Biomethane production from cheese whey in a two-phase anaerobic digestion system: integration of sewage sludge treatment and dairy by-products recovery

摘要

Efficient anaerobic digestion does not only represent a suitable solution for sludge disposal, but also provides additional energy gain from biogas use in cogeneration. Co-digestion of sewage sludge with additional compounds can be beneficial for the whole process because of the synergic interactions between substrates. Furthermore, the integration of different types of local resources often results in significant cost savings, e.g. transport costs. Since disposal of cheese whey, the main by-product of dairy industry, is frequently a problem, a suitable utilization of this substrate could enhance the profitability of cheese production and could also reduce the cost of sewage sludge disposal. Unfortunately, raw whey tends to rapidly acidify and it is, therefore, difficult to treat by single-phase anaerobic digestion.In our previous studies, a significant improvement in sludge treatment and energy recovery by an innovative two-phase anaerobic digestion (TPAD) process was reported (1).