What is the range of ...
Published by Mike Dempsey, Managing Director, Advanced Bioprocess Development Ltd.
What is the range of concentration of nitrate and nitrite?
A biological treatment could be used, e.g. autotrophic denitrification using sulphur-oxidising bacteria. Unlike ion exchange, this process does not produce a waste stream, other than a small amount of non-hazardous biomass sludge. This process produces acid, so limestone is often used to buffer the water.
Denitrification is a bacterial process where the oxygen combined in e.g. nitrate and nitrite can be used as the terminal electron acceptor in respiration but only in the absence of dissolved, molecular oxygen. However, even if there is dissolved oxygen in the water, it will soon be consumed once the process starts up and, because it will dissolve more slowly than the bacteria consume it, will be maintained at a low level that triggers nitrate/nitrite consumption.
If sulphur is used as the electron donor (energy source), then sulphate is produced. This ion is non-toxic and occurs in high concentration in many mineral waters. There is no WHO guideline limit for health, although it can be detected by taste above 500 mg/L. Therefore, unless the nitrite and nitrate concentration is extremely high, replacing these ions with sulphate will not cause a problem.
Sulphur should be easily and cheaply available in Nigeria, assuming that desulphurisation of petroleum is carried out locally.
Alternatively, organic matter can be used as the electron donor. However, as a microbiologist, I would be concerned about potential pathogens or toxin-producers growing in such a system.
1 Comment
Bonjour Les microbes sont des bactéries qui ont l'intelligence du Vivant. Dans un milieu où l'oxygène se fait rare, elles s'adaptent et réduisent leur mobilité et bien entendu leur travail qui va aussi de pair avec leur pérennisation.
Une concentration élevée d'une pollution X ou Y va les détruire. Il faut reprendre les bases de la biologie et du vivant. une adaptation s'effectue dans le temps, on parle de mutation. Cela ne peut se faire d'un coup de baguette magique à la demande.
Hello Microbes are bacteria that have the intelligence of the living. In an environment where oxygen is scarce, they adapt and reduce their mobility and of course their work which also goes hand in hand with sustainability.
A high concentration of pollution X or go to destroy them. Get the basics of biology and the living. an adaptation is made in time, we're talking about changing. This can be done a magic wand at the request.