H. Siegrist, NITROGEN REMOVAL FROM DIGESTER SUPERNATANT - COMPARISON OF CHEMICAL AND BIOLOGICAL METHODS, Water science and technology, 34(1-2), 1996, pp. 399-406
Citations number
13
Categorie Soggetti
Water Resources","Environmental Sciences","Engineering, Civil
Physical/chemical elimination of ammonium from digester supernatant wi
th magnesium-ammonium-phosphate (MAP) precipitation and with air strip
ping is investigated in pilot scale and compared with separate intermi
ttent denitrification, denitrification in wastewater treatment and in
tertiary filtration. MAP-precipitation is feasible but most expensive
due to required chemicals as well as dewatering and drying of the prec
ipitate. Air stripping is slightly cheaper, but still more expensive t
han biological treatment due to the complex process, cost of chemicals
and reconditioning of the ammonium sulfate solution to a fertilizer p
roduct. In nutrient removal plants the additional nitrogen from the di
gester supernatant can be eliminated by increasing the anoxic volume o
r using a carbon source. Denitrification with methanol will be the che
apest solution with today's methanol price. If digester supernatant in
hibits nitrification substantially or if the anoxic zone is too small
for organic carbon addition a separate intermittent denitrification wi
th addition of a carbon source, as used in some treatment plants in Sc
andinavia, might be a good solution. Copyright (C) 1996 IAWQ.