RESUMO
Wastewater from a cosmetic factory, with an initial chemical oxygen demand (COD) of 1140â¯mg/L, was treated using a combined light/Fe0/H2O2 process followed by biological treatment. The light/Fe0/H2O2 process, with 1000/2280â¯mg/L Fe0/H2O2 doses and 120â¯min process time, resulted in 70% COD removal, to final COD of 341â¯mg/L. The chemically treated wastewater was successfully subjected to biological treatment in a sequencing batch reactor (SBR), with up to 20% volume fraction in the influent, without significant deterioration of COD, nitrogen and phosphorus removal, but with possible small negative effects on polyphosphate accumulating organisms (PAOs), nitrifiers and other bacteria present in the microbial community. The COD of the effluent was in the range of 14-28â¯mg/L, resulting in overall COD removal of up to 97.7%. Untreated cosmetic wastewater, subjected to biological treatment in SBR, caused crucial changes in the microbial community structure, leading to a significant decrease in the efficiency of organic carbon, nitrogen and phosphorus removal.
Assuntos
Cosméticos/análise , Peróxido de Hidrogênio/química , Ferro/química , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análise , Purificação da Água/métodos , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos/microbiologia , Carbono/química , Resíduos Industriais , Luz , Microbiota , Nitrogênio/química , Oxigênio , Fósforo/química , Polifosfatos/químicaRESUMO
Filamentous population in activated sludge and key operational parameters of full-scale municipal wastewater treatment plants (WWTPs) with bulking problems representative for Poland were investigated with quantitative fluorescence in situ hybridization. Statistical analyses revealed few relationships between operational parameters and biovolume of filamentous bacteria. Sludge age was not only positively correlated with abundance of Chloroflexi (parametric correlation and principal component analysis (PCA)), but also differentiated Microthrix population (analysis of variance (ANOVA)). Phylum Chloroflexi and pH presented a negative relation during the study (PCA). ANOVA showed that pH of influent and sludge volume index (SVI) differentiated abundance of types 0803 and 1851 of Chloroflexi and candidate division TM7. SVI increased along with higher abundance of Microthrix (positive parametric and non-parametric correlations and positive relation in PCA). Biovolumes of morphotypes 0803 and 1851 of Chloroflexi were differentiated by organic matter in influent, also by nutrients in the case of Chloroflexi type 1851. Chemical and biological oxygen demands (COD and BOD5, respectively) were negatively correlated with Microthrix. COD also differentiated the abundance of Haliscomenobacter hydrossis. Results of the study can be used to prevent WWTPs from excessive proliferation of filamentous bacteria and operational problems caused by them--bulking and foaming of activated sludge.