S. Hallin et M. Pell, ACETYLENE INHIBITION FOR MEASURING DENITRIFICATION RATES IN ACTIVATED-SLUDGE, Water science and technology, 30(6), 1994, pp. 161-167
Citations number
27
Categorie Soggetti
Water Resources","Environmental Sciences","Engineering, Civil
A method of determining the actual and potential denitrification rates
in activated sludge samples by measuring accumulation of nitrous oxid
e after inhibition by acetylene was adapted and applied. Rates obtaine
d with the acetylene inhibition technique were compared with those cal
culated through mass balances of total nitrogen from process data as w
ell as those measured as nitrate utilisation. The acetylene inhibition
technique was a reliable method for determination of denitrifying act
ivity. The influence of acetate, ethanol, methanol and nitrate additio
ns was examined. Acetate gave the best response upon denitrification f
ollowed by ethanol and methanol. The bacteria in the activated sludge
could not denitrify at full capacity due to limitations in the supply
of electron donors. The actual rates measured with the acetylene inhib
ition technique corresponded to the rates obtained from process data.
The potential rates, determined with additions of acetate and nitrate
in excess (240 mg l(-1) and 28 mg N l(-1)), were 3-7 times higher than
the actual rates and the rates calculated from process data. There is
, thus, a potential for a more rapid denitrification rate. The potenti
al denitrification rate measured with the acetylene inhibition techniq
ue was equivalent to the nitrate utilisation rate.