... affecting the operation factors of MBR systems in piggery wastewater treatment is necessary to make a precondition for the application of this technology for piggery wastewater treatment in Vietnam... affecting the operation factors of MBR systems in piggery wastewater treatment is necessary to make a precondition for the application of this technology for piggery wastewater treatment in Vietnam... with real piggery wastewater in one month as starting-up phase - Membrane used in this study was polyvinylidene fluoride (PVDF) hollow fiber (Motimo, China) It has pore size of 0.1 µm and membrane