Sorption and degradation of estrogen-like-endocrine disrupting chemicals in soil

Abstract

Studies were undertaken to assess sorption of seven endocrine-disrupting chemicals (EDCs), namely, estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE2), bisphenol A (BPA), 4-tert-octyl phenol (4-t-OP), and 4-n-nonyl phenol (4-n-NP) on four soils (from sandy to clay soil) with different physicochemical properties and biodegradation of five EDCs (BPA, E2, EE2, 4-t-OP, and 4-n-NP) in a loam soil associated with wastewater reuse. We also characterized the biotransformation of E2 to E1 in the loam soil under aerobic and anaerobic conditions. Sorption test using a batch equilibrium method demonstrated that alkylphenols (4-t-OP and 4-n-NP) had the strongest sorption onto soils, followed by estrogens (EE2, E2, E1, E3) and BPA. This laboratory study showed that all five EDCs, including the degradation product E1, were degraded rapidly in the soil within 7 d under aerobic conditions. However, under anaerobic conditions in the soil, little or no degradation of the five EDCs was noted except for E2, which showed slow degradation during the 70-d study. The calculated half-lives for E2 under anaerobic conditions were 24 d in the soil. Estradiol was found to be biotransformed to E1 under both aerobic and anaerobic conditions. The study suggested that the five EDCs as well as E1, which may be present in reclaimed wastewater, would not persist in well-aerated soil. But these EDCs persisting in anaerobic soil may affect soil and groundwater quality and ecosystem.