Research and application of natural zeolite in the processes of gas purification and drying

This article describes the adsorption capability of natural zeolites for the purification and dehydration of natural gases. Studies were carried out with natural clinoptilolite treated with various cadmium and titanium solutions. Zeolite-containing rocks were used as a natural adsorbent and experiments using a synthetic CaA zeolite were also carried for comparison. The experiments showed that zeolite from the Ai-Dag deposits possesses the highest activity in terms of sulfur compound. Its activity is closer to that of synthetic CaA zeolite. Studies showed that natural zeolites and adsorbents obtained on their basis allow the gas to be dehydrated to a dew point temperature of minus 40-45 °C. This is sufficient to prepare gas for transportation directly from the fields under any climatic conditions. Keywords: gas dehydration; zeolite; adsorbent; sulfur compounds.

Alkali-activated metallurgical slag as a sustainable adsorbent

This paper is devoted to obtaining a zeolite-containing sorbent based on metallurgical waste — slag. The synthesis of zeolite adsorbent from ash and slag was carried out by hydrochemical and thermal treatment. The initial object and the obtained material were characterized using following methods: Fourier-transform infrared spectroscopy, scanning electron microscopy, energy dispersive analysis, X-ray phase analysis, titrimetry. The way of converting solid-phase waste into a beneficial product has been demonstrated. The study results showed that the surface of the obtained material is saturated with functional groups (hydroxy-, carboxy-, lactone), which predetermine the ability to bind metal ions during adsorption. The adsorption capacity of the product has been estimated for iodine and methylene blue. A thermodynamic analysis of the process of sorption of copper (II) ions from an aqueous solution has been conducted. It has identified that the sorbent can also be used for the adsorptive concentration of ions of rare-earth elements by the example of lanthanum and erbium. Laboratory testing of the possible use of the sorbent to purify industrial water was carried out using the example of wastewater from a chromium plating shop

Modelling and optimization of free fatty acid reduction in bulk palm cooking oil

Bulk cooking oil from palm oil processing is one of the biodiesel materials which is available in large quantities. The pre-treatment process can be done by adding 100 mesh activated zeolite adsorbent as a substitute for the esterification process to reduce free fatty acid (FFA). The purpose of this research was to model and optimize the zeolite concentration and adsorption time to reduce free fatty acids in bulk palm cooking oil. This study used a response surface method with a central composite design (CCD), resulting in 13 experimental combinations of two factorial treatments, i.e. the concentration of zeolite adsorbent and adsorption time. The zeolite concentration and the adsorption time with an upper limit of 30% and 120 minutes and a lower limit of 10% and 60 minutes had a significant effect on the FFA reduction. The best model was a quadratic model. The testing of validation data used the recommended optimum combination, i.e. the zeolite concentration of 10.59% and the adsorption time of 101.57 minutes resulting in a deviation of 5.37% between the predicted data and the actual data.

Prepared 13X Zeolite as a Promising Adsorbent for the Removal of Brilliant Blue Dye from Wastewater

The research discussed the possibility of adsorption of Brilliant Blue Dye (BBD) from wastewater using 13X zeolite adsorbent, which is considered a byproduct of the production process of potassium carbonate from Iraqi potash raw materials. The 13X zeolite adsorbent was prepared and characterized by X-ray diffraction that showed a clear match with the standard 13X zeolite. The crystallinity rate was 82.15% and the crystal zeolite size was 5.29 nm. The surface area and pore volume of the obtained 13X zeolite were estimated. The prepared 13X zeolite showed the ability to remove BBD contaminant from wastewater at concentrations 5 to 50 ppm and the removal reached 96.60% at the lower pollutant concentration. Adsorption measurements versus time showed 48.18% removal of the dye during just the first half-hour and the maximum removal closest to the removal at the equilibrium after one and half hour. Langmuir isotherm was described the adsorption equilibrium data with a maximum adsorption capacity of 93.46 mg/g and the kinetics data of the adsorption process was followed the pseudo-second-order.

Removal of disperse orange and disperse blue dyes present in textile mill effluent using zeolite synthesized from cenospheres

In the present research, an efficient, eco-friendly method of utilization of coal fly ash in the form of zeolite, to treat wastewater containing dyes has been studied. Response surface methodology involving Box-Behnken design was applied for a batch process to evaluate the effect of process parameters like contact time, dye concentration, agitation speed, pH and adsorbent dosage onto zeolite. Disperse Orange 25 (DO) dye showed maximum 96% removal under optimal conditions of contact time (119 min), dye concentration (38.00 mg/L), agitation speed (158 rpm), pH (6.10) and adsorbent dosage (0.67 g/L), whereas 95.23% of Disperse Blue 79:1 (DB) dye removal was observed at adsorbent dose (1.05 g/L), dye concentration (26.72 mg/L), agitation speed (145 rpm), pH (5.68) and contact time (122 min). Study concluded that cenospheres derivatized zeolite adsorbent is efficient, eco-friendly and economical along with high potential for removal of DO and DB dyes from the aqueous solutions.

FEASIBILITY STUDY FOR THE USE OF NATURAL MORDENITE IN PURIFICATION PROCESSES OF WASTEWATERS FROM PHARMACEUTICAL POLLUTANTS

The present research concerns the possibility of adsorptive removal of the frequently used antibiotics – moxifloxacin and norfloxacin on natural zeolites – mordenite and its acid-modified form from aqueous solutions. The adsorption of the above-mentioned antibiotics on the selected natural zeolite samples was investigated under static and dynamic conditions. Adsorption experiment under dynamic conditions carried out using the specially constructed dynamic type of laboratory equipment. Based on the data of chemical, IR spectroscopic, X-ray diffraction analyses, it has shown that when the zeolite adsorbent is treated with an acid, an equivalent exchange of extra framework cations for a hydrogen ion and dealumination occurs and silanol groups are formed at the same time. The increase in the adsorption activity of mordenite as a result of its treatment with acid is associated with an increase in the pore size due to the unblocking of the adsorbent aluminosilicate framework channels during dealumination.

Adsorption of Methylene Blue Dye using Fe3O4 Magnetized Natural Zeolite Adsorbent

Preparation and characterization of Fe3O4 magnetized natural zeolite adsorbent for adsorption of methylene blue dye have been carried out. Natural zeolite/Fe3O4 adsorbent preparation was carried out using coprecipitation of Fe2+ and Fe3+ ions (1: 2 mol ratio) on the natural zeolite surface. Characterization was carried out using X-Ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR), and Scanning Electron Microscopy (SEM) to determine the effect of Fe3O4 on the natural zeolite surface. UV-Vis spectroscopy was used to determine the concentration of methylene blue after the adsorption process. The characterization results showed that Fe3O4 was successfully embedded in the natural zeolite without damaging the natural zeolite's crystallinity. Natural zeolite/Fe3O4 adsorbent showed easy separation from water medium after the adsorption process. The optimum conditions for adsorption were achieved at the contact time of 60 minutes, and the initial concentration of methylene blue was 30 ppm with an adsorbent mass of 25 mg. Adsorption kinetics followed pseudo-second-order reaction kinetics, and adsorption isotherm followed Langmuir isotherm with an adsorption capacity of 32.258 mg/g.