Environmental observations of antibiotics and other pharmaceuticals have received attention as indicators of an urbanizing global water cycle. When connections between environment and development of antibiotic resistance (ABR) are considered, it is increasingly important to understand the life cycle of antibiotics. Here we examined the global occurrence of erythromycin (ERY) in: 1. wastewater effluent, inland waters, drinking water, groundwater, and estuarine and coastal systems; 2. sewage sludge, biosolids and sediments; and 3. tissues of aquatic organisms. We then performed probabilistic environmental hazard assessments to identify probabilities of exceeding the predicted no-effect concentration (PNEC) of 1.0 μg L for promoting ABR, based on previous modeling of minimum inhibitory concentrations and minimal selective concentrations of ERY, and measured levels from different geographic regions. Marked differences were observed among geographic regions and matrices. For example, more information was available for water matrices (312 publications) than solids (97 publications). ERY has primarily been studied in Asia, North America and Europe with the majority of studies performed in China, USA, Spain and the United Kingdom. In surface waters 72.4% of the Asian studies have been performed in China, while 85.4% of the observations from North America were from the USA; Spain represented 41.9% of the European surface water studies. Remarkably, results from PEHAs indicated that the likelihood of exceeding the ERY PNEC for ABR in effluents was markedly high in Asia (33.3%) followed by Europe (20%) and North America (17.8%). Unfortunately, ERY occurrence data is comparatively limited in coastal and marine systems across large geographic regions including Southwest Asia, Eastern Europe, Africa, and Central and South America. Future studies are needed to understand risks of ERY and other antibiotics to human health and the environment, particularly in developing regions where waste management systems and treatment infrastructure are being implemented slower than access to and consumption of pharmaceuticals is occurring.
Resumo: A utilização de metais pesados, principalmente no setor industrial, tem chamado a atenção quanto aos impactos gerados pela utilização de metais potencialmente tóxicos ao meio ambiente e saúde pública. A adsorção é um processo no qual uma substância (adsorvato) é aderida físicamente ou quimicamente à superfície do componente adsorvente e pode ser visto como uma alternativa para a remoção de metais tóxicos. Este trabalho tem o intuito de realizar um estudo sobre a adsorção de Chumbo II (Pb II) em um polímero natural modificado (lignina) obtido a partir do resíduo do milho (palha). Para a extração da lignina a partir de materiais lignocelulósicos, esta foi então isolada da palha do milho por meio da polpação com ácido fórmico (CH2O2) a 80,0% de concentração, obtendo a lignina fórmica (LFOR), que em seguida foi reticulada com ácido clorídrico (HCl) a 37,0%, dando origem ao polímero adsorvente utilizado neste estudo, a lignina fórmica reticulada (LFRT). Foram feitos testes adsortivos com diferentes tempos de contato entre adsorvente e a solução de Chumbo II com concentração de 10,0 mgL -1 , sendo a concentração final da solução medida por espectrofotometria de absorção atômica (EAA). Os resultados obtidos com a adsorção atômica mostraram que o polímero adsorvente apresentou uma capacidade adsortiva para a retenção de íons Pb +2 , removendo após 100 minutos 98,87% de Chumbo II da solução inicial. Sendo assim, o polímero LFRT pode vir a ser utilizado como um possível meio para remover metais pesados de efluentes agroindustriais.Palavras-chave: Adsorção; Metais Pesados; Chumbo II; Polímeros; Lignina Reticulada. Study of adsorption of lead II in lignin modified from corn waste:The use of heavy metals, especially in the industrial sector, has attracted attention for the impacts generated by the use of potentially toxic metals to the environment and public health. Adsorption is a process in which a substance (adsorbate) is physically or chemically attached to the surface of the adsorbent component and currently this process can be seen as an alternative to remove toxic metals from waste of agro-industrial sectors. This article aims to conduct a study about the adsorption of lead II (Pb II) on a modified natural polymer (lignin) obtained from corn stover. For the extraction of the lignin from lignocellulosic material, it was isolated by pulping with formic acid (CH2O2) at 80% concentration, obtaining lignin formica (LFOR). LFOR already been crosslinked with hydrochloric acid (HCl) 37.0% to give the polymer adsorbent used in this study crosslinked lignin formica (LFRT). Adsorption tests were performed with different times of contact between adsorbent and the solution of 10.0 mgL -1 lead II, and the final concentration of the solution was measured by atomic absorption spectrophotometry (AAS). The results which was obtained with atomic adsorption proved the adsorbent polymer show a capability to retain ions of lead II, removing after 100 minutes 98.87% of the heavy metal in the initial solution. Therefore, the polymer ...
A gestão das cidades envolve a implementação de várias políticas públicas, tais como a Política Nacional de Recursos Hídricos - PNRH (BRASIL, 1997), a Política Urbana - Estatuto da Cidade(BRASIL, 2001), a Política Nacional de Proteção e Defesa Civil - PNPDEC (BRASIL, 2012), a Política Nacional de Recuperação da Vegetação Nativa - PROVEG (BRASIL, 2017) entre outras e acordos internacionais como, por exemplo, a Convenção sobre a Diversidade Biológica (ONU, 1992). O objetivo deste trabalho é propor ações que considerem a integração destas políticas públicas adequando a cobertura arbórea urbana do local de estudo de forma a promover a reabilitação ecológica das margens do rio Barigui e a adequação da arborização adjacente aos canais de drenagem existentes. Espera-se contribuir com os processos de conectividade dos fragmentos da cobertura arbórea urbana local, com a redução da erosão das margens e deposição de sedimentos nos cursos de água e, assim, promover melhorias nas condições de escoamento dos canais de drenagem e do rio Barigui, minimizando riscos à população e custos à municipalidade.
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