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Effect of Acid Modification on Porous Structure and Adsorption Properties of Different Type Ukrainian Clays for Water Purification Technologies

Budash Yrii, Plavan Viktoriia, Tarasenko Nataliia, Ishchenko Olena, Koliada Maksym

Journal of Ecological Engineering

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2023

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Vol. 24, nr 5

210--221

EN

Clay minerals, as adsorbents, are widely available, have large specific surface area, and the ability for cation exchange, which makes them applicable in wastewater treatment from heavy metal ions. This study investigated the effect of acid modification on the porous structure and adsorption properties of montmorillonite (MMT) and palygorskite (PAL) clays of the Cherkasy deposit (Ukraine). Acid modification of clay samples was carried out with chloride acid after preliminary refining. Clay particles were analyzed using optical polarization microscopy with recording of digital images of the study. The area and perimeter of individual particles of clay samples were determined. The equivalent diameter and shape factor were calculated. The porosity characteristics of the samples were determined. Pore surface area was calculated by the Brunauer-Emmette-Teller (BET) method. Total volume, mean diameters, and pore size distribution were obtained using the Density Functional Theory (BFT) method. Acid modification improved the porous structure of clay samples. BET surface area of the pores of the initial sample of palygorskite clay is significantly higher compared to the montmorillonite type clay (140.66 and 83.61 m2/g, respectively). Acid modification of the PAL sample contributes to an increase in the BET surface area by approximately 1.7 times. Acid modification increases the surface area and total pore volume by approximately 2.3 times for MMT samples and 1.76 times for PAL samples. Dimensional characteristics of the pores of the MMT sample were to shift after activation, while for the PAL sample, their average size increases sharply by approximately 3.2 times. This suggested the additional formation of pores in the interfibrillar regions of the PAL sample during its acid activation. The effect of acid modification on the sorption capacity was investigated by means of methylene blue exhaustion. Sorption efficiency increases by 6-14%, compared to unmodified samples and is determined by the contact time and the type of clay. Increasing the contact time from 24 to 72 hours leads to an increase in the sorption efficiency of activated MMT and PAL samples by 36 and 30%, respectively. Acid-activated clay minerals, in particular montmorillonite, can be used as part of sorption elements to increase the efficiency of wastewater treatment technologies from heavy metal ions.

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The Strategy of Environmental Danger Minimization from Poultry Farms Waste

Malovanyy Myroslav, Kanda Mariia, Paraniak Roman, Odnorih Zoriana, Tymchuk Ivan

Journal of Ecological Engineering

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2021

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Vol. 22, nr 5

229--237

EN

An impact of poultry farms on the environment caused by ammonia emission from chicken manure has been studied. A negative impact minimisation method by adding natural sorbents to the bedding composition has been proposed. The optimum natural adsorbents compositions (clinoptilolite and palygorskite) for adding to the bedding as well as the optimum mixture ratio of these adsorbents to chicken manure mass have been determined. The optimum conditions for obtaining granulated organic-mineral fertiliser of prolonged action based on this composition have been studied. In the result of the research data analysis a technological scheme for organic-mineral fertiliser production based on chicken manure and a mixture of natural adsorbents have been proposed.

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Ultrafiltration treatment of wastewater contained heavy metals complexed with palygorskite

Ren Jun, Cao Tiany, Yang Xin, Tao Ling

Polish Journal of Chemical Technology

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2020

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Vol. 22, nr 4

1--9

EN

Palygorskite was applied in complexation-ultrafiltration treatment of heavy metals in wastewater under different pH and ionic strength. The results indicated that the rejection of heavy metals increased significantly with pH value, and decreased slightly with an increase of ionic strength of Na+ and Cl-. A certain concentration of NaCl significantly reduced the rejection rate of Cu2+. The rejection of Cu2+, Zn2+ and Cd2+ could reach over 86.8%, 93.6% and 93.7% at pH of 7 and 0.1 mol/L NaCl. The rejection of heavy metals was severely affected by low molecular weight competing complexing agents and the effect of sodium tartrate was greater than triethanolamine. In the presence of sodium tartrate, the rejection of Cu2+, Zn2+ and Cd2+ could arrive over 81.4%, 57.6% and 60.5% at pH of 7 in 20 min. Palygorskite was offered a potential complexing agent for the removal of heavy metals in wastewater at the complexation-ultrafiltration process.

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Zdolność wymiany jonowej (CEC) attapulgitu - glinokrzemianu z grupy pałygorskitów

Grabowska B., Kaczmarska K., Bobrowski A., Kurleto Ż., Mrówka N., Żymankowska-Kumon S.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 4 spec.

43--46

PL

Dane literaturowe wskazują, że istnieje możliwość prowadzenia modyfikacji glinokrzemianów na drodze fizycznej lub chemicznej. Zabieg ten prowadzi się głównie poprzez wymianę kationów w przestrzeni miedzypakietowej w celu poprawy właściwości adhezyjnych i termostabilnych minerałów. W pracy przeprowadzono charakterystykę termiczną i strukturalną attapulgitu (APT) pod kątem jego zdolności do wymiany jonowej (CEC). Stwierdzono, że attapulgit jako naturalny minerał wykazuje niską wartość CEC w zakresie temperatury 23-700 °C w porównaniu do stosowanego szeroko montmorylonitu aktywowanego jonami sodu (MMT-Na). Niska wartość CEC attapulgitu wynika z jego budowy krystalicznej, stąd przeprowadzenie modyfikacji chemicznej APT stanowi kolejny etap prac w tym obszarze.

EN

Literature data indicate that there is a possibility to carrying out the aluminosilicates modification by using a physical or chemical method. The modification process is mainly conducted by exchange of cations into space between layers of packet in purpose to improve the adhesiveness and thermostability of minerals. In this paper the thermal research and structural characteristic of the aluminimumsilicate from palygorskite group - attapulgite (APT) for determine its cation exchange capacity (CEC) were conducted. It was found that attapulgite as a natural mineral has low value of CEC in the temperature range 23-700 °C, compared to widely used montmorillonite activated by sodium ions (MMT-Na). Low values of CEC attapulgite is due to its crystalline structure, thus the conducting chemical modification APT is the next stage of work in this area.

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Studies on Aluminosilicate of Palygorskites Group Used as a Binder in Green Sands System

Grabowska B., Drożyński D., Kaczmarska K., Mrówka N.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 1 spec.

31--36

EN

The possibility of application of aluminosilicate from the palygorskite (attapulgite) group as a potential substitute for bentonite in green sand system application were evaluated. The effectiveness of the application of this aluminosilicate as a binder in sand grains was determined based on the results of the determination flowability, apparent density, permeability, compacability, wear resistance and compressive, tensile and shear strength of the green sands with attapulgite participation or with a mixture of bentonite-attapulgite. The results with the properties obtained for the green sand bonded by bentonite were compared. Based on these results, it was found that attapulgite as a main binder material in the green sand does not guarantee the respective properties of moulding (e.g. it was observed low green strength properties, high apparent density of mixture, low compaction and very low wear resistance). It was recognized that the natural form of attapulgite require modification in order to obtain the appropriate properties of moulding sands, which is the subject of future work within the scope of the development application of aluminosilicate in foundry industry.