MARIA VICTORIA LORUSSO DE MACEDO

MARIA VICTORIA LORUSSO DE MACEDO

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Using microstructured yeast as biotemplate for TiO2 deposition applied on amoxicillin solar photodecomposition
2019 - ORTIZ, N.; MAICHIN, F.; MACEDO, M.V.
The indication of amoxicillin (AMOX) is the most frequent by the public health assistance in Brazil. After the body metabolization, the antibiotic is discharged by excretes in the sewage system; also acting as secondary pollution sources for surface water resources. The microstructured yeast culture (biotemplate) enhances the TiO2 surface area before the amoxicillin solar photodecomposition. The maximum removal percentage was 56% of AMOX with pseudo-second-order kinetics. The use of the low-frequency ultrasonic source in the TiO2 slurry dispersion after the yeast culture enhanced the TiO2 surface area and its effectiveness during the antibiotics solar photodecomposition.
Water removal of oxytetracycline using titanium dioxide/solar photodecomposition and biocarbon adsorption
2018 - GONÇALVES, G.M.; LIMA, G.N.S.; MACEDO, M.V.; ORTIZ, N.
Oxytetracycline (OTC) is a broad-spectrum antibiotic with efficacy against infections, high solubility in water and used both in veterinary and human medicine, primarily in poultry and livestock, but also for human consumption. Nowadays Brazil is the higher protein producer in the world, and the agribusiness is the strongest economy sector in the country. The OTC use is increasing in veterinary medicine and also its detection in surface water resources and sewage treatment effluents. The conventional water treatment processes have to improve to enhance the pharmaceuticals removal efficiency. The occurrence of OTC in the natural environment can affect the selection of genetic variants of resistant microorganisms, inducing a risk to the ecosystem and human health. The experiments started with the dilution of standard oxytetracycline solution. They solutions were preheating before the addition of TiO2 and kept in a solar radiation chamber during 120 minutes. The addition of micronized biocarbon (diameter < 500 mesh) in all collected suspension aliquots followed by shaking, and centrifugation at 1500 rpm for 15 minutes allows the supernatants OCT measurements at UV – Visible Spectrophotometer Cary 13 at λ = 268 nm and 373 nm. The absorbance values were converted to antibiotics concentration using an analytical curve prepared with standard antibiotics solutions. After the processes optimization, the OCT removal percentage reached 95%with pseudo-second-order kinetics and better isotherm agreement with Langmuir R2= 0.689 and Redlich-Peterson with R2 = 0.738.
Integrated water treatment process with Solar/TiO2 photodecomposition and biocarbon adsorption for enrofloxacin removal from contaminated waters
2018 - ORTIZ, N.; LIMA, G.N.S.; MACEDO, M.V.L.; HYPPOLITO, F.
Brazil is well known as the worldwide production of animal protein and there for the highest consumer of the antibiotic enrofloxacin, the most common the second generation antibiotics used in veterinary medicine. The wastewater treatment with TiO2/solar photodecomposition natural, low-cost energy integrated with the renewable biocarbon absorbent. Such integrated process rises a possible tool to control and reduce the enrofloxacin environmental impact on soil and surface water quality loss. The process starts with the TiO2 addition on different initial enrofloxacin concentrations, after the suspension 120 min of the stirring time inside the solar chamber the collected suspension aliquots (20 minutes each) and the addition to micronized biocarbon present in the falcon tubes. The falcon tubes are further centrifugated and the supernatant measured using spectrophotometric analysis. The maximum removal percentage was 74.63 % with higher correspondence with the kinetics of pseudo-second-order and Langmuir isotherm with RL in the range of 0 to 1and the surface coverage percentage of 92 % in the higher concentrated system.
Study of antibiotics binary system treated by TiO2/solar photodecomposition and biocarbon adsorption
2018 - LIMA, G.N.S.; MACEDO, M.V.; HYPPOLITO, F.P.; SILVA, A.; ORTIZ, N.
The study presents the antibiotics TiO2/solar photodecomposition followed by adsorption using micronized biocarbon. The cephalexin and amoxicillin antibiotics are very popular in Brazil and possibly the mostly found in medical prescriptions. The adsorption process using biocarbon reduce the presence of photodecomposition byproducts. The experimental project was planned to optimize the efficiency of the integrated processes (photodecomposition and adsorption) to remove the antibiotics mixture from the polluted water. The first study was only one antibiotic at the time, the amoxicillin followed by cephalexin after that was studied the binary system. The maximum single amoxicillin removal percentage was 94.74 %, the single cephalexin was 69.45%, and for the binary system the higher removal percentage after solar/TiO2 photodecomposition and biocarbon adsorption was 59.95% correspondent with 8.84% of cephalexin and 91.16% of amoxicillin. The cephalexin addition to the binary system reduces the total removal percentage. The integrated processes indicate better correspondence with the pseudo-second-order kinetics K2, and Langmuir, Freundlich, and Radlich-Peterson isotherms to amoxicillin and cephalexin experiments and the binary system.
Biocarbon adsorption and TiO2/solar photodecomposition of binary and tertiary antibiotics systems
2018 - LIMA, G.N.S.; MORAIS, G.; MACEDO, M.V.; AYOUB, J.M.S.; ORTIZ, N.
The occurrence of pharmaceutical residues in a polluted environment includes the exposition to a contaminant mixture including antibiotics rather than individual toxic compounds. Some published results confirm the detection of a variety of antibiotics in soil and water environment as binary and tertiary systems which highlight the importance of antibiotics removal study of from a binary and tertiary mixture. Experimentaly the antibiotic mixture was preheating before adding TiO2 and kept in a solar radiation chamber with constant temperature and pH values. The collection of the suspension aliquots allows the photodecomposition control followed by the addition of micronized biocarbon (diameter < 500 mesh) agitation and centrifugation. The supernatants measurements used spectrophotometer UV-Vis at λ = 273nm, 261nm, and 373nm to amoxicillin, cephalexin, and oxytetracycline, respectively. All results indicate the TiO2/solar photodecomposition followed by biocarbon adsorption have better agreement with pseudo-second-order kinetics. The comparison between the antibiotics photodecomposition removal percentages of the binary mixtures indicates higher decomposition for amoxicillin (57,38%), followed by cephalexin (48,04%) and considering the tertiary antibiotic systems the oxytetracycline (14,63 %). Such removal difference is a result of the antibiotics chemical structure and bounding energy broken by the hydroxy radicals of the solar/TiO2 photodecomposition reaction. For amoxicillin, the results refer to break the weak thiophene sulfur bond, for the cephalexin and oxytetracycline they have to break the strong hydrogen bonding of amide (amino carbonyls group) and the benzamide bond.The use of the biocarbon adsorption in the water treatment is final stage ensure the water quality polishing results.