Further insights into the respiratory response of activated sludge in a lab-scale membrance bioreactor to short-term and long-term exposure to silica nanoparticles

Abstract

The respiratory response of activated sludge measured as oxygen uptake rate is a practical screening indicator of a substance’s toxicity. Silica (SiO2) nanoparticles could partially inhibit activated sludge respiration. But it remains a work in progress how the removal performance of a biological wastewater treatment could remain fairly stable despite the observed activated sludge respiration inhibition. Here, we both considered a batch short-term and a continuous long-term experiment to compare the respiratory response of activated sludge when exposed to 1 mg/L SiO2 nanoparticles in a lab-scale membrane bioreactor (MBR).