Dairy Wastewater Treatment using Three-Stage Rotating Biological Contactor (NRBC)

Dairy wastewater is enriched in organic matter (about 45-72 g/l, COD) and also contains biodegradable carbohydrates. A three-stage system, NRBC was fabricated as a bench scale unit for lab experiments, to remove organic carbon from the whey. The fabricated NRBC had several advantages, such as quick start-up, high biomass concentration and was additionally able to handle high organic loading rates. In this study, the COD removal efficiencies of 80 and 83 percent were achieved at HRT of 16 and 24 h, respectively. While the HRT was increased to 36 h, the COD removal efficiency was increased to 92 percent. High surface COD loading rate of 38-210 g COD/m2.day was achieved. The high organic loading rate of whey was successfully treated in the fabricated NRBC. The COD removal efficiency of 96 percent was achieved, while the discs surface was increased by 10 percent.