Comparison of PEG biodegradation in sediment and soil. In both sediment and soil, the rates and final extents of PEG mineralization to 13 CO2 increased with increasing •OH reaction time, confirming the hypothesis that PEG chain scissions under formation of smaller PEG molecules increase PEG biodegradability -and , thereby, that considering PEG reaction with •OH is sunlit environments is important when estimating PEG biodegradation half-lives.