Currently, landfills are the main method used for the final disposal of urban solid waste. The degradation processes that waste goes through in these sites, alongside rainwater that percolates through them, generate h...Currently, landfills are the main method used for the final disposal of urban solid waste. The degradation processes that waste goes through in these sites, alongside rainwater that percolates through them, generate highly polluting liquids (leachate). In the treatment of leachate, advanced oxidation processes (AOP) can significantly reduce the concentrations of different pollutants. Due to the high documented potential around AOPs, in this study, the effectiveness of anodic oxidation in the removal of the remaining organic load in leachates pretreated in a biological system was evaluated. Graphite electrodes were used as anode and cathode. The efficiency of anodic oxidation, in terms of the removal of chemical oxygen demand (COD) and color, was evaluated under different current densities (7, 12, 17 and 22 mA/cm2) and pH values (3, 4.5 and 6). Under the best conditions found (22 mA/cm2 and pH of 6) and with an oxidation time of 5 hours, a maximum removal of 68% in COD and 91% in color was achieved, which represented a quality in the final effluent of 271 mg/L and 151 Pt-Co in COD and color, respectively. Therefore, considering that graphite is an economic and widely available material, the results obtained show anodic oxidation, with the use of graphite electrodes, as a technically viable alternative as a final purification stage for pretreated leachates.展开更多
Study Objective: To determine the prevalence of vulvovaginitis, predisposing factors, microbial etiology and therapy in patients treated at the Hospital del Nino DIF, Pachuca, Hidalgo, Mexico. Design. This was an obse...Study Objective: To determine the prevalence of vulvovaginitis, predisposing factors, microbial etiology and therapy in patients treated at the Hospital del Nino DIF, Pachuca, Hidalgo, Mexico. Design. This was an observational and descriptive study from 2006 to 2009. Setting: Hospital del Nino DIF, Pachuca, Hidalgo, Mexico. Participants. Patients from 0 to 16 years, with vulvovaginitis and/or vaginal discharge were included. Interventions: None. Main Outcome Measures: Demographic data, etiology, clinical features, risk factors and therapy were analyzed. Results: Four hundred twenty seven patients with diagnosis of vulvovaginitis were included. The average prevalence to 4 years in the study period was 0.19%. The age group most affected was schoolchildren (225 cases: 52.69%). The main signs and symptoms presented were leucorrhea (99.3%), vaginal hyperemia (32.6%), vulvar itching (32.1%) and erythema (28.8%). Identified risk factors were poor hygiene (15.7%), urinary tract infection (14.7%), intestinal parasites (5.6%) and obesity or overweight (3.3%). The main microorganisms found in vaginal cultures were enterobacteriaceae (Escherichia coli, Klebsiella and Enterococcus faecalis), Staphylococcus spp, and Gardnerella vaginalis. Several inconsistent were found in the drug prescription of the patients. Conclusion: Vulvovaginitis prevalence in Mexican girls is low and this was caused mainly by opportunist microorganisms. The initial treatment of vulvovaginitis must include hygienic measure and an antimicrobial according to the clinical features and microorganism found.展开更多
文摘Currently, landfills are the main method used for the final disposal of urban solid waste. The degradation processes that waste goes through in these sites, alongside rainwater that percolates through them, generate highly polluting liquids (leachate). In the treatment of leachate, advanced oxidation processes (AOP) can significantly reduce the concentrations of different pollutants. Due to the high documented potential around AOPs, in this study, the effectiveness of anodic oxidation in the removal of the remaining organic load in leachates pretreated in a biological system was evaluated. Graphite electrodes were used as anode and cathode. The efficiency of anodic oxidation, in terms of the removal of chemical oxygen demand (COD) and color, was evaluated under different current densities (7, 12, 17 and 22 mA/cm2) and pH values (3, 4.5 and 6). Under the best conditions found (22 mA/cm2 and pH of 6) and with an oxidation time of 5 hours, a maximum removal of 68% in COD and 91% in color was achieved, which represented a quality in the final effluent of 271 mg/L and 151 Pt-Co in COD and color, respectively. Therefore, considering that graphite is an economic and widely available material, the results obtained show anodic oxidation, with the use of graphite electrodes, as a technically viable alternative as a final purification stage for pretreated leachates.
文摘Study Objective: To determine the prevalence of vulvovaginitis, predisposing factors, microbial etiology and therapy in patients treated at the Hospital del Nino DIF, Pachuca, Hidalgo, Mexico. Design. This was an observational and descriptive study from 2006 to 2009. Setting: Hospital del Nino DIF, Pachuca, Hidalgo, Mexico. Participants. Patients from 0 to 16 years, with vulvovaginitis and/or vaginal discharge were included. Interventions: None. Main Outcome Measures: Demographic data, etiology, clinical features, risk factors and therapy were analyzed. Results: Four hundred twenty seven patients with diagnosis of vulvovaginitis were included. The average prevalence to 4 years in the study period was 0.19%. The age group most affected was schoolchildren (225 cases: 52.69%). The main signs and symptoms presented were leucorrhea (99.3%), vaginal hyperemia (32.6%), vulvar itching (32.1%) and erythema (28.8%). Identified risk factors were poor hygiene (15.7%), urinary tract infection (14.7%), intestinal parasites (5.6%) and obesity or overweight (3.3%). The main microorganisms found in vaginal cultures were enterobacteriaceae (Escherichia coli, Klebsiella and Enterococcus faecalis), Staphylococcus spp, and Gardnerella vaginalis. Several inconsistent were found in the drug prescription of the patients. Conclusion: Vulvovaginitis prevalence in Mexican girls is low and this was caused mainly by opportunist microorganisms. The initial treatment of vulvovaginitis must include hygienic measure and an antimicrobial according to the clinical features and microorganism found.
