Environmental assessment of refectory waste based on approaches zero-waste project in Turkey: the production of biogas from the refectory waste

Abstract

The zero-waste project in Turkey, which was started in 2017, is planned to be implemented until 2023, starting from public institutions and organizations. However, in refectories where high amounts of organic waste are generated, these organic wastes are generally transported to the landfill site by the municipalities and, consequently, they go beyond the scope of the zero-waste project. In this study, the anaerobic treatment of refectory wastes based on the scope of the zero-waste approach in Turkey has been developed as an innovative and holistic approach. As a result of the informing studies in the refectories, the waste of bread could be zero, while the waste of meals could not be zero, but a significant decrease in meal waste was found. In addition, this holistic approach has also strengthened recycling. Anaerobic digestion was selected to complete the zero-waste target for food wastes that are still generated. In the study using the UASB reactor operated in mesophilic conditions (36.5-37 degrees C), feeding has been done with approximately 21.9 kg VSadded m(-3) OLR in 10-day HRT. As a result, it was observed that the production of biogas and organic fertilizers from food waste using anaerobic technologies is an important solution on behalf of realizing the zero-waste application. The results showed that 1 kg of food waste with 62 +/- 3.2% solid content could produce 640 L of biogas with approximately 62.2 +/- 0.6% methane content. In addition, a 26.2-L bio-fertilizer with an average COD concentration of 3354 +/- 106 mg L-1 was produced. This research paper with a successful method at the Adiyaman University in Turkey focuses on the goal of zero waste. This study illustrated how it is possible to implement an effective initiative to reduce food waste with a holistic approach.