Bee pollen has been promoted as a dietary supplement for humans due to its nutritional and bioactive properties. Sixty-two samples of Apis mellifera dehydrated bee pollen collected in Brazil (eight ...states and Federal District) were analyzed for phenolic compounds, flavonoids, antioxidant activity using DPPH, β-carotene and ORAC methods, and antimicrobial activity. The values obtained for total phenolic compounds ranged from 12.60 to 84.22 mg GAE/g bee pollen while total flavonoids oscillated between 1.90 and 36.85 mg quercetin/g bee pollen. The IC
50
ranged from 0.35 to 13.42 mg bee pollen/mL of extract. The inhibition percentages ranged from 52.58 to 98.37% of bee pollen extract using the β-carotene method. When measured by the ORAC method, antioxidant activity was between 132.98 and 575.85 μmols eq. Trolox/g bee pollen. Bee pollen efficiently inhibited the growth of all the microorganisms studied. Candida albicans was the most resistant, while Staphylococcus epidermides was the most sensitive.
Amoxicillin is a penicillin belonging to the group of beta-lactams commonly used in humans and veterinary medicine. From an environmental point of view, its indiscriminate use and improper waste ...disposal leads to water contamination with carcinogenic consequences and the development of antimicrobial resistance genes. Although there are wide-ranging studies on amoxicillin degradation by oxidation processes, there are no articles dealing with the amoxicillin degradation (AMX) present in expired drugs by the H
2
O
2
-alone process. We present an original study of AMX degradation and mineralization by H
2
O
2
-alone processes in basic and strongly basic media. The study was carried out in a batch mode with 1.50 g of expired commercial pharmaceutical formulation dissolved in 3.00 L of pure water (Type II). The initial concentration of H
2
O
2
was 0.26, 1.31, and 2.62 g L
–1
. The pH-values studied were 9.00, 11.00, and 13.00. By altering these parameters, we obtained a simple, easy to operate, and efficient process. A > 90% degradation was produced within only two minutes of reaction duration. In a pH 9 to 11, we obtained pseudo-first-order constants from 0.230 to 1.395 min
–1
and mineralization of 70% (total organic carbon) and 45% (total nitrogen). A process at pH 13 produced no mineralization due to excessive
ROS
scavenger competition for AMX degradation pathways. Adequate concentrations of H
2
O
2
and
H
O
-
are required to optimize the AMX degradation process.
This work presents an empirical and scaling-up study of the degradation and mineralization of amoxicillin (AMX) from expired pharmaceutical formulations by O3-based processes. A set of UV–ozone-based ...experiments was used to model the kinetics of AMX degradation, considering several chemical/photochemical mechanisms (hydrolysis, direct ozonation, radical reactions, and photolysis). Finally, the modeling data were used for scaling-up purposes, considering CAPEX and OPEX costs on the US Gulf Coast basis. In terms of experimental results, the amoxicillin (AMX) pharmaceutical effluent was successfully degraded by ozone technology at high pH values. The semi-batch ozonation process was effective after 60 min of treatment in all experimental conditions, producing degradation intermediates recalcitrant to O3 oxidative process. From the bench-scale kinetics, scaling-up simulations indicate that the gain provided by adding a UV unit does not compensate for the increase in capital and operational costs of adding irradiation equipment. It suggests ozonation at high pH as the best cost-effective approach to degrade AMX. The figures-of-merit electric energy consumption per order (EEO) corroborates the scaling-up simulations. EEO results indicate no-UV ozonation as the best option to degrade AMX at high pH values. The EEO of the present work showed a lower energy consumption system than previous papers from the literature.
•Photodegradation of amicarbazone herbicide using ultraviolet radiation.•Proposal of transformation products by tandem mass spectrometry (hybrid IT-TOF analyzer).•Transformation products generated ...from AMZ photolysis are described for the first time.•In situ generation of oxidative species (e.g. singlet oxygen and hydroxyl radicals) in the photo process of amicarbazone degradation.•Lower AMZ half-life of 120min was achieved under the following conditions: pH=3; AMZ0=50mgL−1; 75W LP-Hg lamp.
Amicarbazone is a triazolinone herbicide developed to replace atrazine in the world market. Several technologies have been studied aiming at removing pesticides from wastewater, seeking to study the degradation mechanisms involved and the degree of toxicity of the transformation products formed. In this context, our main goal was to study the degradation of amicarbazone in aqueous solution by direct photolysis, suggesting possible chemical structures for the transformation products according to a theoretical and fundamental approach. The effects of herbicide initial concentration, pH, dissolved oxygen and nitrate concentrations, the role of singlet oxygen, and the presence of propan-2-ol as a free radical scavenger in amicarbazone photodegradation are discussed for the first time. Among these variables, pH showed influence on the photochemical degradation pathway. For instance, the transformation product amicarbazole was obtained under mildly acidic conditions, while 4-amino-5-oxo-3-(propan-2-yl)-4,5-dihydro-1H-1,2,4-triazole-1-carboxamide intermediate was found in both acidic and basic conditions. A primary degradation product formed as a result of deamination in acidic medium was found out. Concerning the effect of the variables involved in the process, the lowest AMZ half-life of 120min was achieved under the following conditions: pH=3; AMZ0=50mgL−1; 75W LP-Hg lamp.
Sixty-two commercial samples of dehydrated bee pollen (Apis mellifera bees) collected in Brazil (eight states and the Federal District) were analyzed for commercial quality (moisture, ash, lipids, ...proteins, and carbohydrates), and hygiene (aerobic mesophiles, yeasts and molds, coliforms, Escherichia coli, Staphylococcus aureus and sulfite-reducing Clostridium). The analyzed samples were within the regulatory limits established by the legislation for ash, lipid and protein, except for moisture content. The analyzed hygiene parameters evaluated for bee pollen are not regulated by the Brazilian legislation, and the data discussed can contribute to regulatory agencies. Only moderate and weak correlations were observed between dehydrated pollen samples and the parameters evaluated.
This research evaluated the physicochemical parameters of a leachate sample from a controlled landfill in the city of Guaratinguetá-SP. The evaluation was conducted using spectrometric and ...spectrophotometric methods in order to assess the formation of persistent compounds. The selection of parameters was based on the CETESB Article 18 and CONAMA 357/05 Article 34, as well as organic characterization methods, such as FTIR, NMR (1H-NMR, 13C-NMR and APT), GC-MS, molar mass distribution and elemental analysis (CHN). Chemical and physical stability were also verified. The ammoniacal nitrogen concentration is 20 times greater than tolerance limit established by law (20 mg L-1). The Ba and Ni presented concentrations above those permitted by the legislation (CETESB Article 18 and CONAMA 357/05 Article 34). Those values of chemical oxygen demand (COD) and total organic carbon (TOC) were 1013 mg L-1 and 286 mg L-1, respectively. It was not possible to determine the biochemical oxygen demand (BOD) of slurry sample. In this sense, the biodegradability parameter for the slurry studied was Non-Determinable (ND), indicating that the organic matter of the slurry studied is recalcitrant. Recalcitrant humic substances of landfill leachate the present low polydispersity. These refractory acids play a detached role in carrying pollutants in the environment with regard to carrying toxic metals and pesticides. Finally, it was possible to verify that the humic acids’ complexing capacity indicates that hydroxyl and carboxyl groups may exist in larger quantities than the nitrogen and sulfur groups. Further, the high content of metals may indicate that the waste was not properly separated.
Vinasse is the main residue generated during alcohol, sugar and blue rum production by fermentation process. This residue is effluent that could cause serious environmental pollution due to high ...organic load when is not treated adequately. The aim of this work consists of evaluating the efficiency and application of heterogeneous photocatalysis with TiO2, followed by a biological treatment (activated sludge system) to reduce organic load in the referred effluent. Complete factorial designs indicated the best experimental conditions subsequent to photacatalytic and biological treatments providing a reduction of non-purgeable organic carbon (NPOC) as a variable response. After the photocatalytic process, the sample from the best experiment condition was treated by a biological process in order to verify the degradation efficiency of the effluent organic matter studied according to the hybrid system (Advanced Oxidation Process-Acti- vated Sludge System). This system, which presented more efficiency, had a photochemical treatment of 180 minutes carried out in aerated solutions, pH 9 and effluent in natura, while the biological treatment was performed at pH 8 and sludge concentration of 5 gL-1. The reduction of biochemical oxygen demand (BOD) was >80%.
COD is an important parameter to estimate the concentration of organic contaminants. The closed system technique with the use of K2Cr2O7 is the most important one, however, it has the inconvenience ...to suffer positive chemical interferences from inorganic compounds such as Fe2+ and H2O2 (not enough reported in the literature). This paper considers a statistical-experimental set capable to validate a empirical mathematical model generated from a 23 experimental design, in the presence of Fe2+ and H2O2. The t test shows that mathematical model has 99,99999% confidence degree and the experimental validation test indicates absolute mean error of 4,70%.
A amicarbazona constitui-se em um herbicida do grupo das triazolinonas, desenvolvida para substituir a atrazina no mercado mundial. Diversas tecnologias têm sido estudadas objetivando a remoção de ...pesticidas de efluentes aquosos, procurando estudar os mecanismos de degradação envolvidos e o grau de toxicidade dos fotoprodutos gerados. Neste sentido, este trabalho tem como objetivo principal o estudo de degradação do princípio ativo amicarbazona, em solução aquosa, por fotólise direta, propondo estruturas químicas de produtos de transformação em um estudo teórico-fundamental. Foram avaliados parâmetros como concentração de herbicida, pH do meio reacional, concentração de oxigênio dissolvido, concentração de nitrato e de isopropanol como supressor de radicais livres. Dentre os parâmetros avaliados no processo de fotólise, o valor do pH do meio reacional influencia consideravelmente o mecanismo de fotodegradação do herbicida amicarbazona, favorecendo ou desfavorecendo a formação de determinado intermediário. Verificou-se que a molécula de amicarbazona gera como produto de degradação primário a molécula de amicarbazole, principalmente em meio ácido, como resultado de mecanismo de deaminação. Por sua vez, a utilização de processo UV/H2O2 foi capaz de proporcionar degradação completa da amicarbazona em tempo reacional máximo de 60 minutos. Contudo, mesmo com a utilização de agente oxidante auxiliar, não houve mineralização completa da amicarbazona, havendo 58% de redução de carbono orgânico dissolvido na melhor condição experimental estudada.
Amicarbazone is a triazolinone herbicide developed to substitute atrazine in the world market. Several technologies have been studied aiming at the removal of pesticides from wastewater, seeking to study the degradation mechanisms involved and the degree of toxicity of the photoproducts formed. In this context, the main goal of this work is to study the degradation of amicarbazone in aqueous solution by direct photolysis, suggesting possible chemical structures for the transformation products according to a theoretical and fundamental approach. Parameters such as herbicide concentration, pH, dissolved oxygen concentration, nitrate concentration, and propan-2-ol as a free radical scavenger were considered. Among the parameters studied in the photolysis process, the pH showed influence on the photochemical mechanism of amicarbazone degradation, favoring or not the formation of particular intermediates. It was found that the photolysis generates amicarbazole as the primary degradation product in acidic medium as a result of the deamination mechanism. The use of UV/H2O2 process enabled the complete degradation of amicarbazone in a reaction time of 60 minutes at most. However, even with the use of the auxiliary oxidant reactant, the complete mineralization of amicarbazone was not achieved, with 58% reduction of dissolved organic carbon in the best experimental condition studied.
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