disadvantages like high pH, insolubility, high solid residue in the wash water and needs additives for its activation in the detergent formulation. In this research paper, the better alternative detergent builder known as Complex sodium dislicate (CSDS) is produced using rice husk ash-based sodium silicate. Further CSDS is analyzed using SEM, XRD, and TGA-DSC to explain its physicochemical properties. The calcium exchange capacity evaluation is carried out and is found to be 420 mg eq. CaCO3/gram of CSDS which is higher than STPP and Zeolite 4A. In this study, detergent formulations made with CSDS as a detergent builder were compared with those of STPP and Zeolite 4A to evaluate detergent performances according to the IS 4955:2020 standard.

Characterization of Local Clay for Drilling Mud Production

Oil companies’dealing with drilling operations in Nigeria often spends millions of dollars in importation of bentonite for its operations as a result of its importance and high demand. As a result of this, attempt to source for local substitute has been initiated, which if successful would save the nation from this huge capital flight. In this study, a sample of Umuna local clay deposit was evaluated for drilling fluid application. The viscosity and filtration loss was analyzed and it’s far below that of the imported bentonite. The properties of the local clay was improved by addingmaterials such as HV-CMC, Drispac polymer and bentonite extenders to the formulated mud to enhance its viscosity and filtration loss Also the shearing speed was increased, but the used speed is limited to practical shearing speed. Theclay yield and characterization of the beneficiated samples show that the treated local clay is slightly comparable to the imported bentonite. The Calcium Exchange Capacity (CEC) result for the clay samples fall within the 70 – 150 Meq/100g. This result further suggests that the analyzed clay is of montimorillonite family, with traces of illite which is good for drilling mud production. The obtained results from this study indicates that the filtration loss and plastic viscosity for the analyzed clay samples were generally far from comparing with the imported bentonite, but through beneficiation, they were able to compare with the imported bentonite.

Process engineering approach to conversion of alum sludge and waste glass into zeolite LTA for water softening

This study addressed the need to better understand process engineering aspects of zeolite LTA synthesis from waste materials. In particular, concepts such as zeolite yield, recycling of mother liquor, softening performance and regeneration of calcium loaded zeolite LTA were evaluated. Zeolite LTA was made via alkaline fusion pre-activation of alum sludge and waste glass at 700 °C for 2 h; followed by hydrothermal treatment at 80 °C for 5 h. Increasing the SiO2/Al2O3 ratio of the feed mixture from 1 to 2.3 doubled the yield of zeolite LTA to 67%. Consequently, a feed mixture of composition 9.2Na2O:Al2O3:2.3SiO2:276H2O was adopted for subsequent tests. Recycling of the alkali and other dissolved species in the mother liquor improved zeolite LTA crystallinity (80 to 86 wt%) and calcium exchange capacity from 73 to 78 mg/g. Implementation of recycling depends upon the cost/benefit analysis regarding energy demand for evaporation of mother liquor relative to savings by more effectively using the excess alkali reagent. Calcium uptake on zeolite LTA was reduced when treating simulated river water (65.5 mg Ca2+/g) due to competitive ion-exchange. Regeneration of calcium loaded zeolite LTA required a NaCl solution with a molarity of at least 2 M. A notable reduction of calcium loading capacity was detected after several loading/regeneration cycles. The outlined technology proposed a feasible and scalable approach to recycling of wastes, producing a commodity, which could be successfully used locally by the water treatment plant as a water softener.

Synthesis of LTA zeolite beads using alum sludge and silica rich wastes

This study successfully recycled alum sludge with either lithium slag or bottle glass to make high purity zeolite LTA beads. The basic synthesis approach was to fuse the waste material with sodium hydroxide then complete hydrothermal crystallization. Separate fusion of individual wastes promoted zeolite LTA formation compared to combined fusion. Preferred synthesis conditions were: 10 Na2O:Al2O3:2.5 SiO2:300 H2O; hydrothermal temperature = 80 °C; time = 5 h. Zeolite LTA purity was between 80 and 85 wt% from the two waste combinations. Use of pseudoboehmite and carboxymethyl cellulose favoured granulation/extrusion/spheronization of zeolite LTA powder. However, the beading process decreased calcium exchange capacity (CEC) from 99.5 to 37 mg Ca2+/g for alum sludge + lithium slag and from 64.5 to 37 mg Ca2+/g for alum sludge + waste glass. Additionally, when using 20 wt% pseudo-boehmite as a binder the ion-exchange equilibrium time increased from 60 to 300 min. The importance of not only making zeolite powder from waste materials but also to extend studies to shaped forms was evident. It is recommended that future studies should also focus on making extrudates or beads as these are the forms used commercially.

Influence of Anthropic and Topographic Factors on the Physicochemical Properties of the Soil around Temporary Pools in Ferlo, North Senegal

The temporary ponds at Ferlo constitute wetlands whose pastoral activity is of paramount importance in the economy of Senegal. These zones are characterized by a fairly specific microclimate (soft and humid), a shallow depth of the water table, alternating phases of submersion and exudation whose functioning is linked to the soil. Thus the restoration and conservation of these wetlands requires a good knowledge of the soil factors.
 The objective of this study is to compare the physico-chemical parameters of the soil around temporary pools in grazed and ungrazed areas and different topographical units in order to determine their relative similarities.
 The samples taken at different horizons from seven soil pits (P1, P2, P3, P4, P5, P6 and P7) opened in the different morpho-pedological facies of two grazed ponds and one ungrazed pond were analyzed in the laboratory.
 The results obtained show that the soils of Ferlo have a sandy texture and low fertility in the slopes and plateaus. However, they have a balanced texture and average fertility in ponds and ungrazed areas. The factorial analysis made it possible to highlight three distinct soil classes. A class of sandy texture soil with very low chemical fertility comes from the plateau. A class of soil with a balanced texture which is rich in cation and calcium exchange capacity found in the low zones of strong mineralization. A last class rich in chemical element with a silty texture which is found in wooded areas.
 These results thus reveal the predominant influence of anthropic and topographic factors on the evolution and physico-chemical composition of the soil.

Ammonia removal from giant fresh water prawn farm by using zeolite from oil palm ash

The Empty Fruit Bunch (EFB) and Mesocarp fiber ash (FB) was obtained from the boiler at NAM HONG Palm Oil Company Limited, Thailand. The optimum condition was used in Na-A zeolite synthesis from oil palm ash. The obtain produce was Na12Al12Si12O48· 27H2O. The sample was dried in hot air oven. The calcium exchange capacity (CEC) of 386.39 mg CaCO3/g of product, and the 86.05% of pure Na-A zeolite phase was formed. In batch experimental study, the synthetic wastewater was prepared. In order to find out the optimal zeolite dosage was added into 10 mg/L of total ammonium nitrogen solution. The results of unionized ammonia (NH3) removal efficiency indicated that zeolite A standard and zeolite from oil palm ash are better than commercial zeolite. The optimum dosage of 0.2, 0.25 and 0.2 g of zeolite A standard, zeolite from oil palm ash and commercial zeolite, respectively. The NH3 removal capacity from giant freshwater prawn farm, zeolite A standard is better than zeolite from oil palm ash and commercial zeolite, respectively. In the large volume of synthetic wastewater (1000 mL), the zeolite from oil palm ash is the best ammonia removal capacity when compared with zeolite A standard and commercial zeolite.

Al2O3-2SiO2 Nanoparticles with Defined Al-Si Ratio: Processing Optimization and Conversion

Attempts had been made to synthesize Al2O3-2SiO2 nanopowders by sol-gel method with tetraethoxysilane (TEOS) and aluminum nitrate (ANN) as the starting materials. DTS, TEM, SEM and BET were employed to study the effects of process parameters on the size, specific surface area and structure (morphology) of powders. The alkali-activation reactivity of the powders was tested for manufacturing geopolymers and their hydrothermal reactions were performed for fabricating zeolites. The results show that the optimum process parameters and drying method for preparing Al2O3-2SiO2 nanopowders are as follows: the molar ratio of water and ethanol to TEOS are 0:U1 and 12:U1 respectively at synthetic temperature of 50° and the drying method is azeotropic distillation with microwave drying. The average particle diameters of the powders were about 70 nm and the largest BET specific surface area was up to 669 m2·g−1. The compressive strength of the geopolymer and the calcium exchange capacity (by CaCO3) of NaA zeolite prepared with the powders reached to 29 MPa and 366 mg·g−1 respectively.

IMPLICATIONS OF COVER CROPS FOR SOIL QUALITY AND GEODIVERSITY IN A HUMID‐TEMPERATE REGION IN THE MIDWESTERN USA

ABSTRACTWinter cover cropping plays an important role in conservation farming. In the Midwest region of the USA, strips planted with Austrian winter peas [AWP (Pisum sativum L.)], radishes [RAD (Raphanus sativus L.)], and a mixed cover of both cultivars (MIX) were compared during the spring season to determine their impact on the soil quality at 0–5 and 5–10 cm depths. The treatments RAD, AWP, and MIX had the highest, intermediate, and lowest soil bulk density impacts (1·67, 1·52, and 1·50 Mg m−3, respectively). An opposite trend was observed for the concentrations of soil organic carbon (15·9, 17·6, and 19·4 g kg−1, respectively) and total nitrogen (1·5, 1·7, and 2·8 g kg−1, respectively), the calcium exchange capacity (8·6, 9·5, and 11·4 cmol+c kg−1, respectively), and earthworm density (85, 221 and 226 per m2 x 0·15 m, respectively). The AWP, MIX, and RAD resulted in the highest, intermediate, and lowest water stable aggregates (91·6, 87·4, and 79·9 per cent, respectively), mean weight diameter of aggregates (3·4, 2·7, and 2·1 mm, respectively), saturated hydraulic conductivity (15·7, 13·0, and 6·3 cm h−1, respectively), and intrinsic permeability (1·69, 1·37, and 0·70 cm2 10−10, respectively). The AWP and RAD treatments resulted in a similar C:N ratio (10·5), which was larger than associated with MIX (7·2). Overall, AWP and MIX had a larger positive impact on soil quality than RAD did, and the impact was greater at the 0–5 than the 5–10 cm depth. This indicates the suitability of the various cover crops for improving the soil quality and restoring geodiversity. Copyright © 2012 John Wiley & Sons, Ltd.

Convenient Hydrothermal Synthesis of Zeolite a from Potassium-Extracted Residue of Potassium Feldspar

Zeolite A was successfully synthesized via convenient hydrothermal process using potassium-extracted residue of potassium feldspar as a combined source for silica and alumina. Optimization studies on the molar ratios of Na2O/SiO2 and H2O/SiO2, and aging time have been conducted. The results were that pure zeolite A with high crystallinity could be synthesized when the reaction mixture with molar ratios of Na2O/SiO2 and H2O/SiO2 of 2.0 and of 85, respectively, were crystallized at 100°C for 3h. Aging was found to be not prerequisite for the formation of zeolite A in the system. The product was characterized by XRD, FTIR, SEM and calcium exchange capacity. Finally, a comparative study of the zeolite A formation from the potassium-extracted residue and other industrial waste or natural silicate minerals was also carried out.

4A-Molecular Sieve Synthesis by Microwave Heating with Silicon and Aluminum Materials Produced from the Coal Fly Ash

A new method, using sodium silicate and sodium aluminate synthesize 4A-molecular sieve, was developed by using microwave technology. The sodium silicate was a high modulus liquor by-product of nano-silica production from coal fly ash. Meanwhile, the sodium aluminate was a process by-product of alumina extraction from coal fly ash. Reaction mixture composition was defined as follow:SiO2/Al2O3 ratio in 2.0, Na2O/SiO2 ratio in 1.5, and H2O/Na2O ratio in 65. The gelation process was completed in 1 hr. Microwave crystallization power was (800w) 30%. Microwave crystallization period can last 25 mins. The 4A-molecular sieve was obtained by collecting crystals from the reaction mixture through filtration after washing with water to pH 11-12 and drying inside isotherm oven. The calcium exchange capacity and effective pore size of the product were 316mg/g and 0.4nm respectively. Over 90% of surface pore size reached in sizes of less than or equal to 8μm. Purity of 4A-molecular sieve up to 99%. This method significantly reduced the raw material costs for sodium silicate and sodium aluminate. In addition, the adoption of microwave technology also lowered the energy usage and shortened crystallization time. All these contributed final low costs of 4A-molecular sieve product, which made it possible for many practical applications.

Impact of zeolitic water content on exchange of calcium ions

Abstract 4A and P zeolites were thermally treated to dehydrate them to different extents. The residual water content and calcium exchange capacity (CEC) values of the treated zeolites were evaluated. The study revealed that the CEC of the zeolites depended upon the zeolitic water level. Anhydrous zeolites are devoid of exchange capacity. Mixed zeolites demonstrated mineralisation effect and an additional peak in the thermal studies.

Measurement and interpretation of zeolite NaA builder performance

AbstractIon exchange isotherms are commonly used to describe the distribution of ions between a solid and liquid phase under equilibrium conditions. In the detergent industry, the Ca‐Na‐zeolite A isotherm can be utilized to determine the builder performance of zeolite NaA under a specific set of experimental conditions. In this paper, we demonstrate how the Ca‐Na‐zeolite A isotherm is developed and utilized in measuring and interpreting the calcium exchange capacity score of zeolite NaA. Owing to the large number of testing parameters that affect the equilibrium distribution of calcium between the zeolite and solution phases, and hence the calcium exchange capacity score of the zeolite, a recommendation is made as to a standard set of test conditions that provide for both analytical precision and convenience. With this approach, builder performance differences between any two zeolites can then easily be measured and assessed. As an extension to the isotherm principles developed in this paper, the prediction of zeolite performance in real detergent systems is illustrated. Particular attention is given to the more efficient utilization of the ion exchange capacity of zeolite NaA by the recently developed concentrated detergent systems.

Miscible displacement of reactive solutes in saline-sodic soils under varying flow conditions

SummaryThe paper reports a laboratory study on miscible displacement of reactive solutes during leaching a highly saline-sodic soil rich in soluble sodium carbonate with solutions of calcium chloride. The effect of varying flow velocities, initial soil moisture content and concentration of calcium in the leaching water on the extent of carbonate precipitation and replacement of sodium by calcium from the exchange positions was studied in soil columns. The results showed that precipitation of soluble carbonates in the soil increased with increasing flow velocity, initial soil moisture content and concentration of calcium in the leaching solution. The results further showed that the calcium exchange capacity of the soil was reduced significantly and nearly proportionally with decrease in the degree of water saturation as a consequence of decreased water application rate and initial soil moisture content. In view of the results obtained, a simple model to describe calcium-sodium exchange under unsaturated flow conditions in saline-sodic soils under consideration has been proposed. Possible implications of the results in actual field situations is discussed.

Maryland Soils Developed in Residuum from Chloritic Metabasalt Having High Amounts of Vermiculite in Sand and Silt Fractions

AbstractFrom 60 to 90% of the calcium exchange capacity (pH 7 Ca acetate saturation, Mg acetate replacement) was attributable to > 2µm particles in subsoil horizons of an Ultic Hapludalf developed in residuum from chloritic metabasalt in Maryland's Middletown Valley. Vermiculite was the dominant reactive mineral in several soils examined from the area. For material above the rock from which organic matter and free iron oxides had been removed, the fraction of CaEC attributable to “vermiculite” (measured by CEC methods) interlayers increased with increasing particle size and (for whole soils) with increasing depth. The vermiculite appears to have formed from chlorite at the rock‐saprolite boundary, since vermiculite is absent in the rocks and chlorite is absent in the saprolite and micas are rare in both rocks and saprolites. Weathering also produces kaolinite and free iron oxides and eventually destroys vermiculite as shown by examination of soils of differing degrees of development.Most of the pedons examined in the present and in related studies were included in the Myersville and Fauquier soil series by concepts used for a soil survey of the study area published in 1960. Both soil series are placed in Ultic Hapludulfs in the current Soil Taxonomy, but many pedons mapped as Fauquier and Myersville in the 1960 survey appear to be Dystric Eutrochrepts and some on steep slopes are Udorthents. The soils examined do not meet requirements for vermiculitic family mineralogy in present Soil Taxonomy, even though cation exchange properties appeared governed by vermiculite. Substitute criteria are proposed to base vermiculitic family mineralogy on the “vermiculite” content of whole‐soils.

‘Vermiculite’ Determination on Whole Soils by Cation Exchange Capacity Methods

AbstractThe proposed method is a modification of one by Alexiades and Jackson (1965). Calcium exchange capacity (CaEC) and potassium exchange capacity (KEC) are determined, after removal of organic matter and free iron oxides, by saturating the exchange complex with centrifuge washings of pH 7 acetate solutions of Ca or K, respectively. Excess salt in solutions remaining in contact with the soil after saturation is determined by measuring the weight and concentration of the excess solution. The exchangeable cations and excess salt are then replaced by centrifuge washings with 1 N acetate solutions of Mg (for CaEC) or NH4 (for KEC), after overnight 110°C oven-drying to enhance K fixation for KEC. The replaced cations are determined and CaEC and KEC values are calculated. Per cent ‘vermiculite’ is based on the difference between CaEC and KEC (expressed in m-equiv/100 g) and an assumed ‘vermiculite’ in-terlayer exchange capacity of 154 m-equiv/100 g; percentage Vr = (CaEC-KEC/154) × 100. The ‘vermiculite’ interlayer fraction (VIF) of the CaEC may also be calculated; VIF= CaEC-KEC/CaEC. The measured ‘vermiculite’ is shown in quotation marks since the method is open to criticism regarding exactly what is being measured, the assumptions made, etc. and to emphasize that the determination procedure is an operational one for the characterization of cation exchange complexes.Removal of free iron oxides increased both CaEC and KEC values of several soils but percentage Vr was little affected. The amount of K fixation was affected by the drying treatment employed after K saturation (none vs air-drying vs oven-drying). Thoroughly crushing Montana and African vermiculites dramatically increased their CEC and measured ‘vermiculite’ values, but had little effect with two samples of saprolite from chloritic metabasalt.

Dynamics of calcium‐sodium exchange under unsaturated plow conditions

Abstract An experiment was conducted in soil columns of 84 cm length and 5.7 cm inner diameter to determine the effect of degree of water saturation on the extent of replacement of sodium by calcium from the exchange sites. The experiment was performed by running 0.20 N calcium chloride solution through a saline‐sodic soil into a water table at the lower end at different rates less than the infiltration rate of the soil, thus obtaining unsaturated flow conditions. The effective or the apparent calcium exchange capacity of the soil was reduced significantly and nearly proportionally with a decrease in the degree of water saturation during the flow process. It is suggested that part of exchange sites become inaccessible during the unsaturated flow and that there must be some isolated locations away from the main water stream in which mixing or molecular exchange by diffusion is negligible.

Effect of Aging and X-Irradiation on the Kinetics of Skeletal Metabolism in the Rat

The instantaneous rate of skeletal growth and metabolism in normal aging and after cxposure to x-irradiation is compared. The radioisotope technique of Bauer was employed to quantify the alterations in the rate of accretion (A) and calcium exchange capacity (E) of various bones of young growing rats after whole- and partial-body x irradiation. In the animals in which one limb was exposed to 2000 r of x irradiation and compared with its contralateral control, the accretion rates of both the ends and the shaft of the tibia of the irradiated limb were depressed considerably, but the exchange capacity of the ends of the irradiated tibia showed a marked increase. In the tibiae exposed to 800 r, no effect on the accretion or exchange values was observed. It was found that, the A and E per unit ash weight differ markedly among the various bones and in different fractions of individual bones, and they were also differentially affected by radiation. Both these parameters in all bones, except the incisors, decreased as a function of age over the 140-day study period. After 500 r of whole-body x irradiation, the accretion rate decreased, whereas the exchange capacity of most bones showed a slightmore » increase over that of the controls. These changes were most marked at 75 days after irradiation and showed a tendency toward recovery at 140 days. The whole-body x irradiation (500 r) must have an abscopal effect on skeletal growth, since 800 r delivered directly to the bone hnd no acute effect on either the A or the E value. Whether the effect of 500 r of wholebody irradiation is due to the resulting temporary inanition with its inhibition of body growth, or to a generalized effect on the body's calcium regulatory control mechanism, is not clear. Although the gross effects on skeletal tissue of aging and radiation are similar, closer observation of these processes (by measurement of metabolic parameters) indicates that they differ in certain respects. Thus, in terms of exchange capacity, there is no simple relationship between the effects of x irradiation and those of aging on skeletal metabolism. (auth)« less