Characterization of bottom sediments: cation exchange capacity and exchangeable cation status

1970 ◽  
Vol 4 (11) ◽  
pp. 935-939 ◽  
Author(s):  
Stephen J. Toth ◽  
Arthur N. Ott
Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 369-377 ◽  
Author(s):  
Maja Milošević ◽  
Predrag Dabić ◽  
Sabina Kovač ◽  
Lazar Kaluđerović ◽  
Mihovil Logar

AbstractThis study focuses on the mineralogical characterization of four raw clay samples from Dobrodo deposit, Serbia. Several analytical methods were applied to determine the chemical and mineralogical composition, morphology and physical properties (colour, plasticity, specific surface area, particle size and cation-exchange capacity) of the clay samples. Kaolinite, smectite and illite are the predominant phases in all of the samples studied that contain between 60.2 and 87.1 wt.% of clay. Quartz, feldspars, paragonite and Ti- and Fe-bearing phases were also identified. The relatively high SiO2/Al2O3 mass ratio indicates abundant quartz. The cation-exchange capacity of the samples varied between low and moderately charged clay minerals (12–52 mmol 100 g–1) with specific surface area values ranging from 94 to 410 m2 g–1. The plasticity index values (11–23%) suggest low to moderate plasticity. Preliminary results show that most of the raw clay from Dobrodo deposit might be suitable for use in ceramic applications.


10.30544/413 ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 39-45
Author(s):  
Milica P. Spasojević ◽  
Aleksandra Dakovic ◽  
George E. Rottinghaus ◽  
Ana S. Radosavljević Mihajlović ◽  
Marija A. Marković ◽  
...  

Octadecyldimethylbenzyl ammonium chloride (OA) was used as a surfactant for the preparation of organokaolin. The natural kaolin (from a plant for production of quartz sand in Rgotina, Serbia) was modified with a surfactant in amount equal to 90% of the kaolin cation exchange capacity (CEC). FTIR spectroscopy was used for characterization of the new product. FTIR spectra confirmed the presence of OA ions at the kaolin surface. Adsorption of mycotoxins – zearalenone (ZEN) and ochratoxin A (OCHRA) was studied by organokaolin at different amounts of adsorbent and pHs. Results showed that the presence of organic cations in the kaolin structure increased adsorption of both ZEN and OCHRA. Adsorption of the mycotoxins by organokaolin increased with increasing amounts of adsorbent and, at the lowest amount of solids in suspension, adsorption of ZEN and OCHRA was slightly higher at pH 7 and 9.


Soil Research ◽  
2015 ◽  
Vol 53 (4) ◽  
pp. 377 ◽  
Author(s):  
D. Curtin ◽  
P. M. Fraser ◽  
M. H. Beare

Cultivation of grassland is known to lead to the depletion of soil organic matter (SOM), but the effect on the size and composition of the exchangeable cation suite has not been documented. We measured cation exchange capacity (CEC) and exchangeable cations (calcium, Ca; magnesium, Mg; potassium, K; sodium, Na), as well as soil carbon (C) and nitrogen (N) (0–7.5, 7.5–15, and 15–25 cm), 8 years after conversion of long-term ryegrass–white clover pasture (grazed by sheep) to annual crop production. The trial was near Lincoln, Canterbury, New Zealand. The trial included three tillage treatments: crops established using intensive cultivation (mouldboard ploughing), minimum tillage (shallow cultivation, ~10 cm), or no-tillage. The 8-year rotation was barley, wheat, pea, barley, pea, barley, barley, barley. A sheep-grazed pasture was maintained as an experimental control. The experiment also included a permanent fallow treatment (maintained plant-free using herbicides; not cultivated). After 8 years under arable cropping, soil C stocks (0–25 cm) were 10 t ha–1 less, on average, than under pasture. The vertical distribution of soil organic matter (SOM) was affected by tillage type, but the total amount of organic matter in the top 25 cm did not differ (P > 0.05) among the tillage treatments. Under permanent fallow (C loss of 13 t ha–1 relative to pasture), total exchangeable cation (Ca + Mg + K +Na) equivalents declined by 47 kmolc ha–1, a 20% decrease compared with pasture. Loss of exchange capacity resulted in the selective release of cations with lower affinity for SOM (K, Na, Mg). Smaller losses of exchangeable cations were recorded under the arable cropping rotation (average 31 kmolc ha–1), with no differences among tillage treatments. Effective CEC (at field pH) decreased under permanent fallow and cultivated treatments because of: (1) depletion of SOM (direct effect); and (2) soil acidification, which eliminated some of the remaining exchange sites (indirect effect). Acidification in the permanent fallow can be attributed to the N mineralisation process, whereas in the cropped systems, excess cation removal in harvested straw and grain accounted for about half of the measured acidification. There was evidence that the organic matter lost under arable cropping and fallow had lower CEC than SOM as a whole.


Jurnal Kimia ◽  
2016 ◽  
Author(s):  
Ika Juliana ◽  
Ida Ayu Gede Widihati ◽  
Oka Ratnayani

This research aims to improve characteristics of ledgestone catalyst by using acid activation with various concentrations. The acid used for activation was H2SO4 with concentrations of 1, 2 and 3M. The characterization of catalysts was carried out by acid-base titration method to determine the surface acidity, methylene blue adsorption to measure the spesific surface area of ??the catalyst, and the NH4OAc extraction method to measure the value of cation exchange capacity of the catalyst. Ledgestone catalyst with the best character was applied to convert waste cooking oil into biodiesel. The characterization of biodiesel was carried out by densitometry to determine the density of biodiesel, Oswald viskosimetry to measure the viscosity, and Gas Chromatography-Mass Spectrometry (GCMS) to determine the composition of chemical compounds of the biodiesel. The results showed that the concentration of acid used to activate ledgestone catalyst with the best character was 1M. This acid-activated ledgestone (catalyst A1) had a value of surface acidity, surface area, active sites number, and high cation exchange capacity were 0.3530 ± 0.0011 mmol / gram and35.7581 m2/gram, 2.1258 x 1020 atoms/gram, and 5.88 me/100 g, respectively. The concentration of catalyst A1 producing the highest biodiesel yield was 1% w/v. The produced biodiesel was 74,71% with 0.02% FFA, acid value of 0.0438 mg KOH/gram biodiesel, density of 0.7850 g/mL, kinematic viscosity of 0.4650 cSt. Two major compounds of the biodiesel were methyl hexadecanoate with area of 71.84% and cis methyl-9-octadecenoate with area of 28.16%.


2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Mardi Wibowo

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


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