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RESUMO O tipo de material utilizado como recheio em filtros anaeróbios pode ser determinante na eficiência do tratamento, então a avaliação de novos materiais se torna importante. Assim, o objetivo deste trabalho foi estudar o comportamento de três filtros anaeróbios de fluxo ascendente, operados de modo contínuo, preenchidos com carvão ativado, cerâmica de argila e borracha de pneu, no tratamento de água residuária sintética com glicose como substrato. Os filtros, em escala de bancada (1,3 L), foram operados com tempo de detenção hidráulica (TDH) de oito e quatro horas, em duas etapas. Seu desempenho, avaliado com o emprego dos parâmetros pH, alcalinidade total e bicarbonato e ácidos voláteis, foi estável nas duas etapas de operação. O filtro que obteve maior eficiência em termos de remoção de demanda química de oxigênio (DQO) foi o com carvão ativado, 94 e 81% nas etapas I e II, respectivamente, seguido do com borracha de pneu, 88 e 63%, e do com cerâmica de argila, 81 e 61%, ambos nas etapas I e II, respectivamente. As principais morfologias encontradas nos meios suportes foram bacilos, cocos, filamentos, Methanosaeta sp. e Methanosarcina sp. As diferenças obtidas entre os filtros podem ser relacionadas com as características distintas de cada material utilizado como meio suporte, e as diferenças entre as etapas ocorrem pelo aumento da carga hidráulica, que diminui o tempo de retenção celular, assim como eventuais diferenças de temperatura.
ABSTRACT The type of material used as packing in anaerobic filters may be a determinant factor in the treatment efficiency, so the evaluation of new materials is important. Thus, the objective of this study was to study the behavior of three upflow anaerobic filters, filled with charcoal, clay pottery and tire rubber, in the treatment of synthetic wastewater with glucose as substrate. The filter, in bench scale (1.3 L), was operated at a HRT of 8 and 4 hours, in two phases. The performance of the filters, in terms of pH, total alkalinity and bicarbonate and volatile acids was stable during the two operational phases. The best filter in terms of COD removal efficiency was the one with activated carbon, 94 and 81%, in Phases I and II, respectively, followed by tire rubber filter, 88 and 63%. The lowest efficiency obtained was the ceramic clay filter, with 81 and 61%, in Phases I and II, respectively. The main morphologies found were bacilli, cocci, filaments, Methanosaeta sp. and Methanosarcina sp. The differences obtained between filters are related to the different characteristics of each material, and the differences between phases are due to the hydraulic load increase and subsequent cellular retention time decrease, as well as an eventual temperature difference.
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Objective To develop a pottery frame to facilitate warm acupuncture moxibustion.Methods The frame was made of clay,and was composed of a moxa wool retaining table,a handle,a base and a support.The moxa wool holding table had a hollow structure wide at the top and narrow at the bottom,and there was a slot at its middle to hold the needle;while the base had a hollow structre narrow at the top and wide at the bottom,and there were several air vents at its inner wall to accelerate the full combustion of the moxa wool.Results The frame avoided patient burn due to dropped spark or overweight moxa cone during traditional warm acupuncture moxibustion therapy, and relieved the patients' pain and medical staffs' workload. Conclusion The frame has simple structure, easy operation, high safety, high patient satisfaction and high practicability.
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Objetivo: Describir la relación de los niveles de plomo en sangre y reprobación escolar. Material y métodos: Estudio transversal en 792 escolares de 7 a 14 años de edad asistentes a la consulta externa de cinco hospitales pediátricos de la ciudad de México en 1996. Se midió el nivel de plomo en sangre, se exploró la exposición al metal, así como el desempeño académico. Resultados: Se reportó una media de plomo en sangre de 8.6 μg/dL y una media geométrica de 7.7 μg/dL. La principal fuente de exposición fue el uso de loza de barro vidriado (diferencia de uso = 1.182, p = 0.000). En los escolares que reprobaron algún año, la media geométrica de plomo en sangre fue de 8.1 μg/dL, en comparación con los niños que no reprobaron (media geométrica = 7.6 μg/dL, p = 0.240). El riesgo de reprobar entre el primer y el tercer año de primaria con plomo en sangre mayor a 10 μg/dL fue de 1.73 (p=0.012, IC 95% 1.13-2.66), y del primero al cuarto año de primaria fue de 1.62 (p=0.021, IC 95% 1.07-2.46). Conclusiones: Es probable que el plomo sanguíneo, entre otros condicionantes, contribuya a la reprobación repetida en los escolares de este estudio.
OBJECTIVE: To describe the relationship between blood lead levels (BLL) and poor school performance. MATERIAL AND METHODS: A cross-sectional study was carried out in 1996 among 792 schoolchildren aged 7-14 years, who attended the outpatient units of five pediatric hospitals of Mexico City. BLL was measured together with lead exposure and academic performance. RESULTS: Reported BLL and geometric means (GM) were 8.6 microg/dL and 7.7 microg/dL, respectively. The main source of exposure was the use of glazed pottery (difference of use =-1.182; p = 0.000). Among schoolchildren who failed any school year, GM of the BLL was 8.1 microg/dL, compared with children who did not fail (GM = 7.6 microg/dL; p = 0.240). The risk of failing a school year between the 1st and 3rd grade with a BLL greater than 10 microg/dL was 1.73 (p = 0.012, IC 95% 1.13-2.66) and from 1st to 4th grade was 1.62 (p = 0.021, IC 95% 1.07-2.46). CONCLUSIONS: Blood lead levels, among other conditions, may contribute to the failure in school performance observed in the children participating in this study.
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Humanos , Masculino , Feminino , Criança , Adolescente , Logro , Chumbo/sangue , Estudos Transversais , México , População UrbanaRESUMO
ve To research an effective, economic and simple biological treatment technology process for purification of sewage. Methods With the sufficient supplication of oxygen, the organic compounds in domestic sewage were sufficiently oxidized and decomposed in bio-filter using activated pottery granule as packing materials. CODCr and BOD5 reflecting the effectiveness of purification of sewage were determined. Results After the treatment by activated bio-filter, the levels of CODc, of treated sewage decreased from 444.86 mg/L to 16.76 mg/L with a de-crease rate of 96.23% , the levels of BOD, decreased from 211.54 mg/L to 3.95 mg/L with a decrease rate of 98. 13% . The levels of CODCr and BOD5 of treated sewage all were below the related values of grade I standand of discharge from secondary municipal sewage treatment plant. Conclusion The purification technology using activated bio-filter was effective, economic and simple, which could be widely applied to demestic sewage purification treatment.
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AIM:To observe the influence of the different bore diameter ceramic membranes on the processing parameters of Jinlida Granules(Radix et Rhizoma Salviae miltiorrhizae,Radix Sophorae flavescentis,Rhizoma Polygonati,etc.) and optimize the process of membrane filtration. METHODS: Three different membranes were tested to observe the changes in membrane flux and the content of effective components by Jinlida Granules extract. RESULTS: The 50 nm membrane had the great flux,the transfer rates of matrine and salvianolic acid were the highest;The optimum conditions: the operation differential pressure was 0.08～0.12MPa;the operation temperature was 50～60℃;the membrane surface flow rate was 3.0 m/s.When the volume of filtration solution was condensed to one tenth,adding the same volume aeionized water,and the effective components transfer rate reached 80%.Using the strong acid and strong alkali to wash it in turn,the flux can revivify above 90%. CONCLUSION: Applying the ceramic membrane to ultrafiltrate Jinlida Granule is good and useful to herb purification.