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Copyright of Revista Ciência & Saúde Coletiva is the property of Associacao Brasileira de Pos-Graduacao em Saude Coletiva and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de Saúde Pública is the property of Faculdade de Educacao da Universidade de Sao Paulo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new impregnation method was tested in this study. Without a stabilizing agent, silver and copper metallic compounds were directly impregnated on activated carbon using vacuum impregnation followed by drying at 100°C and vacuum impregnation followed by thermal decomposition at 350°C in an ambient atmosphere. The effect of thermal decomposition on the structural, morphological, and textural characteristics of the modified nanomaterials was analysed by Brunauer–Emmett–Teller, X-ray diffraction, scanning electron microscopy, energy dispersive X-Ray, and transmission electron microscopy. The characteristics of the produced materials were not altered. Silver and CuO nanoparticles were identified in the samples with average diameters ranging from 33.3–36.8 nm and 29.0–33.3 nm, respectively. The materials were tested for their antibacterial capacity and for their potential to leach Ag and Cu into water, thus analysing the effect of the thermal decomposition process on the impregnation process. The vacuum impregnation process followed by thermal decomposition produced the best results, with the resultant material reducing bacterial abundance by 5.31–6.61 log and leaching only low concentrations of metals into the water (Ag – 0.010–0.025 mg L−1 and Cu – 0.270–0.361 mg L−1). Samples produced without the thermal decomposition step reached bacterial reductions of 1.86–1.97 log and yielded higher concentrations of metals in the water (Ag – 0.051–0.086 mg L−1 and Cu – 0.819–0.894 mg L−1). [ABSTRACT FROM AUTHOR]

The present study proposes development of an adsorbent based on combination of graphene oxide (GO) and iron oxide (α-γ-Fe2O3) nanoparticles for atrazine removal from water. The synthesized adsorbent (GO@ α-γ-Fe2O3) was characterized using different techniques. Magnetic measurements proved that the adsorbent has superparamagnetic characteristics, thus facilitating its magnetic separation from the working suspensions. The maximum adsorption capacity was 42.5 mg g−1. The Langmuir isotherm and the pseudo-second order kinetic models correlated adequately with the experimental data. The thermodynamic data showed that atrazine adsorption was spontaneous, endothermic and thermodynamically favorable. [ABSTRACT FROM AUTHOR]

In this work, we synthesized iron-oxide nanoparticles (NPsFeO) via a green synthesis method, using Moringa oleifera leaf extract, and evaluated its fluoride ion adsorption potential, comparing its efficiency with a commercially available adsorbent (activated carbon of bone [BGAC]). The adsorbent materials were characterized using X-ray diffraction, transmission, and scanning electronic microscopy, X-ray dispersive energy spectrometry, and N2 adsorption/desorption. The results showed that the maximum adsorption occurred in pH 7 for NPsFeO and pH 5 for the BGAC. Adsorption kinetic tests showed that the equilibrium was reached in 40 min for the NPsFeO, and 90 min for BGAC, with adsorption potential of 1.40 and 1.20 mg g−1, respectively. The model that best described the kinetic data was pseudo-first-order for NPsFeO and pseudo-second-order for BGAC. The Langmuir isotherm had a better fit for both adsorbents. The thermodynamic parameters indicated spontaneous and endothermic adsorption at 30°C, 40°C, and 50°C for BGAC, and at 30°C for NPsFeO. The regeneration process showed that it is possible to reuse NPsFeO three times in the fluoride ion adsorption process. As a result of its adsorption capabilities and the shortest contact time to achieve equilibrium, the NPsFeO is a highly promising material for fluoride ion removal. [ABSTRACT FROM AUTHOR]

The aim of this study was the development of a new magnetic coagulant based on nano structured iron oxide functionalized by Moringa oleifera (MO) compounds present in aqueous saline extract, for water treatment, with removal of the physical-chemical indicatives parameters, turbidity, apparent color, and compounds with absorption at UV254nm(UV254nm). The nano structured iron oxide(maghemite, γ-Fe2O3) was synthesized without organic solvents use. These nanoparticles were functionalized by the compounds present in aqueous saline MO (without oil, extracted by ethanol and hexane) extract. Tests of coagulation and flocculation were performed by using a Jar Test equipment with medium to high turbidity water (80 NTU). The magnetic coagulant achieved removals of 94.4% for turbidity, 87.5% for apparent color and 63.4% for UV254nm, with surface waters using applied magnetic field within 30 min of settling. The treatment of coagulation followed by flocculation with magnetic functionalized MO coagulant could lessen physico-chemical properties assessed with diminished sedimentation time. The coagulant used in the study can be reused without significant loss of efficiency due to possibility of magnetic separation, showing an economically viable method and low environmental impact. [ABSTRACT FROM AUTHOR]

Continuous flow experiments (450 mL min−1) were performed in household filter in order to investigate the removal and/or inactivation of T4 bacteriophage, using granular activated carbon (GAC) modified with silver and/or copper oxide nanoparticles at different concentrations. GAC and modified GAC were characterized by X-ray diffractometry, specific surface area, pore size and volume, pore average diameter, scanning electron microscopy, transmission electron microscopy, zeta potential and atomic absorption spectroscopy. The antiviral activity of the produced porous media was evaluated by passing suspensions of T4 bacteriophage (∼105 UFP/mL) through filters. The filtered water was analyzed for the presence of the bacteriophage and the release of silver and copper oxide. The porous media containing silver and copper oxide nanoparticles showed high inactivation capacity, even reaching reductions higher than 3 log. GAC6 (GAC/Ag0.5%Cu1.0%) was effective in the bacteriophage inactivation, reaching 5.53 log reduction. The levels of silver and copper released in filtered water were below the recommended limits (100 ppb for silver and 1000 ppb for copper) in drinking water. From this study, it is possible to conclude that activated carbon modified with silver and copper oxide nanoparticles can be used as a filter for virus removal in the treatment of drinking water. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the efficiency of the coagulation/flocculation/dissolved air flotation (C/F/DAF) process using the coagulantMoringa oleifera(MO) seed powder, and to analyse the profile of fatty acids present in the generated sludge after treatment. For the tests, deionized water artificially contaminated with cell cultures ofAnabaena flos-aquaewas used, with a cell density in the order of 104 cells mL–1. C/F/DAF tests were conducted using ‘Flotest’ equipment. For fatty acid profile analyses, a gas chromatograph equipped with a flame ionization detector was used. It was seen that the optimal dosage (100 mg L–1) of MO used in the C/F/DAF process was efficient at removing nearly allA. flos-aquaecells (96.4%). The sludge obtained after treatment contained oleic acid (61.7%) and palmitic acid (10.8%). Thus, a water treatment process using C/F/DAF linked to integral MO powder seed was found to be efficient in removing cells of cyanobacteria, and produced a sludge rich in oleic acid that is a precursor favourable for obtaining quality biodiesel, thus becoming an alternative application for the recycling of such biomass. [ABSTRACT FROM AUTHOR]