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- Application of catalysts developed from compost derived from municipal solid waste in the removal of caffeine by wet peroxide oxidationPublication . Almeida, Flávio V.M.; Oliveira, Jéssica; Díaz de Tuesta, Jose Luis; Praça, Paulo; Guerreiro, Mário C.; Barreiro, M.F.; Silva, Adrián; Faria, Joaquim; Gomes, Helder; Oliveira, JessícaNowadays, waste management through mechanical biological treatment (MBT) consists on the use of the separated organic fraction of municipal solid waste (MSW) to feed anaerobic digestion processes, resulting therein a solid stream, further processed to compost, which can be used as fertilizer. Currently, the production of compost from MBT is higher than the existing demand, and the expected developments on up-coming directives ruling “End-of-waste” criteria are leading to barriers on the use of waste-derived fertilizers (European Commision, 2013). In this context, the current work proposes an alternative strategy to the valorisation of compost, through the production of low-cost materials to be applied in the catalytic wet peroxide oxidation (CWPO) of synthetic wastewater effluents contaminated with caffeine, used as a model pollutant of emerging concern. Caffeine is the most consumed psychoactive drug worldwide. It is one of the components of painkillers, medication against migraine, fatigue, drowsiness and breathing problems. Its consumption is also associated with an overall lower risk of malignant growth like hepatocellular, endometrial or colorectal cancer (Ganzenko et al., 2015). However, the effect of caffeine and its environmental degradation products on aquatic living species is not properly known. Caffeine, is a world wide consumed psychoactive drug, in a way that becomes a persistent compound and cannot be efficiently removed by municipal wastewater treatment facilities (Ganzenko et al., 2015). As a consequence, caffeine and its metabolites are present in the effluents of wastewater treatment plants (Gracia-Lor et al., 2017).
- Simultaneous removal of o-and p-nitrophenol from contaminated water by wet peroxide oxidation using carbon-coated magnetic ferrite as catalystPublication . Dias, Arnaldo; Silva, Adriano S.; Silva, Ana P. F.; Roman, Fernanda; Díaz de Tuesta, Jose Luis; Oliveira, Jéssica; Ferrari, Ana M.; Lenzi, Giane G.; Gomes, Helder; Oliveira, JessícaGroundwater is the most common source of drinking water worldwide and is currently facing contamination problems with the discharge of pollutants into aquatic systems through different means, namely through municipal, industrial and agricultural activities. Contaminants, such as herbicides, pharmaceuticals, phenolic compounds and personal care products are not removed by conventional treatments from wastewater treatment plants, leading to their accumulation in the environment. In this regard, o-nitrophenol (o-NP) and p-nitrophenol (p-NP), commonly used as raw materials in chemical and pharmaceutical engineering, represent a severe risk to humans and aquatic life, leading to the necessity to properly treat wastewaters containing these contaminants before discharge into the aquatic environment. Catalytic wet peroxide oxidation (CWPO) showed promising results for removing nitrophenols from wastewater in previous works. In this technology, H2O2 is used as an oxidant, and its interaction with a suitable catalyst leads to the formation of hydroxyl radicals under determined conditions already established in literature (pH and temperature have a strong influence) [1]. Typical catalysts employed have a transition metal in its structure. Carbon-based catalysts also have activity in this technology, mostly ascribed to the electronic properties of the carbonaceous surface. Furthermore, carbon-coated metal oxide materials (hybrid) have also demonstrated potential applications in CWPO. Those structures combine carbon and metal activities with the advantage of protecting the metal core from leaching, increasing the efficiency and stability of the catalysts.
- Green magnetic nanoparticles CoFe2O4@Nb5O2 applied in Paracetamol removalPublication . Oliveira, Jéssica; Ribas, Laura S.; Napoli, José Salvador; Abreu, Eduardo; Díaz de Tuesta, Jose Luis; Gomes, Helder; Tusset, Angelo M.; Lenzi, Giane G.; Oliveira, JessícaThis study describes the synthesis of an innovative nanomaterial (patent application number BR 1020210000317) composed of cobalt ferrite functionalized in niobium pentoxide CoFe2O4@Nb5O2 (CFNb), synthesized via green synthesis using tangerine peel extract. The material emphasizes the combination of a magnetic material (which allows for easy recovery after application) with niobium pentoxide (a metal which is abundant in Brazil). CFNb was applied as a catalyst for the paracetamol (PCT) degradation by photocatalysis. The new materials were characterized through surface and pore analysis (S-BET, S-EXT, S-mic, V-mic, and V-TOTAL), photoacoustic spectroscopy (PAS), zero charge point (pHPZC, scanning electron microscopy (SEM/EDS), and X-ray diffraction (XRD). The reaction parameters studied included pH and catalyst concentration. The results indicated that the CFNb nanocatalysts were efficient in the paracetamol degradation, presenting better results in conditions of low pH (close to 2) and low catalyst concentration under irradiation of the 250Wmercury vapor lamp (greater than 28 mW center dot cm(-2)) at 60 min of reaction.
- Development and functionalization of magnetic nanocomposites for cancer treatmentPublication . Oliveira, Jéssica; Oliveira, Jessíca; Gomes, Helder; Marchesi, Luís FernandoGreen routes, considering the use of plant extracts with high reducing power, have been investigated as alternative methods to obtain superparamagnetic cores for biomedical applications. Usually, these magnetic cores are further coated either with metal or non-metal materials. In particular, carbon-coated nanoparticles have several advantages in comparison to other coatings, since they usually offer higher chemical and thermal stability, larger surface area, biocompatibility and easier functionalization. In this research, different plant hydromethanolic extracts with high reducing power (i.e., Tamus communis L. shoots, Crateagus monogyna Jacq. flowers and Rubus ulmifolius Schott flowers) were investigated in the synthesis of magnetic cores for carbon-coated yolk-shell magnetic nanoparticles (CYSMNPs). Overall, the extract of Rubus ulmifolius has shown great ability to produce highly magnetic cores with more stability in distilled water. The nanocomposites were chemically functionalized with nitric acid to enhance the colloidal stability of the product synthesized. To set the best conditions for drug loading, different working solutions (i.e., phosphate buffer solutions (PBS) pH 6.0, pH 7.4 and pH 8.0) were investigated. It is known that there are differences between the pH of the normal tissues (pH 7.4), the extracellular environment of the tumor (pH 6.5) and the endosome and lysosome (pH lower than 5.0). Then, according to the best loading, the drug release was also studied in different working solutions (i.e., PBS pH 4.5, PBS pH 6.0 and PBS pH 7.4), to determine the efficiency of the synthesized material for drug delivery in cells targeted to cancer treatment. The results showed a drug release quantity 20% higher in acid environment than in neutral environment. However, this research demonstrates the outstanding ability to use the developed and optimized green CYSMNPs, as super-drug nanocarriers with great ability to load high content of the anticancer drug Doxorubicin.
- Carbon-based magnetic nanocarrier for controlled drug release: a green synthesis approachPublication . Oliveira, Jéssica; Rodrigues, Raquel Oliveira; Barros, Lillian; Ferreira, Isabel C.F.R.; Marchesi, Luís; Koneracka, Martina; Jurikova, Alena; Zavisova, Vlasta; Gomes, Helder; Oliveira, JessícaIn this study, hydrophilic magnetic nanoparticles were synthesized by green routes using a methanolic extract of Rubus ulmifolius Schott flowers. The prepared magnetic nanoparticles were coated with carbon-based shell for drug delivery application. The nanocomposites were further chemically functionalized with nitric acid and, sequentially, with Pluronic® F68 (CMNPs-plur) to enhance their colloidal stability. The resulting material was dispersed in phosphate buffer solution at pH 7.4 to study the Doxorubicin loading. After shaking for 48 h, 99.13% of the drug was loaded by the nanocomposites. Subsequently, the drug release was studied in different working phosphate buffer solutions (i.e., PB pH 4.5, pH 6.0 and pH 7.4) to determine the efficiency of the synthesized material for drug delivery as pH-dependent drug nanocarrier. The results have shown a drug release quantity 18% higher in mimicking tumor environment than in the physiological one. Therefore, this study demonstrates the ability of CMNPs-plur to release a drug with pH dependence, which could be used in the future for the treatment of cancer "in situ" by means of controlled drug release.
- Kinetic insights on wet peroxide oxidation of caffeine using EDTA-functionalized low-cost catalysts prepared from compost generated in municipal solid waste treatment facilitiesPublication . Díaz de Tuesta, Jose Luis; Almeida, Flávio V.M.; Oliveira, Jéssica; Praça, Paulo; Guerreiro, Mário C.; Gomes, Helder; Oliveira, JessícaNowadays, sorted organic fraction of municipal solid waste is typically treated by anaerobic digestion processes, resulting therein a solid stream, further processed to obtain compost, whose production is higher than the existing demand as fertilizer. The current work proposes an alternative strategy for the recovering of compost through the production of low-cost catalysts by calcination (1073 K) and sulfuric acid treatments, followed by sequential functionalization with tetraethyl orthosilicate (TEOS) and ethylenediamine tetraacetic acid (EDTA). Activity and stability of the catalysts are assessed in the wet peroxide oxidation of synthetic wastewater effluents contaminated with caffeine, a model micro-pollutant, achieving its complete removal after 6 h at 353– 383 K and catalyst loads of 0.5–2.5 g L−1. The increase of the catalytic activity of the materials upon functionalization with TEOS and EDTA is demonstrated and a kinetic modeling of caffeine degradation and hydrogen peroxide consumption with the best catalyst is assessed by pseudo-first power-law rate equations.