Composite materials modified with amines and copper ions, and their potential application in adsorption from liquid phase

Wydział ChemiiJedną z najskuteczniejszych metod oczyszczania ścieków jest adsorpcja. Wśród wielu sorbentów można wyróżnić materiały kompozytowe. Terminem kompozyty określa się materiały złożone z co najmniej dwóch komponentów o różnych właściwościach. Celem naukowym rozprawy doktorskiej była synteza i charakterystyka właściwości fizykochemicznych kompozytów polimerowych oraz węglowych jako efektywnych adsorbentów zanieczyszczeń z fazy ciekłej. W ramach pracy doktorskiej nanokompozyty polimerowe oraz kserożele węglowe zostały zsyntetyzowane w procesie polikondensacji rezorcyny i formaldehydu. Nanokompozyty polimerowe, będące produktem pośrednim w syntezie kserożeli węglowych, zostały modyfikowane metyloaminą oraz impregnowane chlorkiem miedzi(II). W przypadku kserożeli węglowych, przeprowadzono utlenianie roztworem nadsiarczanu amonu, funkcjonalizację grupami aminowymi oraz jonami miedzi(II). Modyfikacja jonami metalu odbywała się w oparciu o dwie metody, przy użyciu: chlorku miedzi(II) - na drodze impregnacji mokrej, a także octanu miedzi(II) - dodanego na etapie polikondensacji. Otrzymane materiały zostały szczegółowo scharakteryzowane za pomocą różnych technik badawczych i zastosowane w roli adsorbentów rodaminy B i żółcieni pomarańczowej FCF. Dodatkowo kserożele węglowe zostały poddane badaniom sorpcyjnym względem zieleni brylantowej, błękitu tymolowego i kofeiny z fazy ciekłej. W ramach realizowanej pracy doktorskiej wykazano, że przeprowadzone modyfikacje powierzchni materiałów kompozytowych powodują znaczny wzrost ich pojemności sorpcyjnych względem analizowanych zanieczyszczeń w odniesieniu do niemodyfikowanych próbek.One of the most effective methods for wastewater purification is adsorption on a range of materials, including composites. Composite materials are by definition composed of at least two materials of different functions. The aim of doctoral dissertation presented was the synthesis and characterization of physicochemical properties of polymer and carbon composites that could be used as effective adsorbents of a wide range of pollutants from the liquid phase. The polymer nanocomposites and carbon xerogels were synthesized in the process of polycondensation of resorcinol and formaldehyde. The polymer nanocomposites, which are the intermediate products in the synthesis of carbon xerogels, were modified with methylamine and then impregnated with copper(II) chloride. The carbon xerogels obtained were at first oxidized with ammonium persulfate and then functionalized with amine groups. Finally they were modified with copper ions by two methods, i.e. using copper(II) chloride by wet impregnation or using copper(II) acetate added by polycondensation. The structures and textural properties of the materials obtained were characterized by different methods. The composites obtained were tested as adsorbents of rhodamine B and sunset yellow FCF. The xerogels obtained were also tested as adsorbents as brilliant green, thymol blue and caffeine from liquid phase. The modifications of composite materials were proved to significantly enhance the sorption capacities of the materials studied towards the pollutants tested

Amine-Modified Carbon Xerogels as Effective Carbon-Based Adsorbents of Anionic Dye from Aqueous Solutions

Carbon xerogels were obtained by polycondensation of resorcinol and formaldehyde in a water medium. Their surface was oxidized by ammonium persulfate and then modified with amine groups. Four amines were used: methylamine, ethylamine, propylamine, and ethylenediamine, differing in carbon chain length and number of amine groups. The materials were characterized by low-temperature nitrogen sorption, elemental analysis, thermal analysis, X-ray diffraction, infrared spectroscopy, and determination of the surface oxygen group content with the use of the Boehm method. The final carbon adsorbents had surface areas ranging from 172–663 m2/g and acid–base nature. They were applied for adsorption of thymol blue from water solution. The sorption capacities of the studied adsorbents ranged from 83 to 140 mg/g. The presence of amine groups on the xerogel surface was found to increase its sorption capacity towards the dye studied. The dye adsorption process is endothermic and spontaneous, as indicated by the positive values of ΔH and the negative values of ΔG, respectively. The kinetics of adsorption of thymol blue was established to be described by the pseudo-second-order model. The equilibrium data were analyzed by the Langmuir and Freundlich models. The character of thymol blue adsorption is much better described by the Langmuir isotherm

Photodegradation of antihistamine chlorpheniramine using a novel iron-incorporated carbon material and solar radiation

Water impact The presence of antihistamines in the aquatic environment is an issue that must be addressed with particular relevance. Like many other contaminants, these drugs can affect living beings and directly impact their health. The implementation of advanced oxidation processes for their removal is being evaluated, considering its favorable results with different compounds.Water pollution due to emerging contaminants is a topic that should be researched to a greater extent because of the ignorance of adverse effects these pollutants may have on living beings. For this reason, the implementation of tertiary treatments is important for the removal of these contaminants from aqueous effluents including the heterogeneous photo-Fenton like (HPFL) process. In this investigation, an organic carbon xerogel incorporated with Fe3+ (XFe) has been used as a photocatalyst for the degradation of the antihistamine chlorpheniramine in an aqueous media with pH 3 at room temperature. The characterization of the material revealed the presence of Fe(III) and oxygenated groups on the surface as well as its ability to be activated with visible radiation, thereby, making it a viable material for the oxidation of contaminants present in the aqueous phase. The kinetic study has revealed that the degradation kinetic constants were 4.20 × 10−1 min−1 and 1.57 × 10−3 min−1 for HPFL and photolysis processes, respectively, revealing that the oxidation process is favored in the presence of the carbonaceous material. The by-products derived from various post-degradation processes presented low toxicity when verified by cytotoxicity tests. Moreover, the catalyst activation mechanism demonstrated that the process occurs through the formation of the ˙HO radical. In conclusion, the HPFL process was the most feasible for the degradation of chlorpheniramine in aqueous media, as it had greater interaction with the ˙HO radical in the rupture of the contaminant.University of Granada through the Project of the Ministry of Science and Innovation CTQ2016-80978-C2-1-RConsejo Nacional de Ciencia y Tecnologia (CONACyT) 88589