Abstract:Chlornitrofen is a diphenyl ether herbicide, which is a typical persistent organic pollutant and has been widely used in 70~90 years in twentieth Century. Although it has been banned for 20 years, chlornitrofen still exists in water and soil systems, which has the potential threats to the agro-ecology systems. In the present study, humic acid ester ether (HAEE) was synthesized via regulating the dosage of glycerol triglycidyl ether while humic acid ester (HAE) was uniting as raw material. HAEE was analyzed by the analysis methods of Fourier transform infrared spectroscopy and contact angles. The results indicated that hydrophobic HAEE has the structure of humic acid and the characteristic functional groups of HAE. The adsorption characteristics and mechanisms of HAEE to chlornitrofen were investigated via a series of batch equilibrium experiments. As the results showed, the hydrophobic angle is increased from 30 to 96 degrees before modification. The degree of hydrophobic of HAEE is positively correlated with the adsorption capacity of chlornitrofen, and equilibrium reached after 2.0 h. The kinetics of adsorption is described well by the pseudo-second-order model, and Freundlich models are more suitable for the sorption isotherm. The adsorption capacity reduces gradually after 5 cycles. The removal rate is still above 78%. The adsorption mechanisms are π-π interaction and hydrophobic distributional effects. Adsorbent prepared by this method may provide a novel approach for remediation of chlornitrofen in aqueous-soil environment.
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