Divergence in the distribution of di(2-ethylhexyl) phthalate (DEHP) in two soils

Understanding the distribution of di(2-ethylhexyl) phthalate (DEHP) is necessary for future risk evaluation of DEHP in agricultural soils. This study used C-14-labeled DEHP to examine its volatilization, mineralization, extractable residues, and non-extractable residues (NERs) incubated in Chinese typical red and black soil with/without Brassica chinensis L. Results showed that after incubated for 60 days, 46.3% and 95.4% of DEHP were mineralized or transformed into NERs in red and black soil, respectively. The distribution of DEHP in humic substances as NER descended in order: humin > fulvic acids > humic acids. DEHP in black soil was more bioavailable, with 6.8% of initial applied radioactivity left as extractable residues at the end of incubation when compared with red soil (54.5%). Planting restrained the mineralization of DEHP by 18.5% and promoted the extractable residues of DEHP by 1.5% for black soil, but no such restrain was observed in red soil. These findings provide valuable information for understanding the distribution of DEHP in different soils and develop the understanding for the risk assessments of PAEs in typical soils.

Automated summary

Understanding the distribution of DEHP in agricultural soils is crucial for future risk evaluation. This study found that, after 60 days, 46.3% and 95.4% of DEHP in red and black soil, respectively, were either mineralized or transformed into non-extractable residues (NERs). DEHP was mainly distributed in humic substances as NERs, with humin having the highest concentration. DEHP was more bioavailable in black soil compared to red soil. Planting Brassica chinensis L. limited the mineralization of DEHP in black soil and increased the extractable residues, but had no significant effect in red soil. These findings provide valuable information for the risk assessment of DEHP in different soil types.