Assessment of the effect of drying temperature and composition on the biochemical methane potential of in-house dried household food waste

Abstract

Household food waste management and treatment has been recognised as a significant issue worldwide and at a European Union level. Source-separation of household food waste following drying at source presents a viable solution to this problem. The present research aims at investigating the effect of drying of model household food waste at different temperatures (i.e. 63 ±3 °C and 83 ±3 °C) on its biochemical methane potential. The drying process was carried out using a prototype household waste dryer. The model sample consisted of 77%w/w vegetables and fruits (48%w/w and 29%w/w, respectively), 12%w/w pasta/rice, 6%w/w meat and fish, 3%w/w bread and bakery and 2%w/w dairy. Moreover, drying at the same temperatures was applied for two household food wastes samples with different composition, in order to assess the influence of the samples’ composition on both the drying process and the methane generation. For all temperatures used, the higher %w/w mass reduction was observed for model waste (MD) (67.39%w/w and 75.79%w/w for 63 °C and 83 °C, respectively), then for rich-in-protein content (PRO) (66.18%w/w and 69.73%w/w for 63 °C and 83 °C, respectively) and finally for rich-in-fat content (FAT) samples (54.35%w/w and 66.31%w/w for 63 °C and 83 °C, respectively), which confirmed the effectiveness of the drying process. The biochemical methane potential experiments have confirmed that the substrate produced the highest methane yields was the FAT, producing 524.25 ±2.86 L CH4 kg-1 volatile solids.

Comparison of 3 household food waste dryers in the context of food waste prevention and bioeconomy

“…All 3 systems, operated at a laboratory scale for a period of 12 months at the National technical University of Athens. In order to implement the research, a fixed mix of food waste was used based on [20]. Some of the main technical features of these systems are recorded in Table 1.…”

“…Εach drying system operated for at least 20 full cycles, with different amounts of food waste (in terms of mass) that corresponded to the quantities produced by a one-, two-and three-member family respectively in Papagos-Cholargos Municipality in Greece. The food waste amount for a 1 member family was considered to be 410 g, for a 2 member 821 g and for a 3 member 1230 g based on [20]. Table 2 presents the percentage proportion (%w/w) of food waste material contained in the total quantity of each sample used.…”

The Influence of Low-Temperature Food Waste Biochars on Anaerobic Digestion of Food Waste

“…The ash content (AC) of the mixture was 4.2%. The FW composition was based on the work of Valta et al [ 19 ]. The properties of moisture content, total solids (TS), volatile solids (organic matter content), and ash content, of used food materials, and mixture composition per fresh, dry, and volatile solids percentage share bases are presented in Table 1 .…”

Investigating the Environmental Benefits of Novel Films for the Packaging of Fresh Tomatoes Enriched with Antimicrobial and Antioxidant Compounds through Life Cycle Assessment

“…Although food constitutes a precious commodity [1], approximately one-third of the food produced for human consumption is wasted or lost before it is consumed [1,2]. The issue of Food Waste and Loss (FWL) has attracted increased international attention due to its environmental, economic, and social impacts [1, [3][4][5], as reflected in the United Nations 2030 Agenda for Sustainable Development [3,4]. In particular, Target 12.3 of the Sustainable Development Goals (SDGs) calls for halving the global food waste per capita at the retail and consumer level by 2030 and for a reduction in food losses in production and supply chains, including post-harvest losses [2,3,6].…”