Sorption of Uranium(6+) and Neptunium(5+) by Surfactant-Modified:Natural Zeolites

1999 ◽  
Vol 556 ◽  
Author(s):  
James D. Prikryl ◽  
Roberto T. Pabalan
Keyword(s):  
Anion Exchange ◽  
Cationic Surfactant ◽  
Natural Zeolite ◽  
Natural Zeolites ◽  
Radionuclide Concentration ◽  
Modified Zeolite ◽  
Surfactant Modification ◽  
Naci Concentration ◽  
Carbonate Complexes

AbstractExperiments were conducted to determine the ability of surfactant-modification to enhance the ability of natural zeolites to sorb U(6+) and Np(5+). Natural zeolite material, comprised mainly of clinoptilolite and treated with the cationic surfactant exadecyltrimethylammonium-bromi(le (IDTMA), was reacted with U(6+) and Np(5+) solutions open to the atmosphere and having a range of radionuclide concentration, pH, and NaCI concentration. The results indicate surfactantmodification of the zeolite enhances its ability to sorb U(6+), particularly at pHs greater than six where U(6+) sorption on unmodified zeolite is typically low due to formation of anionic U(6+) aqueous carbonate complexes. In contrast, there is little enhancement of Np(5+) sorption onto surfactant-modified zeolite. The presence of chloride anions in solution makes surfactantmodification less effective. The enhanced sorption of U(6+) is interpreted to be due to anion exchange with counterions on the external portion of a surfactant bilayer or admicelles.

ION Exchange Characterisation of Modified Zeolite

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2269-2272 ◽  
Author(s):  
Š Cerjan-Stefanovic ◽  
M. Kaštelan-Macan ◽  
T. Filipan
Keyword(s):  
Drinking Water ◽  
Ion Exchange ◽  
Anion Exchange ◽  
Natural Zeolite ◽  
Deionized Water ◽  
Isomorphous Substitution ◽  
Waste Waters ◽  
Modified Zeolite ◽  
Water Drinking

Isomorphous substitution of phosphorus into a natural zeolite affords the possibility to change the overall framework charge from negative to positive. The substances so created should be used for purification of waste waters. The work describes the preparation of phosphated zeolite, their characterisation and examples of their anion exchange of NO3 on observed in deionized water, drinking water and in the solution containing varying amounts of nitrate.

scholarly journals Defluoridation of drinking water by modified natural zeolite with Cationic surfactant, in case of Ziway town, Ethiopia

2021 ◽  
Author(s):  
Dessalegn Geleta Ebsa ◽  
Adisu Befekadu Kebede
Keyword(s):  
Drinking Water ◽  
Cationic Surfactant ◽  
Natural Zeolite ◽  
Fluoride Concentration ◽  
Aggregate Size ◽  
Effect Of Temperature ◽  
Fluoride Removal ◽  
Ammonium Bromide ◽  
Modified Zeolite ◽  
Peasant Farmers

Abstract. In Ethiopia (Ziway town) an excess fluoride (≥ 1.5 mg/L) consumption in drinking water (ground water and Lake Ziway) sources causes a health problem on the communities. The surrounding of inhabitant's peasant farmers of drinking water sources was extremely relying on this polluted fluoride concentration of water. This investigation was focused on defluoridation of drinking water by natural zeolite modified with a cationic surfactant in a batch system and Hexadecy Trimethyl Ammonium Bromide were used for zeolite modification. The Batch experiments also conducted to test for preferential removal of fluoride from water by surfactant-modified zeolite. The zeolite treatments had an aggregate size of 1.4 to 2.4 mm. The cationic surfactant-modified zeolite, and raw zeolite were used in all experiments. The removal efficiency of the treatment was influence by pH of solution (5.5 ± 0.2–8.5 ± 0.2), initial concentration of fluoride (1–10 mg/L), dose of surfactant-modified zeolite (2.5–18 g/L), contact time (30–180 Minute), and effect of temperature was investigated. The study investigated that, at the constant Blank of 10 mg/L, 5 g/L of Hexadecy Trimethyl Ammonium Bromide dosage noted the highest fluoride removal potential at the end of the 3hours runtime: Na-LSX (88.4 %), Na-LTA (64.6 %) and ZR (79.8 %). Incompatible to this reflection, the model waters with pH maintained at 5.5 ± 0.2 and 6.5 ± 0.2 verified rapid fluoride removal (89.7 % and 72.3 % respectively) within the first 60 minutes of runtime.

scholarly journals Modified Alkali Activated Zeolite Foams with Improved Textural and Mechanical Properties

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 483 ◽  
Author(s):  
Kateřina Hrachovcová ◽  
Zdeněk Tišler ◽  
Eliška Svobodová ◽  
Jan Šafář
Keyword(s):  
Natural Zeolite ◽  
Chemical Properties ◽  
Acid Leaching ◽  
Earth Metal ◽  
Partial Replacement ◽  
Alkali Activation ◽  
Natural Zeolites ◽  
Modified Zeolite ◽  
Potential Applicability ◽  
Alkali Activated

Natural zeolites are crystalline hydrated alkali metal and alkaline earth metal aluminosilicates with unique ion-exchange and sorption properties. The exceptional structure of pores gives natural zeolites several application possibilities, especially for water treatment and construction. For a wider use of natural zeolites, such as catalysis, properties—especially chemical, textural, and mechanical—need to be modified. In this study, the basic natural zeolite foam was synthesized by alkali activation of natural zeolite with an activator (KOH + Na2SiO3) and foamed by hydrogen peroxide solution. Other foams were prepared by a partial replacement of the natural zeolite with CaO, MgO, and metakaolin (MK) and alkali activated and foamed in the same manner as the basic natural zeolite foam. Other properties of the foams were modified by acid leaching. The aim of the study was to compare the basic alkali activated zeolite foam with the CaO, MgO, and MK modified zeolite foams and determine the effect of the CaO, MgO, and MK modification and the subsequent leaching of the alkali activated zeolite foams on the textural, mechanical, and chemical properties. Properties of alkali activated zeolite foams were determined by Hg porosimetry, N2 physisorption, NH3-TPD, XRF, XRD, and strength analyses. From the data, it is apparent that all modified samples have an increase of pore volume in the mesoporous region and the partial replacement by MgO or CaO significantly increased surface area up to 288.2 m2/g while increasing the strength several times. The obtained data showed an improvement in properties and extension of the potential applicability of modified zeolite foams in the chemical industry, especially for catalytic and sorption applications.

Adsorptive removal of trace oxytetracycline from water by acid-modified zeolite: influencing factors

2013 ◽  
Vol 68 (11) ◽  
pp. 2473-2478 ◽  
Author(s):  
Wenhao An ◽  
Hua Xiao ◽  
Man Yu ◽  
Xiaoyang Chen ◽  
Yuxin Xu ◽  
...  
Keyword(s):  
Humic Acid ◽  
Removal Efficiency ◽  
Natural Zeolite ◽  
Opposite Effect ◽  
Swine Wastewater ◽  
Adsorption Efficiency ◽  
Tetracycline Antibiotics ◽  
Modified Zeolite ◽  
Alkaline Conditions ◽  
Acidic Conditions

Because of the wide use of antibiotics in the livestock industry, trace tetracycline antibiotics are frequently detected in swine wastewater and water bodies near pig farms. Based on natural zeolite, modified zeolite was synthesized by treatment with nitric acid. As one kind of typical tetracyclines, oxytetracycline (OTC) was chosen as the target adsorbate. Removal of trace OTC by modified zeolite and the effects of several main water matrices on OTC adsorption were studied in detail. OTC removal efficiency by acid-modified zeolite was about 90%, compared to less than 20% by natural zeolite. In general, in acidic conditions the removal efficiency of OTC by modified zeolite was about 90%, which was much higher than 20–35% in alkaline conditions. An increase in ionic strength from 0.01 to 1.0 M led to a decrease in adsorption efficiency from 90 to 27%. The presence of 10.0 mg L−1 dissolved humic acid accelerated sorption of OTC on modified zeolite, while 100.0 mg L−1 humic acid resulted in the opposite effect. An increase in temperature contributed to enhancing the adsorption efficiency.

Study of the pozzolanic activity and hydration products of cement pastes with addition of natural zeolites

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 241-250 ◽  
Author(s):  
V. Lilkov ◽  
O. Petrov ◽  
V. Petkova ◽  
N. Petrova ◽  
Y. Tzvetanova
Keyword(s):  
Surface Area ◽  
Cement Paste ◽  
Chemical Reactions ◽  
Natural Zeolite ◽  
Early Stage ◽  
Pozzolanic Activity ◽  
Large Surface Area ◽  
Natural Zeolites ◽  
Hydration Products ◽  
Cement Pastes

AbstractThis paper presents results from comparative thermogravimetric, calorimetric and pozzolanic activity analyses of five natural zeolite samples from Bulgaria, Slovakia, Philippines, USA and North Korea. The zeolites actively participate in the hydration processes of cement. Their activity in the early stage of hydration is based mainly on the large surface area of the particles while, in the later stages of activation, chemical reactions occur between the products of the hydration of cement and the soluble SiO2 that is present in the bulk of the zeolites. It has been shown that in all cement pastes which contain zeolite additives, the quantity of portlandite is lower than that in pure cement paste or is even totally absent. The amounts of hydration products are greater when 30% zeolite is used than when 10% zeolite is added (excluding the sample with chabazite). The lowest pozzolanic activity is shown by chabazite, which possessed the lowest SiO2/Al2O2 ratio.

scholarly journals REDUCTION OF METAL CATIONS CONTENT FROM THE AQUEOUS SOLUTIONS BY SORBENTS

2021 ◽  
Vol 2021 (6) ◽  
pp. 5307-5311
Author(s):  
IVETA PANDOVA ◽  
◽  
MIROSLAV RIMAR ◽  
Keyword(s):  
Heavy Metals ◽  
Aqueous Solutions ◽  
Natural Zeolite ◽  
Metal Cations ◽  
Sorption Kinetics ◽  
Synthetic Zeolite ◽  
Natural Zeolites ◽  
Chemically Treated ◽  
Synthetic Zeolites

The article presents the results of research on reducing the concentration of heavy metals, such as copper and nickel, on natural zeolite in comparison with synthetic zeolite and chemically treated natural zeolite. The reduction of the content of specific types of heavy metals from aqueous solutions was investigated by the method of sorption kinetics. The results indicate the ability of natural zeolites to compete with synthetic zeolites.

scholarly journals Pengujian Zeolit Alam Mordenit Sebagai Penjerap Proses Pendegradasian Kandungan Amonium di dalam Air Tambak

2020 ◽  
Vol 21 (1) ◽  
pp. 49-55
Author(s):  
Nuryoto Nuryoto ◽  
Teguh Kurniawan ◽  
Indar Kustiningsih
Keyword(s):  
Particle Size ◽  
Natural Zeolite ◽  
The Other ◽  
Ammonium Concentration ◽  
Small Fish ◽  
Natural Zeolites ◽  
Absorption Time ◽  
Adsorption Time ◽  
Research Results ◽  
Other Hand

ABSTRACTIndonesia has an abundant quantity of natural zeolites that have not yet been utilized maximally. On the other hand, fishpond farmers have a problem regarding the presence of ammonium in the fishpond water which will negatively impact to survival of fish, especially small fish. To solve this problem, this research was utilizing natural zeolite to degrade ammonium in the fishpond water. This research aimed to test mordenite natural zeolite from Bayah as an adsorbent to collaborate some variables impact to reach more maximal adsorption. The variables that were used to be observed were: mordenite natural zeolite from Bayah as an adsorbent which has been activated by 1-7 N H2SO4 and the other was without activation, ammonium concentration of 80-800 ppm, the particle size of adsorbent of 80 and 150 mesh, stirring speed of 600 and 800 rpm, and without stirring by duration adsorption time of 60 minutes. The research results showed that mordenite natural zeolite after activated was able to adsorb of 100% ammonium, while for the mordenite natural zeolite from Bayah without stirring was of 80%, by the same absorption time. These results will give significant benefits for fishpond farmers to increase their productivity because of the increase in fish survival.Keywords: adsorption, adsorbent, zeolite, amoniumABSTRAKKandungan zeolit alam di Indonesia cukup melimpah dan belum termanfaatkan secara maksimal. Pada sisi lain petani tambak dihadapkan pada masalah terdapatnya kandungan amonium di dalam air tambak, yang akan berdampak negatif bagi keberlangsungan hidup ikan, terutama ikan yang masih kecil. Penelitian ini mencoba memanfaatkan zeolit alam guna mendegradasi kandungan amonium dalam air tambak. Tujuan penelitian ini adalah melakukan pengujian terhadap zeolit alam mordenit dari Bayah sebagai adsorben, baik dilakukan dengan pengadukan maupun tanpa pengadukan, serta mengkolaborasi beberapa variabel yang berpengaruh agar hasil adsorpsi lebih maksimal. Observasi dilakukan dengan zeolit alam mordenit dari Bayah yang telah diaktivasi dengan 1-7 N H2SO4 maupun tanpa aktivasi, rentang konsentrasi larutan amonium 80-800 ppm, ukuran partikel adsorben 80 dan 150 mesh, kecepatan pengadukan 600 dan 800 rpm, dan tanpa pengadukan serta lamanya waktu penyerapan 60 menit. Hasil penelitian menunjukan hasil yang sangat baik, dan secara umum zeolit alam mordenit Bayah teraktivasi telah mampu melakukan adsorpsi amonium sebesar 100%, sedangkan untuk zeolit alam mordenit Bayah tanpa pengadukan sebesar 80% pada waktu adsorpsi yang sama.Kata kunci: adsorpsi, adsorben, zeolit, amonium

scholarly journals Fluoride ion adsorption from wastewater using magnesium(II), aluminum(III) and titanium(IV) modified natural zeolite: kinetics, thermodynamics, and mechanistic aspects of adsorption

2017 ◽  
Vol 8 (4) ◽  
pp. 479-489 ◽  
Author(s):  
Zhijun Ma ◽  
Qi Zhang ◽  
Xingyuan Weng ◽  
Changye Mang ◽  
Liwei Si ◽  
...  
Keyword(s):  
Natural Zeolite ◽  
Adsorption Process ◽  
Fluoride Ion ◽  
Ion Adsorption ◽  
Order Model ◽  
Fluoride Ions ◽  
Modified Zeolite ◽  
Fluoride Adsorption ◽  
Pseudo Second Order ◽  
Modified Zeolites

Abstract Natural zeolite was modified using metal ions, including magnesium(II), aluminum(III) and titanium(IV). The modified zeolite was then used as an adsorbent for the investigation of the adsorption kinetics, isotherms, and thermodynamic parameters of fluoride ions in wastewater at various pHs and temperatures. The kinetics and thermodynamics for the removal of the fluoride ions onto the modified zeolite have also been investigated. The fluoride ion adsorption capacity of the three types of modified zeolites exhibited an increase, then decrease, with rising pH. The fluoride adsorption capacity of the modified zeolites decreased with an increase in temperature. The pseudo-second-order model is more suitable for describing the adsorption kinetic data than the pseudo-first-order model for modified zeolite and the adsorption process of the fluoride ions reveals pseudo-second-order kinetic behavior, respectively. It was found that the adsorption equilibrium data fit the Freundlich isothermal equation better than that of the Langmuir isothermal and Dubinin–Radushkevich (D–R) isothermal equations. Thermodynamic analysis suggests that the negative values of ΔG0 and ΔH0 further indicate that the fluoride adsorption process is both spontaneous and exothermic. The results of competitive adsorption tests suggest that the modified metal zeolite materials adsorb fluoride ions with high selectivity.

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