Search results for "DENITRIFICATION"

Dénitrification et émission de N2O par des sols soumis à une fertilisation organique ou minérale. Cas des effluents porcins

2007

Les effets des apports à long terme (9 ans) de lisier de porc ou de nitrate d’ammonium sur l’activité énitrifiante, la production de N2O et le carbone organique du sol (C extractible, C de la biomasse microbienne et C organique total) ont été comparés sur des parcelles adjacentes à trois profondeurs différentes. L’activité dénitrifiante a été mesurée sur des cylindres de sol non remanié et sur des échantillons de sol tamisés avec la méthode à l’acétylène afin d’estimer la vitesse de dénitrification aux conditions du champ ou en conditions potentielles. Les applications de lisier ont eu un effet modéré sur les pools de C. La teneur en C organique total a été augmentée de 6,5% et la taille de…

Promenade among terrestrial denitrifiers: from genetics to ecology

2011

Technosols to reclaim industrial wastelands: depth distribution of abundance and activity of N-cycling microbial communities

2012

International audience; Construction of Technosols through assemblage of treated soil and recycled wastes is an innovative option for the restoration of degraded lands and re-use of industrial wastes. Recent studies have evidenced that Technosols could support soil functions such as primary production but the knowledge about other ecosystemic services, such as nutrient cycling, is limited. In this work, we investigated the abundance and the activity of microbial communities involved in N-cycling in different horizons (0–15, 15–35, 35–70 cm) of two types of Technosols constructed to reclaim an industrial wasteland. The estimation by real-time PCR of the abundances of the different microbial …

How agricultural practices affect the different bacterial communities involved in the denitrification process: the case of direct seeding in Madagasc…

2007

International audience

Nitrogen cycling microbial communities: from diversity to interactions and functions

2019

Soil microorganisms form one of the largest biodiversity reservoirs on earth. They also play essential roles in ecosystem functions such as biogeochemical cycling. However, the importance of microbial community diversity and composition for ecosystem functioning is still debated. A sound understanding of the ecological processes governing the assembly of these communities in the environment is also missing. In this talk, I will give examples of how we addressed these knowledge gaps using nitrogen cycling microorganisms as model functional guilds. Nitrogen is the most limiting nutrient for crop production in agriculture. The nitrogen cycle is also one which was pushed by human activities out…

Traking nitrate reducers and denitrifiers in the environment

2005

The ability to respire nitrate when oxygen is limited has been described in taxonomically diverse microorganisms including members of the alpha-, beta-, gamma- and epsilon-proteobacteria, high and low GC Gram-positive bacteria and even Archaea. Respiratory nitrate reduction is the first step of the denitrification pathway, which is important since it is the main biological process responsible for the return of fixed nitrogen to the atmosphere, thus completing the nitrogen cycle. During the last decade, considerable knowledge has been accumulated on the biochemistry and genetics of the nitrate reductases. In this paper, we summarize the recent progress in molecular approaches for studying th…

Impact des systèmes de culture en protection intégrée contre les adventices sur l'intensité des émissions de N2O par les sols

2013

Design of nutrient removal activated sludge systems

2003

A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed.

Calcium effect on enhanced biological phosphorus removal.

2006

The role of calcium (Ca) in enhanced biological phosphorus removal and its possible implications on the metabolic pathway have been studied. The experience has been carried out in an SBR under anaerobic–aerobic conditions for biological phosphorus removal during 8 months. The variations of influent Ca concentration showed a clear influence on the EBPR process, detecting significant changes in YPO4. These YPO4 variations were not due to influent P/COD ratio, pH, denitrification and calcium phosphate formation. The YPO4 has been found to be highly dependent on the Ca concentration, increasing as Ca concentration decreases. The results suggest that high Ca concentrations produce “inert” granul…

DESASS: A software tool for designing, simulating and optimising WWTPs

2008

This paper presents a very useful software tool to design, simulate and optimise wastewater treatment plants. The program is called DESASS (DEsign and Simulation of Activated Sludge Systems) and has been developed by CALAGUA research group. The mathematical model implemented is the Biological Nutrient Removal Model No.1 (BNRM1) which allows simulating the most important physical, chemical and biological processes taking place in treatment plants. DESASS calculates the performance under steady or transient state of whole treatment schemes including primary settlers, volatile fatty acid generation systems by primary sludge fermentation, activated sludge systems for biological organic matter a…