Considerando a crescente contaminação da água e os vários problemas ao meio ambiente e a saúde humana decorrentes dessa contaminação, os produtos farmacêuticos e de higiene pessoal, como antibióticos e outros, constituem uma grande preocupação, pois não são completamente removidos nos sistemas de tratamento de esgoto, além de serem resistentes à biodegradação. Antibióticos como a tetraciclina (TeC), por exemplo, são excretados em grande parte eliminados pela urina e/ou fezes, sendo cada vez mais detectados em uma grande variedade de matrizes ambientais, causando inúmeros efeitos tais como, alergias e aumento da resistência de bactérias. Assim, esse estudo visou a degradação da TeC em meio de urina artificial por método eletroquímico utilizando um ânodo dimensionalmente estável (ADE), o qual foi selecionado pela alta concentração de cloreto no meio. Foram realizados estudos de densidade de corrente e pH inicial, avaliando a concentração remanescente de TeC, creatinina, uréia e COT e, comparando os resultados com os obtidos em meio aquoso contendo NaCl 0,1 mol L-1. A TeC sofreu degradação eletroquímica devido à eletrogeração de espécies oxidantes de cloro ativo a partir do cloreto presente no meio. O decaimento da concentração da TeC ajustou-se ao modelo de cinética de pseudo-primeira ordem e aumentou como o aumento da densidade de corrente aplicada. O tratamento eletroquímico pode ser realizado em valores de pH próximos ao neutro, em que a TeC na forma aniônica e a espécie HOCl, favorecem a degradação, mesmo na presença de EDTA. A creatinina e a uréia interferem no processo eletroquímico, fazendo com que a degradação da TeC apresente velocidades de reação mais baixas e o consumo energético do processo seja mais elevado do que em meio aquoso contendo NaCl. / Considering the increase contamination of water and various environmental and human health problems resulting from this contamination, the pharmaceuticals and personal care products, such as antibiotics, etc., constitute a major concern because they are not removed completely from the sewage treatment systems, and they are resistant to biodegradation. Antibiotics such as tetracycline (TeC), for example, are largely excreted in the urine and/or feces increasingly being detected in a wide variety of environmental matrices and causing numerous effects such as allergies and increasing resistance to bacteria. Thus, this study aimed in degradation TeC amid in artificial urine medium by electrochemical method using a dimensionally stable anode (DSA), which has been selected from a highly concentrated chloride in the medium. The studies were resulted from current density and initial pH by assessing the remaining concentration of TeC, creatinine, urea and TOC and comparing the results with those obtained in an aqueous medium containing NaCl 0,1 mol L-1. It was observed that, TeC undergoes electrochemical degradation due to the electrogeneration of oxidizing species of active chlorine from the chloride present in the medium. The decaing of TeC concentration was adjusted to a pseudo-first order kinetic model and increased as current density was increased. It was also observed that the electrochemical treatment may be performed on pH close to the neutral, wherein the anionic form TEC species and HOCl favor degradation, even in the presence of EDTA. The presence of creatinine and urea interfere in the electrochemical process, causing the degradation of TeC to present lowers reaction rates and highers energy consumption in the process than in aqueous medium containing NaCl.

Considerando a crescente contaminação da água e os vários problemas ao meio ambiente e a saúde humana decorrentes dessa contaminação, os produtos farmacêuticos e de higiene pessoal, como antibióticos e outros, constituem uma grande preocupação, pois não são completamente removidos nos sistemas de tratamento de esgoto, além de serem resistentes à biodegradação. Antibióticos como a tetraciclina (TeC), por exemplo, são excretados em grande parte eliminados pela urina e/ou fezes, sendo cada vez mais detectados em uma grande variedade de matrizes ambientais, causando inúmeros efeitos tais como, alergias e aumento da resistência de bactérias. Assim, esse estudo visou a degradação da TeC em meio de urina artificial por método eletroquímico utilizando um ânodo dimensionalmente estável (ADE), o qual foi selecionado pela alta concentração de cloreto no meio. Foram realizados estudos de densidade de corrente e pH inicial, avaliando a concentração remanescente de TeC, creatinina, uréia e COT e, comparando os resultados com os obtidos em meio aquoso contendo NaCl 0,1 mol L-1. A TeC sofreu degradação eletroquímica devido à eletrogeração de espécies oxidantes de cloro ativo a partir do cloreto presente no meio. O decaimento da concentração da TeC ajustou-se ao modelo de cinética de pseudo-primeira ordem e aumentou como o aumento da densidade de corrente aplicada. O tratamento eletroquímico pode ser realizado em valores de pH próximos ao neutro, em que a TeC na forma aniônica e a espécie HOCl, favorecem a degradação, mesmo na presença de EDTA. A creatinina e a uréia interferem no processo eletroquímico, fazendo com que a degradação da TeC apresente velocidades de reação mais baixas e o consumo energético do processo seja mais elevado do que em meio aquoso contendo NaCl. / Considering the increase contamination of water and various environmental and human health problems resulting from this contamination, the pharmaceuticals and personal care products, such as antibiotics, etc., constitute a major concern because they are not removed completely from the sewage treatment systems, and they are resistant to biodegradation. Antibiotics such as tetracycline (TeC), for example, are largely excreted in the urine and/or feces increasingly being detected in a wide variety of environmental matrices and causing numerous effects such as allergies and increasing resistance to bacteria. Thus, this study aimed in degradation TeC amid in artificial urine medium by electrochemical method using a dimensionally stable anode (DSA), which has been selected from a highly concentrated chloride in the medium. The studies were resulted from current density and initial pH by assessing the remaining concentration of TeC, creatinine, urea and TOC and comparing the results with those obtained in an aqueous medium containing NaCl 0,1 mol L-1. It was observed that, TeC undergoes electrochemical degradation due to the electrogeneration of oxidizing species of active chlorine from the chloride present in the medium. The decaing of TeC concentration was adjusted to a pseudo-first order kinetic model and increased as current density was increased. It was also observed that the electrochemical treatment may be performed on pH close to the neutral, wherein the anionic form TEC species and HOCl favor degradation, even in the presence of EDTA. The presence of creatinine and urea interfere in the electrochemical process, causing the degradation of TeC to present lowers reaction rates and highers energy consumption in the process than in aqueous medium containing NaCl.

The human skin is the largest and most complex body organ but accessible and attractive for biomarker sampling and transdermal drug delivery. The two procedures are significantly impacted by several biophysical properties of the skin, especially the pH and stratum corneum (SC)hydration. The varying levels of pH on the skin surface usually impact the permeability barrier function of the SC, contributing to the onset of dermatological disorders such as incontinence-associated dermatitis (IAD). Consequently, this scholarly work provides a comprehensive in vitro investigation of the effect of pH on the skin including the effect of artificial urine. The pig skin membranes were used to conduct electrical impedance spectroscopy (EIS)experiments using a four-electrode Franz cell set-up. Artificial urine and buffered solution with varying pH gradients were utilized to induce reversible changes in effective membrane capacitance (Ceff) and membrane resistance (Rmem). The in vitro investigation revealed that exposure to urine changed the electrical impedance properties of the skin. Specifically, we found that the application of artificial urine to the skin reduced skin resistance. At the same time, we also find systematic changes in skin capacitance. Skin capacitance increased with increased pH. Hence the two skin impedance parameters showed a clear effect of artificial urine on the skin. These changes, i.e., the decrease of Rmem and increase of Ceff of skin membranes when they are exposed to artificial urine, can be interpreted as skin barrier deterioration The information provided herein is relevant in describing the detrimental effect of urine on the skin, which probably makes skin barrier more permeable.

No description available.

The fate and behaviour of estrogens in the environment are of concern due to the compounds’ endocrine disruption potential. Estrogens, namely 17β-estradiol (E2), estrone (E1), and estrogen sulphates, i.e. 17β-estradiol-3-sulphate (E2-3S) and estrone-3-sulphate (E1-3S) excreted by livestock constitute a potential source for estrogen contamination in the environment. A method was developed to separate and quantify the hormones by high-performance-liquid-chromatography (HPLC) and ultraviolet detection (UV). A combination of dichloromethane (DCM) and dicyclohexylamine hydrochloride (DCH·HCl) gave recoveries from 97.3 to 107% for E1-3S extraction from aqueous solutions. The recoveries from soil samples ranged from 80.9 to 95.2% (E2-3S), and from 86.3 to 91.7% (E1-3S), respectively. Results of batch sorption studies showed that Freundlich isotherms were nonlinear (N ≠ 1) with Kf values ranging from 34.2 to 57.2, and from 3.42 to 4.18 mg¹-N LN kg⁻¹ for E1, and E1-3S, respectively, indicating the sorption affinity of E1-3S was about an order of magnitude lower than that of E1. The hydrophilic sulphate group of E1-3S possibly shielded the compound from hydrophobic interactions with the soil organic matter and allophanic clay minerals that were proposed as sorbents for E1. Contraction of clay minerals, “salting out” and competitive sorption of artificial urine constituents were likely to have been responsible for observed changes in Freundlich parameters when artificial urine was used as mediator matrix. Plotting the effective distribution coefficient as a function of hypothetical exposure concentrations facilitated the comparison of the sorption behaviour of both compounds as influenced by the mediator solution. The results emphasized that using the CaCl₂ matrix might result in false inferences for the sorption behaviour of these compounds in a dairying environment. The four hormones rapidly degraded in the agricultural soils under aerobic conditions, and the majority of the compounds degraded > 50% within the first 24 hrs. Soil arylsulphatase activities were directly correlated with degradation rate constants of the estrogen sulphates. Estrone was identified as a metabolite of E2 and E1-3S, and these three compounds were observed as metabolites of E2-3S. Single-first order (SFO) and double first-order in parallel (DFOP) kinetics were used to model the degradation and metabolite formation data. The results showed that the DFOP model was in most cases better able to predict the parent compound degradation than the SFO model, and also enabled to estimate accurate degradation endpoints. ER-CALUX® analysis revealed the formation of estrogenicity during E2-3S degradation, which could partly be explained by the formation of the metabolites E2 and E1. Transport studies with E1-3S and E1 showed that the transport and retention of both compounds were significantly influenced by the mediator matrix. While no breakthrough curves (BTCs) were recorded during hormone application in CaCl₂ (10 mM) both hormones were detected in the leachate when applied in artificial urine. Rate-limited sorption processes were proposed for the delayed arrival of the hormone BTCs compared with a conservative bromide tracer. Intense colouration of the leachate during the artificial urine experiments suggested the hormones were likely to be moved by colloid-facilitated transport. Furthermore, the detection of residue hormone and metabolite concentrations implied that degradation of E1-3S and E1 was hampered by urine constituents such as glycine and urea.