Produção científica sobre o biogas dos resíduos do beneficiamento da mandioca no Brasil: características e abordagens

The presented research proposes an investigation on how scientific production has been carried out regarding biogas produced from cassava processing residues in Brazil. In this direction, a Systematic Literature Review (SLBR) was carried out, inspired by the principles of the methodology proposed by Tranfield et al. (2003). Data was extracted from the articles according to: a) Characterization of publications; and b) Research approach. Thus, it was found that 2018 was the year with the largest scientific publication on the subject; the formation of the main authors is concentrated in the field of Engineering; and publications are especially focused on the state of Paraná. The predominant methodological approach was the Experimental, which prioritized research with the objective of verifying the Efficiency in the production of biogas, according to: a) Co-digestion, inoculum and alkalinizing strategies; b) Performance of operational parameters; and c) Reactor design performance. It was also verified that most articles do not consider the issue of production scale in their research, and when this parameter was considered, it met the large scale of production. Although the Brazilian cassava crop and its processing are marked by a mostly small-scale production, carried out by family farming and destined for internal trade, it appears that this reality was not addressed in any of the articles analyzed.A pesquisa apresentada propõe uma investigação sobre como tem sido feita a produção cientifica a respeito do biogas produzido a partir dos resíduos do beneficiamento da mandioca no Brasil, Nessa direção foi feita uma Revisão Bibliográfica Sistemática da Literatura (RSB) inspirada nos princípios da metodologia proposta por Tranfield et al. (2003). Os dados foram extraídos dos artigos segundo: a) Caracterização das publicações; e b) Abordagem das pesquisas. Assim, foi verificado que 2018 foi o ano com maior publicação cientifica sobre o tema; a formação dos autores principais concentra-se na área das Engenharias; e as publicações concentram-se especialmente no estado no Paraná. A abordagem metodológica predominante foi a Experimental, que priorizou pesquisas com o objetivo de verificar a Eficiência na produção de biogás, segundo: a) Estratégias de codigestão, inoculos e alcalinizantes; b) Desempenho de parâmetros operacionais; e c) Desempenho do desenho dos reatores. Também foi verificado que a maioria dos artigos não considera a questão da escala de produção em sua pesquisa, e quando esse parâmetro foi considerado atendeu a larga escala de produção. Apesar da cultura brasileira da mandioca e seu beneficiamento serem marcados por uma produção de escala majoritariamente pequena, protagonizada pela agricultura familiar e destinada ao comercio interno, verifica-se que essa realidade não foi contemplada em nenhuma dos artigos analisados

Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

Background: Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke. Methods: We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515. Findings: Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes. Funding: GlaxoSmithKline

Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

Closed-Loop Biodigesters on Small-Scale Farms in Low- and Middle-Income Countries: A Review

Anaerobic digestion (AD) systems are prominent in low- and middle-income countries (LMICs), although their implementation within organic farms to enhance resource efficiency and “close the loop” has been limited. This paper thus reviewed existing literature on the potential of AD technologies as part of closed-loop rural family farming communities in LMICs. Data from eleven existing case studies matching this criterion was then collated to understand practical considerations of implementing and maintaining viable AD systems for small farmers. The case studies analyzed indicate that most, if not all, of the biogas produced in the AD process is used for household purposes such as cooking, lighting and heating. The AD systems are either based on the fixed biogas dome or the floating drum design, although the tubular flexible balloon model is mentioned as a low-cost alternative. Future research opportunities in this topic include studying the applicability of recommendations offered across different geographies, consideration of long-term sustainability and impact of biodigester technology, and sociocultural factors such as community ownership and indigenous practices

Sugarcane bagasse ash and its blends with triple-superphosphate reduce the dependency on rock phosphate

Optimal crop production depends on a supply of phosphorus. Sugarcane bagasse ash (BA), a by-product of sugarcane processing, contains up to 1.6 wt% phosphorus. BA use in agriculture can reduce the dependency on rock phosphate.The potential of BA as phosphorus fertilizer was tested for soybeans on Oxisol soil under Brazilian field conditions. Fertilizing effects of 40, 80 and 160 kg/ha P2O5 from BA were compared to conventional fertilization with 40 kg P2O5 from triple-superphosphate (TSP). Additionally, BA/TSP blends consisting of 70% P2O5 from BA and 30 % from TSP (resulting in 32, 65 and 130 P2O5 kg/ha) were evaluated with respect to fertilizing efficiency. The bioavailability of P2O5 from BA to soybeans was lower than from TSP, so that doubling of P2O5 dose was necessary to compensate for the lower offtake. Grain yields following BA-based fertilizations did not statistically differ compared to TSP fertilization, albeit tended to increase by 11% when fertilized with BA/TSP blend supplied at 65 kg P2O5/ha. Thus, while 80 kg P2O5/ha in form of BA could replace 40 kg P2O5/ha in form of TSP, fertilization with 65 kg P2O5/ha in form of BA/TSP could save 50% of TSP and increase the grain yield

Sugarcane bagasse-based ashes as fertiliser for soybeans and the relevance of ash mineral composition on plant phosphorus availability

Sugarcane bagasse, the lignocellulosic remains of sugar cane processing is commonly burnt to generate electricity. Recycling strategies for the resulting ashes rarely take the remaining plant nutrients into account. The objective of this study was to investigate the potential of ashes sourced from combustion and gasification of bagasse alone and in combination with chicken manure and sewage sludge, respectively, as fertiliser for soybeans. The analyses were based on chemical ash characterisation, 31P NMR, X-ray diffraction, sequential phosphorus (P) extraction, P extraction in citric acid and greenhouse pot experiments with soybean plants. Fertilization effects were lower than those of triple-superphosphate and K2SO4 and depended on plant P availability. Calcium-based phosphates dominated in all ashes and determined plant P availability. XRD analyses revealed whitlockite (Ca9M(PO4)7) and CaK2P2O7 in all ashes, while AlPO4 was detected only in an ash with low plant P availability and two undefined P phases and Ca(Na,K)PO4 in ashes with high plant P availability. In conclusion, plant P availability was highest in alkali-rich ashes, as observed in ashes from co-processing bagasse with chicken manure. To increase plant P availability in ashes, we recommend co-combustion of the biomass with sodium and potassium rich biofuels

Soybean Fertilized by P-Phases from Bagasse-Based Materials: P-Extraction Procedures, Diffusive Gradients in Thin Films (DGT), and X-ray Diffraction Analysis (XRD)

The Brazilian sugarcane industry produced around 173 million tons (Mt) of bagasse in 2018. Bagasse is a by-product of juice extraction for ethanol and sugar production and is combusted in order to generate power, producing up to 10 Mt of ash per year. This ash contains various concentrations of plant nutrients, which allow the ash to be used as a crop fertilizer. However, the concentration and extractability of phosphorus (P), an essential plant nutrient, are low in bagasse ash. To increase the P content, we co-gasified and co-combusted bagasse with P-rich chicken manure. The resulting ash was thermochemically post-treated with alkali additives (Na2SO4 and K2SO4) to increase the availability of P to plants. We aimed to: (i) investigate the effect of thermochemical post-treatment of co-gasification residue and co-combustion ash on P availability to soybeans, (ii) explore the potential of chemical extraction methods (citric acid, neutral ammonium citrate, formic acid, and Mehlich-I) and diffusive gradients in thin films (DGT) to predict the availability of P to soybeans, and (iii) identify the responsible P-phases using X-ray diffraction . We evaluated P availability to soybeans growing in Brazilian Oxisol soil in two independent greenhouse pot experiments. The positive effect of thermochemical treatment on P availability from gasification residue was confirmed through the observation of increased P uptake and biomass in soybean plants. These findings were confirmed by chemical extraction methods and DGT. The gasification residue contained whitlockite as its main P-bearing phase. Thermochemical post-treatment converted whitlockite into highly soluble CaNaPO4. In contrast, co-combustion ash already contained highly soluble Ca(Na,K)PO4 as its main P-bearing phase, making thermochemical post-treatment unnecessary for increasing P availability. In conclusion, increased extractability and availability of P for soybeans were closely connected to the formation of calcium alkali phosphate. Our findings indicate that this combined methodology allows for the prediction of P-fertilization effects of ash