Publications by authors named "Tereza Silva Martins"

2 Publications

  • Page 1 of 1

Mineral sorbents for ammonium recycling from industry to agriculture.

Environ Sci Pollut Res Int 2020 Apr 6;27(12):13599-13616. Epub 2020 Feb 6.

Instituto de Ciências Ambientais, Químicas e Farmacêuticas da Universidade Federal de São Paulo (UNIFESP - Campus Diadema), Rua São Nicolau, 210, Diadema, SP, CEP: 09913-030, Brazil.

In tropical environments, nutrient-poor soils are commonly found, leading to high fertilizers application rates to support agricultural activities. In contrast, anthropogenic activities generate large amounts of effluents containing nitrogen. In this study, two minerals (natural zeolite and vermiculite) were tested to remove NH from an industrial effluent with high pH and contents in Na and K. Afterwards, they were tested as an alternative slow-release fertilizer in the soil. To verify the best conditions to adsorb NH, batch tests were conducted using synthetic solutions and an industrial effluent. In general, the efficiency of both minerals in removing NH was high (85% for zeolite and almost 70% for vermiculite) as well as the ability to decrease the industrial effluent pH. In this process, more NH and K ions were removed in comparison with Na, which remained in solution. These minerals were tested as slow-release fertilizers by leaching with distilled water (both minerals releasing 2 mg L NH) and with an acid solution (releasing 10 mg L NH from zeolite and 50 mg L NH from vermiculite-corresponding only to 12% of total NH retained by zeolite and 29% by vermiculite). During the test of soil incubation with zeolite-NH, the NH ions of the exchangeable sites were retained for a longer period, minimizing their loss by leaching and biological nitrification. Consequently, soil acidification was prevented. Therefore, both minerals showed high efficiency in removing NH from solution which can then be slowly released as a nutrient in the soil.
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http://dx.doi.org/10.1007/s11356-020-07873-7DOI Listing
April 2020

Improvement of cutaneous delivery of methylene blue by liquid crystals.

Int J Pharm 2018 Sep 2;548(1):454-465. Epub 2018 Jul 2.

Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1524, São Paulo, SP, Brazil.

The purpose of this study was to evaluate the effect of composition and characteristics of liquid crystalline phases (LCPs) on cutaneous delivery of methylene blue (MB). LCPs were obtained by mixing Brij97® with water at various ratios; Brij97®:water at 8:2 (F8:2), 7:3 (F7:3), and 6:4 (F6:4) were selected, and MB was incorporated at 0.1%. F8:2 and F7:3 exhibited textures and small angle X-ray scattering (SAXS) patterns corresponding to lamellar phase, whereas F6:4 displayed characteristics of hexagonal phase. All three LCPs were stable for 9 months, and exhibited thixotropic pseudoplastic behaviour. Increasing water content increased viscosity. All three LCPs released less (3.2- to 6.6-fold) MB than control gel (3.0% hydroxyethylcellulose (HEC) + 0.1% MB), demonstrating their ability to sustain release. Despite the lower release, all LCPs improved skin retention of MB at 6 h post-application (1.3- to 2.1-fold) compared to the control gel. Among the LCPs, F8:2-mediated skin retention of MB was more pronounced, followed by F7:3. Consistent with the increased penetration, transepidermal water loss (TEWL) also increased after treatment with the LCPs (2.0-2.8 fold), which suggests their influence on skin barrier. Irritation studies by Hen's Egg Test - Chorioallantoic Membrane (HET-CAM) suggest that F7:3 and F6:4 may be better tolerated by the skin than F8:2.
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http://dx.doi.org/10.1016/j.ijpharm.2018.07.003DOI Listing
September 2018