Co-composting of vegetable wastes and carton: Effect of carton composition and parameter variations

- Temperature data followed typical composting temperature variation trends.
- Carton and paper containing high lignocellulosic content slowed the composting rate.
- All composting mixes yielded phytotoxic-free composts.
- Key process parameters were within the relevant compost standards.

The aim of the study was to investigate the effects of carton in the composting process of mixed vegetable wastes using an experimental composter of capacity 80 L. Three different mixes were set-up (Mixes 1, 2 and 3) which consisted of vegetable wastes, 2.0 kg paper and bulking agents, vegetable wastes, 1.5 kg carton and bulking agents, vegetable wastes, 4.5 kg carton and bulking agents, respectively. Temperature evolution, pH trends, moisture levels, respiration rates, percentage volatile solids and electrical conductivity were monitored for a period of 50 days. The system remained under thermophilic conditions for a very short period due to the small size of the reactor. The three mixes did not exceed a temperature of 55 °C, where sanitization takes place by the destruction of pathogens. The highest peak of CO2 evolution was observed in Mix 2 indicating that maximum microbial degradation took place in that mix.