This paper presents findings of an investigation into the relationships between nitrate utilization rate (NUR), pH and oxidation reduction potential (ORP) during anoxic transformation processes in municipal wastewater. The study utilized municipal wastewater obtained from a wastewater treatment plant located within Shah Alam, Malaysia. Denitrification was observed by monitoring the change in ni...

18 Denitrification was measured in three structurally different coastal microbial mats by 19 using the stable isotope technique. The composition of the denitrifying community was 20 determined by analyzing the nitrite reductase (nirS and nirK) genes using clone libraries 21 and the GeoChip. The highest potential rate of denitrification (7.0±1.0 mmol N m d) 22 was observed during summer at stati...

The feasibility of removing nitrogen from mature landfill leachate using the nitrite route was investigated in a two-stage SBR system – (1 first stage, short-cut nitrification; second stage, denitrification via nitrite. With a volumetric exchange rate (n) of 0.3 d and an oxygen concentration of between 1.2 and 1.3 mg/L, the nitrite accumulation ratio – (NO2-N)×100/(NOx-N)% – was between 32% and...

The objective of this research was to investigate the performance of a hollow fibre membrane bioreactor (HFMB) for hydrogenotrophic denitrification of contaminated drinking water. In the HFMB, H2 flows through the lumen of the hydrophobic hollow fibres and diffuses to an attached H2 oxidizing biofilm. Nitrate in the contaminated water serves as an electron acceptor. A hydrogenotrophic denitrify...

In response to impending anoxic conditions, denitrifying bacteria sustain respiratory metabolism by producing enzymes for reducing nitrogen oxyanions/-oxides (NOx) to N2 (denitrification). Since denitrifying bacteria are non-fermentative, the initial production of denitrification proteome depends on energy from aerobic respiration. Thus, if a cell fails to synthesise a minimum of denitrificatio...

..................................................................................................................................... 18 Introduction................................................................................................................................ 19 Experimental Methodology ..............................................................................................

A solar photo-Fenton process combined with a biological nitrification and denitrification system is proposed for the decontamination of a landfill leachate in a pilot plant using photocatalytic (4.16 m(2) of Compound Parabolic Collectors - CPCs) and biological systems (immobilized biomass reactor). The optimum iron concentration for the photo-Fenton reaction of the leachate is 60 mg Fe(2+) L(-1...

Homogeneous freezing of nitric acid hydrate particles can produce a polar freezing belt in either hemisphere that can cause denitrification. Computed denitrification profiles for one Antarctic and two Arctic cold winters are presented. The vertical range over which denitrification occurs is normally quite deep in the Antarctic but limited in the Arctic. A 4 kelvin decrease in the temperature of...

The aim of this study was to investigate efficiency of ammonium nitrogen removal from municipal landfill leachate in activated sludge in two-stage SBR reactors. Treated leachate contains low concentrations of organic substances measured as chemical oxygen demand (COD) − 757 mg O2/dm 3 and high concentrations of ammonium − 362 mgNNH4/dm 3. Nitrification was studied in two parallel, aerated SBR r...