%0 Journal Article
%T Effect of ammonia load on efficiency of nitrogen removal in an SBBR with liquid-phase circulation
%A Canto
%A C. S. A.
%A Ratusznei
%A S. M.
%A Rodrigues
%A J. A. D.
%A Zaiat
%A M.
%A Foresti
%A E.
%J Brazilian Journal of Chemical Engineering
%D 2008
%I Brazilian Society of Chemical Engineering
%R 10.1590/S0104-66322008000200007
%X the removal of biological nitrogen from a synthetic wastewater with different ammonium nitrogen concentrations (50 and 100 mgn-nh4+/l) by a nitrification and denitrification process using a sequencing batch biofilm reactor (sbbr) with liquid-phase circulation was studied. the system with a total working volume of 4.6 l (3.7 l in the reactor and 0.9 l in the reservoir) treated 2.1 l of synthetic wastewater in 12-h cycles. as inoculum two types of biomass were used: an anaerobic/anoxic one from an up-flow anaerobic sludge blanket reactor (uasb) and an aerobic one from a prolonged aeration activated sludge system. the system, maintained at 30 ¡À 1 oc, operated in batch mode followed by fed-batch mode and was aerated intermittently. during fed-batch operation the reactor was fed with an external carbon source as electron donor in the denitrifying step and with no aeration. when the reactor was fed with 50 mgn-nh4+/l, efficiencies of removal of ammonium nitrogen and total nitrogen from the effluent were 93.8 and 72.2%, respectively, and nitrite, nitrate and organic nitrogen concentrations were 0.07, 6.4 and 0.5 mg/l, respectively. on the other hand, when the influent ammonium nitrogen concentration was 100 mgn-nh4+/l, residual nitrite and nitrate were 0.17 and 20.4, respectively, and no n-org was found in the effluent. it should be mentioned that residual nitrate remained unaltered at the different c/n ratios used. consequently, efficiency of total nitrogen removal was reduced to 66.7%, despite efficiency of ammonium nitrogen removal exceeding 90%. these results show the potential of the proposed system in removing ammonium nitrogen from liquid effluents with a moderate ammonium nitrogen concentration.
%K nitrification and denitrification
%K immobilized biomass
%K sequencing batch biofilm reactor
%K liquid-phase circulation.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0104-66322008000200007&lng=en&nrm=iso&tlng=en