RESUMEN
Today, problems of treating wastewater spent caustic produced by refinery units with high toxic compounds and chemical oxygen demand (COD) become concerns of many managers of these industries and environmental experts. Hence, emission without application of treatment methods will have adverse environmental impacts. In this study, two direct acid neutralization (DAN) and wet air oxidation (WAO) processes were selected to treatment the wastewater of the Bandar Abbas oil refinery in southern Iran. The aim was to reduce COD and harmful substances, compare the two methods, optimize processes, and evaluate their performance. Experimental experiments were performed in a reactor system with different input variables related to two different methods. Parameter optimization was performed based on Box-Behnken (BBD) method and Design Expert software. The analysis of the results based on statistical methods and response procedure diagrams was used to evaluate the status of COD changes to the parameters. The best operating conditions of temperature, pressure, residence time, and stoichiometric coefficient of air were 148.269 °C, 15.716 bar, 3.563 h, and 8.415 l/h respectively in WAO with 68% reduction in COD, and for DAN process, temperature, pH, and agitation speed were 30.082 °C, 2.008, and 203.672 rpm, respectively, with 43% reduction in COD. Results of rapid impact assessment matrix (RIAM) showed that WAO process with a higher score is a more environmentally friendly method and DAN process has been considered by experts due to its popularity, ease of testing, less equipment requirements, and lower cost.
Asunto(s)
Cáusticos , Contaminantes Químicos del Agua , Aire , Análisis de la Demanda Biológica de Oxígeno , Monitoreo del Ambiente , Residuos Industriales/análisis , Industria del Petróleo y Gas , Oxidación-Reducción , Eliminación de Residuos Líquidos , Aguas ResidualesRESUMEN
In this study, the immunomodulatory effects of Salvia mirzayanii were investigated. Study of the effect of this plant on activated human peripheral blood lymphocytes showed stimulatory effects at lower concentrations and inhibitory effects at higher ones (p < 0.01). In flow cytometry analysis, accumulation of apoptotic cells in the sub-G1 phase of the cell cycle of the mitogen-treated lymphocytes exposed to the inhibitory doses of the extract was observed. DNA fragmentation analysis of these cells showed a typical DNA laddering. Immunisation of extract-treated mice with the antigen decreased delayed hypersensitivity skin reaction as well as the antibody titre at higher concentrations (p < 0.007). These results indicated the presence of immunomodulatory compounds in the extract of S. mirzayanii and suggest that the induction of apoptosis in lymphocytes might be the mechanism responsible for the inhibitory effect of the extract that was observed at higher concentrations.