Monitoring of Composting Process Parameters: A Case Study in Jordan

This study aimed to monitor the composting process of the first small-scale segregated bio-waste composting scheme in Jordan to divert different types of organic wastes and to evaluate the final product quality, which can be recovered and used as compost. In this study, four experimental windrow piles were first initiated and temporally monitored. The composting process was monitored against temperature, moisture and oxygen content, indicating that the biological conditions were sufficiently developed. The monitored experimental process showed overall decreasing profiles versus composting time for moisture, organic carbon and carbon/nitrogen content, as well as overall increasing profiles for electrical conductivity and total nitrogen, which represented qualitative indications of progress in the process. The product quality was examined and assessed against the quality specifications of EU End of Waste Criteria for bio-waste, which has been subjected to composting, aiming to specify whether the different types of organic wastes that have undergone recovery cease to be waste and can be classified as high quality compost. More specifically, on the one hand the heavy metal concentrations (Cr, Cu, Ni, Cd, Pb, Zn and Hg) were within the set limits and much lower compared to the European standards. On the other hand, compost respiration in the samples varied from 3.6 to 15.3 mgO(2)/g dm, which, in turn, indicates that all the compost samples appeared to be stable and rated as class IV and V final products.