Feasibility assay in phase-separated anaerobic treatment of cheese industry wastewater

This research was conducted as a part of continuous development of innovative bioprocess technology for the treatment of high strength wastewater. Mixed cheese processing wastewater was tested for the feasibility of phase separated anaerobic digestion in batch mode. Three concentrations of soluble chemical oxygen demand (SCOD) made by dilution of raw wastewater were tested for acidification of organics in the wastewater at two pHs, 6.0 and neutral. More than 95% of fat, 97% of soluble protein and 100% of lactose in the mixed waste were acidified in the acidogenic phase. Three different concentrations of artificial substrate consisting of a mixture of short chain organic acids, acetic, propionic, butyric, and valeric acids, along with alcohol were investigated for waste stabilization in methanogenic phase experiments. More than 95% of SCOD reduction was achieved in the methanogenic phase. This translated that 73.5–83.8% of organics in the wastewater could be recovered as energy (methane gas) instead of massive production of sludge.