The influence of amendment material on biosolid composting of sludge from a waste-water treatment plant

Abstract

Aerobic composting employing manual turning was evaluated by using the sludge produced by EMCALI EICE ESP’s Cañaveralejo wastewater treatment plant (PTAR-C). Compost (in 1,0 ton piles) consisted of sludge, a fixed proportion of bulking agent (10%) and amendment material. Sugarcane waste and solid organic (marketplace) waste were evaluated as amendment material using 20/80 and 40/60 weight/weight (amendment/sludge) ratios. Incorporating the amendment material improved the compost, being reflected in a faster start for the thermophilic phase, higher temperatures being maintained (>55°C) and better C/N ratio obtained in the compost in all treatments compared to the pile which had no amendment added to it. Incorporating the bulking agent improved sludge manageability during composting; the best combination was 54% sludge + 10% sugarcane bagasse + 36% liquid sugarcane waste.