Exploring the Biochemical Methane Potential of Wholesale Market Waste from Jordan and Tunisia for a Future Scale-Up of Anaerobic Digestion in Amman and Sfax

Abstract

Purpose 3Local open markets, trading fruits and vegetables, are widespread in Mediterranean 4 countries, such as Tunisia and Jordan, producing large amounts of organic waste. 5Applying an anaerobic digestion process on this substrate makes it crucial to evaluate 6 the waste mixture composition and seasonal variability properly. In this study, after 7 defining an average composition of the fruit and vegetable waste (FVW) mixture 8 produced in Sfax (Tunisia) and Amman (Jordan) in three seasonal intervals (autumn-9 winter, spring, and summer), the biochemical methane potential (BMP) of an 10 artificially created FVW mixture was individually determined by three European 11 institutions located in Spain, Italy, and Greece. The average BMP from all three 12 seasons and laboratories was 286±52 NmL CH 4 g COD added -1 , close to the theoretical 13 maximum yield of 350 NmL CH 4 g COD added -1 , indicating a high biodegradability of 14 the waste. Τhe biochemical methane yields of the spring mixtures were not 15 statistically different across the three labs. The most significant differences among the 16 BMP results were obtained for the autumn/winter and the summer mixtures used in 17 Spain, likely due to the variety or ripeness of fruits and vegetables collected in the 18 local markets. In the other two labs in Italy and Greece, no statistical difference was 19 observed for the BMPs of the three season mixtures within the same lab. Therefore, 20 not a critical difference in the biodegradability of such FVW is expected along the 21 different seasons, indicating that the operation of a full-scale digester over a whole 22 year would constantly benefit from the supplementation of a high biochemical 23 methane potential feedstock.

Does seasonality of feedstock affect anaerobic digestion?

“…A total of three mixtures as model substrates of FVW, i.e., autumn and winter mixture (AWM), spring mixture (SpM), and summer mixture (SM) were used, according to the seasonal variation in the waste generated by the wholesale markets. Autumn and winter mixtures were considered one since no significant difference were observed in the waste generated during these seasons [26]. These mixtures represented the generation of FVW in the wholesale markets of Sfax (Tunisia) and Amman (Jordan) and were previously defined by Papirio et al [26].…”

“…Autumn and winter mixtures were considered one since no significant difference were observed in the waste generated during these seasons [26]. These mixtures represented the generation of FVW in the wholesale markets of Sfax (Tunisia) and Amman (Jordan) and were previously defined by Papirio et al [26]. The compositions of the different mixtures are shown in Table 1.…”

Assessment of Hydrogen and Volatile Fatty Acid Production from Fruit and Vegetable Waste: A Case Study of Mediterranean Markets

“…Fruit and vegetable waste (FVW) is an abundant mixture made up of edible and non-edible leftovers deriving from wholesale market activities, which are widespread in the Mediterranean area for both economic and social aspects [1]. Specifically, some Mediterranean countries characterized by recent demographic development intensified the production of organic waste.…”

“…Specifically, some Mediterranean countries characterized by recent demographic development intensified the production of organic waste. As an example, FVW and kitchen waste account for about 50-65% of 2,825,000 (2018) and 3,330,000 (2020) tons in Tunisia and Jordan, respectively [1]. It was estimated in 2011 [2] that approximately 1728 million tons of FVW were produced per year worldwide, against 1.3 billion tons per year of food waste [3].…”

Seasonal variation of the biochemical methane potential of fruit and vegetable wastes produced in the Mediterranean area

“…There are few studies focusing on the effect of the seasonal variation on BMP of FVW (Edwiges et al, 2018), and moreover, they do not take into account the size these wastes are chopped to, which may be critical to determine the rate of methane production. The present study is part of a concerted effort to assess the BMP of FWW mixtures produced in the open markets of Tunisia and Jordan as typical Mediterranean countries in the framework of CEOMED project (Papirio et al 2021).…”