COMPETITIVE ADSORPTION OF CR(VI), K(I) AND NH4(I) IONS ONTO NATURAL ZEOLITES AND BENTONITES
Chromium, ammonium, and potassium compounds are pollutants in the environment released mainly by industrial wastewater and they can negatively influence the quality of surface water. Zeolites and bentonites are commonly used adsorbents for removal of pollutant from water. In the study, the adsorbents were used in their natural form, without chemica...
By Tomáš Bakalár
COLUMN SORPTION OF TOXIC IONS IN VARIOUS QUARTZ SAND - PACKED COLUMNS
In this study the adsorption of As(V), Cu(II) and Zn(II) ions from multi-species model solution was tested in dynamic conditions in sand columns containing a thin layer of bentonite (B), iron-based sludge (IS) and synthetic magnetic particles (MP). Adsorption experiments were performed in order to evaluate the removal efficiency and selectivity of ...
By Alexandra Bekényiová, Zuzana Danková, Michal Hegedüs, Zuzana Mitróová, Silvia Dolinská, Ingrid Znamenáčková
ELIMINATION OF TOXIC ELEMENTS BY NATURAL AND SYNTHETIC ADSORBENTS
The adsorption of Zn(II) and Cu(II) onto siderite (S) and kaolin (K) and adsorption of As(V) onto bentonite (B) was studied. The chemical modification – precipitation of MnO2 on the kaolin (KM) and siderite (SM) surface was used to improve the adsorption properties of natural materials for their application in columns. In the batch tests the higher...
By Zuzana Danková, Alexandra Bekényiová, Zuzana Mitróová, Danka Gešperová
STUDY OF Cu(II) ADSORPTION BY BENTONITE AND FOLLOWING REGENERATION BY BIOLEACHING
The natural bentonite and bentonite/iron oxide composite were used as sorbents of Cu(II). Their sorption properties were examined under the different conditions such as pH of the solution, initial metal ion concentration. The bentonite removed 71 % Cu(II) while composite 90 %. Their maximum adsorption capacities were 34.1 and 44.4 mg Cu(II) g -1, r...
By Zuzana Danková, Zuzana Dakos, Iveta Štyriaková, Alexandra Bekényiová
BENTONITE/IRON OXIDE MAGNETIC COMPOSITES: CHARACTERIZATION AND APPLICATION AS Pb(II) ADSORBENTS
The natural clay bentonite (B) as adsorbent of lead cations was studied. To enhance its adsorption capacity, the coating by iron oxide particles, in two selected weight ratios: 2:1 (BM1) and 4:1(BM2), was used. The changes of the textural and surface parameters after the modification were studied by the low temperature nitrogen adsorption, XRD and ...
By Zuzana Danková, Erika Fedorová, Alexandra Bekényiová
SORPTION OF COPPER AND ZINC BY GOETHITE AND HEMATITE
In the present work, the abilities of natural and synthetic samples of goethite and hematite to remove copper Cu(II) ) and zinc Zn(II) ions from aqueous solutions were compared. Batch adsorption experiments were performed in order to evaluate the removal efficiency of iron oxide samples. The effect of initial metal ion concentration, initial pH and...
By Alexandra Bekényiová, Iveta Štyriaková, Zuzana Danková
SURFACE AND STRUCTURE STUDY OF CLAY-BASED COMPOSITES AFTER THERMAL TREATMENT
The composite materials prepared from clay and iron oxides in different weight ratios and temperatures denoted as A85 and E20 were heated at 300 °C in reductive atmosphere and up to 650 °C in inert atmosphere. The changes in the structure, surface and pore properties were examined by XRD, N2 adsorption method and TG, DTA method. The morphology was ...
By Annamária Mockovčiaková, Zuzana Danková, Jaroslav Briančin
EFFECT OF THERMAL TREATMENT ON THE BENTONITE PROPERTIES
The main objective of this study is to investigate the changes in structure, surface area and porosity of monomineral fraction of the local bentonite upon heating at 300, 500 and 650 °C. IR spectroscopy, DTA, XRD and N2 adsorption method were employed for the analyses. The non-heated montmorillonite was characterized by a basal spacing of 1.50 nm, ...
By Zuzana Orolínová, Annamária Mockovčiaková, Silvia Dolinská, Jaroslav Briančin