Treatment of Slaughterhouse Wastewater by Integrated Anaerobic/Aerobic Bioreactors Loaded with Immobilized Nanoporous Activated Carbon

Abstract

Slaughterhouse wastewater consists of moderate to high strength complex wastewater comprising about 45% soluble and 55% coarse suspended organics exhibiting high COD and BOD levels. Conventional wastewater treatment methods cannot effectively treat slaughterhouse wastewater. Thus, a four-stage sequential anaerobic/aerobic immobilized bio reactor system comprising a two stage Fluidized Anaerobic immobilized Reactor (FAIR – I and FAIR – II), a Fluidized Immobilized Cell Carbon Oxidation (FICCO) reactor and a Chemo Autotrophic Activated Carbon Oxidation (CAACO) reactor was tested in a slaughterhouse treating wastewater between 3 m³ /day to 17 m³ /day. Nanoporous activated carbon (NPAC) was used for the immobilization of microorganisms in all of the reactors. The NPAC BET surface area was found to be 291 m²/g with the average pore diameter of 28 Å. Spin density (free electrons) in the NPAC, was calculated to be 16 x 10¹⁸ spins/g using ESR spectroscopy. The overall NH₃-N, TKN, COD and BOD removal efficiency was 64%, 71%, 82% and 85% respectively. Multivariate analysis (PCA and cluster analysis) found that the COD removal by the FICCO and CAACO reactors is more efficient than the FAIR reactors. The treatment was confirmed through UV-visible and UV-fluorescence spectroscopic analysis.