Resource recovery potential from source-separated organic municipal solid waste: opportunities for organic fertilizer production and creating sustainable urban agriculture in Ethiopia

Increasing waste production and its disposal into the environment without treatment and resource recovery is considered as a threat to the environment and human health. This study aimed to determine the current commercial and institutional solid waste generation rates, physicochemical and compositional analyses at selected sub-cities in Addis Ababa (Arada, Kirkos and Yeka), Ethiopia and to estimate its nutrient recovery potential for the production of organic fertilizer. The study covered a sample size of 44 commercial and 44 institutional centers. Physiochemical analyses of organic fraction of mixed commercial and institutional solid wastes were determined following standard methods. The study finding showed that the average municipal (commercial and institutional) solid waste generation rates was 0.24 kg/capita/day with 0.33 kg/capita/day and 0.16 kg/capita/day, respectively. The bulk densities of commercial and institutional solid waste were 421.80 kg/m³ and 361.87 kg/m³, respectively. The composition of commercial and institutional solid waste in the selected area was dominated by food waste (42.3%) followed by paper waste (30.8%). Yard & plastic wastes accounted for 9.9% and 8%, respectively. The rest waste fractions were accounted for a total of 9%. The average percentage composition of compostable wastes of the solid waste was significantly high (53%) followed by recyclable wastes (41%). The average value of pH and moisture content of the organic wastes were in the range of 6–7.5 and 47–81%, respectively. With the exception of paper waste, the highest amount of hemicellulose was recorded. Generally, the overall results showed that most of the generated waste was organic, easily biodegradable, and can be suitable feedstocks for processing organic fertilizer through composting.