Among the food industries, the dairy industry is considered to be the most polluting one because of the large volume of wastewater generated and its high organic load. In this study, an aerobic membrane bioreactor (MBR) was used for the treatment of wastewater from a large dairy industry and two hydraulic retention times (HRT), 6 and 8 hours, were evaluated. For both HRTs removal efficiencies of organic matter of 99% were obtained. Despite high permeate flux (27.5 L/h.m²), the system operated fairly stablely. The molecular weight distribution of feed, permeate and mixed liquor showed that only the low molecular weight fraction is efficiently degraded by biomass and that the membrane has an essential role in producing a permeate of excellent quality.
Membrane Bioreactor (MBR); Dairy wastewater; Molecular weight distribution; Hydraulic Retention Time (HRT); Dynamic membrane; Soluble Microbial Products (SMP); Extracellular Polymeric Substances (EPS)
