Treatment of Dairy Wastewater by a Combined Technologies Approach: Anaerobic Digestion and Membrane Technology Chapter in Scopus uri icon

abstract

  • The dairy industry generates large volumes of whey, which is separated and sold as by-products or discarded into wastewater collection systems. These effluents are composed by lactose, soluble proteins, soluble mineral salts and small fraction of fat. The objective of this research was to carry out the treatment of dairy wastewater through a continuous flow system of two coupled biological reactors: Upflow Anaerobic Sludge Blanket (UASB), followed by a fixed bed membrane biological reactor, namely hybrid membrane bioreactor (H-MBR). The system was operated for 85 days and chemical oxygen demand (COD), volatile suspended solids (VSS), total nitrogen (TN) and phosphate were monitored for both reactors. The results showed a high COD removal efficiency with 97%. It is important to mention that UASB system efficiency was increased by 18% when increasing the organic loading rate in addition to a higher production of biogas (from 7 to 10 L/d). However, the relationship between alkalinity and volatile fatty acids (VFA) was important to control for higher quality of biogas. It is also important to mention that within the implementation of the H-MBR reactor, the removal of COD, TN and phosphorus, increased up to 72%, 52% and 19%, respectively. The installation of the membrane module resulted in the total removal of the VSS in permeate. In general, the application of a high organic load resulted in an increase of biomass production, which was recirculated to the UASB and purged as sludge from the system. A good control of sludge can avoid problems of destabilization of the UASB and delay in the clogging of the membrane module of the H-MBR. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

publication date

  • January 1, 2024