Phthalic acid esters in dissolved fractions of landfill leachates.
The distribution of phthalic acid esters (PAEs) (including diisobutylphthalate (DIBP), di-n-butylphthalate (DnBP) and bis(2-ethyl)hexylphthalate (DEHP)) in dissolved organic matter (DOM) fractions of leachates from sanitary or bioreactor landfills was evaluated. The leachate DOM was fractionated into humic acid (HA), fulvic acid (FA) and hydrophilic (HyI) fractions. Measurements showed that the PAEs were bound mostly to the HA fraction in leachate, regardless of their landfill age or the presence of leachate recirculation. The PAEs affinity for HA and FA differed considerably relative to the sorption coefficients reported for model compounds. Molecular weight of DOM correlated with PAEs partition in collected leachate samples fractions while aromaticity was a poor predictor. Based on the presence of phenolic, carboxyl or amide groups in DOM fractions, hydrogen bonding is likely to be involved in interactions between PAEs and leachate DOM. The peptide groups, particularly presented in HA fraction, might explain the strong affinity of PAEs for HA. The fluorescence excitation emission matrix contour plots showed that the HyI fractions shared certain similarities with humic substances in terms of molecular structure, which may be one reason why PAEs exhibited a clear sorption to the HyI fractions.
Zheng
Zhong
Z
State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, PR China.
He
Pin-Jing
PJ
Shao
Li-Ming
LM
Lee
Duu-Jong
DJ
D000327:Adsorption; D001578:Benzopyrans / Q000737:chemistry*; D002681:China; D004784:Environmental Monitoring; D006812:Humic Substances; D010795:Phthalic Acids / Q000032:analysis* / Q000737:chemistry; D012037:Refuse Disposal; D012995:Solubility; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
D001578:Benzopyrans; D006812:Humic Substances; D010795:Phthalic Acids; D014874:Water Pollutants, Chemical; C005023:fulvic acid