Wyniki wyszukiwania - Biblioteka Nauki

1

Use of Natural Nanotubes of Halloysite Clay for Thermochemical Conversion of Cottonseed Oil

100%

Mammadova T. A. , Hasankhanova N. V. , Teyubov K. S. , Askerova E. N. , Latifova T. S. , Abbasov V. M.

Catalysis for Sustainable Energy

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2014

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tom 2

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nr 1

EN

The process of obtaining low molecular weight C2-C4 olefins, as a result of thermal and thermocatalytic conversion of cottonseed oil was investigated. The total content of olefin gases obtained by the thermal conversion of cottonseed oil in the temperature range of 700-800°C is 57.2-65.2 wt. %. Thermocatalytic conversion of cottonseed oil on the natural halloysite nanotubes as a catalyst in the temperature range of 500-800 ° provides the total content of olefins 10.8-69.2 wt. with increased yield of propylene and butenes.

2

Mechanically milled aluminium matrix composites reinforced with halloysite nanotubes

100%

Dobrzański L. A. , Tomiczek B. , Adamiak M. , Gołombek K.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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tom Vol. 55, nr 2

654--660

EN

Purpose: The present work describes fabrication of aluminium AlMg1SiCu matrix composite materials reinforced with halloysite nanotubes by powder metallurgy techniques and hot extrusion. Design/methodology/approach: Mechanical milling, compacting and hot extrusion successively are considering as a method for manufacturing metal composite powders with a controlled fine microstructure and enhanced mechanical properties. It is possible by the repeated welding and fracturing of powders particles mixture in a highly energetic ball mill. Findings: The milling process has a huge influence on the properties of powder materials, changing the spherical morphology of as-received powder during milling process to flattened one due to particle deformation followed by welding and fracturing particles of deformed and hardened enough which allows to receive equiaxial particles morphology again. The investigation shows that so called brittle mineral particles yields to plastic deformation as good as ductile aluminium alloy particles. That indicates that the halloysite powder can play a role of the accelerator during mechanical milling. High energy ball milling as a method of mechanical milling improves the distribution of the halloysite reinforcing particles throughout the aluminium matrix, simultaneously reducing the size of particles. The apparent density changes versus milling time can be used to control the composite powders production by mechanical milling and the presence of halloysite reinforcements particles accelerates the mechanical milling process. Research limitations/implications: Contributes to knowledge about technology, structure and properties of aluminium alloy matrix composite material reinforced with mineral nanoparticles. Practical implications: Conducted research shows that applied technology allows obtaining very good microstructural characteristics. Originality/value: It has been confirmed that halloysite nanotubes can be applied as an effective reinforcement in the aluminium matrix composites. Deformation, grain size reduction and dispersion conduce to hardening of the composite powders. Mechanical milling cause a high degree of deformation, decrease the grain size even to nanoscale and create an enormously uniform distribution of reinforcing phases or oxides in the structure of the metal.

3

The sorption capability of halloysite

100%

Skibińska M.

Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia

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2017

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tom 72

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nr 1

EN

Halloysite is commonly occuring in Poland a natural mineral which, due to its structure is very popular among researchers. First of all, the large number of sorption areas and their various selectivity makes the material capable of adsorbing the compounds of different nature at the same time. As a result, there is a lot of possible applications. In addition, ease of functionalization of the surface of the material increases its sorption capacity and makes its more attractive.

4

Enhanced adsorption of Direct Orange 26 dye in aqueous solutions by modified halloysite

100%

Kuśmierek K. , Świątkowski A. , Wierzbicka E. , Legocka I.

Physicochemical Problems of Mineral Processing

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2020

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tom Vol. 56, iss. 4

693--701

EN

The usefulness of untreated (H-NM) as well as modified by sodium benzoate (H-SB) and sulfuric acid (H-SA1 and H-SA2) halloysites as low-cost adsorbent for the removal of Direct Orange 26 azo dye from aqueous solutions was investigated. The kinetic data were evaluated in terms of the pseudo-first order and pseudo-second order kinetic models, while the equilibrium adsorption data were analyzed by the Freundlich and Langmuir isotherm equations. The data follows the pseudo-second order kinetic and Langmuir adsorption models. The DO26 adsorption capacities were 64.93, 74.07, 303.0, and 384.4 μmol/g for the H-NM, H-SB, H-SA1, and H-SA2, respectively. Adsorption of the dye was strongly pH dependent; no effect of ionic strength was observed. The study revealed that halloysites, especially acid-activated halloysites, could be used as an effective and low-cost adsorbents.

5

Influence of heat treatment on the structure and properties of polyamide 6/ halloysite nanocomposites

100%

Mencel K. , Kemnitz Ł.

Archives of Mechanical Technology and Materials

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2019

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tom Vol. 39

7--10

EN

The nanocomposites of polyamide 6 (PA6) with halloysite nanotubes (HNT) were prepared by extrusion using co-rotating twin-screw extruder and then the standard test specimens were injected using a screw injection moulding machine. The content of HNT in the nanocomposites was 5 or 10 weight percent. The heat treatment of unmodified PA6 and nanocomposites was carried out in silicone oil in temp. 150±2°C. The samples were annealed for 3 hours and then cooled at a rate of 4 K/min. Differential scanning calorimetry (DSC) causes annealing to increase the crystallinity of the polyamide matrix. After an annealing treatment a nanocomposite with better mechanical properties was obtained. Halloysite nanotubes in polyamide matrix play the role of a nucleating agent.

6

Purification of halloysite by magnetic separation

100%

Sakiewicz P. , Lutynski M. , Soltys J. , Pytlinski A.

Physicochemical Problems of Mineral Processing

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2016

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tom Vol. 52, iss. 2

991--1001

EN

Rational use of mineral resources requires advanced separation methods in order to obtain high quality products. In this study chemical treatment with magnetic separation of halloysite from Dunino (Poland) is presented. Initial crushing, hydrochloric acid absorption treatment, sedimentation (settling) and polygradient magnetic separation in weak magnetic field were applied to separate aluminosilicates from iron and titanium oxides (impurities). The process allowed to obtain a product of approximately 98% purity of the aluminosilicate fraction (halloysite + kaolinite). The tailings from magnetic separation consisted of iron oxides, while the intermediate product consisted mainly of aluminosilicate and iron chlorides resulting from the HCl treatment. The obtained products can be used as a component of polymer nanocomposites, sorbents and in ceramics industry.

7

Content of Selected Heavy Metals In Ni-Contaminated Soil Following the Application of Halloysite and Zeolite

100%

Radziemska M. , Mazur Z.

Journal of Ecological Engineering

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2016

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tom Vol. 17, nr 3

125--133

EN

Nickel has been listed as a priory control pollutant by the United States Environmental Protection Agency (US EPA). Compared with other methods, the combination of vegetation and the addition of mineral sorbents to heavy metal-contaminated soils can be readily applied on a large scale because of the simplicity of technology and low cost. Halloysite and zeolite, among others, can be used for this purpose. A greenhouse study was performed to evaluate the feasibility of using natural zeolite, as well as raw and modified halloysite for the remediation of simulated Ni-contaminated soil. The soil was spiked with five doses of nickel, i.e. 0 (control), 80, 160, 240 and 320 mg·Ni kg-1·soil. The average accumulation of heavy metals in nickel-contaminated soil was found to follow the decreasing order of Ni>Zn>Cr>Cu>Pb. The highest reduction of Pb content was observed in soil samples taken from pots containing 80 and 160 mg·kg-1 of Ni along with the addition of modified halloysite. The strongest effects were caused by natural zeolite, which significantly reduced the average content of chromium. Contamination at 320 mg Ni·kg-1

8

Effects of acid leaching on halloysite

88%

Saklar S. , Yorukoglu A.

Physicochemical Problems of Mineral Processing

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2015

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tom Vol. 51, iss. 1

83--94

EN

A characteristic iron-containing halloysite sample from Turkey was subjected to acid leaching using organic and inorganic acids for removing iron impurities. The aim of this study was to compare the raw hydrated and dehydrated halloysites with the leached products. Hydrochloric acid and oxalic acid were chosen as leaching agents for the removal of iron impurities at 80 °C for 2.5 h. The physicochemical properties of the acid-treated halloysite were analyzed by XRF, XRD, FTIR, TGA, DTA, SEM, and TEM. The XRF results showed that the acid treatment caused the dissolution of minor amounts of Al3+ ions from the clay layer. The XRD results indicated that the crystalline structure was unchanged after the leaching. However, it was observed that the hydrated (1 nm) halloysite readily lost its interlayer water and was transformed to the dehydrated (0.7 nm) form. In addition, no visible effects of the acid treatment on the tubular structure of halloysite were detected in the SEM and TEM images. Typical pores of varying dimensions were observed in all of the samples regardless of their form or treatment. Furthermore, the TG-DTA and FTIR analysis results were similar for both the raw and the acid-treated samples.

9

Halloysite composites with Fe3O4 particles: the effect of impregnation on the removal of aqueous Cd(II) and Pb(II)

88%

Maziarz P. , Matusik J.

Mineralogia

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2017

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tom Vol. 48, iss. 1/4

107--126

EN

In this study, halloysite-Fe3O4 composites were synthesized by a chemical-precipitation method to facilitate magnetic separation of the sorbents from aqueous solution. The research focused on the effect of Fe3O4 phase on the halloysite sorption properties. The X-ray diffraction (XRD) results confirmed successful deposition of Fe3O4 particles on a halloysite surface. They showed that the coating with Fe3O4 particles enhanced the halloysite adsorption affinity toward Cd(II) and Pb(II). The highest adsorption capacity was determined for the composites having 10% of the surface deposited with Fe3O4. In this case, the adsorption capacity for Cd(II) and Pb(II) was 33 and 112 mmol•kg-1, respectively. The point of zero charge (pHPZC) and desorption results indicated that the removal mechanism of metals is mainly related to chemisorption involving reaction with hydroxyls of either halloysite or Fe3O4 phase. The ion exchange is of limited importance due to the low cation exchange capacity (CEC) of halloysite - Fe3O4 composites.

10

The Removal of Organic Acids and Aldehydes from Gases Emitted from Composting Municipal Waste

88%

Wierzbińska M.

Journal of Ecological Engineering

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2021

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tom Vol. 22, nr 3

58--66

EN

The article describes an experiment conducted under industrial (real) conditions in a municipal waste composting facility. The waste gases emitted from composting processes were passed through an experimental installation built in a semi-technical scale. The installation consisted of two biofilters which were filled with different aluminosilicate beds with average granulation of 4–10 mm. The sorbents were inoculated with a mixture of microorganisms bred on the mineral bed, previously operating in the tank with the waste from that composting facility. Malodorous gases were passed through the installation and concentrations of organic acids and aldehydes before and after passing through biofilters with the examined sorbents. The aim of the experiment was to determine which of the two mineral sorbents better removes the analysed contaminations from post-production gases. The experiment lasted for a month, as difficult and highly variable industrial conditions caused problems with operation and the experiment was suddenly interrupted. The study will be continued after the introduction of design changes in the installation. After the month of conducting the study it can be conclude that in the first weeks of the study, before the dampness of sorbents took place, halloysite reduced the concentrations of acetic acid in 80–99%, and of acetaldehyde in 96–98%. The other aluminosilicate caused a drop in the concentrations by 97–98% and 92–86%, respectively. Moreover, in the experiment planned in the semi-technical scale, it was not possible to determine the overall performances of mineral biofilters due to unstable operating conditions and ending the experiment prematurely. The halloysite sorbent finally turned out to be potentially the more efficient than the other aluminosilicate sorbent.

11

Green method of conversion of geraniol to value-added products in the presence of selected minerals

88%

Fajdek-Bieda A. , Wróblewska A. , Perec A. , Miądlicki P.

Polish Journal of Chemical Technology

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2023

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tom Vol. 25, nr 1

47--60

EN

The study presents the results of research on the process of geraniol (GA) transformation in the presence of natural minerals: montmorillonite, mironekuton, halloysite and also in the presence of halloysite modified with 0.1 M water solution of H2SO4. To obtain information on the structure of the used catalysts, instrumental studies were performed (SEM, XRD, FT-IR, XRF, BET). The second part of the research consisted in examining the influence of individual parameters (temperature, catalyst content, and reaction time) on the course of GA transformation process. The syntheses were carried out without the application of solvent and under atmospheric pressure. To determine the most beneficial process conditions, two functions were selected: GA conversion and selectivity of GA. The proposed method of GA transformation on such minerals: montmorillonite, mironekuton, halloysite, has not been described in the literature so far.

12

Chemical Composition of Spring Rapeseed Grown in Copper-contaminated Soil Amended with Halloysite and Zeolite

88%

Radziemska M. , Mazur Z.

Journal of Ecological Engineering

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2017

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tom Vol. 18, nr 2

38--43

EN

The purpose of this study was to determine the effect of soil contamination with copper doses of 0, 150, 300, and 450 mg.kg-1 of soil and the application of zeolite, raw and modified halloysite on the biomass of spring rapeseed and the content of nitrogen compounds and macronutrients in the above-ground parts of the tested plants. The content of macronutrients in plants was determined spectrophotometrically. The applied soil amendments and copper doses led to significant variations in the concentrations of the analyzed nutrients in spring rapeseed. Zeolite and halloysite were most effective in increasing the average above-ground biomass of the tested plants. Zeolite had a beneficial effect on the content of total nitrogen, ammonia nitrogen and phosphorus in the above-ground parts of spring rapeseed. Raw halloysite increased the content of sodium and calcium, whereas modified halloysite contributed to an increase in the nitrogen, potassium, sodium, calcium and magnesium content of the tested plants.

13

The Application of Mineral Sorbents to Remove Volatile Organic Compounds from the Gases Emitted from the Composting Processes

75%

Wierzbińska M.

Journal of Ecological Engineering

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2021

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tom Vol. 22, nr 2

98--110

EN

The disposal of organic waste in processes such as composting is related to the emission of malodorous compounds. Owing to their character and low odour detection threshold, there is often a need for a hundred percent elimination of the contaminants from waste gases. One of alternative methods of treating the waste gases from malodorous contaminants, occurring in low concentrations in post-process air, is the biofiltration method. Most often, the method uses an organic filtration material. However, this method of air purification is still developing; therefore, there is a search for new sorbents among mineral materials, which would be an alternative for organic sorbents. The article presents the research into the application of aluminosilicate sorbents, including halloysite, for deodorization of the gases emitted from the processes of composting municipal waste. The semitechnical scale research was conducted for several weeks in a municipal waste composting plant, passing real gases through two biofilters filled with mineral sorbents. In spite of the fact that some problems occurred and the research cycle was not completed, the experiment proved that halloysite removes odours to a much higher extent than the other examined aluminosilicate sorbent. While the VOCs reduction on a bed with halloysite was 88%, the reduction on a bed with a second aluminosilicate reached 35%. The process conditions were very unstable; therefore, the efficiency of the VOCs removal process varied widely. However, halloysite has always been a better sorbent than the other aluminosilicate.

14

Halloysite-based system for controlled delivery of clindamycin phosphate

75%

Karewicz A. , Machowska A. , Klara J.

Engineering of Biomaterials

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2020

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tom Vol. 23, no. 158 spec. iss.

14

15

The composting of PLA/HNT biodegradable composites as an eco-approach to the sustainability

75%

Czarnecka-Komorowska D. , Bryll K. , Kostecka E. , Tomasik M. , Piesowicz E. , Gawdzińska K. , Czarnecka-Komorowska D. , Bryll K. , Kostecka E. , Tomasik M. , Piesowicz E. , Gawdzińska K.

Bulletin of the Polish Academy of Sciences: Technical Sciences

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2021

16

The properties of moulding sand with halloysite

75%

Cholewa M. , Kozakiewicz Ł.

Archives of Foundry Engineering

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2012

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tom Vol. 12, iss. 2

205-210

EN

Until now, the mould sand in general use in the foundry industry are based on bentonite, which resulted from the fact that a good recognition properties and phenomena associated with this material. Come to know and normalized content of montmorillonite and carbonates and their important role in the construction of bentonite, and mass properties of the participation of compressive strength or scatter. Halloysite is widely used in industry and beyond them. However, little is known about its use in the foundry in Poland and abroad. This article presents preliminary research conducted at the Foundry Department of Silesian University of Technology on this material. Will raise the question of the representation of this two materials, which contains information connected with history and formation of materials, their structure and chemical composition. In the research, the results of compressive strength tests in wet masses of quartz matrix, where as a binder is used halloysite and bentonite in different proportions.

17

Possible use of halloysite in phytoremediation of soils contaminated with heavy metals

75%

Swiercz A. , Smorzewska E. , Slomkiewicz P. , Suchanek G.

Journal of Elementology

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2016

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tom 21

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nr 2

EN

The impact of adding a natural clay sorbent such as halloysite on the content of selected heavy metals in the biomass of common orchardgrass (Dactylis glomerata L.) was studied in a pot experiment. The study was conducted on mucky soil enriched anthropogenically with heavy metals, whose values exceeded permissible standards of soil quality and values of the geological background. The experiment included three variants with differentiated percentage of halloysite, i.e. 10%, 30% and 50%, as well as two control cultivations. The results confirm the impact of halloysite on the physicochemical properties of soil, consisting in increased soil pH and sorption capacity. Addition of halloysite to soil also differentiated the quantity of crop yield and concentration of heavy metals in the plant and soil. Halloysite was found to have an inconsistent impact on the concentration of heavy metals in the biomass of common orchardgrass, which was proven by some elevation in the level of heavy metals and a higher bioaccumulation factor (BAF). Halloysite constituting 50% of the mass of substrate substantially increased the consumption of Pb and reduced the sorption of Cr. Addition of halloysite stabilised Zn and Cu in soil. The results of our preliminary investigation indicate that addition of halloysite to soils with excessive concentrations of heavy metals influences the level of soil sorption to the extent which may be effective for soil remediation.

18

Composite materials based on AlMg1SiCu aluminium alloy reinforced with halloysite particles

75%

Tomiczek B. , Dobrzański L. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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tom Vol. 61, nr 1

39--46

EN

Purpose: The present work describes microstructure and technological, as well as mechanical properties of AlMg1SiCu matrix composite materials reinforced with halloysite particles by powder metallurgy techniques and hot extrusion. Design/methodology/approach: Mechanical milling, compacting and hot extrusion successively are considering as a method for manufacturing metal composite powders with a controlled fine microstructure and enhanced mechanical properties. Findings: A structure of newly developed composite materials reinforced with halloysite nanotubes prove that a mechanical milling process allow to improve the arrangement of reinforcing particles in the matrix material. A homogenous structure with uniformly arranged reinforcing particles can be achieved by employing reinforcement with halloysite nanotubes if short time of milling is maintained thus eliminating an issue of their agglomeration. Strong plastic deformations and fine grain size and the dispersion of halloysite reinforcing particles caused by mechanical milling is substantially reinforcing the composite materials reinforced with halloysite nanotubes as expressed with nearly a threefold increase in the hardness of composite powders as compared to the value of this quantity before milling. Research limitations/implications: Contributes to knowledge about technology, structure and properties of aluminium alloy matrix composite material reinforced with mineral nanoparticles. Practical implications: As the fraction of halloysite nanotubes is growing to 15%, structural changes in the powders of composite materials subjected to mechanical milling are reaching the set condition 3 times faster as compared to the matrix material. Originality/value: It has been confirmed that halloysite nanotubes can be applied as an effective reinforcement in the aluminium matrix composites. Deformation, grain size reduction and dispersion conduce to strengthening of the composite powders.

19

Selected properties of the halloysite as a component of Geosynthetic Clay Liners (GCL)

75%

Sakiewicz P. , Nowosielski R. , Pilarczyk W. , Gołombek K. , Lutyński M.

Journal of Achievements in Materials and Manufacturing Engineering

|

2011

|

tom Vol. 48, nr 2

177--191

EN

Purpose: The aim of this paper was to present some properties of halloysite and its applications as a component of Geosynthetic Clay Liners (GCL). The following article presents results of comparative tests of the influence of different factors on the halloysite and halloysite - bentonite mixture properties. Design/methodology/approach: Many studies including SEM, XRD, FTIR, EDS, ICP and XRF have been made to examine the halloysite and halloysite - bentonite mixture properties. Findings: Influence of the halloysite additive on characteristics of sealing GCL properties. Research limitations/implications: Studies described in this work should help to improve composition and optimize parameters of sealing clay mixtures improving activities and functioning of GCL during a long period of time. Comparison of the effects of the halloysite additive on characteristics of sealing clay layers properties and the possibility of its application in this area. Practical implications: Knowledge about changing of GCL properties during long time exploitation in landfills allows for selection of theirs main sealing parameters. The wrong choice of GCL parameters leads to multiplication of environmental costs and pollution of the area around storage place. Originality/value: Halloysite shows high sorption properties in relation to toxic heavy metals (eg cadmium, lead) and solutions containing harmful hydrocarbons, eg benzene, as well as toxic gases (ammonia, hydrogen sulfide). They are in aqueous solutions, therefore, their capacity for migration through protective barriers sometimes pose a growing threat to the environment. Using halloysite as a component of GCL significantly reduced this problem. The halloysite additive to GCL reduces the vulnerability of the sealing barrier towards the influence of calcium ions improving quality and durability of mineral insulation.

20

Zastosowanie haloizytu w celu zmniejszenia stężenia zanieczyszczeń w ściekach komunalnych

63%

Machnicka A. , Nowicka E.

Inżynieria Ekologiczna

|

2016

|

tom Nr 50

217--222

PL

Jedna z metod oczyszczania ścieków komunalnych pozwala na zastosowanie złóż biologicznych. W badaniach zastosowano złoże wypełnione haloizytem. Podczas pracy złoża w zależności od zastosowanego obciążenia hydraulicznego uzyskano redukcję stężeń fosforanów, azotu amonowego i materii organicznej. Najwyższą redukcję PO43- (89%) i N–NH4+ (81%) w ściekach uzyskano przy obciążeniu hydraulicznym złoża wynoszącym 0,04 m3/m2h. Stężenie substratu organicznego uległo redukcji o ok. 86%.

EN

One of the methods of municipal wastewater treatment allows the use of biofilters. The study used a bed filled halloysite. In operation of the bed, depending on the hydraulic load, the concentration of phosphate, ammonium and organic matter was reduced. Highest reduction of the concentration PO43- (89%) and NH4+ (81%) in the waste water of the hydraulic load –0,04 m3/m2h.was obtained. The concentration of the organic substrate was reduced by approximately 86%.