Zeolites

The aim of our study was to determine the efficacy of three different adsorbents, inorganic (modified zeolite), organic (esterified glucomannans) and mixed (inorganic and organic components, with the addition of enzymes), in protecting broilers from the toxic effects of ochratoxin A in feed. Broilers were fed diets containing 2 mg/kg of ochratoxin A (OTA) and supplemented with adsorbents at the recommended concentration of 2 g/kg for 21 days. The presence of OTA led to a notable reduction in body weight, lower weight gain, increased feed conversion and induced histopathological changes in the liver and kidneys. The presence of inorganic, organic and mixed adsorbents in contaminated feed only partially reduced the negative effects of OTA on the broiler performances. Broilers that were fed with adsorbent-supplemented feed reached higher body weight (17.96%, 19.09% and 13.59%), compared to the group that received only OTA. The presence of adsorbents partially alleviated the reduction i...

A simple and versatile method for the synthesis of 1,5-benzodiazepines is via condensation of o-phenylenediamines (OPDA) and ketones in the presence of catalytic amount of H-MCM-22 using acetonitrile as solvent at room temperature. In all the cases, the reactions are highly selective and are completed within 1–3 h. The method is applicable to both cyclic and acyclic ketones without significant differences. The reaction proceeds efficiently under ambient conditions with good-to-excellent yields.

Coal fly ash (CFA) is a waste product produced from the electrical power plant and hazardous towards the environment. However, the high composition of silica and alumina in the CFA makes it useful as raw materials in the zeolite synthesis. However, the presence of silica in the form of quartz in the CFA does not facilitate the transformation of CFA to zeolite at 100oC and autogeneous pressure. In this study, CFA was converted to zeolites in various NaOH concentrations by microwave heating at various heating time. All synthesized product were characterized by X-ray diffraction(XRD), and gravimetric analysis. XRD has shown that quite pure sodalite in nanosize has been formed as early as 15 minutes and increase with time. Prolong heating up to 45 minutes has reduced the content of quartz to ca 20%. Gravimetric analysis performed on the liquor of the reaction showed that the dissolved silica decrease with increase of heating time indicating that most of the dissolved quartz is used up to form sodalite framework. Hence, quartz of CFA did help in enhancing the crystallinity of the formed sodalite after prolong heating.

The aim of this research was to evaluate the fertilizing capacity of an innovative zeolite product, characterised by an encapsulated structure with an organic matrix on vegetable and ornamental plants and the interaction with soil microorganisms present in the cultivation substrates. The experiments, started in January 2021, were conducted in the greenhouses of CREA-OF in Pescia (PT), Tuscany. The experimental groups were: i) group control, irrigated with water and substrate previously fertilized; ii) group with zeolite 21% ammoniacal nitrogen; iii) group with zeolite coated with Ecoat; iv) group with zeolite 21% ammoniacal nitrogen, SO3 57.7% with nitritification inhibitor dcd (dicyandiamide) and DMPP 3,4 dimethylpyrazole-phosphate. The trial carried out on strawberry and Polygala myrtifolia actually showed how the use of zeolite can improve the fertilizing properties of the substrate. In particular, the use of encapsulated zeolite resulted in an increase in plant height, vegetative and root weight, number and flowers life, number and weight of fruits in strawberry and Polygala myrtifolia. In addition, there were changes in substrate pH, microbiological count and nitrogen, phosphorus and potassium content depending on the type of zeolytic product used. Research has shown that the use of loaded zeolite can significantly improve the agronomic and production quality of strawberry and Polygala myrtifolia plants. For example, Ecoat treatment with zeolite encapsulated with organic matrices in strawberries resulted in a pot production of 39.61 fruits and a weight of 36.39 g/fruit, compared to 24.21 and 26.48 g/fruit for the untreated control. While in Polygala myrtifolia the same treatment (Ecoat) resulted in 48.00 flowers per plant and a flowers life of 9.20 days compared to 34.86 flowers and 6.20 of the control. The trial also showed that treatment with Ecoat can promote the development of microbial colonies in the substrate, 3.5 x 104 cfu/g compared with 2.3 x 102 cfu/g in the control in strawberries and 3.2 x 104 cfu/g compared with 2.6 x 102 cfu/g in Polygala myrtifolia. In addition, the application of these aluminosilicates in substrates can influence the pH and the microbial component that is essential for the cultivation and defence of plants. The Ecoat product that performed best in the trial can play the role of both a nitrogen based fertiliser and, thanks to its organic matrix, of stimulating microbial development in the substrate in which the plants are grown.

A simple and versatile method for the synthesis of 1,5-benzodiazepines is via condensation of o-phenylenediamines (OPDA) and ketones in the presence of catalytic amount of H-MCM-22 using acetonitrile as solvent at room temperature. In all the cases, the reactions are highly selective and are completed within 1–3 h. The method is applicable to both cyclic and acyclic ketones without significant differences. The reaction proceeds efficiently under ambient conditions with good-to-excellent yields.

In this study, the possibility of optimizing the use of fertilizers on Ranunculus asiaticus by adding chabazite with Plant Growth Promoting Rhizobacteria (PGPR) to the substrate was evaluated. The five experimental groups in cultivation were: i) group without zeolites (CTRL), irrigated with water and substrate previously fertilized; ii) group with natural chabazite (CN) and 100% fertilised substrate; iii) group with chabazite enriched with PGPR (CM) and 100% fertilised substrate; iv) group with natural chabazite (CN2) and 50% fertilised substrate; v) group with chabazite enriched with PGPR (CM2) and 50% fertilised substrate. All plants treated with chabazite (CN and CN2) and chabazite enriched with PGPR (CM and CM2) showed a significant increase in the agronomic characteristics analysed compared to the untreated control (CTRL). The results show that the microorganisms are able to improve the performance of zeolitite, probably increasing the efficiency of nutrient and water absorption by the roots. This is also evident when evaluating physiological parameters where the photosynthesis rate and chlorophyll content are significantly better in (CM) and (CM2) than in (CN) and (CN2). Zeolites can act as a "home" for microorganisms, as is normally the case in nature with clays. In fact, under conditions of water stress, microorganisms take refuge inside the clay particles until the environmental conditions are suitable again to colonize the soil. Zeolites are able to actively interact with the organic components present in the soil or brought with fertilization, and have the ability to make more available the mineral and nutritional components present within their crystalline lattice, according to the needs of the plant.

The development of recyclable solid acids is of major industrial importance and challenging in many reactions, for instance, the Friedel-Crafts alkylation as one of the most prevalent examples, which generally requires the presence of acid catalysts. However, not only the replacement of traditional toxic acid catalyst by solid acidic zeolites but also the improvement such catalysts in term of high efficiency has been addressed through environmental technologies. Our present study explores the use of hierarchical faujasite zeolite nanosheets as catalysts in industrial applications with the frame of development of green and sustainable technologies. The simple and efficient route to prepare the faujasite zeolite with the nanosheet-assembled structure together with the roles of synthetic parameters on the characteristics and properties are systematically investigated. This first example of hierarchical zeolite, which has uniform mesoporous features derived from the interstitial pores between the nanosheet assemblies, exhibits a superior catalytic activity in terms of conversion and selectivity for the benzylation of toluene with benzyl chloride. In conclusion, the fine-tuning of structural characteristics of zeolites by a simple optimization of surfactant contents and crystallization temperatures allows the design of the candidate catalyst for a green and sustainable future. This work also demonstrates the next step forward in the development of an industrial catalyst based on the concept of cleaner production.

This research work evaluates the impact of stormwater infiltration on the removal of organics, solids, nitrogen and phosphorus in a LECA-based horizontal subsurface flow constructed wetland. Stormwater runoff for the period between January 2008 and June 2010 (30 months) was estimated for the drainage basin of the Vila Fernando wastewater treatment plant (constructed wetland system) and it was observed proportionality between the increase in surface runoff and the infiltration flow rate that reached the plant. The average stormwater infiltration rate that reached the plant was 67.4 m(3) d(-1) (77% of the influent flow rate into the plant). The 30 month monitoring campaign set up at one of the reed beds showed that stormwater infiltration led to a high variation of the hydraulic loading rate (HLR) throughout the bed, which affected its performance in the removal of organic matter, suspended solids and nitrogen. For a HLR below 20 cm d-1 the removal efficiencies for BOD5, COD and TSS doubled. The removal of nitrogen was too low and was associated with the weak development of nitrifying biofilm and the poor growth of reeds. However, it was observed a good relationship between the applied and removed loads for most of the parameters, which seems to indicate that the organic, solid, nitrogen and phosphorus loading rates influenced the respective removal rates. The use of a bed material with high specific surface area, such as LECA, can only improve the treatment capacity of horizontal subsurface flow systems if the organic and solid loading rates, as well as the HLR, can be effectively controlled.

Nanoclays have potential applications in biomedicine raising the need to evaluate their toxicity inin vitromodels as a first approach to its biocompatibility. In this study,in vitrotoxicity of clinoptilolite and sepiolite nanoclays (NC) was analyzed in highly phagocytic cultures of amoebas and human and mice macrophages. While amebic viability was significantly affected only by sepiolite NC at concentrations higher than 0.1 mg/mL, the effect on macrophage cultures was dependent on the origin of the cells. Macrophages derived from human peripheral blood monocytes were less affected in viability (25% decrease at 48 h), followed by the RAW 264.7 cell line (40%), and finally, macrophages derived from mice bone marrow monocytes (98%). Moreover, the cell line and mice macrophages die mainly by necrosis, whereas human macrophages exhibit increased apoptosis. Cytokine expression analysis in media of sepiolite NC treated cultures showed a proinflammatory profile (INFγ, IL-1α, IL-8, and IL-6)...

This study aims to examine the effect of zeolites in optimizing the process of food waste composting. A novel method of sequential hydrothermal was introduced to modify the natural zeolite and apply to in-vessel compost bioreactors. Raw and modified natural zeolites were applied at 10 and 15% (w/w) of the total waste and compared with un-amended control trial. Both raw and modified zeolites affected the composting process, but the notable results were observed for modified natural zeolite. The results for compost stability parameters were prominent at 15% modified natural zeolite concentration. The rapid and long-term thermophillic temperature and moisture content reduction to the optimum range was observed for modified natural zeolite. Furthermore, the total ammonium (NH 4 +) and nitrate (NO 3 −) concentration in modified natural zeolite were increased by 11.1 and 21.5% respectively as compared to raw zeolite. Compost stability against moisture contents (MC), electrical conductivity (EC), organic matters (OM), total carbon (TC), mineral nitrogen, nitrification index (NI) and germination index (GI) was achieved after 60 days of composting that was in accordance with the international compost quality standards. The findings of this study suggested the suitability of modified natural zeolite addition at 15% to the total waste as the optimum ratio for the composting of food waste in order to achieve a stable nutrient-rich compost.

Nigeria is blessed with abundant kaolin clay and solid mineral deposits scattered in various parts of the country, yet the country solely depends on imported zeolite as commercial adsorbent for wastewater treatment, catalyst for the petroleum industry and other applications. This work describes the development of a process to produce zeolite from clay mineral.The beneficiated kaolin clay was converted to metakaolin at 600 o C, and then leached with sulphuric acid to achieve the required silica-alumina ratio for zeolite synthesis. An alkaline fusion stage was then carried-out to transform the metakaolin into zeolite. Identification of the crystalline phase by X-Ray Diffraction analysis showed that it consists of both zeolite X and Y. Infrared spectra analysis confirmed the presence of zeolite framework structure. Transmission electron microscopy, surface area and pore volume of the synthesized zeolite were examined and the results from all the analysis confirmed that zeolite can be produced from the kaolin clay.

This paper reviews the synthesis and the absorbing properties of the wide variety of porous sorbent materials that have been studied for application in the removal of organics, particularly in the area of oil spill cleanup. The discussion is especially focused on hydrophobic silica aerogels, zeolites, organoclays and natural sorbents many of which have been demonstrated to exhibit (or show potential to exhibit) excellent oil absorption properties. The areas for further development of some of
these materials are identified.

Given their unique structural and morphological features, nanomaterials have gained considerable attention for
their applications in membrane desalination. Recent advances in nanomaterial-incorporated membranes have
resulted in membranes with very high water flux and salt rejection, both being sought after in membrane desalination.
Nevertheless, the economic feasibility of scaling up such membranes remains questionable. The present
paper surveyed the recent published literatures and current studies on nanomaterials and their applications in
membrane desalination. The goal of this workwas to reveal, through reviewing experimental and computational
studies, the potential of nanomaterials in desalination. The paper reviewed three of the most studied
nanomaterials in membrane desalination namely; carbon nanotubes, zeolites, and graphene. The investigation
included preparation and synthesis of nanomaterial membranes, their properties with respect to desalination,
and their applications in membrane desalination. This includes different membrane processes, and opportunities
and challenges of those materials in desalination applications. The environmental and economic sustainability of
nanomaterials in desalination for future prospects has also been presented.

Bu çalışmada, ülkemizde zengin rezervleri olduğu bilinen, Balıkesir-Bigadiç üst tüf birimi zeolitik tüfleri (klinoptilolit) ile su sertliğinin giderilme potansiyeli araştırılmış; su kaynağı olarak, klorlama hariç herhangi bir ön arıtma işlemi uygulanmayan, sertlik derecesi yüksek, Selçuk Üniversitesi Kampüs kullanım suyu kullanılmıştır. Bunun için -0.85+0.60 mm fraksiyon aralığında zeolit numuneleri NaOH ile rejenere edilerek, iyon değiştirme kolonundaki zeolitik yataktan sabit akış hızında geçen suyun zamana bağlı sertlik değişimi incelenmiştir. Rejenerasyon şartları bu şekilde optimize edildikten sonra zeolitik yatağa beslenen suyun akış hızının ve kolonda bırakılan su birikintisinin suyun sertliğinin giderilmesine etkisi de araştırılmıştır.
Sonuç olarak; zeolit yataktan geçen suyun sertliği, en düşük değere, besleme suyu hızı 10 ml/dak tutularak ve 0.75M NaOH ile rejenere edilmiş zeolit kullanılarak düşürülmüş ve bu şartlarda çalışılması durumunda, en yüksek işletme kapasitesine ulaşılacağı tespit edilmiştir.

This study aspires to design a plant for the treatment of phenolic wastewater from Tema Oil Refinery using modified spent FCC catalyst. This project was undertaken to mainly provide clean water and to subsequently curb the degradation of environment that results from the disposal of the wastewater in the Heavy Industrial Area community. The raw material was obtained from the Dissolved Air Floatation (DAF) effluent. This stream is made up of physically and chemically treated wastewater from the already existing wastewater treatment plant. In order to accomplish the aim of the project, the DAF effluent went through further chemical and physical separation processes, peroxide dosing, adsorption and oxidation processes, ultrafiltration and fluoridation. Specifically, the properties of other treatment processes were evaluated and the Catalytic Wet Air Oxidation (CWAO) process was chosen after careful consideration. Spent FCC catalyst was obtained from Residual Fluidized Catalytic Cracking (RFCC) unit and modified by calcining it with Fe3+ at high requiring temperatures. The use of the modified spent FCC catalyst optimizes the process by, enhancing the reaction rate, and thus shortening the reaction time. The plant is designed to produce 528 m3/day of treated water and will work for 300 days in a year. The plant has an attainment of 82.2%. It has a working life of 30 years in which viability has been established at 31.2% rate of return and a discounted rate of 34.53%. The payback period is estimated at 3 years after the commencement of the project. Based on the findings of this project, modified FCC catalyst treatment is a very efficient means of treating wastewater and the economic analysis proves its economic feasibility.

A B S T R A C T One of the potential raw materials for preparation of geopolymers is the natural zeolite. In the present report, the used natural zeolite (clinoptilolite) is from huge deposit near Beli Plast, Bulgaria. Geopolymer pastes and mortars are prepared by using three different alkaline activators—sodium hydroxide, sodium silicate and sodium carbonate. The hardened geopoly-mers are tested for determination of mechanical properties by traditional standardized methods. The structure and the composition of the materials are studied by direct physical methods—X-ray diffraction (XRD), thermal analysis (DTA and TGA) and scanning electron microscopy (SEM). The results show variable degree of dissolutions of the raw zeolite material when using different activators and formation of solid geopolymer materials with qualitatively different structure. Despite its relatively low compressive strength, geopolymers based on natural zeolite cured at room temperature and used as coating, show very good adhesion to concrete.

Se explica cómo el fundamento de la agricultura es la ciencia del suelo para saber cómo se nutren las plantas. Se propone una metodología para sustituir los agroquímicos con un paquete sustentable a base de zeolita, químicos naturales y composta.