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Article

Nivin M. Ahmed, Hassan S. Emira and Mohamed M. Selim

Organic coatings remain the most widely used way of protecting steel structures from corrosion. Traditional anticorrosive paints contain lead or hexavalent chromium…

Abstract

Purpose

Organic coatings remain the most widely used way of protecting steel structures from corrosion. Traditional anticorrosive paints contain lead or hexavalent chromium compounds as active pigments. The use of these classical chromates is nowadays restricted by increasing environmental awareness and stringent national and international regulations. An alternative is the use of ion‐exchangeable pigments. The purpose of this paper is to show that cation‐exchanged zeolites can be considered as a safe and efficient alternative to traditional hazardous pigments in protecting steel surfaces.

Design/methodology/approach

The new pigments were characterised using different analytical and spectro‐photometric techniques. Characterisation of these pigments using X‐ray diffraction and scanning electron microscopy were done. X‐ray fluorescence was employed to elucidate the concentration of different elements in the prepared pigments. Evaluation of the ion‐exchanged and initial zeolite pigments using international standard testing methods (ASTM) was estimated. Testing the anticorrosive protection of cation‐exchanged zeolites in alkyd paints formulated based on their pigment volume concentration/critical pigment volume concentration was studied, and then these new pigments were applied on cold‐rolled steel panels. The physico‐mechanical properties of dry films and their corrosion properties using accelerated laboratory test in 3.5 per cent NaCl for 28 days were tested.

Findings

The results of this work revealed that paint films containing initial Na‐zeolite performed the least protection behaviour, while films including Zn, Ca and Mg‐zeolites were better in their corrosion protection performance, and they can be arranged as Zn‐zeolite>Ca‐zeolite>Mg‐zeolite.

Practical implications

These pigments can be applied in other polymer composites, e.g. rubber and plastics as reinforcing agent and fillers.

Originality/value

The paper shows that these prepared pigments are environmentally friendly pigments which impart high anticorrosive behaviour to paint films with great economic savings.

Details

Pigment & Resin Technology, vol. 40 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Ahmad Mashal, Jehad Abu-Dahrieh, Ashraf A. Ahmed, Lukumon Oyedele, No’man Haimour, Ahmad Al-Haj-Ali and David Rooney

The purpose of this paper is to investigate the performance of natural Jordanian zeolite tuff to remove ammonia from aqueous solutions using a laboratory batch method and…

Abstract

Purpose

The purpose of this paper is to investigate the performance of natural Jordanian zeolite tuff to remove ammonia from aqueous solutions using a laboratory batch method and fixed-bed column apparatus. Equilibrium data were fitted to Langmuir and Freundlich models.

Design/methodology/approach

Column experiments were conducted in packed bed column. The used apparatus consisted of a bench-mounted glass column of 2.5 cm inside diameter and 100 cm height (column volume = 490 cm3). The column was packed with a certain amount of zeolite to give the desired bed height. The feeding solution was supplied from a 30 liter plastic container at the beginning of each experiment and fed to the column down-flow through a glass flow meter having a working range of 10-280ml/min.

Findings

Ammonium ion exchange by natural Jordanian zeolite data were fitted by Langmuir and Freundlich isotherms. Continuous sorption of ammonium ions by natural Jordanian zeolite tuff has proven to be effective in decreasing concentrations ranging from 15-50 mg NH4-N/L down to levels below 1 mg/l. Breakthrough time increased by increasing the bed depth as well as decreasing zeolite particle size, solution flow-rate, initial NH4+ concentration and pH. Sorption of ammonium by the zeolite under the tested conditions gave the sorption capacity of 28 mg NH4-N/L at 20°C, and 32 mg NH4-N/L at 30°C.

Originality/value

This research investigates the performance of natural Jordanian zeolite tuff to remove ammonia from aqueous solutions using a laboratory batch method and fixed-bed column apparatus. The equilibrium data of the sorption of Ammonia were plotted by using the Langmuir and Freundlich isotherms, then the experimental data were compared to the predictions of the above equilibrium isotherm models. It is clear that the NH4+ ion exchange data fitted better with Langmuir isotherm than with Freundlich model and gave an adequate correlation coefficient value.

Details

World Journal of Science, Technology and Sustainable Development, vol. 11 no. 2
Type: Research Article
ISSN: 2042-5945

Keywords

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Article

Walaa M. Abd El-Gawad, Nivin M. Ahmed, Mohamed M. Selim, E. Hamed and Eglal R. Souaya

In recent years, zeolites have been highlighted as a new component in many industrial applications owing to their unique properties. The purpose of this study is to apply…

Abstract

Purpose

In recent years, zeolites have been highlighted as a new component in many industrial applications owing to their unique properties. The purpose of this study is to apply three prepared types of zeolites Na-X, Na-Y and hydroxysodalite (Na-HS) in anticorrosive paint formulations to be evaluated as a partial replacement to zinc phosphate in anticorrosive paint formulations to protect carbon steel.

Design/methodology/approach

The three types of zeolites were characterized using different instrumental analysis such as X-ray diffraction, scanning electron microscopy and X-ray fluorescence. Evaluation of zeolites was done using American society for material and testing. Then, they were incorporated in paint formulations based on medium oil-modified soya-bean dehydrated castor oil alkyd resin in the presence and absence of zinc phosphate. Their corrosion behavior was estimated using both immersion test and electrochemical impedance measurements in 3.5% NaCl.

Findings

Generally, the prepared zeolites exhibited good corrosion protection performance, but in presence of zinc phosphate the performance was better. This proves that, zeolites by themselves can resist corrosion but not efficiently, while in presence of zinc phosphate and owing to a synergistic effect between them, the performance was better. This opens the way to partial replacement of zinc phosphate with another safer and cheaper ingredient, which is zeolite.

Practical implications

The three zeolites can be applied in many industries besides the paint industry, such as reinforcing filler in rubber, plastics and ceramic composites, also can be applied in paper filling, paper coatings and electrical insulation.

Originality/value

The three zeolites are environmentally friendly materials that can partially replace other expensive anticorrosive pigments (e.g. zinc phosphate).

Details

Pigment & Resin Technology, vol. 48 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Mica Grujicic, Ramin Yavari, Jennifer Snipes and S Ramaswami

In the present work, a new blast-/ballistic-impact mitigation concept is introduced and its efficacy analyzed using advanced computational methods and tools. The concept…

Abstract

Purpose

In the present work, a new blast-/ballistic-impact mitigation concept is introduced and its efficacy analyzed using advanced computational methods and tools. The concept involves the use of a zeolite protective layer separated by air from the structure being protected and in contact with a water layer in front. The paper aims to discuss these issues.

Design/methodology/approach

To properly capture the attendant nano-fluidics phenomena, all the calculations carried out in the present work involved the use of all-atom molecular-level equilibrium and non-equilibrium molecular-dynamics simulations.

Findings

Under high-rate loading, water molecules (treated as a nano-fluidic material) are forced to infiltrate zeolite nanopores wherein, due to complex interactions between the hydrophobic nanopore walls and the hydrogen bonds of the water molecules, water undergoes an ordering-type phase transition and acquires high density, while a significant portion of the kinetic energy of the water molecules is converted to potential energy. Concomitantly, a considerable portion of this kinetic energy is dissipated in the form of heat. As a result of these energy conversion/dissipation processes, the (conserved) linear momentum is transferred to the target structure over a longer time period, while the peak loading experienced by the structure is substantially reduced.

Originality/value

To the authors’ knowledge, the present work constitutes the first reported attempt to utilize pure SiO2 hydrophobic zeolites in blast-/ballistic-impact protection applications.

Details

International Journal of Structural Integrity, vol. 6 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

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Article

Siti Salwa Alias, Zawati Harun and Salina Abu Mansor

The purpose of this study is to investigate the using of rice husk (RH) which is a green material derived from agricultural waste with the ability to absorb heavy metal…

Abstract

Purpose

The purpose of this study is to investigate the using of rice husk (RH) which is a green material derived from agricultural waste with the ability to absorb heavy metal. It has been used in wastewater treatment. In this research, a kaolin-based green ceramic water filter (CWF) incorporated with two different additives (RH and zeolite-based RH ash [RHA]) was successfully fabricated.

Design/methodology/approach

The weight ratio of kaolin:additive was varied (90:10, 80:20 and 70:30) and fabricated via the slip-casting technique. The green CWFs were dried (60°C for 1 h), followed by sintering (1,200°C).

Findings

The green CWF of kaolin:RH with a weight ratio of 70:30 showed the best properties and satisfactory performance with a porous cross-section microstructure, highest porous area (4.58 µm2), good structure, lowest shrinkage (8.00%), highest porosity (45.10%), lowest density (1.79 g cm−3), highest water absorption (55.50%) and hardness (241.40 Hv). This green CWF has also achieved good permeability (42.00 L m−2h−1) and removal of the textile dye (27.88%). The satisfactory characterization and good textile dye removal performance (75.47%) were also achieved from green CWF with kaolin:zeolite at a weight ratio of 80:20.

Research limitations/implications

This research is focused on green CWF and zeolite at a certain amount with the specific characterization analysis methods.

Practical implications

The use of low-cost waste materials to treat dye wastewater from agricultural by-products/wastes sources in treating the dye will enhance the using of green material.

Social implications

Avoiding the waste sludge that can pollute the environment can create a health issue. The use of low-cost waste materials to treat dye wastewater from agricultural by-products/wastes sources in treating the dye can avoid the waste sludge that can pollute the environment and create serious health issue.

Originality/value

All the kaolin-based green CWFs incorporated with two different additives (RH and zeolite-based RHA) fabricated using a simple slip-casting technique have shown the potential to be used as a filter in wastewater treatment applications.

Details

World Journal of Engineering, vol. 17 no. 4
Type: Research Article
ISSN: 1708-5284

Keywords

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Article

Luigi Calabrese, Angela Caprì and Edoardo Proverbio

This paper aims to evaluate the efficacy of a zeolite-filled silane sol–gel coating as protective layer on pretreated AZ31 magnesium alloy substrates.

Abstract

Purpose

This paper aims to evaluate the efficacy of a zeolite-filled silane sol–gel coating as protective layer on pretreated AZ31 magnesium alloy substrates.

Design/methodology/approach

Anti-corrosion properties of a silane–zeolite composite coating, at various zeolite content, have been investigated on AZ31 magnesium substrates subjected to different surface pretreatment procedures before coating deposition. A short time etching by hydrofluoric acid (HF) and an anodic polarization in NaOH solution were used as surface pretreatments.

Findings

High hydrophobicity and good adhesion performances of coatings have been observed. Corrosion protection performance, during immersion in 3.5 per cent NaCl solution, was evaluated by means of electrochemical impedance spectroscopy tests. All coating formulations evidenced good barrier properties. Better durability properties have been shown by coating obtained on HF pretreated magnesium substrate and with a 60 per cent of zeolite content.

Originality/value

High electrochemical reactivity of magnesium alloys represents the mayor limit of its application in many different fields. In this concern, zeolite-based coatings are emerging as potentially effective environmentally friendly coating for metallic substrates. Despite aluminum and stainless steel substrates, in the literature, only expensive direct synthesis zeolite coating was investigated for its application on magnesium alloys protection. For this reason, this paper fulfills the need to assess the adhesion and anti-corrosion behavior of sol–gel silane–zeolite coating in magnesium alloy substrates.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

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Article

Faeze Nejati, Samira Ahmadi and S.A. Edalatpanah

Modern construction methods have been developed with the goal of reducing construction time as much as possible, which results in some situations during construction and…

Abstract

Purpose

Modern construction methods have been developed with the goal of reducing construction time as much as possible, which results in some situations during construction and within the first few days after it, when concrete is subjected to exceptionally high loads. The precast concrete, which is the concrete in very early ages, may result in severe cracks or damages. In conventional construction projects, sometimes working with concrete, which had not reached its ultimate strength, is an unavoidable matter of fact. This paper aims to discuss these issues.

Design/methodology/approach

Researchers in the field of construction materials have done their best to make some changes in the different parts of the concrete in order to bring about reforms, based on the existing needs, and achieve new quality and primacy from concrete. One kind of concrete, the emergence of which dates back to many years ago, is self-compacting concrete. Thanks to its high efficiency for the parts with complex forms of high-density steel, this kind of concrete suggests new prospects.

Findings

This study aims at evaluating the effect of early loads on the 28-day compressive strength of concretes with zeolite and limestone powder under different curing conditions (wet or dry). In this regard, two self-compacting concrete mix designs with the same ratio of water to cementations materials and 0.4 percent and 10 percent zeolite have been considered; therefore, concrete cube samples with zeolite and limestone powder in different curing conditions at ages of three, one and seven days under preloading with 80–90 percent of compressive strength are damaged, and after curing in different conditions, their 28-day compressive strength is measured. According to the results, the recovery of the 28-day compressive strength of damaged samples, compared to that of intact samples, is possible in all curing conditions. The experiments that have been performed on concrete samples under dry and wet curing conditions show that the full recovery of compressive strength of damaged samples compared to that of intact ones happened only in preloaded samples at the age of one days, and in other ages (three and seven days) the 28-day strength reduction has occurred in damaged samples compared to the that in intact samples. The results of concrete samples with zeolite and without limestone powder at the age of one day indicate the greatest impact on other samples on the 28-day compressive strength of damaged samples compared to that of intact ones, occurring under dry condition.

Originality/value

This research analyzed and studied the influence under wet and dry curing conditions and the presence of limestone powder and zeolite fillers in recovering of the 28-day compressive strength of preloaded concrete samples at early stages (one, three and seven days) after the construction of the concrete.

Details

International Journal of Structural Integrity, vol. 10 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

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Article

Nilufer Durmaz Hilmioglu

The purpose of this paper is to demonstrate applicability of the pervaporation technique for separation ethanol/water mixtures.

Abstract

Purpose

The purpose of this paper is to demonstrate applicability of the pervaporation technique for separation ethanol/water mixtures.

Design/methodology/approach

For the purposes of membrane material development for pervaporation zeolite filled and unfilled cellulose acetate membranes were prepared. Zeolite types were 4A, 13X. The effect of incorporation of nano‐sized zeolites prepared in a colloidal form in membranes was also investigated. Equilibrium sorption experiments were carried out. Degrees of swelling were calculated at different liquid feed mixture compositions for separating an azeotrope forming mixture, ethanol/water by pervaporation.

Findings

Zeolite 13X filled CA membrane may have the better pervaporation performance than zeolite 4A filled CA membrane. From the sorption tests it is concluded that ethanol/water azeotropy can be achieved by pervaporation.

Practical implications

Application of CA membranes in industrial scale pervaporation units may be feasible for separation of ethanol/water mixtures. Specially ethanol/water azeotropy will be achieved by pervaporation. Using distillation and pervaporation hybrid systems, bioethanol can be produced economically.

Orginality/value

The paper illustrates the success of pervaporation techniques in separating ethanol/water mixtures.

Details

Management of Environmental Quality: An International Journal, vol. 20 no. 2
Type: Research Article
ISSN: 1477-7835

Keywords

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Article

Maaza Lamia, Djafri Fatiha, Bouchekara Mohammed, Djebbar Mustapha and Djafri Ayada

The purpose of this paper is to examine the batch adsorption system of a cationic dye (methylene blue, widely used in various sectors) on two adsorbents; ZSM-5 zeolite

Abstract

Purpose

The purpose of this paper is to examine the batch adsorption system of a cationic dye (methylene blue, widely used in various sectors) on two adsorbents; ZSM-5 zeolite which was prepared with the molar composition: 0.2057 Na2O-0.00266 Al2O3-SiO2-0.68 (pyrrolidine)-40 H2O-0.12 H2SO4.

Design/methodology/approach

By the hydrothermal synthesis method, and the purified clay and is analyzed by IR and DRX method.

Findings

For this, the authors conducted a parametric study of adsorption and effect of several important parameters on the adsorption of BM on the material used, in particular, the contact time (equilibrium is established after 120 min), different concentrations of adsorbents, different masses, the pH and temperature. The experiments demonstrated the crucial role of these parameters. A kinetic study was done and kinetic models were applied to the experimental results such as the pseudo-first order, pseudo-second order.

Originality/value

This work is original.

Details

International Journal of Clothing Science and Technology, vol. 28 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

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Article

Oriana D'Alessandro, Christian Eduardo Byrne, Gonzalo Selmi and Cecilia Deyá

This paper aims to formulate and prepare a series of alkyd paints with new anticorrosive pigments, eco-friendly to the environment, based on a natural zeolitic rock…

Abstract

Purpose

This paper aims to formulate and prepare a series of alkyd paints with new anticorrosive pigments, eco-friendly to the environment, based on a natural zeolitic rock modified by ion exchange to incorporate passivating cations.

Design/methodology/approach

The electrochemical characterization of the painted steel was carried out by conductivity measurements, linear polarization tests, measurements of the corrosion potential and electrochemical noise measurements. Besides, accelerated tests in standard environmental chambers were also carried out.

Findings

The results show that clinoptilolite–mordenite-based pigments incorporated in the paint provide acceptable anticorrosive properties, taking into account their low environmental impact and the use of a natural resource of low cost. The inhibitory efficiency of ZLa is higher than 80% and of ZPr is close to 70%. The electrochemical assays of the coated panels with the alkyd paints ZLa and ZPr shows similar behavior.

Research limitations/implications

In this work, good results were obtained with an alkyd resin, but other resins could be tested. Paints could also be formulated with modified zeolites as a complement to others traditional anticorrosive pigments.

Practical implications

These paints could be used for the protection of metal structures in low corrosive environments.

Originality/value

There are not many published works using zeolites as anticorrosive pigments.

Details

Pigment & Resin Technology, vol. 50 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

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