SILVA FILHO, H. A.; http://lattes.cnpq.br/3891736199860891; SILVA FILHO, Heraldo Antunes.
Resumo:
In domestic sewers, total nitrogen Kjeldahl (NTK) with concentration around 40
mg/L the 60 mg/L, this being approximately 75% in the ammoniac nitrogen form and
the remain (25%) as organic nitrogen. The ammoniac nitrogen is a nutrient capable to
promote eutrophication in water bodies and, therefore its launching in the environment
must be controlled. The nitrification is the biological oxidation o f ammonia, having as
end item the nitrate. This process requires the mediation of specific bacteria and i f it
carries through in two sequential stages: nitritacao (ammonia oxidation the nitrito) and
nitratacao (nitrito oxidation the nitrate). Searching to characterize kinetic of the
nitrification in the two different systems of activated sludge, this study it had as
objective to operate under the same operational conditions and of sizing, the systems of
activated sludge Bardenpho and UCT, comparing them in the removal of nutrients and
organic substance; to determine the kinetic constants: of specific growth ( p m ) and
maximum specific growth ( p m ) , o f half substratum saturation ((K0 ) , dissolved oxygen;
Ka , nitrogen in the ammonia form; e kn , nitrogen in the nitrito form), the constant of
decline and the tax of substratum use (bn and rn , respectively) and to study the effect of
pH, temperature and OD on the metabolism of the generated autotrophic sludge in
systems of activated sludge. The two systems (Bardenho and UCT) had been operated
with ages o f silt of 20 and 15 days. For the determination of the kinetic factors of the
nitrificacao it was applied theory of activated silt proposal for van Haandel and Marais
(1999) and was used it respirometria as tool. The gotten results had shown satisfactory
nitrificacao in the two operated systems, reaching an effluent ammonia average below
of 1 mgN/L. The respirometry revealed a tool adjusted for the determination of the
kinetic constants studied ( u m a x = 0,52 d"1; bn = 0,033 d"1). It was observed that the
ambient factors pH, oxygen and temperature, exert significant influence in the kinetic
nitrificante, being recommended to values of pH next the 8, temperature of 35°C and
band of OD above of 1 mg/L establishing the excellent conditions for the development
of the nitrificacao.
