RESUMO
This study investigates the treatment of the distilleries vinasse using a hybrid process integrating ozone oxidation and granular activated carbons (GAC) in both batch and continuous operation mode. The batch-process studies have been carried out to optimize initial influent pH, GAC doses, the effect of the ozone (O3) and hydrogen peroxide (H2O2) concentrations on chemical oxygen demand (COD) and color removal of the distilleries vinasse. The continuous process was carried out on GAC and ozone treatment alone as well as the hybrid process comb both methods to investigate the synergism effectiveness of the two methods for distilleries vinasse COD reduction and color removal. In a continuous process, the Yan model described the experimental data better than the Thomas model. The efficiency of ozonation of the distilleries vinasse was more effective for color removal (74.4%) than COD removal (25%). O3/H2O2 process was not considerably more effective on COD and color removal. Moreover, O3/GAC process affected negatively on the removal efficiency by reducing COD and color from distilleries vinasse. The negative effect decreased by increasing pH value of the influent.
Assuntos
Carvão Vegetal/química , Corantes/química , Resíduos Industriais , Ozônio/química , Poluentes Químicos da Água/química , Humanos , Oxigênio/química , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodosRESUMO
Nowadays, the adverse effect of toxic metals on humans is well known, especially in the fetal period such as preventing cognitive development and congenital abnormalities of the central nervous system. Hence, this study aims to evaluate the toxic metal burden in mothers and newborns in Sabzevar. Obtained data can be useful for authorities in public health issues. To determine heavy metals in placental blood and umbilical cord blood, one hundred eighty blood samples were taken from ninety mothers referred to Shahidan Mobini Hospital for delivery. The amount of metals in samples was analyzed using inductively coupled plasma optical emission spectrometry (ICP OES). The results of this study revealed that 21.52%, 26.19%, and 60.71% of maternal blood samples (placental blood) and 16.47%, 56.47%, and 20% of umbilical cord blood samples were higher than the US center for disease control (CDC) recommended levels for Pb, Cd, and As respectively. According to the multiple linear regression analysis, the Pb (p = 0.054), As (p < 0.001), and Se (p < 0.001) levels had an association with the mother's living area. Also, there was a significant association between Se (0.021) and the age of the mother. However, the Se values in its optimum concentrations in the blood (60-140 µg/L) can decrease the adverse effects of toxic metals, 72.5% of the pregnant women had Se values below the 60 µg/L and only 6% of pregnant women had Se levels higher than 140 µg/L. We concluded that the mothers inhabiting the rural areas need more Se sources in their diets.
Assuntos
Monitoramento Biológico , Metais Pesados , Feminino , Recém-Nascido , Humanos , Gravidez , Exposição Materna , Cádmio/análise , Placenta , Gestantes , Irã (Geográfico) , Chumbo/análise , Metais Pesados/análise , Intoxicação por Metais Pesados , Sangue Fetal/química , Fatores de RiscoRESUMO
Fetuses and young children are sensitive to even low levels of exposure to Hg, which can damage their brain and adversely affect their central nervous system and cognitive development. This study was conducted to determine the maternal and fetal mercury burden levels in mothers presenting to Shahidan Mobini Hospital for delivery. Eighty-nine mothers were included in this study and 360 samples were taken from their placental tissue and blood (maternal blood) as well as their umbilical cord tissue blood (infant blood). Findings revealed a significant strong correlation (râ¯=â¯0.890, pâ¯<â¯0.001) in blood mercury between mothers and their infants. According to multiple linear regression analysis, there was a significant positive association between living in rural areas and the level of mercury in the placental tissue (ßâ¯=â¯11.09, pâ¯<â¯0.001). This positive association was also found in other samples. In addition, there was a significant association between maternal age and mercury level in the placental tissue (ßâ¯=â¯5.56, pâ¯=â¯0.049), placental blood (ßâ¯=â¯11.67, pâ¯=â¯0.003), umbilical cord tissue (ßâ¯=â¯8.33, pâ¯=â¯0.004) and umbilical cord blood (ßâ¯=â¯9.51, pâ¯<â¯0.001).