Remoção de matéria orgânica natural em águas usando cavitação hidrodinâmica e peróxido de hidrogênio (CH-H2O2)

The presence of natural organic matter (NOM) in water does not present direct risk to the human body or to the environment. However, its presence along with other pollutants can lead to countless issues and damage human health and the environment. The hydrodynamic cavitation (HC) phenomenon started being used in the early 21st century as a process capable of treating supply-water and wastewater based on pollutant and pathogen degradation. Process effectiveness increases when it is combined to chemical agents, creating an advanced oxidation process (AOP). Although several studies have presented broaden applications for the HC process, its use for NOM removal from supply-water was not yet assessed; therefore, it remains a gap in scientific knowledge. The aim of the current study is to assess HC potential in NOM removal. In order to do so, the experiments were carried out in bench scale hydrodynamic cavitation system operated at batch model within 15-min duration period-of-time. In addition, decantation experiments (24-h period-of-time) were performed in order to check HC influence on molecules found in reaction medium after the exposure of NOM to the phenomenon. NOM was produced by a synthetic humic acid (HA) matrix at fixed concentration of 100 ppm. In total, 16 experiments were carried out; each experiment was featured by the following pair: pH (2.6, 3.0, 3.5 and 5.5) and hydrogen peroxide (0, 1, 5 and 30 mL). The best removal efficiencies (34%-36%) were observed in the most acidic pH ranges (2.6-3.0) at H2O2 concentration of 15mL. Results have presented high NOM removal efficiency (approximately 90%) after decantation at the most acidic pH ranges, as well. It can be explained by the fact that hydrodynamic cavitation in acid solution can break molecular structures suspended in the liquid medium, which favors decantation. Based on the present study, hydrodynamic cavitation with hydrogen peroxide addition can remove NOM from water; moreover, pH control is an essential factor for process development

Remoção de matéria orgânica natural em águas usando cavitação hidrodinâmica e peróxido de hidrogênio (CH-H2O2)

The presence of natural organic matter (NOM) in water does not present direct risk to the human body or to the environment. However, its presence along with other pollutants can lead to countless issues and damage human health and the environment. The hydrodynamic cavitation (HC) phenomenon started being used in the early 21st century as a process capable of treating supply-water and wastewater based on pollutant and pathogen degradation. Process effectiveness increases when it is combined to chemical agents, creating an advanced oxidation process (AOP). Although several studies have presented broaden applications for the HC process, its use for NOM removal from supply-water was not yet assessed; therefore, it remains a gap in scientific knowledge. The aim of the current study is to assess HC potential in NOM removal. In order to do so, the experiments were carried out in bench scale hydrodynamic cavitation system operated at batch model within 15-min duration period-of-time. In addition, decantation experiments (24-h period-of-time) were performed in order to check HC influence on molecules found in reaction medium after the exposure of NOM to the phenomenon. NOM was produced by a synthetic humic acid (HA) matrix at fixed concentration of 100 ppm. In total, 16 experiments were carried out; each experiment was featured by the following pair: pH (2.6, 3.0, 3.5 and 5.5) and hydrogen peroxide (0, 1, 5 and 30 mL). The best removal efficiencies (34%-36%) were observed in the most acidic pH ranges (2.6-3.0) at H2O2 concentration of 15mL. Results have presented high NOM removal efficiency (approximately 90%) after decantation at the most acidic pH ranges, as well. It can be explained by the fact that hydrodynamic cavitation in acid solution can break molecular structures suspended in the liquid medium, which favors decantation. Based on the present study, hydrodynamic cavitation with hydrogen peroxide addition can remove NOM from water; moreover, pH control is an essential factor for process development.A presença de matéria orgânica natural (MON) em águas não apresenta riscos diretos relacionados ao seu contato com o organismo humano e nem mesmo ao meio ambiente. Entretanto, sua presença, em conjunto a outros poluentes, pode acarretar inúmeros problemas e danos à saúde humana e ao meio ambiente. O fenômeno de cavitação hidrodinâmica (CH) passou a ser utilizado no início do século XXI como um processo capaz de realizar o tratamento de águas de abastecimento ou residuárias a partir da degradação de poluentes e patógenos. A efetividade do processo aumenta quando aliado à adição de agentes químicos no meio reacional, configurando um processo oxidativo avançado (POA). Por mais que diversos trabalhos apresentem amplas aplicações para o processo de CH, sua utilização para remoção de MON de águas de abastecimento ainda não foi avaliada e, portanto, apresenta-se como uma lacuna no conhecimento científico. O objetivo deste trabalho é avaliar o potencial da CH em remover MON. Para tanto, os experimentos foram realizados em um sistema de cavitação hidrodinâmica, em escala de bancada, operado em modo batelada com duração de 15 minutos. Adicionalmente, experimentos de decantação (período de 24 horas) foram conduzidos com intuito de verificar a influência da CH sobre as moléculas presentes no meio reacional após exposição ao fenômeno. A MON foi constituída por uma matriz de ácido húmico (AH) sintética à uma concentração fixa de 100 ppm. No total foram realizados 16 experimentos, no qual cada experimento foi caracterizado pelo par: pH (2,6; 3,0; 3,5; e 5,5) e peróxido de hidrogênio (0; 1; 15 e 30 mL). As melhores eficiências de remoção (34-36%) foram encontradas para faixas de pH mais ácidas (2,6-3,0), para uma concentração de 15 mL de H2O2. Após decantação, os resultados apresentaram uma elevada eficiência de remoção de MON (aproximadamente 90%), também para faixas de pH mais ácidas. Isso pode ser explicado pelo fato de que, em soluções ácidas, a cavitação hidrodinâmica consegue romper estruturas moleculares suspensas no meio líquido, favorecendo a decantação. Este estudo mostrou que a cavitação hidrodinâmica aliada a peróxido de hidrogênio é capaz de remover MON presentes em águas e que o controle do pH é fator crucial para o desempenho do processo

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Modeling polyhydroxyalkanoates production from sugarcane vinasse by mixed microbial cultures

Os polímeros microbianos são uma classe de materiais considerados uma alternativa aos polímeros derivados do petróleo, pois são biodegradáveis e produzidos a partir de matérias-primas renováveis. Os polihidroxialcanoatos (PHA) é uma família de polímeros microbianos que tem se destacado nos últimos anos. PHA são poliésteres sintetizados intracelularmente como fonte de energia e carbono por vários microrganismos. Atualmente, a produção e comercialização de PHA em grandes escalas é prejudicada pelo alto custo produtivo, que está associado ao uso de substratos bem definidos e culturas puras de microrganismos. Dessa maneira, os PHA têm atraído a atenção de pesquisadores no sentido de viabilizar um processo de produção economicamente viável e, eventualmente, aumentar a produção para minimizar os problemas ambientais causados pelo uso de plásticos derivados do petróleo. A opção mais promissora para isso é a combinação de consórcios microbianos e águas residuárias. Diversos estudos ao redor do mundo já foram conduzidos nesse sentido, incluindo experiências em escala piloto. Entretanto, estudos brasileiros que investigaram a produção de PHA aplicando consórcios microbianos e águas residuárias são escassos. Recentemente, esse cenário foi impulsionado por um trabalho, no qual foi avaliado o reaproveitamento de uma água residuária abundante no Brasil, a vinhaça de cana-de-açúcar, para produção de PHA. Os resultados encontrados foram promissores e mais pesquisas são necessárias para resolver os gargalos e viabilizar o processo de produção de PHA a partir de vinhaça de cana-de-açúcar. Nesse sentido, o presente trabalho visa a construção de modelos matemáticos que descrevam a produção de PHA a partir de vinhaça de cana-de-açúcar. Tais modelos podem ser usados para estimar e identificar parâmetros cinéticos e estequiométricos característicos do processo, auxiliando na elaboração de experimentos e previsão do efeito de variáveis operacionais. Os modelos desenvolvidos nesta pesquisa descrevem as etapas de seleção de espécies produtoras de PHA e de acumulação de PHA. O modelo de seleção descreve o processo ocorrendo em um reator de bateladas sequenciais (SBR) submetido a condições de feast-famine e fornecimento desacoplado de carbono e nitrogênio sendo capaz de simular dados experimentais em diferentes condições operacionais. O modelo de acumulação descreve o processo em um reator de batelada alimentada e considera que tanto o consumo de substrato e produção de PHA são processos que ocorrem sem inibição, além disso o modelo de acumulação também considera a evolução de biomassa dentro do reator. Todos os modelos construídos foram submetidos a uma análise de sensibilidade local relativa a parâmetros e variáveis sendo possível identificar os parâmetros mais influentes dos processos e diminuir o número de parâmetros a serem determinados. Para determinação dos parâmetros, foi aplicado o método de otimização de parâmetros de Monte Carlo com Cadeia de Markov (MCMC), que também permitiu validar estatisticamente os modelos. A utilização destas técnicas fez com que os modelos descrevessem de forma correta o processamento da vinhaça de cana-de-açúcar em PHA e permitiu analisar o impacto que operar o reator SBR de seleção sob diferentes relações DQOt/Nitrogênio possui nos parâmetros livres dos modelos. Foi constatado que o consórcio microbiano selecionado sob maior relação DQOt/Nitrogênio apresentou maior rendimento de PHA referente a ácidos orgânicos (YPHA/H.Org) (0.740 ± 0.017). Além disso, o consórcio microbiano selecionado sem suplementação externa de nitrogênio apresentou uma resposta de crescimento em detrimento a acumulação de PHA, reforçado pelo maior crescimento de biomassa e rendimento de biomassa referente a ácidos orgânicos (YX/H.Org) (0.248 ± 0.020) observados nas corridas de acumulação.Microbial polymers are a class of materials that are considered an alternative to petroleum-based polymers because they are biodegradable and produced from renewable raw materials. Polyhydroxyalkanoates (PHA) is a family of microbial polymers that has come to prominence in recent years. PHA are polyesters synthesized intracellularly as a source of energy and carbon by various microorganisms. Currently, large-scale production and commercialization of PHA is hampered by the high production cost, which is associated with the use of well-defined substrates and pure cultures of microorganisms. Thus, PHA have attracted the attention of researchers in order to enable an economically viable production process and, eventually, increase production to minimize the environmental problems caused by the use of petroleum-based plastics. The most promising option for this is the combination of microbial consortia and wastewater. Several studies around the world have already been conducted in this direction, including pilot-scale experiments. However, Brazilian studies investigating the production of PHA by applying microbial consortia and wastewater are scarce. Recently, this scenario was boosted by a study that evaluated the reuse of an abundant wastewater in Brazil, the sugarcane vinasse, for PHA production. The results were promising and more research is necessary to solve the bottlenecks and make the process of PHA production from sugarcane vinasse feasible. In this sense, the present work aims to build mathematical models that describe the production of PHA from sugarcane vinasse. These models can be used to estimate and identify kinetic and stoichiometric parameters characteristic of the process, helping in the design of experiments and predicting the effect of operational variables. The models developed in this research describe the stages of selection of PHA-producing species and PHA accumulation. The selection model describes the process taking place in a sequencing batch reactor (SBR) under feast-famine conditions and uncoupled nitrogen supply and is capable of simulating experimental data under different operating conditions. The accumulation model describes the process in a fed-batch reactor and considers both substrate consumption and PHA production to be processes that occur without inhibition, and the accumulation model also considers the evolution of biomass within the reactor. All the built models were submitted to a local sensitivity analysis concerning parameters and variables being possible to identify the most influential parameters of the processes and decrease the number of parameters to be determined. For this, the parameter optimization method of Monte Carlo with Markov Chain (MCMC) was applied, which also allowed to statistically validate the models. The use of these techniques made the models correctly describe the processing of sugarcane vinasse into PHA and allowed to analyze the impact that operating the selection SBR reactor under different CODt/Nitrogen ratios has on the free parameters of the models. It was found that the microbial consortium selected under higher CODt/Nitrogen ratio showed higher PHA yield related to organic acids (YPHA/H.Org) (0.740 ± 0.017). Furthermore, the microbial consortium selected without external nitrogen supplementation showed a growth response rather than PHA accumulation, reinforced by the higher biomass growth and biomass yield related to organic acids (YX/H.Org) (0.248 ± 0.020) observed in the accumulation runs

Remoção de matéria orgânica natural em águas usando cavitação hidrodinâmica e peróxido de hidrogênio (CH-H2O2)

The presence of natural organic matter (NOM) in water does not present direct risk to the human body or to the environment. However, its presence along with other pollutants can lead to countless issues and damage human health and the environment. The hydrodynamic cavitation (HC) phenomenon started being used in the early 21st century as a process capable of treating supply-water and wastewater based on pollutant and pathogen degradation. Process effectiveness increases when it is combined to chemical agents, creating an advanced oxidation process (AOP). Although several studies have presented broaden applications for the HC process, its use for NOM removal from supply-water was not yet assessed; therefore, it remains a gap in scientific knowledge. The aim of the current study is to assess HC potential in NOM removal. In order to do so, the experiments were carried out in bench scale hydrodynamic cavitation system operated at batch model within 15-min duration period-of-time. In addition, decantation experiments (24-h period-of-time) were performed in order to check HC influence on molecules found in reaction medium after the exposure of NOM to the phenomenon. NOM was produced by a synthetic humic acid (HA) matrix at fixed concentration of 100 ppm. In total, 16 experiments were carried out; each experiment was featured by the following pair: pH (2.6, 3.0, 3.5 and 5.5) and hydrogen peroxide (0, 1, 5 and 30 mL). The best removal efficiencies (34%-36%) were observed in the most acidic pH ranges (2.6-3.0) at H2O2 concentration of 15mL. Results have presented high NOM removal efficiency (approximately 90%) after decantation at the most acidic pH ranges, as well. It can be explained by the fact that hydrodynamic cavitation in acid solution can break molecular structures suspended in the liquid medium, which favors decantation. Based on the present study, hydrodynamic cavitation with hydrogen peroxide addition can remove NOM from water; moreover, pH control is an essential factor for process development

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P &lt; 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)