RESUMO
The short- and long-term influence of quinoline on the properties of anaerobic ammonium oxidation (anammox) biogranules was evaluated. During batch tests, the bioactivity of anammox granules in the presence of different quinoline concentrations was monitored, and the IC50 of quinoline was calculated to be 13.1â¯mgâ¯L-1 using a non-competitive inhibition model. The response of anammox granules to pre-exposure to quinoline was dependent on metabolic status, and the presence of both quinoline and NO2--N had a rapid detrimental effect, resulting in a 64.5% decrease within 12â¯h. During continuous-flow experiments, the nitrogen removal rate (NRR) of the reactor decreased sharply within 3â¯days in the presence of 10â¯mgâ¯L-1 quinoline and then was restored to 2.6â¯kgâ¯Nâ¯m-3â¯d-1. In the presence of quinoline-induced stress, the specific anammox activity and levels of extracellular polymeric substance and heme c were decreased, while settling velocity persistently increased. After cultivation and acclimation obtained by adding a medium level of quinoline to the influent, the anammox granule sludge was able to tolerate 10â¯mgâ¯L-1 quinoline in 178â¯days.
Assuntos
Compostos de Amônio/química , Nitrogênio/química , Quinolinas/química , Poluentes Químicos da Água/química , Anaerobiose , Relação Dose-Resposta a Droga , OxirreduçãoRESUMO
The broad-spectrum antibiotic sulfamethoxazole (SMX) was chosen to assess its short- and long-term effects on denitrifying granules. The SMX concentration and pre-exposure time in batch testing influenced the denitrifying granule activity. In the continuous-flow experiments, no inhibitory effects on the upflow anaerobic sludge blanket performance were observed at SMX concentrations up to 100mgL-1, probably because of functional redundancy and long-term acclimation. The specific denitrifying activity first decreased to a minimum of 49.3% and then recovered to a level comparable to the initial level as the SMX concentration increased. The changing trend of the extracellular polymer content was consistent with the specific denitrifying activity throughout the process, and relatively high EPS loss ratios (maximum loss of 61.8%) were observed. Additionally, the diameter of the denitrifying granules monophonically increased to a final value of 35.0%. This research provided the application of denitrifying granules to treat wastewater that contained antibiotic.