Modification Of Natural Zeolite Research Articles

Tailoring Natural and Fly Ash-Based Zeolites Surfaces for Efficient 2,4-D Herbicide Adsorption: The Role of Hexadecyltrimethylammonium Bromide Modification

Global development has led to the generation of substantial levels of hazardous contaminants, including pesticides, which pose significant environmental risks. Effective elimination of these pollutants is essential, and innovative materials and techniques offer promising solutions. This study examines the modification of natural zeolite (clinoptilolite) and fly ash-based NaA and NaX zeolites with hexadecyltrimethylammonium bromide (CTAB) to create inexpensive adsorbents for removing 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide from water. Detailed characterization of these materials was performed, along with an evaluation of the effects of pH, contact time, temperature, and initial 2,4-D concentration on their sorption capacities. The modified samples exhibited significant changes in elemental composition (e.g., reduced SiO2 and Al2O3 content, presence of Br) and textural properties. The adsorption of the pesticide was found to be an exothermic, spontaneous process of pseudo-second-order kinetics and was consistent with the Langmuir model. The highest sorption capacities were observed for samples modified with 0.05 mol L−1 CTAB, particularly for CliCTAB-0.05.

Advanced modification of natural zeolites for optimized biogas, syngas, and hydrogen production and purification

Advanced modification of natural zeolites for optimized biogas, syngas, and hydrogen production and purification

Hydrothermal modification of natural zeolite and its application in anti‐inflammatory removal

Hydrothermal modification of natural zeolite and its application in anti‐inflammatory removal

Enhanced Ammonium Adsorption from Aqueous Solutions Using Ethylenediaminetetraacetic Acid (EDTA) Modified Lampung (Indonesia) Natural Zeolite: Isotherm, Kinetic, and Thermodynamic Studies

The environmental concern related to excessive ammonium in water bodies necessitates efficient and cost-effective removal techniques. This study investigated the modification of natural zeolite collected from the Tanggamus district of Lampung Province, Indonesia, with ethylenediaminetetraacetic acid (EDTA) to enhance its performance for ammonium adsorption from aqueous solution. The modified and natural zeolites were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), N2 adsorption-desorption isotherm, and scanning electron microscopy (SEM). Results indicated that the modification did not cause significant structural changes but increased the mesoporosity of the zeolites, which was beneficial for ammonium adsorption. The adsorption studies revealed that the EDTA modified zeolites consistently outperformed the natural zeolite and that the adsorption process was exothermic in nature. The Langmuir and Freundlich isotherm models fit the adsorption data well, indicating that the adsorption process occurs on both homogenous and heterogeneous surfaces. Thermodynamic studies confirmed that the adsorption process was exothermic and that the EDTA modification increased the spontaneity of the ammonium adsorption process. Overall, this study highlights the potential of EDTA-modified zeolites as an effective material for ammonium removal from aqueous solutions.

Modification of Natural Zeolite from Klaten, Indonesia Using Ammonium Chloride by Ion-Exchange and Its Application as Catalyst in Ethanol Dehydration to Produce Diethyl Ether

Modification of a natural zeolite from Klaten, Indonesia, as a catalyst in the dehydration of ethanol to produce diethyl ether (DEE) has been conducted. Raw Klaten natural zeolite (ZA) was modified using 1 and 2 M of an ammonium chloride solution for 24 h while stirring for 18 h, then calcined at 500 °C for 5 h under N2 gas flow produced HZA1 and HZA2 catalyst, respectively. The catalysts were characterized using XRD, BET surface area, SEM-EDX, XRF, FTIR and gravimetric acidity test using ammonia-based vapor. The dehydration process was conducted under variations of temperature (200, 250, and 300 °C) and catalyst mass of 0.1, 0.2, and 0.4 g for 20 mL of 96% ethanol. The HZA1 catalyst produced the highest yield of DEE (2.41%) at 250 °C and 0.1 g catalyst. This catalyst showed needle-like of 66.22 nm crystal size, consisting of 32.57% mordenite, the highest surface area (48.32 m2/g), crystallinity (32.93%) and Brønsted acid sites (2.75 mmol/g), the lowest pore diameter (1.77 nm) and Si/Al mol ratio (4.03). The HZA1 catalyst can be used repetitively and produced DEE yield at the second and third runs (2.40 and 2.61%).

Modification of natural zeolites and their applications for heavy metal removal from polluted environments: Challenges, recent advances, and perspectives

In recent decades, environmental pollution has become a significant problem for human health and environmental impact. The high accumulation of heavy metals in waters and soils from different sources was conducted by finding efficient and environmentally friendly treatment methods and materials for their removal. Natural zeolites have found wide-ranging applications in environmental remediation and protection, considering various treatment and modification methods designed to enhance the natural zeolites' adsorptive or ion-exchange capabilities for increased efficiency. This paper briefly consolidates the recent scientific literature related to the main characteristics of natural and modified zeolites, the advantages and limitations of their environmental remediation application, and summarizes the methodologies applied to natural zeolites in order to improve their properties. Their application for removing heavy metals from water systems and soils is also comprehensively discussed. This review highlights the excellent potential of natural zeolites to be used after specific treatment or modification as a sustainable and green material to solve numerous environmental pollution issues.

Composition of Chemical Elements and Ion Exchange Complex of Acid- and Alkali-Modified Natural Zeolites From the Sokyrnytsky Deposit

Natural zeolites are abundant and inexpensive resources. They are crystalline hydrated aluminosilicates with a framework structure that has pores and channels occupied by water, alkali, and alkaline earth cations. Having high cation exchange capacity, acting as a molecular sieve, natural zeolites have been widely utilized in recent decades as adsorbents in separation and purification processes. Modification of natural zeolite increases its adsorption capacity of environmental pollutants, in particular, radionuclides from low-level liquid radioactive waste. The article presents results obtained from a study of the chemical composition of the structural elements and ion exchange complexes of natural, acid-modified and alkali-modified zeolites from the Sokyrnytske deposit. The main rock-forming mineral of the Sokyrnytske zeolite is clinoptilolite. The zeolite was modified by a 5.5 M HCl solution for 2 hours at 100 oC using a backflow condenser. The ratio of solid to liquid phases was 1:2. For alkaline modification, 1.4 M NaOH solution was used. The exposure time was 2.75 hours. The conditions and phase ratio were similar to those in acidity modification. By composition of the ion exchange complex, natural zeolite belongs to potassium-calcium-sodium (K > Ca > Na) clinoptilolites. In the process of acidity and alkaline modification of the natural zeolite, redistribution of the exchangeable cations is observed and the content of structural cations in the clinoptilolite lattice changes. In alkali-modified zeolite, the content of exchangeable Na and Ca cations increases, and the content of K and structural Al cations decreases. In the acid-modified zeolite, the number of exchangeable Na, Mg, Ca, K cations decreases. At the same time, the content of Fe and Al decreases and the relative amount of Si in the lattice increases. The Si/Al ratio increases in the following succession: natural zeolite → alkali-modified zeolite → acid-modified zeolite. The specific surface area of the modified zeolites increases compared to the natural ones. The largest increase is observed for the acid-modified zeolite. The textural characteristics and mineral composition of the studied samples indicate that the natural, acid-modified and alkali-modified zeolites from the Sokyrnytske deposit may be used for removal of radionuclides from low-level liquid radioactive waste.

Thermal Stability and Surface Area Modification of Natural Zeolite Through HCl & NaCl Treatment to Apply in Pyrolysis Systems

Pyrolysis technology relies on efficient catalyst materials to expedite the process and improve the quality of the final product. Modified natural zeolite has emerged as a promising heterogeneous catalyst in this regard. This study presents a comprehensive analysis of natural zeolite sourced from Tasikmalaya, West Java, with the primary aim of evaluating its potential as a catalyst. The samples underwent acid treatment procedures and were extensively characterized using BET, TGA, SEM-EDX, X-Ray Diffraction (XRD), and FT-IR tests. XRD results indicated that the predominant frame structure of the Indonesian raw natural zeolite was mordenite, with a Si/Al ratio ranging from 5.0 to 6.0 and a surface area of approximately 23 m²/g. Following the 1M HCl acid treatment, a significant enhancement in the Si/Al ratio to 7.8 and a considerable expansion in surface area to 125.37 m²/g were observed. Moreover, the natural zeolite demonstrated remarkable thermal stability, thus underscoring its potential as a highly suitable catalyst for various pyrolysis applications.

Effect of Surface Modification of Natural Zeolite on Ammonium Ion Removal from Water Using Batch Study: an Overview

Effect of Surface Modification of Natural Zeolite on Ammonium Ion Removal from Water Using Batch Study: an Overview

Modification of Clinoptilolite as a Robust Adsorbent for Highly-Efficient Removal of Thorium (IV) from Aqueous Solutions.

The natural zeolite has been modified with sulphate and phosphate. The adsorption of thorium from the aqueous solutions by using the natural and modified zeolites has been investigated via a batch method. The adsorbent samples were characterized by X-ray Diffraction (XRD), N2 adsorption-desorption (BET), Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDX). Modification of natural zeolite with sulphate and phosphate was found to increase its adsorption capacity of thorium but reduced its specific surface area (SBET). The adsorption experiments were expressed by Langmuir, Freundlich and Dubinin-Radushkevitch (D-R) isotherm models and the results of adsorption demonstrated that the adsorption of thorium onto the natural and modified zeolites correlated better with the Langmuir isotherm model than with the Freundlich isotherm model. The maximum adsorption capacity (Qo) was determined using the Langmuir isotherm model at 25 °C and was found to be 17.27, 13.83, and 10.21 mg/g for phosphate-modified zeolite, sulfate-modified zeolite, and natural zeolite, respectively. The findings of this study indicate that phosphate-modified zeolite can be utilized as an effective and low-cost adsorbent material for the removal of thorium from aqueous solutions.

The ‘chimie douce’ process towards the modification of natural zeolites for removing drugs and pesticides from water

AbstractBACKGROUNDDrugs and pesticides are emerging contaminants, and their presence in surface and groundwater have been increasing. Therefore, this work aims to study the modification of natural zeolite to remove these contaminants from water.RESULTSAmong the modifications carried out, hydrothermal treatment in the presence of surfactant (CTAB) was highlighted. The hydrothermal treatment with surfactant provided a structural rearrangement. As a result, the zeolite became more hydrophobic, with a smaller specific area and a more significant amount of mesopores and macropores. Changes in textural and chemical characteristics resulted in a significant increase in the removal of the evaluated pesticides and drugs. In order to evaluate the potential of zeolites to remove emerging contaminants under conditions closer to reality, the modified samples were evaluated in the adsorption process of simulated contaminated water. The maximum adsorption capacities obtained were 28.24, 3.07, and 20.06 mg g−1 for 2,4‐D, diuron, and diclofenac, respectively, using HT‐H2O_CTAB under conditions closer to real water treatment (30 °C and natural pH of the solution).CONCLUSIONThe results demonstrate that hydrothermal modification with CTAB is a promising ‘chimie douce’ technique to use natural zeolites to remove emerging contaminants. © 2022 Society of Chemical Industry (SCI).

Recycling of waste plastics to liquid fuel mixture over composite zeolites catalysts

Plastic waste production and consumption is increasing at an alarming rate with the increase of the human population, rapid economic growth, continuous urbanization, and changes in lifestyle. In addition, the short life span of plastic accelerates the production of plastic waste on a daily basis. Plastic waste recycling is carried out in different ways, but in most developing countries, open or landfill disposal is a common practice for plastic waste management. Plastic recycling into feedstocks, also known as chemical recycling, is encouraged all over the world. One such area is the thermal and catalytic thermal degradation of plastics into hydrocarbon fractions, which can be used as high-quality motor fuel after appropriate processing. Hydrocracking in the presence of a catalyst is a promising method of converting waste plastic materials to high quality liquid transportation fuels with decreased amounts of olefins and heteroatoms such as S, N, Cl, N, and O. The article deals with the study of hydrocracking of waste plastic into high quality liquid fuel on various catalysts based on natural zeolite deposits Taizhuzgen. The aim of the work is to determine the effect of new composite catalysts on the yield of liquid products by studying the specific surface and porous structure based on natural zeolite modified with Mо salt. It is established that the modification of natural zeolite with Mo affects the morphology of the catalyst, therefore, the obtained catalysts have different effects on the yield and composition of liquid fractions during the hydrogenation thermocatalytic transformation of hydrocarbons. The highest yield of liquid products (61.56%) was achieved using the 2% Mo/Taizhuzgen zeolite catalyst, which was chosen as optimal.

Penggunaan ZnO/zeolit sebagai katalis dalam degradasi tartrazin secara ozonolisis

An investigation on modification of natural zeolite with ZnO for the degradation of tartrazine. In this study, ZnO as a semiconductor is modified into a natural zeolite as support to form ZnO/zeolite that can increase the efficiency degradation of tartrazine. Further, the formed catalyst was added to tartrazine by determining the variation in ozonolysis time, the amount of addition of the catalyst, and the addition of a catalyst time. The results of degradation were determined by UV-Vis spectrophotometer at 424 nm. The result showed that the percentage of degradation obtained on each catalyst in the degradation. The resulted percent degradation of 20 ml of tartrazine at concentration of 15 mg/L using 20 mg ZnO/zeolite was 56.80%, while using 0.77 mg ZnO was 42.25%, and with the addition of 19.23 mg of Zeolite was 31.18%, all of that condition was proceeded by 40 minutes of ozonolysis. Thus, the result indicates that the ZnO/zeolite catalyst can increase percentages of tartrazine degradation by ozonolysis. It is known that the catalyst ZnO/zeolite is very effective in increasing the degradation of tartrazine. Analysis of tartrazine compounds using fourier-transform infrared spectroscopy (FTIR) after degradation changes in wavenumber indicates that there is a breaking of the bonds of tartrazine compounds. Characterization of ZnO/zeolite catalyst using FTIR, X-Ray diffraction (XRD) and scanning electron microscope (SEM), in each spectrum there was no shift, indicating that there is no change in ZnO/zeolite structure

Physicochemical evaluation of the effect of natural zeolite modification with didodecyldimethylammonium bromide on the adsorption of Bisphenol-A and Propranolol Hydrochloride

Wastewater pollution by organic anions is of great interest. Surfactant-modified zeolites exhibit high adsorption of both organic and inorganic toxicants. Here, bisphenol-A and propranolol hydrochloride were adsorbed on natural zeolite modified with the cationic surfactant didodecyldimethylammonium bromide with and without pretreatment of the zeolite with NaCl and HCl. Detailed physicochemical analysis shows chemisorption, electrostatic and hydrophobic interactions with the surfactant and bisphenol-A, and in the case of propranolol, also physisorption.

Mechanochemical modification of natural zeolite to improve the adsorption and hydrolysis properties of metsulfuron-methyl

For the first time, potentially active samples of zeolites were obtained by their mechanochemical modification with the polysaccharide arabinogalactan and aerosil. The most positive effect on the desorption properties of aerosil addition is shown.

Dealuminated and Desilicated Natural Zeolite as a Catalyst for Hydrocracking of Used Cooking Oil into Biogasoline

<p align="justify">The modification of natural zeolite has been conducted by dealumination and desilication using HCl and NaOH treatments as a catalyst for hydrocracking of used cooking oil into biogasoline. This research aimed to study the effect of dealumination and desilication on the natural zeolite activity and selectivity of a hydrocracking process. A variety of catalysts was prepared by applying 3, 6, and 9 M HCl in the dealumination of natural zeolite to produce DNZ(3-1), DNZ(3-2) DNZ(3-3), DNZ(6-1), DNZ(6-2), DNZ(6-3), DNZ(9-1), DNZ(9-2), and DNZ(9-3) catalysts and NaOH in the desilication of natural zeolite to obtain NZB catalyst. The results showed that the dealumination and the desilication treatments affected the liquid product conversion of used cooking oil from catalytic hydrocracking. The hydrocracking of used cooking oil with NZB catalyst produced the highest gasoline fuel conversion of 94.87%. </p><p align="justify"> </p><p align="justify"> </p>

Crystal structure of Ag-exchanged levyne intergrown with erionite: Single-crystal X-ray diffraction and Molecular Dynamics simulations

Abstract The modification of natural zeolites via ion exchange is an efficient technique used to improve their performances and tune their properties for specific applications. In this study, a natural levyne-Ca intergrown with erionite was fully exchanged by Ag+ and its structure [with idealized chemical composition Ag6(Si,Al)18O36·18H2O] was investigated by combining a theoretical and experimental approach. Single-crystal X-ray diffraction data demonstrated that Ag-levyne maintained the R3m space group, characteristic of the natural levyne. Ag ions distribute over partially occupied sites along the threefold axis and, differently from the pristine material, at the wall of the 8-membered ring window of the lev cavity. The lack of ~30% of Ag ions that could not be located by the structural refinement is ascribed to the strong disorder of the extraframework occupants. The structural results obtained by Molecular Dynamics simulations are in overall agreement with the experimental data and showed that, on average, Ag+ is surrounded by ~2 H2O and 1 framework oxygen at distances between 2.43 and 2.6 Å. Molecular Dynamics trajectories indicate that the occurrence of silver inside the D6R cage depends on the water content: silver occupancy of D6R cages is estimated to be 83, 30, and 0% when the structure contains 3, 2.5, and 2 H2O per Ag ion, respectively. The cation-exchange process, as demonstrated by scanning electron microscopy and energy-dispersive spectroscopy (SEM-EDS) spectrometry, affects the intergrown erionite as well. A structural characterization of the Ag-erionite phase (with dimension <100 μm) was possible by means of a CuKα micro-focus source: structure solution pointed to P63/mmc space group, indicating no change with respect to natural erionite. In agreement with previous studies, K ions in the cancrinite cage could not be exchanged, whereas Ag+ is found in the eri cavity.

Removal of Heavy Metals from Polluted Solutions by Zeolitic Adsorbents: a Review

The usage of zeolites in wastewater treatment has been extended in the two recent decades. This review investigates recent developments on the zeolite usage in the removal of heavy metals from polluted solutions. Various databases were used to search, evaluate, combine and analyze. The number of specific publications based on keywords linked with zeolite usage used in searching engines was more than 1000. However, about 200 publications passed the criteria set. The synthesis methodology for the production of zeolitic adsorbents, the modification of natural zeolites and their effect on the removal of heavy metals are described. Furthermore, the capacity of adsorbents to remediate polluted solutions and identify optimum conditions are reported and compared. The maximum adsorption capacity among heavy metals was for Pb(II) for all types of zeolite adsorbents (27.70 mg/g for chloride-modified zeolite, 113 mg/g for Fe-modified zeolite, 653 mg/g for surfactant modified zeolite, 808 mg/g for synthesized zeolites and 909.09 mg/g for nanozeolite). Cr(IV), Cu(II), Ni(II), Zn(II) and Co(II) were other heavy metals having good adsorption capacities on synthesized zeolites. According to the literature review, the adsorption of heavy metals by synthesized and nanozeolites is the most efficient.

Theoretical Objectives and Development of Methods to Protect the Water Resources of the Angara Region from Heavy Metals Pollution

This paper presents the results of a investigations on the possibility of obtaining new sorption materials based on modifying the natural zeolites of the Eastern Transbaikalia deposit, investigation the laws of sorption extraction of heavy metals and oil products from industrial wastewater of railway transport enterprises with a new sorbents. It is shown that chemical modification of natural zeolites allows obtaining sorbents with a more ordered structure compared to natural layered silicates, an increased surface area and a transient nature of porosity, which ensures their high sorption activity and, therefore, the perspectivity of application in the sorption technology of wastewater treatment.

Surface Area Modification of Natural Zeolite Through NaCl Counterbalanced Treatment to Apply in Adsorption Heat Storage System

Surface Area Modification of Natural Zeolite Through NaCl Counterbalanced Treatment to Apply in Adsorption Heat Storage System