scholarly journals IONTOVÁ VÝMĚNA V POČÁTEČNÍCH STÁDIÍCH INTERAKCE ŽIVEC–VODA

2016 ◽  
Vol 22 (1-2) ◽  
Author(s):  
Markéta Camfrlová ◽  
Karel Vybíhal ◽  
Jiří Faimon
Keyword(s):  
Ion Exchange ◽  
Batch Reactor ◽  
Alkali Feldspar ◽  
Glass Electrode ◽  
Icp Oes ◽  
Advanced Stages ◽  
Electrode Solutions ◽  
Feldspar Dissolution ◽  
Alkaline Cations ◽  
Vessel Axis

The sample of perthitic alkali feldspar (62.5 wt. % of KAlSi3O8 and 37.5 wt. % of albite, Na0,996Ca0,004Al1,004Si2,996O8) was dissolved in a special stirred batch reactor (polyethylene vessel of 5 liter volume situated horizontally and rotating at few rotations per hour). The reactor was opened to atmosphere (log PCO2 ~ -3.5) through the mouth at the vessel axis. During the experiment, pH was monitored by pH-meter with combined glass electrode. Solutions were analyzed for Si, Al (spectrophotometry), K, Na (flame AAS), and Ca (ICP-OES). The results showed a fast preferential leaching of alkaline cations with respect to both Al and Si during the early stages of experiment that was diminishing during more advanced stages of the experiment. The released cations exceeded the consumed H+ ions by the range of two up to four magnitudes. The preponderance of cations over H+ ions was especially apparent during few initial days, when the buffering by atmospheric CO2 was insufficient. Simulation of the process by the PHREEQC code covering the CO2 buffering indicated that system feldspar–water–CO2(g) was evolving near the equilibrium in open system during the period after 5th day of the experiment. The results suggested that the mechanism of feldspar dissolution during the initial stages of the process does not correspond to a simple ion exchange and that it is more complicated.

scholarly journals Evaluation of a pilot plant for removal of nitrate from groundwater using ion exchange and recycled regenerant

2017 ◽  
Vol 12 (3) ◽  
pp. 541-548
Author(s):  
Sheldon Tarre ◽  
Michael Beliavski ◽  
Michal Green
Keyword(s):  
Ion Exchange ◽  
Batch Reactor ◽  
Nitrate Removal ◽  
Bacterial Count ◽  
Water Volume ◽  
Foam Fractionation ◽  
Well Water ◽  
Combined System ◽  
Blow Down ◽  
Product Water

A combined system of ion exchange (IX) and advanced biophysical treatment of a recirculating regenerant was tested for nitrate removal from groundwater with minimal brine discharge and chloride addition to the product water. Using well water containing 21.5 ± 1.4 mg NO3−-N/L, optimal IX operation was found at a service cycle of 500 bed volumes (BV). Product water nitrate concentrations (7.4 ± 1.4 mg/L as N) met regulations while minimizing both Cl− addition to the treated water (1.03 meq Cl− added per meq NO3−-N removed) and waste brine production (0.2% of the water volume treated). The total organic carbon in the product water was slightly higher (1.5 ± 0.5 vs. 1.3 ± 0.4 mg/L) than the well water and before disinfection the bacterial count was 10–700 cfu/ml. Brine used to regenerate the IX columns was treated first in a sequential batch reactor (SBR) for biological denitrification followed by ozonation for polishing. The SBR was operated at 8 hour cycles and achieved complete nitrate removal. An ozone dose of 3 to 5 mg/L brine allowed for efficient recycling of the denitrified regenerant by removing suspended solids by foam fractionation. In spite of the low brine blow-down, DOC in the recycled regenerant brine after a year of continuous operation was maintained at relatively low levels of 61.0 ± 11.6 mg/L.

scholarly journals Ion Exchange Separation Using a Masking Reagent for the Determination of Trace Impurities in Iron and Steels by ICP-OES

2004 ◽  
Vol 90 (1) ◽  
pp. 48-50 ◽  
Author(s):  
Hitoshi YAMAGUCHI ◽  
Shinji ITOH ◽  
Shin'ichi HASEGAWA ◽  
Kunikazu IDE ◽  
Takeshi KOBAYASHI
Keyword(s):  
Ion Exchange ◽  
Icp Oes ◽  
Trace Impurities ◽  
Ion Exchange Separation

Isotopic Evidence Disproving Ion Exchange Reaction Between H+ and Na+ in pH Glass Electrode

1995 ◽  
Vol 142 (10) ◽  
pp. L175-L176 ◽  
Author(s):  
Chia‐Ming Huang ◽  
Y. C. Jean ◽  
K. L. Cheng ◽  
F. C. Chang
Keyword(s):  
Ion Exchange ◽  
Exchange Reaction ◽  
Glass Electrode ◽  
Isotopic Evidence ◽  
Ion Exchange Reaction

Modelling of dissolution–reprecipitation ion-exchange reactions for the development of flame perthite in a suite of sheared alkaline rocks: an example from Chimakurthy, Eastern Ghats, India

2014 ◽  
Vol 78 (5) ◽  
pp. 1301-1323 ◽  
Author(s):  
Sudip Bhattacharyya ◽  
P. Sengupta
Keyword(s):  
Ion Exchange ◽  
Alkali Feldspar ◽  
Eastern Ghats ◽  
Partial Replacement ◽  
Exchange Reactions ◽  
Complex Interplay ◽  
Differential Stress ◽  
Western Margin ◽  
Ductile Shearing ◽  
Chemical Evidence

AbstractA suite of sheared syenites occurring along the western margin of the Eastern Ghats Belt, India have developed extensive flame perthite in K-feldspar. Albite flames show large variation in size, shape and abundance. Field, petrographic and chemical evidence suggests complex interplay between differential stress, recycling of K-Na-Ca and supply of Na by infiltration for the development of flame perthite. Partial replacement of pyroxenes, plagioclase and alkali feldspar by amphibole, biotite, nepheline and calcite causes internal recycling of Na-Ca-K in a closed system. Representative compositions of the minerals are used to constrain the model dissolution–reprecipitation ion-exchange reactions involving Na and K either as reactants and/or as products. A substantial proportion of Na+ required for the development of the albite flames, originates from Na metasomatism accompanied by ductile shearing in the feldspathic rocks, providing an ideal open system wherein both the differential stress and Na+ are made available for the development of the flame perthites. This process probably augmented the replacement of K-feldspar grains by flame albite and the K+ released was carried away by the fluid or, possibly, augmented the biotite-forming reactions in the associated quartz-poor syenites and, hence, trigger the Na-K cycle in these rocks.

Alkali feldspar dissolution in response to injection of carbon dioxide

2019 ◽  
Vol 109 ◽  
pp. 104419
Author(s):  
Jörgen Rosenqvist ◽  
Andrew D. Kilpatrick ◽  
Bruce W.D. Yardley ◽  
Christopher A. Rochelle
Keyword(s):  
Carbon Dioxide ◽  
Alkali Feldspar ◽  
Feldspar Dissolution

Leucite-Na-feldspar incompatibility: an experimental study

1975 ◽  
Vol 40 (312) ◽  
pp. 377-384 ◽  
Author(s):  
Alok K. Gupta ◽  
Alan D. Edgar
Keyword(s):  
Experimental Study ◽  
Ion Exchange ◽  
High Temperatures ◽  
Atmospheric Pressure ◽  
Alkali Feldspar ◽  
Phase Relations ◽  
Alkali Feldspars ◽  
Alkali Ion

SummaryPhase relations at atmospheric pressure in the pseudobinary join KAlSi2O6 (Lc)-NaAlSi3O8(Ab) and in the pseudoternary join Lc-Ab-CaAl2Si2O8(An) indicate that leucite is in-compatible with Na-feldspar. In the former join leucite can exist with an alkali feldspar of maximum albite content Ab54. In the Lc-Ab-An join, leucite only coexists with ternary feldspars with high An contents (approximately An50). Under PH2O conditions leucites may only coexist with alkali feldspars even poorer in Ab than those found at atmospheric pressure. Rare occurrences of coexisting leucite and Na-feldspar in nature have probably not crystallized directly from a melt but may have formed by a process of alkali ion exchange; or they may be unstable assemblages. No support can be found for the suggestions based on thermochemical calculations that albite and leucite are compatible at high temperatures.

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