AVALIAÇÃO DO PROCESSO DE COAGULAÇÃO/FLOCULAÇÃO UTILIZANDO COAGULANTES NATURAIS NA REMOÇÃO DE CIANOBACTÉRIAS

A ocorrência de cianobactérias em mananciais de abastecimento é preocupante, principalmente, devido à possibilidade de algumas espécies liberarem toxinas para a água. Essas toxinas podem causar danos à saúde humana e levar à morte. No Brasil tem-se verificado um aumento de relatos da ocorrência de florações tóxicas de espécie Cylindrospermopsis raciborskii. Neste contexto, o trabalho teve como objetivo avaliar a eficiência de dois coagulantes naturais, um obtido a partir da semente de Moringa oleífera (MO) e outro, o coagulante comercial Tanfloc SG (um tanino vegetal extraído da Acácia Negra) para remoção de cor aparente, turbidez e células de C. raciborskii pelo processo de coagulação/floculação/sedimentação. Também avaliaram-se diferentes dosagens de MO e Tanfloc. Para os ensaios, foi utilizada uma água deionizada contaminada com cultura de células da espécie C. raciborskii para obter turbidez entre 50 e 450 NTU. Para a preparação da solução coagulante com a semente de MO, utilizou-se 1g das sementes descascadas e trituradas em 100 mL de solução salina NaCl (1M). Após a trituração, a solução foi agitada por 30 min e filtrada a vácuo. Para o tanino vegetal utilizou-se o produto comercial Tanfloc SG. Os resultados mostraram que o coagulante à base de semente de MO é tão eficiente quanto Tanfloc SG e pode se constituir em uma alternativa adequada para tratamento de águas com florações de cianobactérias

REMOÇÃO DE CIANOBACTÉRIAS E CIANOTOXINAS EM ÀGUAS DE ABASTECIMENTO PELA ASSOCIAÇÃO DE FLOTAÇÃO POR AR DISSOLVIDO E NANOFILTRAÇÃO

O aumento nas ocorrências e a preocupação com a potencialidade das toxinas produzidas pelas cianobactérias remetem a estudos que sejam eficazes na remoção destes compostos no tratamento de água. Neste sentido, a flotação por ar dissolvido se destaca como um processo eficiente na remoção de células intactas de cianobactérias, de forma a reduzir a potencialidade de liberação de toxinas para a água tratada. A nanofiltração se apresenta como tecnologia eficaz na remoção de cianotoxinas e, por este motivo, a associação destes processos com coagulantes naturais, como a Moringa oleifera Lam, foi adotada como objetivo do estudo. Para os ensaios, foi preparada uma “água sintética”, utilizando-se água deionizada e posterior contaminação com culturas de células do gênero Microscystis sp para obter turbidez na faixa de 50 - 450 NTU. O processo de coagulação/floculação foi realizado com a extração do coagulante natural Moringa oleifera Lam em solução salina NaCl (1M) com posterior flotação no equipamento “Floteste”. A partir desta etapa, procurou-se avaliar a remoção da microcistina, utilizando as membranas NF-90 e NF-270. O desempenho do sistema de tratamento como um todo foi avaliado a partir dos parâmetros físico-químicos (cor, turbidez e pH) e microbiológicos (cianobactérias e cianotoxinas)

EMPREGO DAS SEMENTES DE MORINGA OLEIFERA LAM, COMO COAGULANTE ALTERNATIVO AO POLICLORETO DE ALUMÍNIO (PAC), NO TRATAMENTO DE ÁGUA PARA FINS POTÁVEIS

Este trabalho avaliou a eficiência das sementes de Moringa oleifera Lam como coagulante natural no processo de coagulação/floculação/sedimentação (C/F/S), seguido de ultrafiltração (UF), para a obtenção da remoção de cor, turbidez, coliformes totais, Escherichia coli e pH da água tratada. Para os ensaios, foi utilizada água bruta com turbidez na faixa de 150 à 550 uT proveniente do Rio Pirapó. O processo C/F/S foi realizado com o coagulante natural Moringa oleifera (MO) extraído em solução salina de KCl e NaCl (1M) e com o coagulante químico Policloreto de Alumínio (PAC), nas dosagens de 25 à 300 mg.L-1. Para os ensaios de UF foi utilizada uma membrana de poli (éter sulfona) à pressão de 3 bar. Pode-se observar que a Moringa não influencia o pH do meio, o qual manteve-se estável em todas as dosagens. O processo combinado C/F/S+UF se apresentou eficiente, pois os parâmetros analisados atingiram os valores estabelecidos pela Portaria nº 2914 do Ministério da Saúde. PALAVRAS-CHAVE: Coagulação/floculação/sedimentação, ultrafiltração, Moringa oleífera.AbstractThis study investigated the efficiency of Moringa oleifera seeds as natural coagulant in coagulation/flocculation/sedimentation (C/F/S) process, followed by ultrafiltration (UF) for color, turbidity, total coliforms and Escherichia coli removal and pH of the treated water. For the tests a raw water with turbidity 150-550 uT, from the River basin Pirapó was used. The C/F/S process was performed using the Moringa oleifera extracted in saline solution of KCl and NaCl (1M), and Poly Aluminum Chloride (PAC) as chemical coagulant, in dosage from 25 to 300 mg.L-1 . In UF process, it was used a membrane of poly (eter sulfone) in a working pressure of 3 bar. In the results, one can observe that the Moringa does not influence the pH of the medium, which remained stable at all dosages. The combined process C/F/S+UF showed efficient, because the analyzed parameters reach the values established by Regulation nº 2914 of the Ministry of Health

Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants

© The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit