The Effects of Fill Strategies on SBR Performance under Nitrogen Deficiency and Rich Conditions

Abstract

The effects of anoxic and oxic fill strategies on SBR performance under nitrogen (NH4Cl as the nitrogen source) deficiency and rich conditions are evaluated using glucose as the sole substrate. The performance is evaluated according to substrate removal, sludge settleability, supernatant suspended solids (SS), and reactor biomass concentration. Substrate removal efficiencies are found to be independent of the fill strategies adopted under all conditions tested. The incorporation of anoxic selector environment fails to prevent the development of bulking sludge under nitrogen deficiency conditions thereby resulting in a gradual depletion of reactor biomass. Under nitrogen rich conditions, on the other hand, the sludge settleability improves significantly by adopting the anoxic fill strategy. Furthermore, SS readings taken at the end of settling period are greater with anoxic fill than with oxic fill, indicating that the latter discourages the growth of dispersed bacteria.

Integrated production of biopolymers with industrial wastewater treatment: Effects of OLR on process yields, biopolymers characteristics and mixed microbial community enrichment

“…Regarding the sludge settling properties, a significant SVI decrease from 250 mL gTSS -1 to about 50 mL gTSS -1 was observed in Period 1, probably due to the transition from a continuous feeding system to a SBR type. Indeed, the intermittent feeding conditions generate substrate concentration gradients that are more favorable to the growth of floc-forming bacteria than filamentous ones, with an important benefit on the settling properties of the activated sludge [42]. In Period 2, a slight worsening of the sludge settling properties was observed especially in the early stage when the SVI increased to about 100 mL gTSS -1 , although it decreased to about 40 mL gTSS -1 in the following days, indicating excellent settling characteristics of the activated sludge, comparable with granular biomass systems [43].…”

Reatores Biológicos Em Bateladas Sequenciais Com E Sem Material Suporte Para Remoção Simultânea De Nitrogênio E Fósforo De Esgoto Sanitário

“…O tratamento de águas residuais em RBS tem despertado grande interesse, devido às pequenas áreas 53 ocupadas pelas unidades de tratamento, redução de custos em relação aos processos contínuos e possibilidade de remoção conjunta de matéria carbonácea e dos nutrientes fósforo e nitrogênio (Sheker et al, 1993;Lee et al, 1997;Morgenroth e Wilderer, 1998;Van Loosdrecht e Jetten, 1998;Moreira et al, 2002).…”