Characterization and performance of constructed nitrifying biofilms during nitrogen bioremediation of a wastewater effluent

Abstract

Constructed ammonium oxidizing biofilms (CAOB) and constructed nitrite oxidizing biofilms (CNOB) were characterized during the bioremediation of a wastewater effluent. The maximum ammonium removal rate and removal efficiency in CAOB was 322 mg N-NH4+ m(-3) d(-1) and 96%, respectively, while in CNOB a maximum removal rate of 255 mg N-NH4+ m(-3) d(-1) and a removal efficiency of 76% was achieved. Both constructed biofilms on low-density polyester Dacron support achieved removal efficiencies higher than that of the concentrations normally present in reactors without constructed biofilms (P < 0.05). Nitrifying bacteria from the constructed biofilms cultures were typed by sequencing 16S rRNA genes that had been amplified by PCR from genomic DNA. Analysis of enrichment biofilms has therefore provided evidence of high removal of ammonium and the presence of Nitrosomonas eutropha, N. halophila and N. europaea in CAOB, while in CNOB Nitrobacter hamburgensis, N. winogradskyi and N. alkalicus were identified according to 16S rRNA gene sequences comparison. The biofilm reactors were nitrifying over the whole experimental period (15 days), showing a definite advantage of constructed biofilms for enhancing a high biomass concentration as evidenced by environmental electron microscopic analysis (ESEM). Our research demonstrates that low-density polyester Dacron can be effectively used for the construction of nitrifying biofilms obtaining high removal efficiencies of nitrogen in a relatively short time from municipal effluents from wastewater treatment plants. CAOB and CNOB are potentially promissory for the treatment of industrial wastewaters that otherwise requires very large and expensive reactors for efficient bioremediation of effluents.

Optimization of Nitrification Process by a Bacterial Consortium in the Submerged Biofiltration System with Ceramic Bead Carrier

“…The stimulating effect of pretreatment with molasses was more pronounced at a lower initial concentration of ammonium sulphate, i.e., 2.5 g/L ( Figure 6). As previously documented [29], the activity of ammonium-oxidizing bacteria, in particular Nitrosomonas spp., varies with ammonium concentrations.…”

“…The ability of Nitrobacter spp. to grow heterotrophically has also been documented previously [29,32,33].…”

Simultaneous Nitrification and Denitrification of Wastewater Using a Silicone Membrane Aerated Bioreactor

“…Other benefits of the membrane system include the protection of the microorganisms against microbial loss by flushing, shear stress, and inhibitory substances. The support matrix provided by the membrane tubing helped maintain the biofilm and promoted greater flow rates through the reactor systems (Franco-Rivera et al, 2007).…”

Desenvolvimento de métodos miniaturizados de extração em fase sólida para a pré-concentração de produtos de degradação de fluoroquinolonas e sulfonamidas em matrizes aquosas

“…Um dos fatores chave no desenvolvimento de reatores anaeróbios é o ajuste das condições hidrodinâmicas para favorecer a compactação da biomassa, mas ainda assim garantir grande contato entre os substratos do esgoto e a biomassa 63 . A operação de biorreatores anaeróbios depende do desempenho da população microbiana presente no lodo.…”

“…A operação de biorreatores anaeróbios depende do desempenho da população microbiana presente no lodo. Dessa forma, torna-se indispensável a caracterização do lodo em termos microbiológicos, cinéticos e físico-químicos 63 .…”