Fate of triphenyl phosphate in soil

The adsorption and degradation behaviour of triphenyl phosphate (TPP) in soil was investigated using radiolabelled test substance. TPP was found to be absorbed strongly to three soil types. Triphenyl phosphate was degraded rapidly and mineralized to a great extent in soil in laboratory experiments. Under aerobic conditions the amount of TPP in soil decreased steadily and accounted for 46.6% of the applied compound after an incubation time of 32 days. Under the same conditions using heat-sterilized soil, mainly unchanged test compound was recovered after 101 days of incubation. According to these results the degradation of TPP in soil is mostly of microbial nature. Under anaerobic conditions the dissipation was equally as rapid and extensive as under aerobic conditions. The half-life of TPP under anaerobic conditions was 32 days in the same loamy sand soil. Several known and unknown degradates were detected, carbon dioxide being the main metabolite under aerobic and anaerobic conditions.