RESUMO
The proposal of effluent treatment systems, based on circular economy principles, is a great challenge that leads to the reduction of waste from other activities, thus reducing the environmental and economic cost of the global process. In this work, buildings demolition waste is proposed to be used for metals removal from industrial effluents. To validate these hypotheses, tests were carried out on batch reactors using Copper, Nickel, and Zinc solutions, in concentrations between 8 and 16 mM. As results, removals greater than 90% were obtained. With these preliminary outcomes, it was decided to use equimolar multicomponent solutions with 8 and 16 mM of these metals in a column packed with demolition waste as adsorbent. From the breakthrough curves, it was observed that the adsorption occurs in the order Copper > Nickel > Zinc. The columns' saturated filler could be safely disposed of by incorporating it into conventional or special mortars and concrete. Preliminary studies on the leaching and resistance of mortars prepared with exhausted adsorbents are also promising. It is concluded that these materials emerge as an economic and sustainable alternative for metal contaminants removal.
Assuntos
Metais Pesados , Poluentes Químicos da Água , Cobre , Níquel , Adsorção , Metais , Zinco , Metais Pesados/análise , Resíduos Industriais/análiseRESUMO
The University of Buenos Aires (UBA) develops the UBANEX program, focused on service-learning projects for students involving social, environmental and public health concerns. One of the proposals was a collaborative project between UBA and the National University of General Sarmiento. Based on the hypothesis that students' voluntary involvement in social concerns improves their attitudes towards themselves and learning, the aim was to focus on the development of social and professional skills by implementing an interdisciplinary work for water quality and supply assessment in low-income homes from a southern district of the Buenos Aires Metropolitan Area. Eighteen volunteers-Chemical and Civil Engineering students-were recruited during August-December 2016. Tasks were distributed according to their interests: survey making, sampling, lab analysis, infrastructure checking, etc. Volunteers were surveyed in social involvement, lab skills, data compilation and analysis, leading to a final report with recommendations for a proper water use. The survey results compiled their feedback: 72% admitted an update on water quality problems, 60% learned new lab techniques and were able to analyze results, 89% supported the University's involvement in social concerns and 56% expanded their opinion about the professional field. The students confirmed their interest in participating in the next UBANEX project.
Assuntos
Estudos Interdisciplinares , Laboratórios , Estudantes , Humanos , Saúde Pública , Universidades , Qualidade da ÁguaRESUMO
This work describes a sampling strategy that will allow the use of portable EDXRF (energy dispersive X-ray fluorescence) instruments for "in situ" soil analysis. The methodology covers a general approach to planning field investigations for any type of environmental studies and it was applied for a soil characterization study in the zone of Campana, Argentina, by evaluating data coming from an EDXRF spectrometer with a radioisotope excitation source. Simulating non-treated sampled as "in situ" samples and a soil characterization for Campana area was intended. "In situ" EDXRF methodology is a powerful analytical modality with the advantage of providing data immediately, allowing a fast general screening of the soil composition.
RESUMO
The aim of this work is to explore the use of chemometric tools for the classification of synthetic and natural polymers with a mean molecular weight greater than 10(6). Total Reflection X-Ray Fluorescence (TXRF) spectra were obtained and analyzed in order to retrieve matrix information and to illustrate the calibration procedure. The intensities of the coherent and incoherent scattered peaks were specially selected for this purpose. The polymers studied were aqueous solutions of scleroglucan, polyacrilamide, polyoxyethylene oxide, glucomannan, 2,3,6-tri-o-ethylamylose and xhantan, in concentrations upto 1% (m/m). matlab software was used for numerical calculations. Using a combination of principal component analysis and cluster analysis, the differences in composition of various analyzed polymers can be visualized.
RESUMO
Para la determinación de elementos presentes en el orden de las partes por billón (ppb) en medios acuosos resulta de interés disponer de técnicas analíticas rápidas y sensibles que no requieren tratamiento de preconcentración de las muestras lo que implicaría riesgos de contaminación. En este trabajo se presenta el estudio de la aplicación de la técnica de Fluorescencia de Rayos X por Reflexión Total (TRXRF)para el análisis multielemental de aguas de lluvia. Muestras provenientes de cinco puntos de la ciudad de Buenos Aires, Argentina y cuatro de la ciudad de Campinas, Brasil fueron analizadas con un sistema de reflexión total que se encuentra en el Laboratorio X-Lab del Centro Atómico Constituyentes de la Comisión Nacional de Energía Atómica
Assuntos
Microbiologia da Água , Água de ChuvaRESUMO
Para la determinación de elementos presentes en el orden de las partes por billón (ppb) en medios acuosos resulta de interés disponer de técnicas analíticas rápidas y sensibles que no requieren tratamiento de preconcentración de las muestras lo que implicaría riesgos de contaminación. En este trabajo se presenta el estudio de la aplicación de la técnica de Fluorescencia de Rayos X por Reflexión Total (TRXRF)para el análisis multielemental de aguas de lluvia. Muestras provenientes de cinco puntos de la ciudad de Buenos Aires, Argentina y cuatro de la ciudad de Campinas, Brasil fueron analizadas con un sistema de reflexión total que se encuentra en el Laboratorio X-Lab del Centro Atómico Constituyentes de la Comisión Nacional de Energía Atómica