Simultaneous formaldehyde biodegradation and denitrification in batch assays and in a continuous lab-scale reactor were studied. In batch assays, initial biodegradation rates between 0.7 and 3.3 g CKH2O g VSS(-1) d(-1) were obtained at formaldehyde concentrations between 300 and 2150 mg l(-1). The denitrification process was affected by the presence of formaldehyde. The nitrite accumulation inc...

In this study granular sludge taken from a denitrifying upflow sludge reactor was characterized. Denitrification rates were determined in batch tests with and without external carbon source addition and pH microprofiles of the granules were studied. The microbial community structure was also determined. The results showed that denitrification without carbon source addition occurs; however, the ...

Despite decades of measurements, the nitrogen balance of temperate forest catchments remains poorly understood. Atmospheric nitrogen deposition often greatly exceeds streamwater nitrogen losses; the fate of the remaining nitrogen is highly uncertain. Gaseous losses of nitrogen to denitrification are especially poorly documented and are often ignored. Here, we provide isotopic evidence (δ(15)NNO...

Denitrifying organisms are essential in removing fixed nitrogen pollutants from ecosystems (e.g. sewage sludge). They can be detrimental (e.g. for agricultural soil) and can also produce the greenhouse gas N2O (nitrous oxide). Therefore a more comprehensive understanding of this process has become increasingly important regarding its global environmental impact. Even though bacterial genome seq...

A novel combined system established for nitrate removal from aqueous solution consisted of two parts: sulfur autotrophic denitrification and bio-electrochemical denitrification based on proton-exchange membrane electrodialysis (PEMED). The system was operated at various hydraulic retention times (HRT) and current intensities. Its optimum operation condition was also determined. The combined pro...

The great diurnal variation in the quality of wastewater of small communities is an obstacle to the efficient removal of high nitrogen with traditional activated sludge processes provided by pre-denitrification. To verify this problem, the authors developed a pilot plant, in which the domestic wastewater of community of 15,000 inhabitants was treated. The results demonstrate that average and pe...

Coastal waters are severely threatened by nitrogen (N) loading from direct groundwater discharge. The subterranean estuary, the mixing zone of fresh groundwater and sea water in a coastal aquifer, has a high potential to remove substantial N. A network of piezometers was used to characterize the denitrification capacity and groundwater flow paths in the subterranean estuary below a Rhode Island...

Several studies have employed rotating biological contactors (RBCs) for nitrogen removal. However, partially submersed disks are used for nitrification, while completely submersed disks are used for denitrification. The objective of this study was to investigate the effect of disk submergence in the performance of rotating biological contactors, in terms of the denitrification process. Two RBCs...

Because of its mild reaction condition, relatively high denitrification efficiency and ability of combined removal of various pollutants, the flue gas denitrification technology based on oxidation theory has become a new and feasible method for flue gas denitrification. The technology has been applied extensively and studied in depth. This paper reviews the influencing factors, reaction mechani...

CEB Biofilm Group In biological denitrification of wastewater nitrate (NO3 -) or nitrite (NO2 -) are converted into nitrogen gas (N2), in the absence of dissolved oxygen (DO) or under limited DO concentrations. A rotating biological contactor (RBC) is an attached growth bioreactor, that constitutes a very unique and superior alternative technology for carbon oxidation, phosphorus removal, nitri...