Evaluation of membrane bioreactor-hollow fiber (MBR-HF) pilot performance in the treatment of wastewater facing with different concentrations of amoxicillin (AMX) as shock loads

This research mainly aims at evaluating the function of Membrane Bioreactor (MBR) facing with different concentrations of Amoxicillin as different shock loads. A pilot MBR with an effective volume of 20 L equipped with a hollow fiber (HF) ultrafiltration membrane was applied. Hydraulic retention time and flow rate were kept at 12 h and 1.6 L/hr, respectively. 70 days after the pilot setup, the reactor at MLSS concentration of upper than 7000 mg/L reached the desired steady state. After the setup period, the concentration of the shock began at 5 mg/L and then reach 10,20,40,70, and 100 mg/L, respectively. The percentage removal of AMX, at shock concentrations of 5-20 mg/L, was up to 95 AMX removal at concentrations of over 40 mg/L abruptly decreased to 72 %. However, at concentrations of 70 mg/L and 100 mg/L the removal rates of 62.85 % and 61 % were achieved, respectively. The sorption percentage of AMX through sludge biomass equals 12.1 %. At any concentration of AMX the removal efficiency of COD reached upper than 95 % excluding 70 mg/L and 100 mg/L which is about 94 % and 92 % respectively. The nitrification efficiency was first 53.6 %, whereas after applying the shock, it decreased over time and 24 h after the shock reached its lowest level, i.e. 29.6 %.