Based on samples analysed in the laboratory, the concentration of ammonia (NH4) in the blackwater liquid was increased in the effluent after separation of bio-solids. some liquid is remaining in the separator and mixed with new liquids. Is this the reason behind the increase in the ammonia levels?. Why NH4 is not converted into NO3 by nitrifying bacteria. Is this because no aeration has occurred?
Perhaps this link may help, you may note the potential for ammonium spikes in small samples.
https://www.pollutionsolutions-online.com/article/water-wastewater/17/chris_sergeant/the_management_of_ammonia_levels_in_an_aquaculture_environment/1557
The N that is bound up in the biodegradable organics can always be released into the bulk liquid as ammonia at anywhere in the process when some hydrolysis of these organics takes place, this will increase its concentration. it does not have to be in the bioreactor it can happen anywhere in the process when the biological conditions are just right for it. Furthermore, to nitrify ammonia to NO3- depends on many things, for example, you have to grow the ammonia ntrifying organisms in the system before you get nitrification, that may mean the solids retention time has to be equal or greater than the minimum required to have nitrification. even with enough oxygen in the system (aerated) you may not get nitrification. the nitrifies have to grow in the system first and that depends on the sludge age, kinetics etc.
Hi Mr. Alnahhal,
I understand that NH4 concentration in black water increased after seperation of biomass. It means, before seperation of biomass, NH4 concentration is not high, is it right? Please give information about it.
Hi Mr. Olcayto Keskinkan
Thanks for your answer and question.
Yes, exactly what happens that NH4 - N concentration in black water increases after the separation of biomass from 89.6 to 130.4 mg/l. this could be due to the hydrolysis of the organic-N as the TKN dec reases
The increase of NH4 can be due to hydrolysis of organic nitrogen to NH4 in anaerobic condition. in aerobic condition, NH4 will be oxidized to NO3. The TKN will be reduced in any case.
Dear Alnahhal,
All reserchers explained everything you needed. There's nothing left to me. Thanks to all researchers.
Hello Samir !!!
The increase of [NH4+] in black water (anaerobic conditions) is due to organic nitrogen's hydrolysis resulting to NH4+ formation. In Contrary , in aerobic conditions the NH4+ oxidation will happen toproduce NO3-.
But the T.K.N decreases in all cases.
Hi,
Just after primary treatment NH4 concentration increases because in biological treatment after it, aerobic microorganisms biodegrade the organic waste into CO2 and ammonical nitrogen i.e. NH4+. Further in aeration tank NH4 is oxidised into nitrite by Nitrosomonas bacteria and then into nitrate by Nitrobacter bacteria.
"......in black water increases after the separation of biomass from 89.6 to 130.4 mg/l. ....."
130.4-89.6=40.8 40.8/130.4=31%
If preciceness of the method of ammonium determination is plus-minus 15% than this difference of about 30% could be just in the frames of possible error.
But I also support idea about continued biodegradation. If suspended matter was removed, still bacteria remain as colloids and substrate for them remains as dissolved and colloidal matter.
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