Adsorption of EDCs On Reclaimed Water-Irrigated Soils: A Comparative Analysis of A Branched Nonylphenol, Nonylphenol and Bisphenol A

Abstract Nonylphenol (NP) and bisphenol A (BPA) are two typical endocrine disrupter chemicals (EDCs) in the reclaimed water. The adsorptions of NP, a branched NP (NP7) and BPA on reclaimed water-irrigated soils were studied by isothermal experiments, and the different environmental factors on their adsorptions were investigated. The results showed that the adsorptions of NP and NP7 on soils conformed to Linear model, and the adsorption of BPA conformed to Freundlich model. The adsorptions of NP, NP7 and BPA on soils decreased with the increasing temperatures and pHs, while increased with the cation valence. Adsorption equilibrium constant (Kd or Kf) were maximum at pH=3, temperature 25℃ and As (Ⅲ)-soil, respectively; The adsorption capacity of NP, NP7, and BPA to soils increased in accordance with cation valence: trivalent cations > divalent cations > mono- cations. Kd of NP7 on soil was less than that of NP under the different pH and temperatures; while under different cations concentrations, it was inverse. Fourier Transform Infrared Spectrometer (FTIR) analysis showed alkyl chains of NP and BPA seemed to form van der Waals interactions with the cavity of soil. Results of this study will provide further comprehensive fundamental data for human health risk assessment of nonylphenol in the soil.