Study of energy potential and process variables in covered lagoon anaerobic digesters

Este estudo teve como objetivo (i) estimar o potencial energético proveniente de suinoculturas de diferentes portes no estado de Minas Gerais; e (ii) avaliar a influência entre as temperaturas no interior e exterior do biodigestor com a remoção da matéria orgânica e as tendências típicas das temperaturas em diferentes períodos do ano. (i) O potencial energético de Minas Gerais foi estimado a partir do volume de esterco gerado por fase de criação dos animais e condições reais de geração de eletricidade a partir da operação de sistemas de moto-geração. Os dados do plantel de suínos para o estado foram obtidos junto ao IMA. Constatou-se que as mesorregiões Triângulo Mineiro/Alto Paranaíba e Zona da Mata são os maiores polos suinícolas de Minas Gerais, sendo responsáveis por concentrar o maior número de granjas e de animais. Obteve-se que a potência elétrica total no estado foi igual a 31MW, enquanto que a potência atual correspondeu a 20 MW. No que tange a potência instalada outorgada, o valor ainda é reduzido, sendo 35,4% da potência atual, o que prediz que nem todas as mesorregiões produtoras de suínos que possuem biodigestores instalados fazem o aproveitamento energético do biogás. (ii) A influência e relação das temperaturas sobre a eficiência do processo de tratamento foi avaliada a partir do monitoramento realizado em uma suinocultura localizada no município de Teixeiras, MG. O monitoramento foi realizado a partir da instalação de sensores na área experimental para a aferição das temperaturas do biogás, substrato, solo, ambiente e efluente, além de coletas do efluente (entrada e saída) realizadas semanalmente. A partir do monitoramento, a eficiência de remoção de DQO apresentou valor médio igual a 40,6% para o período do verão e 36,8% para o inverno. Para os valores de sólidos não observaram variações consideráveis entre a entrada e saída do sistema. Observou-se uma maior variação térmica na temperatura ambiente e do biogás. No périodo verão/inverno observou-se que no verão a temperatura do solo foi superior a temperatura do substrato e que no inverno o comportamento das temperaturas são o oposto. Contatou-se que todas as temperaturas monitoradas se correlacionam linearmente, apresentando r acima de 0,8. No entanto, quando se associa as temperaturas com a eficiência de remoção de DQO, observa-se que não há uma correlação linear entre elas. Contudo, nota-se uma maior associação com as temperaturas do substrato (0,42), seguida das temperaturas do biogás (0,36), solo (0,31) e ambiente (0,16). Em resumo, o sistema anaeróbio monitorado está operando com eficiência de remoção da matéria orgânica abaixo do esperado. No entanto, observou-se que a temperatura do substrato nos dois períodos, verão e inverno, foi inferior a temperatura ótima para os microrganismos anaeróbios. E que a temperatura do substrato apresenta uma maior correlação com a temperatura do solo. Palavras-chave: Biodigestor canadense. Digestão anaeróbia. SuínosThe objective of this study was (i) to estimate the energy potential from pig farms of different sizes in the state of Minas Gerais; and (ii) evaluate the influence between the temperatures inside and outside the biodigester with the removal of organic matter and the typical temperature trends at different times of the year. (i) The energy potential of Minas Gerais was estimated from the volume of manure generated by the animal husbandry phase and the actual conditions of electricity generation from the operation of motorcycle generation systems. The pig herd data for the state were obtained from the IMA. It was found that the Triangulo Mineiro / Alto Paranaíba and Zona da Mata mesoregions are the largest swine hubs in Minas Gerais, being responsible for concentrating the largest number of farms and animals. The total electric power in the state was 31MW, while the current power corresponded to 20 MW. Regarding the installed power granted, the value is still low, being 35.4% of the current power, which predicts that not all pig producing mesoregions that have installed biodigesters make the energy use of biogas. (ii) The influence and relationship of temperatures on the efficiency of the treatment process was evaluated from the monitoring performed in a swine production located in Teixeiras, MG. Monitoring was carried out from the installation of sensors in the experimental area to measure biogas, substrate, soil, environment and effluent temperatures, as well as weekly effluent collections (inlet and outlet). From monitoring, COD removal efficiency was 40.6% for summer and 36.8% for winter. For the solids values there were no considerable variations between the system input and output. There was a greater thermal variation in room temperature and biogas. In the summer / winter period it was observed that in summer the soil temperature was higher than the substrate temperature and that in winter the temperature behavior is the opposite. All monitored temperatures were found to correlate linearly, with r above 0.8. However, when temperatures are associated with COD removal efficiency, there is no linear correlation between them. However, there is a greater association with substrate temperatures (0.42), followed by biogas (0.36), soil (0.31) and ambient (0.16) temperatures. In summary, the monitored anaerobic system is operating with lower than expected organic matter removal efficiency. However, it was observed that the substrate temperature in both periods, summer and winter, was lower than the optimum temperature for anaerobic microorganisms. And that the temperature of the substrate has a greater correlation with the soil temperature. Keywords: Canadian biodigester. Anaerobic digestion. Pig

As, Cu and Zn concentration in sanitary sewage sludge fertilized soil and in crambe and corn grains

This study aimed to evaluate the total contents of As, Cu and Zn in the profile of a Haplic Cambisol cultivated with crambe and corn and fertilized with sanitary sewage sludge and to compare them with those obtained in other forms of fertilization, as well as the content of metals in the grain of these crops. Two experiments were carried out in the field, one with maize cultivation and another with crambe, both were delineated as randomized blocks with four treatments and six replicates, which were: without fertilization, fertilization with sewage sludge dewatered and dried in the sun, with dry sewage sludge and with mineral fertilizers. At the end of the experiments soil samples were collected at 15, 50, 100, 150 and 200 cm depth for analysis of the total contents of As, Cu and Zn, as well as the grain of the crops. No differences were observed among the treatments. The total contents of As, Cu and Zn in the soil in both experiments and in the corn grains are below the limits of prevention and the maximum limit in grains established by the Brazilian resolutions. In relation to depth, the metal contents in the samples collected from the soil submitted to the fertilization treatments were similar to those quantified in the plots that did not received fertilization, but there was accumulation of Cu and Zn in the upper layers of the soil that received fertilization

Possible use of Si-Phytoliths in metal anomaly prospection. Example from Riacho dos Machado region, Cerrado, Minas Gerais, Brazil.

International audienceThis work investigates the distribution of selected heavy elements in soil samples and Si-Phytoliths from plants. The aim is to verify if metal contents are indicative for metal anomalies in the soil. Samples were collected in profiles near the Riacho dos Machados Goldmine. Granitic-gneissic rocks, in tectonized contact with the overlaying rocks, form the basis of the investigated region, which belongs to the Rio dos Machados Group of the Espinhaço Super Group. The whole rock substrate is covered by lateritic to arenitic soils with different exposure depths. Metal-rich fluid invaded this unit, forming metal anomalies, forming Zn-Pb-Au deposits, like that of Salobre-Porteirinha. After appropriate preparation, the samples were analyzed by ICP-OES (Si-Phytoliths) and XRF (soil). Anomalies in the investigated profile are indicated by high metal contents in the Si-Phytoliths of the selected species. Using different species, the metal concentration at different depths can be determined

Possible use of Si-Phytoliths in metal anomaly prospection. Example from Riacho dos Machado region, Cerrado, Minas Gerais, Brazil.

International audienceThis work investigates the distribution of selected heavy elements in soil samples and Si-Phytoliths from plants. The aim is to verify if metal contents are indicative for metal anomalies in the soil. Samples were collected in profiles near the Riacho dos Machados Goldmine. Granitic-gneissic rocks, in tectonized contact with the overlaying rocks, form the basis of the investigated region, which belongs to the Rio dos Machados Group of the Espinhaço Super Group. The whole rock substrate is covered by lateritic to arenitic soils with different exposure depths. Metal-rich fluid invaded this unit, forming metal anomalies, forming Zn-Pb-Au deposits, like that of Salobre-Porteirinha. After appropriate preparation, the samples were analyzed by ICP-OES (Si-Phytoliths) and XRF (soil). Anomalies in the investigated profile are indicated by high metal contents in the Si-Phytoliths of the selected species. Using different species, the metal concentration at different depths can be determined

Euterpe oleracea Mart.-Derived Polyphenols Protect Mice from Diet-Induced Obesity and Fatty Liver by Regulating Hepatic Lipogenesis and Cholesterol Excretion.

The aim of this study was to investigate the effect of a polyphenol-rich Açaí seed extract (ASE, 300 mg/kg-1d-1) on adiposity and hepatic steatosis in mice that were fed a high-fat (HF) diet and its underlying mechanisms based on hepatic lipid metabolism and oxidative stress. Four groups were studied: C57BL/6 mice that were fed with standard diet (10% fat, Control), 10% fat + ASE (ASE), 60% fat (HF), and 60% fat + ASE (HF + ASE) for 12 weeks. We evaluated the food intake, body weight gain, serum glucose and lipid profile, hepatic cholesterol and triacyglycerol (TG), hepatic expression of pAMPK, lipogenic proteins (SREBP-1c, pACC, ACC, HMG-CoA reductase) and cholesterol excretion transporters, ABCG5 and ABCG8. We also evaluated the steatosis in liver sections and oxidative stress. ASE reduced body weight gain, food intake, glucose levels, accumulation of cholesterol and TG in the liver, which was associated with a reduction of hepatic steatosis. The increased expressions of SREBP-1c and HMG-CoA reductase and reduced expressions of pAMPK and pACC/ACC in HF group were antagonized by ASE. The ABCG5 and ABCG8 transporters expressions were increased by the extract. The antioxidant effect of ASE was demonstrated in liver of HF mice by restoration of SOD, CAT and GPx activities and reduction of the increased levels of malondialdehyde and protein carbonylation. In conclusion, ASE substantially reduced the obesity and hepatic steatosis induced by HF diet by reducing lipogenesis, increasing cholesterol excretion and improving oxidative stress in the liver, providing a nutritional resource for prevention of obesity-related adiposity and hepatic steatosis

Effects of HF diet and ASE on body mass, food intake, energy intake, visceral adipose mass and liver parameters of C57BL/6 mice

<p>Data are means ± SEM, n = 8 for all groups.</p><p>*Significantly different from the Control and Control+ASE groups (p< 0.05).</p><p>^†Significantly different from the corresponding HF group (p< 0.05).</p><p>Effects of HF diet and ASE on body mass, food intake, energy intake, visceral adipose mass and liver parameters of C57BL/6 mice</p

MALDI-TOF mass spectrum of the aqueous fraction residue from ASE.

<p>The spectrum was obtained on a Bruker Autoflex Speed; DHB matrix, 1:1:10 (sample: NaCl:matrix). Mass peaks are of sodium adducts of B-type proanthocyanidins: [M + Na] + m/z = 889, 903, 1177, 1193, 1465, 1481, 1753, 1769, 2041, 2058, 2329, 2347, 2617, 2634, 2907, 2922, 3193 and 3211.</p

Food intake and body weight.

<p>Effects of ASE on food intake (A) and body weight (B) were analyzed weekly. Body weight gain (C) was measured from the 4^th week until the 17^th week in HF fed mice. Values are means±SEM, n = 8 for all groups. *Significantly different from the control and ASE groups (p≤.05). ⁺Significantly different from the corresponding HF group (p≤.05). ^#Significantly different from the control and ASE groups (p≤.05).</p