Impact of compost process temperature on organic micro-pollutant degradation

Aerobic composting has gained considerable attention because of its ability to remove organic micro-pollutants. Compost process temperature is a key parameter controlling degradation rate. Impact of process temperature on removal of 15 key organic micro-pollutants often found in sewage sludge (including two metabolites) during sewage sludge composting was investigated at 18-70 °C over 52 days. Removal rates generally depended strongly on temperature and for all compounds an optimal temperature for removal was observed. Optimal temperatures for the 13 parent compounds ranged from 25 to 70 °C and relative removal of the 13 parent compounds was as high as 99% across all combinations of compound and temperature with an average removal of 66%. The two metabolites were both formed and removed during the course of composting and the data indicated that metabolites may very well have other optimal removal temperatures than their parent compounds.