RESUMO
The applicability of four industrial waste streams from potato processing, canola processing and oil refining, biodiesel production (glycerol), and glycol as substitutes to methanol and ethanol in denitrification of anaerobically digested sludge dewatering liquor (centrate) was evaluated in bench-scale sequencing batch reactors. It was found that glycerol was the best substitute with the specific denitrification rate (SDNR) of 13 mg NO3-N/(g VSS x h) followed by potato processing wastewater at 12mg NO3-N/(g VSS x h). Both substrates produced faster SDNR than methanol's 10mg NO3-N/(g VSS x h); however, they were inferior to ethanol's 17 mg NO3-N/(g VSS x h). Glycol had SDNR of 8 mg NO3-N/(g VSS x h) and demonstrated a very fast acclimation rate, i.e. the response in increased denitrification rate was visible in three days following glycol addition. Canola processing and oil refining wastewater was considered an inappropriate carbon source due to a low SDNR of 5 mg NO3-N/(g VSS x h) and apparent inhibitory effect on nitrification.
Assuntos
Carbono/metabolismo , Resíduos Industriais/prevenção & controle , Nitrogênio/metabolismo , Esgotos/microbiologia , Águas Residuárias/microbiologia , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos , Indústria Alimentícia , Nitrificação , Nitrogênio/química , Nitrogênio/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
The effect of a full-scale municipal wastewater treatment plant (WWTP) and each of the treatment units within the stream on the removal of endocrine-disrupting compounds was evaluated by tracking 17-beta-estradiol (E2), estrone (E1), and 17-alpha-ethinylestradiol (EE2). The overall performance of the WWTP compared well with other plants, as 90.5% removal of E1+E2 and 74.9% removal of EE2 were observed. A larger fraction of EE2 entered the plant in particulate form than E1 and E2, while a lower fraction of EE2 left the plant in particulate form than soluble form. The activated sludge units reduced the concentration of E1+E2 and EE2 in the liquid phase by 88.2% and 44.6%, respectively. The UV treatment process did not reduce the amount of estrogens. The aqueous phase of the tertiary lagoon solids contained higher levels of estrogens compared with the lagoon influent.