Physicochemical Characterization and Preliminary Assessment of the Composting Potential of Market Biowaste in Diffa, Niger

Urban solid waste management is a major environmental challenge, particularly in markets where commercial activities generate substantial quantities of organic and non-biodegradable waste. This study aimed to characterize market biowaste generated in the urban municipality of Diffa, Niger, and to preliminarily assess its suitability for composting. The study was conducted in the central, vegetable, and fish markets using a stratified sampling approach. Waste generation was monitored through daily weighing, while representative samples of 100 kg from each market were characterized according to waste category, particle-size distribution, apparent bulk density, moisture content, and volatile organic matter. The results showed substantial differences in waste generation among the three markets. The overall mean generation rate was 3.32 ± 2.37 kg/trader/day, with the highest mean rates recorded at the vegetable market (4.32 ± 3.43 kg/trader/day) and fish market (4.07 ± 3.59 kg/trader/day), whereas the central market recorded the lowest rate (1.57 ± 0.09 kg/trader/day). Organic waste was the dominant fraction in the vegetable and central markets, whereas plastic waste predominated in the fish market. The mean apparent bulk density was 260.03 ± 60 kg/m³, while mean moisture and Volatile organic matter contents were 36.33% and 43%, respectively. These physicochemical characteristics indicate that market biowaste in Diffa has potential for biological recovery, particularly composting, provided that non-biodegradable materials are removed through effective sorting. The study provides baseline information for developing locally appropriate organic-waste recovery strategies and improving sustainable solid-waste management in Diffa.