Papers by Keyword: Natural Zeolites

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Authors: Hao Ding, Yue Bo Wang, Ning Liang, Bai Kun Wang
Abstract: Activation methods to improve the adsorption property of natural zeolite by inorganic acid and heat treatments at high temperature were investigated and its function of adsorbing harmful gases was evaluated. The results show that both methods can improve the adsorption property. Natural zeolite which was heat treated for 24 h has an adsorption ratio of 14.67% to H2O in air, which indicates the remarkable improvement of adsorption property. Meanwhile, the adsorption ratios to simulated refrigerator smelling gas such as NH3 and H2S after 10 min are 99.00% and 95.20%, respectively.
Authors: Nikolay I. Vatin, Viktor N. Chechevichkin, Aleksey V. Chechevichkin, Yekaterina Shilova, Leonid A. Yakunin
Abstract: One of the factors that determine the humankind existence and development is the environment. Man as a biological system is a part of nature, however the cooperation between them is quite complex [1]. On the one hand, men need permanent protection against it’s negative impact, on the other hand, they are the source of these impacts themselves [1, 2].Thanks to their unique characteristics, natural zeolites (NZ) are widely applied for solution of different ecological problems as cheap and available sorbing agents and also as basics for catalytical materials that are used for aquatic and air medium purification [3, 4]. The most frequently applied NZ are clinoptilolites that are widespread on the territory of Russia [5, 6].
Authors: Maria Teresa Tavares, Cristina Quintelas, Hugo Figueiredo, Isabel Neves
Abstract: This study aims the definition of a new material that may act as a robust and yet cost effective biosorbent for treatment of wastewater with low concentration of heavy metals. A comparative study was made between two biosorption systems composed of an Arthrobacter viscosus biofilm supported on Cuban natural zeolites and on prepared NaY and NaX, in terms of their ability to retain ionic chromium. The bacterium is able to reduce Cr(VI) to Cr(III) and, only then, this smaller and positive ion may be entrapped in the zeolite cages by ion exchange. The first support was tested in a continuous flow semi-packed bed column. The highest removal ratio, 42%, was achieved for initial chromium concentration of 10 mg/L, but the best up-take, 5.5 mg/gzeolite, was obtained for initial concentration of 70 mg/L. Biosorbents prepared with the same biofilm supported in NaY and NaX zeolites were also considered in batch studies, with a typical kinetics of biosorption processes, reaching 20% of initial chromium removal within an initial range of Cr(VI) concentration between 50 and 250 mg/L. These last structures were characterized by spectroscopic methods (FTIR and ICP-AES), surface analysis (DRX) and thermal analysis (TGA). All these techniques indicated that the biosorption process does not modify the morphology and structure of the FAU-zeolites.
Authors: Vitalii Petranovskii, Maria Khrepoun, Andrey Efimov, Alexey Pestryakov
Abstract: The removal and recuperation of copper from the residual liquors of galvanic industry by ion exchange have been studied using the natural clinoptilolite and mordenite zeolites from different deposits of Russia and Georgia.
Authors: Shigeo Hayashi, Junpei Onoe, Kazuyoshi Ebina, Nobuhiro Kodama
Abstract: Electrophoretic deposition (EPD) and infiltration (EPI) behavior of a natural zeolite (clinoptilolite, produced in Akita prefecture, Japan) particles on/into a steel and a porous glass substrates were investigated for the purpose of the environmental purification. The obtained deposit of the zeolite prepared by the EPD was less durable against peeling off compared with the EPI process, but it was improved by use of silica sol particles as a binder. Ion uptake efficiency of the EPD sample was superior to that of the EPI sample, that will be caused by the shape factor of the zeolite particle deposit.
Authors: Hyung Mi Lim, Ji Sook Jung, Dae Sung Kim, Dong Jin Lee, Seung Ho Lee, Woo Nyon Kim
Abstract: The application of VOC-free materials for building interior is the first step to reduce the contamination level, however, it is practically unavoidable to find a way to eliminate existing pollutants from furniture, adhesives, etc. As a positive way of controlling the air indooors, the air conditioner may be applied with high functional filter, which uses electricity for compulsory air circulation. As an alternative, we modified natural zeolite powder by ion exchange and also by addition of TiO2 photo-catalyst for multifunctional powder to contribute to controlling the indoor air quality. The modified zeolites were applied on the interior non-woven polypropylene sheet to reduce indoor air pollutants not only by adsorption mechanism but also by decomposition mechanism. We studied deodorization of the multi-functional powders and also their coating on non-woven textiles by a Gastec method.
Authors: Ming Liang Yuan, Liang Yu, Jia Hua Tao, Cong Song
Abstract: Natural zeolites combined with the magnetic iron oxides are prepared by a chemical coprecipitation process. A detailed characterization of our magnetically modified zeolite (MMZ) is given, including powder X-ray diffraction (XRD), nitrogen adsorption and vibrating sample magnetometer (VSM). The results reveal that in comparison with Na-zeolite, the structure of MMZ has no obvious change but its surface area increases from 25.13 m2 g-1 to 100.90 m2 g-1. The adsorption properties of MMZ to Pb2+ and Cu2+ were studied. The results show that the maximum loading capacities for Pb2+ and Cu2+ in the initial concentration range are 123.74 and 14.633 mg g-1, respectively. The MMZ can be used as an adsorbent for removal of heavy metal ions from industrial effluents or municipal waters, and the saturated adsorbent is separated from the medium by a simple magnetic process.
Authors: Usa Onthong, Pornpan Pungpo, Wikanda Thongnueakhaeng
Abstract: The removal of the cadmium ion from aqueous solution was studied in batch experiments using five natural zeolites were obtained from South of Thailnd, Clinoptiolite, Mordenite, Willhensonite, Offretite and Ferrierite, on the basis of experimental models on laboratory scale. Clinoptiolite was used for preliminary study of the adsorption parameters. An hour contact time and 40 g/L of the ratio of zeolite per water sample are optimum adsorption parameters with an average cadmium removal efficiency of 91.68 %. The optimum adsorption conditions were then used for other four natural zeolites. The results show that the effective removal sequence can be listed as Offretite  Clinoptiolite > Willhensonite > Mordenite > Ferrierite. Clinoptiolite, Offretite and Willhensonite are successfully used to reduce significantly cadmium from sample water with removal efficiency ranging from of 87-92%, respectively. Accordingly, the natural zeolites are recommendable adsorbents for highly cadmium removal of industrial wastewater with low cost of wastewater treatments and environmentally friendly chemical processes.
Authors: Ani Tjitra Handayani, Bagus Hario Setiaji, Sri Prabandiyani
Abstract: Asphalt Concrete mixture of polymer modification are used to reduce the damage early and increasing the durability of pavement to various damage such as permanent deformation, cracking due to temperature changes, fatigue During this process the polymer asphalt mixing using Hot Mix Asphalt / HMA. In accordance with the name and nature of hot mix asphalt, require high enough heating temperature on the Asphalt Mixing Plant (AMP), and also requires a high temperature compaction. As a result, it takes quite a lot of fuel so produced a large exhaust emissions. Emissions generated during the mixing process and compaction of HMA is a challenge for the environment. Some countries have developed a method of asphalt mixture to overcome this by using Warm Mix Asphalt technology. Warm Mix Asphalt is the technology of mixing and compaction temperatures of asphalt mixtures using mixing and compaction temperatures lower than Hot Mix Asphalt. Decreasing the mixing and compaction temperatures by adding additives to the asphalt mixture. Types of additives that have been widely used and developed for Warm Mix Asphalt them is the use of synthetic zeolites with various trademarks such as Aspha-min (R), Sasobit(R) dan Advera(R). In this paper the synthetic zeolite will be replaced by natural zeolite as an additive to be mixed with a mixture of Polymer Modified Asphalt Concrete. This study uses laboratory testing, using aggregate materials from Subang, West Java, Asphalt Elastomer Polymers, natural zeolite mineral mordenite sourced from Bayat, Central Java, Indonesia. Tests using a mixture Marshall Test. Marshall test results stated that the levels of natural zeolite 1% can reduce the temperature of mixing and compaction temperatures on Polymer Modified Concrete Asphalt mix 30°C, lower than the temperature of the mixture of Polymer Modified Asphalt Concrete without zeolite. Keywords: additive, Natural Zeolites, Warm Mixed Asphalt, Polymer Modified Asphalt Concrete
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