RESUMO
Soluble microbial products (SMP) generated by activated sludge cultures receiving a mixed feed of phenol and glucose were characterized with respect to molecular weight (MW) distribution, octanol-water partition coefficient (K(ow)), and Microtox toxicity. Short-term batch reactor tests using 14C-labeled substrates were performed to collect SMP derived from each substrate, while long-term tests were performed with SMP accumulated over multiple feed cycles using fed-batch reactors receiving non-labeled substrates. Yield of SMP in the batch tests, 10%-20% for phenol and 2%-5% for glucose, differed for each substrate and was independent of initial concentration. The MW distribution (MWD) of SMP was independent of feed composition, and was bimodal in the < 1 kDa and 10-100 kDa MW ranges for phenol-derived SMP and predominantly < 1 kDa for glucose-derived SMP. In the non-labeled tests, the fraction of SMP of MW > 100 kDa increased with the proportion of glucose in the feed. The K(ow) of phenol-derived SMP was higher compared to glucose-derived SMP, indicating that the phenol-derived SMP were more hydrophobic. This was particularly true at an acidic pH, where the K(ow) was 4.2 +/- 1.0 for phenol-derived SMP versus 0.13 +/- 0.13 for glucose-derived SMP. Toxicity testing indicated that phenol-derived SMP, exerting a mean Microtox inhibition of 1%, were less toxic than phenol itself, and showed little correlation between toxicity and concentration. However, glucose-derived SMP were generally more toxic than glucose itself (a non-toxic substrate), and the toxicity increased linearly with the concentration of SMP.
Assuntos
Reatores Biológicos/microbiologia , Glucose/metabolismo , Fenol/metabolismo , Esgotos/microbiologia , Aliivibrio fischeri/efeitos dos fármacos , Biodegradação Ambiental , Biomassa , Misturas Complexas/química , Misturas Complexas/farmacologia , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Peso Molecular , Octanóis/química , Solubilidade , Testes de Toxicidade , Eliminação de Resíduos Líquidos/métodos , Água/químicaRESUMO
Tomando en cuenta los distintos efluentes industriales que tienen una precipitación de metales pesados, este trabajo trata distintos procesos para su separación y da datos de reacciones químicas
Assuntos
Adsorção , Carvão Vegetal , Compostos Orgânicos , Efluentes Industriais , Metais Pesados , Oxidação , Tratamento de Efluentes Industriais , Troca IônicaRESUMO
Tomando en cuenta los distintos efluentes industriales que tienen una precipitación de metales pesados, este trabajo trata distintos procesos para su separación y da datos de reacciones químicas
