Bioprocess Biosyst Eng
September 2021
Biomass samples from a structured-bed reactor subjected to recirculation and intermittent aeration (SBRRIA) were analyzed to investigate the bacterial community shift along with the changes in the C/N ratio. The C/N ratios tested were 7.6 ± 1.
View Article and Find Full Text PDFThe ADNMED (Anaerobic Digestion, Nitrification, and Mixotrophic Endogenous Denitrification) system comprises a triple chamber configuration that was shown to provide high-quality effluent regarding carbon, nitrogen, and sulfide. Hydraulic retention time (HRT) was 7 h in the anaerobic and anoxic chambers, and 5 h in the aerobic chamber (stage A). Sewage was directly added to the anoxic chamber to provide extra organic electron donors for denitrification (stage B) to improve the nitrogen removal efficiency (stage A 47 ± 19%).
View Article and Find Full Text PDFA microbial community was enriched in the anoxic compartment of a pilot-scale bioreactor that was operated for 180 days, fed with sewage and designed for organic matter, nitrogen and sulfide removal by coupling anaerobic digestion, nitrification and mixotrophic denitrification. Denitrification occurred with endogenous electron donors, mainly sulfide and residual organic matter, coming from the anaerobic compartment. The microorganisms involved in denitrification with sulfide as electron donor were identified by DNA-stable isotope probing with [U-C]-labelled CO and NaHCO.
View Article and Find Full Text PDFAnaerobic granule sizes from various types of anaerobic biological wastewater treatments were investigated in order to understand the influence of this characteristic on the performance of the treatment system. To date, there is no standardised methodology in the current literature, which provides details of a process to obtain data, such as a suitable sample volume, a description of the precision and limitations of the techniques used. Therefore, the aim of this protocol is to standardise the granulometry assay that can measure granule sizes accurately and quickly.
View Article and Find Full Text PDFA pilot-scale reactor treating domestic sewage was operated to promote anaerobic digestion and denitrification using endogenous electron donors. While 55 % of organic matter was removed, nitrogen and sulfur showed a different dynamics during the operation. Pyrosequencing analysis clarified this behavior revealing that specific microbial communities inhabited the anaerobic (47.
View Article and Find Full Text PDFThe most-probable number (MPN) technique along with methane uptake determinations were used to estimate the density of methanotrophic organisms in the biological reactors used for wastewater treatment. The experimental technique was conducted using serum bottles seeded with an inoculum taken from an aerobic sequencing batch reactor that used methane as the sole carbon source. To verify the presence ofmethanotrophic organisms in the support media, biomass samples were subjected to molecular cloning and sequencing techniques.
View Article and Find Full Text PDFA polyurethane packed-bed-biofilm sequential batch reactor was fed with synthetic substrate simulating the composition of UASB reactor effluents. Two distinct ammonia nitrogen concentrations (125 and 250 mg l(-1)) were supplied during two sequential long-term experiments of 160 days each (320 total). Cycles of 24h under intermittent aeration for periods of 1h were applied, and ethanol was added as a carbon source at the beginning of each anoxic period.
View Article and Find Full Text PDFThe performance and the granules characteristics of a 450 m(3) -UASB reactor operating for 1228 days, treating poultry slaughterhouse wastewater with an average COD reduction of 85% was examined. Granules were sampled in three different positions along the vertical central line of the reactor, revealing variations in the concentration of volatile total solids. Although the reactor had been in operation for an extended period of time, granule sizes of 0.
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