RESUMO
This work investigated the biological activities and nitrogen and phosphorus removal during the anabaena flos-aquae biofilm growth on the polyvinyl chloride (PVC) carriers, in different nutrient form mediums. The study showed that the production of dehydrogenase activity (DHA) and extracellular polymeric substances (EPS) can reach 40.4â¯g/(h·m2) and 115â¯×â¯10-2â¯g/m2 in an 11-day period, respectively, indicating that the anabaena flos-aquae biofilm had high biological activities. The results showed that the nitrogen and phosphorus removal reached 94.9 and 96.8%, respectively, in the ammonium form nitrogen group; while 97.7% of phosphorus were removed in the orthophosphate form phosphorous group. A comparison study was conducted and results showed that the present anabaena flos-aquae based biofilm provided a better removal of nitrogen and phosphorus than the other microalgae biofilms.
Assuntos
Dolichospermum flosaquae , Nitrogênio , Fósforo , Anabaena , Biofilmes , MicroalgasRESUMO
A novel method for the determination of the diffusion coefficient (D) of methanol in water and olive oil has been developed. Based on multiple headspace extraction gas chromatography (MHE-GC), the methanol released from the liquid sample of interest in a closed sample vial was determined in a stepwise fashion. A theoretical model was derived to establish the relationship between the diffusion coefficient and the GC signals from MHE-GC measurements. The results showed that the present method has an excellent precision (RSD<1%) in the linear fitting procedure and good accuracy for the diffusion coefficients of methanol in both water and olive oil, when compared with data reported in the literature. The present method is simple and practical and can be a valuable tool for the determination of the diffusion coefficient of volatile analyte(s) into food simulants from food and beverage packaging material, both in research studies and in actual applications.