17 documents found, page 1 of 2
Occurrence of micropollutants in surface water and removal by catalytic wet per...
Silva, Adriano S.; Zadra Filho, Paulo Cesar; Ferreira, Ana Paula; Roman, Fernanda; Baldo, Arthur Pietrobon; Rauhauser, MadeleineMonitoring campaigns of contaminants of emerging concern (CECs) in surface waters is of utmost importance in evaluating the anthropogenic impact on riparian ecosystems. Beyond identifying pollutants and threats, treatment solutions are also needed to mitigate the adverse effects caused by polluted water discharged into the environment. For years, grab samples have been used to assess water quality, but the resu...
New magnetic clays MnFe2O4/Shymkent for removal of heavy metals from wastewater
Baimuratova, Zhaina; Ermekov, Sayat; Silva, Adriano S.; Gomes, Helder; Kalmakhanova, MarzhanThis paper reports the development of a new method. Production of modified clay with magnetic properties based on natural clay from the Shymkent deposit (MnFe2O4/Shymkent nanocomposite), determination of its chemical composition and structure, as well as the study of basic physicochemical properties. The resulting magnetic nanocomposite was then used as an adsorbent to remove nickel (II) ions from wastewater. T...
Wastewater treatment in Central Asia: treatment alternatives for safe water reuse
Kalmakhanova, Marzhan; Díaz de Tuesta, Jose Luis; Malakar, Arindam; Gomes, Helder; Snow, Daniel D.Due to water scarcity and ready availability, treated wastewater in Central Asia is increasingly reused and seen as a valuable resource, requiring effective management with particular care for human health, environmental protection, and water security. Due to limited technical and economic support and poorly developed regulatory systems, many cities have inadequate wastewater treatment infrastructure. Improved ...
Pillared clay-based catalysts for treatment of 4-nitrophenol solutions by catal...
Kalmakhanova, Marzhan; Nurlybayeva, Aisha Nurlybaevna; Seitbekova, G.A.; Naurzkulova, Symbat Muratbekovna; Díaz de Tuesta, Jose Luis; Gomes, HelderThe constant development of technological processes aggravates the problem of pollution, due to a significant change in the composition of effluents, which makes necessary new (and/or improved) treatment methods and catalytic materials. In this sense, the use of natural clays in the synthesis of low cost pillared clays for application as catalysts in oxidation technologies for the treatment of wastewaters are r...
Performance and modeling of Ni(II) adsorption from low concentrated wastewater ...
Díaz de Tuesta, Jose Luis; Roman, Fernanda; Marques, Vitor da Costa; Silva, Adriano S.; Silva, Ana P. F.; Bosco, Tatiane; Shinibekova, Assem A.The 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 ...
MnFe2O4/ZHETISAY composite as a novel magnetic material for adsorption of Ni(II)
Baimuratova, Zhaina; Kalmakhanova, Marzhan; Shynazbekova, SH.S.; Kybyraeva, N.S.; Díaz de Tuesta, Jose Luis; Gomes, HelderThis paper deals with the preparation of magnetic adsorbents from natural clays for the adsorption of Ni(II) from aqueous matrices. The phase composition and structure parameters of natural clays and their modified forms, as well as their application as adsorbing agents for the purification of drinking water and their sources were studied. In the study, natural clays from the Zhetisay deposit of Kazakhstan were...
Methods of preparation and physico-chemical characteristics of organic modified...
Serikbayeva, Aizhan Mukhammedalievna; Kalmakhanova, Marzhan; Gomes, Helder; Shagraeva, Bibigul Bekenovna; Shertaeva, Nailya TurdygalievnaThe main sources of many environmental problems associated with the formation of wastewater are industrial enterprises that release water streams containing pollutants. Wastewater treatment is a complex task that requires a combination of different methods to achieve maximum efficiency. Increasing the efficiency of removing heavy metals, nutrients, anionic pollutants and organic compounds from liquid media is o...
Assisted hydrothermal carbonization of agroindustrial byproducts as effective s...
Díaz de Tuesta, Jose Luis; Saviotti, Marcus Chamahum; Roman, Fernanda; Pantuzza, Gabriel F.; Sartori, Hiram J.F.; Shinibekova, Assem A.This 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 pres...
Synthesis and characterization of a new magnetic composite MnFe2O4/clay based o...
Baimuratova, Zhaina; Kalmakhanova, Marzhan; Massalimova, Bakytgul Kabykenovna; Nurlibaeva, A.A.; Kulazhanova, A.S.; Díaz de Tuesta, Jose LuisThe 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, du...
Pillared clays from natural resources as catalysts for catalytic wet peroxide o...
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 ...