Integration of effective microorganisms and membrane bioreactor for the elimination of pharmaceutical active compounds from urine for safe reuse

Abstract

The present study aims to investigate the efficiency of integrated effective microorganisms (EM) and membrane bioreactor (MBR) for eliminating pharmaceutical active compounds (PhACs) from urine. Natural urine was separated using a ‘diversion toilet’. The toilet users were under medication with some pharmaceuticals, namely levofloxacine (LEF), ibuprofen (IBP) and atorvastatin (ATV). For correlation, three MBR pilot-scale sequences were examined. In Sequence 1, the MBR was used without pre-treatment. In Sequence 2, EM was added as pre-treatment in the mixing tank. The effluent was further treated with the MBR. In Sequence 3, EM was added directly to the activated sludge of the MBR. The results showed that Sequence 1 could decrease the PhACs from 10 mg/L to 1.5 mg/L, 0.5 mg/L and 0.9 mg/L for LEF, IBP and ATV, respectively. Sequence 2 exhibited remarkable improvement in PhACs removal. The overall residual concentration reached 0.7, 0.13 and 0.28 mg/L for LEF, IBP and ATV, successively. Applying Sequence 3 gives higher removal efficiency, where the residual concentration of LEF, IBP and ATV decreased to 0.50 mg/L, 0.10 mg/L and 0.22 mg/L, respectively. It was concluded that the contaminated urine was efficiently treated by adding EM directly to the activated sludge of the MBR, and the treated urine can be safely used as fertilizer.