Abiotic association of PAEs with humic substances and its influence on the fate of PAEs in landfill leachate.
An equilibrium dialysis combined with a (14)C-labeling method was used to study the abiotic association of phthalic acid esters (PAEs) with dissolved humic substances (HS) and its influence on the fate of PAEs in landfill leachate. Elemental analysis and FTIR spectral analysis were carried out on the humic acid (HA) and fulvic acid (FA) components of HS to examine the relationship between the structure of HS and the intensity of the association of the PAEs with HS (K(A)). The results show that the association intensity of HS with PAEs depends greatly on both the properties of the PAEs and the source of HS. The HS have a strong association reaction with dibutyl phthalic acid, which might explain the higher concentration of dibutyl phthalic acid detected in landfill leachate. The pH value strongly affects the K(A) of HS, and it decreases radically when the pH increase from 3.0 to 9.0. The non-specific hydrophobic interaction between HS and PAEs plays a more important role in the abiotic association of HS with PAEs. Elemental analysis and FTIR spectra suggest that the high K(A) values are related to the high aromatic content and larger molecular weight of HS.
Xiaoli
Chai
C
The State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China. xlchai@tongji.edu.cn
Rong
Ji
J
Jun
Wu
W
Huanhuan
Tong
T
Youcai
Zhao
Z
D001578:Benzopyrans / Q000737:chemistry / Q000302:isolation & purification; D003956:Dialysis / Q000379:methods*; D004952:Esters / Q000737:chemistry / Q000302:isolation & purification; D006812:Humic Substances / Q000032:analysis*; D015394:Molecular Structure; D010795:Phthalic Acids / Q000737:chemistry* / Q000302:isolation & purification; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification
D001578:Benzopyrans; D004952:Esters; D006812:Humic Substances; D010795:Phthalic Acids; D014874:Water Pollutants, Chemical; C032279:phthalic acid; C005023:fulvic acid