Browsing by Author "Massalimova, Bakytgul Kabykenovna"
Now showing 1 - 9 of 9
Results Per Page
Sort Options
- Assisted hydrothermal carbonization of agroindustrial byproducts as effective step in the production of activated carbon catalysts for wet peroxide oxidation of micro-pollutantsPublication . Díaz de Tuesta, Jose Luis; Saviotti, Marcus Chamahum; Roman, Fernanda; Pantuzza, Gabriel F.; Sartori, Hiram J.F.; Shinibekova, Assem A.; Kalmakhanova, Marzhan; Massalimova, Bakytgul Kabykenovna; Pietrobelli, Juliana Martins Teixeira; Lenzi, Giane G.; Gomes, HelderThis work deals with the valorisation of bagasse of sugarcane – BC, bagasse of malt – BM and seed of chia – SC, through its transformation into pyrochars, hydrochars and activated carbons (ACs) by pyrolysis, hydrothermal carbonization (HTC) and sequential HTC and pyrolysis, respectively. The HTC process was carried out in the presence of H2O, FeCl3 and H2SO4 solutions. The materials resulting by HTC in the presence of FeCl3 revealed the highest burn-off, but the contents of carbon released into the liquid phase, measured as total organic carbon, and to the gaseous phase, determined by carbon balance, depend strongly on the carbon precursor. In this sense, BC generates more volatile organic compounds (up to 34% of the initial carbon content), followed by BM (< 15%) and SC (< 5%) in their HTC and pyrolysis (70%). The pyrochars, hydrochars and ACs prepared from BC also show the highest specific surface areas (SBET < 447 m2⋅g-1) when compared to the specific surface areas of the materials prepared from BM and SC. The carbon-based materials prepared with FeCl3 show the highest catalytic activity, but iron leaching into solution is observed. On the other hand, the materials prepared with H2SO4 show high activity, enabling its application in successive cycles and the complete degradation of caffeine in concentrations ranging from 1 to 100 mg⋅L-1, after 5–60 min of reaction.
- Novelty pillared clays for the removal of 4-nitrophenol by catalytic wet peroxide oxidationPublication . Kalmakhanova, Marzhan; Massalimova, Bakytgul Kabykenovna; Díaz de Tuesta, Jose Luis; Gomes, Helder; Nurlibaeva, A.A.One solution passes through the study of wastewater treatment by catalytic wet peroxide oxidation (CWPO).In this work, catalysts based on pillared clays with Zrcations have been prepared from nature clays of Kazakhstan, which were obtained from Zhambyl region of Karatau,Akzhardeposit, to be tested in catalytic oxidation of 4-nitrophenol, used as amodel pollutant. The Zr-pillared clay showed higher activity than nature clays in 4-nitrophenol oxidation.
- Obtaining of zirconium catalysts based on pillared clays for peroxide oxidation of 4-nitrophenolPublication . Kalmakhanova, Marzhan; Massalimova, Bakytgul Kabykenovna; Gomes, Helder; Díaz de Tuesta, Jose Luis; Tsoy, Irina; Aidarova, A.O.Natural resources, including abundant and cheap natural clays in the southern regionare one of the main wealth of the Republic of Kazakhstan. The chemical industry in Kazakhstanis being developedrapidly in recent years and there is an urgent need to find solutions for the treatment of wastewaters. This work aims to explore natural clays for the synthesis of low-cost pillared clays that can be used as catalysts in oxidation technologies for the treatment of wastewaters. Nitrophenols are commonly found in many types of wastewaters (plastic, pharmaceutical, paper or pesticide production).The purification of suchspecific wastewater according to classical schemes does not always ensure a safe level of pollution in waters discharged into water ponds. Thus, further development of the chemical industry will inevitably be associated with the need for more effective disposal of wastewater containing toxic products. 4-nitrophenol was used as a representative model compound in catalyst screening studies.Catalysts based on pillared clays modified with Zr4+cations were synthesized from natural clays of Karatau and Kokshetau deposits and investigated for the catalytic wastewater peroxide oxidation (CWPO) of 4-nitrophenol (4-NP) at 323 K. Pillared clays with Zr4+ showed the higher catalytic activity in the removal of 4-NP and Total organic carbon (TOC) by CWPO and selectivity for the formation of CO2 and H2O than natural clays.The best 4-NP and TOC conversion results were obtained by using the pillared clay from Karatau deposit as a catalyst. A complete removal of the contaminant was achieved after 2 hours with 97.3 % conversion.
- Performance and modeling of Ni(II) adsorption from low concentrated wastewater on carbon microspheres prepared from tangerine peels by FeCl3-assisted hydrothermal carbonizationPublication . Díaz de Tuesta, Jose Luis; Roman, Fernanda; Marques, Vitor da Costa; Silva, Adriano S.; Silva, Ana P. F.; Bosco, Tatiane; Shinibekova, Assem A.; Aknur, Sadenova; Kalmakhanova, Marzhan; Massalimova, Bakytgul Kabykenovna; Arrobas, Margarida; Silva, Adrián; Gomes, HelderThe presence of heavy metals in the environment as a consequence of human activity is an issue that has caught the attention of researchers to find wastewater treatment solutions, such as adsorption. In this work, hydrochars and activated carbon microspheres are prepared from tangerine peels as carbon precursor and FeCl3 as activating and structure-directing agent in the hydrothermal carbonization, allowing to obtain hydrochar microspheres ranging from 50 to 3615 nm. In addition, a pyrochar was prepared by pyrolysis of the same precursor. The activated carbon shows the highest surface area (SBET up to 287 m2 g–1), but the basicity of the pyrochar (1.83 mmol g-1, SBET = 104 m2 g–1) was determinant in the adsorption of Ni, being considered the carbon-based material with the highest uptake capacity of Ni. Isotherm and kinetic adsorption of Ni on the most representative activated carbon microsphere, pyrochar and hydrochar microsphere are assessed by 10 and 7 models, respectively.
- Pillared clays from natural resources as catalysts for catalytic wet peroxide oxidation: Characterization and kinetic insightsPublication . Kalmakhanova, Marzhan; Díaz de Tuesta, Jose Luis; Massalimova, Bakytgul Kabykenovna; Gomes, HelderPillared clays with Zr and Fe/Cu/Zr polycations have been prepared from natural clays found in large deposits of Kazakhstan and assessed as catalysts for the catalytic wet peroxide oxidation (CWPO), using 4-nitrophenol (4-NP) as model compound. The performance of the catalysts was followed by measuring the concentration of 4-NP, H2O2 and the total organic carbon (TOC), considering C4-NP = 5 g L-1, CH2O2 = 17.8 g L-1, Ccat = 2.5 g L-1, initial pH = 3.0 and T = 50°C. At those selected conditions, the pillared clays showed higher activity than natural clays in the CWPO of 4-NP. The conversion of the model pollutant was complete when Fe/Cu/Zr-PILCs were used, with the TOC removal reaching 78.4% after 24 h with the best Fe/Cu/Zr-PILC. The H2O2, 4-NP and TOC time-evolution was well described by a kinetic model based on TOC lumps in three blocks, considering the initial TOC (corresponding to 4-NP), the production of oxidizable intermediates and the formation of refractory products.
- Preparation and characterization of natural and pillared clays for catalytic wet peroxide oxidation of 4-nitrophenolPublication . Díaz de Tuesta, Jose Luis; Kalmakhanova, Marzhan; Massalimova, Bakytgul Kabykenovna; Gomes, HelderThis work deals with the evaluation of two natural clays (NCs) extracted from Karatau (KNC) and Akzhar (ANC) deposits (located in the Zhambyl region of Kazakhstan) to prepare pillared clays (PILCs) for catalytic wet peroxide oxidation (CWPO) of 4-nitrophenol (4-NP), used as model pollutant. NCs were washed with HCl 1 M and then pillared using a solution containing Fe, Cu and Zr. NCs and PILCs were characterized by Electron Microprobe (EMP), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microscopy (TEM), as detailed elsewhere [1,2]. EMP confirms the cation exchange of the Ca contained in the NCs (Ca > 15%) in the form of calcite (according to DRX and FTIR), by polycations of the pillaring solution (Ca < 2% for the PILCs). TEM reveals that the impregnation of polycations on the washed NCs also take place, coupling with its pillarization. CWPO runs were performed following the methodology and operational conditions described in previous works [1,2]. All materials show catalytic activity, since the H2O2 is consumed (Fig. 1A) to oxidize the 4-NP. Both KPILC and APILC, prepared from KNC and ANC, respectively, allow the complete removal of 4-NP after 4 h, whereas the conversion of 4-NP was less than 20% with the NCs (Fig. 1B). TOC conversions higher than 60 % were achieved with PILCs after 8 h. The subtraction of the theoretical TOC contribution of 4-NP from experimental TOC allowed to observe the formation of oxidazable intermediate compounds (maximum value of TOCexperimental- TOC4-NP at 1 h of reaction), which are oxidized to form refractory products (Fig. 1C). Based on these contributions of the TOC, a kinetic model based on TOC lumping into three blocks (TOCA à TOCB à TOCC, corresponding to the initial TOC of 4-NP, oxidazable intermediates and refractory products, respectively) was developed for the NCs and PILCs, predicting suitably the evolution of 4-NP, H2O2 and TOC in the CWPO of 4-NP (Fig. 1).
- Synthesis and characterization of a new magnetic composite MnFe2O4/clay based on a natural clay obtained from Turkestan depositPublication . Baimuratova, Zhaina; Kalmakhanova, Marzhan; Massalimova, Bakytgul Kabykenovna; Nurlibaeva, A.A.; Kulazhanova, A.S.; Díaz de Tuesta, Jose Luis; Gomes, HelderThe work is devoted to the development of a new method for the synthesis of magnetic composites based on manganese ferrite on a natural clay, coupling with their physico-chemical characterization. In the study, a natural clay of Kazakhstan obtained from the Turkestan deposit was used for the preparation of magnetic composites. The formation of materials with magnetic properties is an urgent task of our time, due to the needs of various applications of magnetically controlled materials for biomedical systems, electronic devices, catalytic and adsorption processes. The advantage of such materials is the ability to control them using a magnetic field for shaking, recovery, induction heating, among others. In this work, samples were prepared by co-precipitation of manganese and iron salts with 5 mol L-1 NaOH over the Turkestan clay (TC). Materials were characterized by various analyses, such as Fourier-Transform infrared spectroscopy (FTIR), X-ray diffractometric analysis (XRD), and elemental analysis. According to the results of physical and chemical studies of the XRD and thermal analysis, kaolinite is the main mineral in the composition of TC. Magnetic adsorbents MnFe2O4/clay with perfect magnetic separation characteristics were successfully obtained by chemical co-precipitation.
- Synthesis of low cost pillared clays for the removal of pollutants by oxidation with hydrogen peroxidePublication . Díaz de Tuesta, Jose Luis; Kalmakhanova, Marzhan; Massalimova, Bakytgul Kabykenovna; Gomes, HelderResearch on catalytic wet peroxide oxidation (CWPO) has been mainly focused on the development of highly active, stable and efficient solid catalysts, whereas kinetic studies are scarcely present in this matter. The current work deals with the lumped kinetic modelling of TOC in the CWPO of 4-nitrophenol (4-NP), used as model pollutant, considering natural clays as catalysts from the Akzhar and Karatau regions of the republic of Kazakhstan.
- Wet peroxide oxidation of paracetamol using acid activated and Fe/Co-pillared clay catalysts prepared from natural claysPublication . Silva, Adriano S.; Kalmakhanova, Marzhan; Massalimova, Bakytgul Kabykenovna; Sgorlon, Juliana; Díaz de Tuesta, Jose Luis; Gomes, HelderMany pharmaceuticals have been recently identified at trace levels worldwide in the aquatic environment. Among them, the highly consumed paracetamol (PCM), an analgesic and antipyretic drug, is largely being accumulated in the aquatic environment due to ine cient removal by conventional sewage treatment plants. This work deals with the treatment of PCM, used as a model pharmaceutical contaminant of emerging concern, by catalytic wet peroxide oxidation using clay-based materials as catalysts. The catalysts were prepared from natural clays, extracted from four di erent deposits using acid-activated treatment, calcination, and pillarization with Fe and Co. Pillared clays show the highest catalytic activity owing to the presence of metals, allowing to remove completely the PCM after 6 h under the following operating conditions: CPCM = 100 mg L1, CH2O2 = 472 mg L1, Ccat = 2.5 g L1, initial pH = 3.5 and T = 80 C. The prepared materials presented high stability since leached iron was measured at the end of reaction and found to be lower than 0.1 mg L1.