沉积物中有机化合物的缓慢及极缓慢解吸：吸附质平面性的影响

Slow and very slow desorption of organic compounds from sediment: influence of sorbate planarity.

作者信息

van Noort Paul C M, Cornelissen Gerard, ten Hulscher Theodora E M, Vrind Bea A, Rigterink Henk, Belfroid Angelique

机构信息

Institute for Inland Water Management and Wastewater Treatment (RIZA), PO Box 17, 8200 AA, Lelystad, The Netherlands.

出版信息

Water Res. 2003 May;37(10):2317-22. doi: 10.1016/S0043-1354(02)00628-0.

DOI:10.1016/S0043-1354(02)00628-0

PMID:12727240

Abstract

The kinetics of desorption of in situ chlorobenzenes, PAHs, and PCBs from four different sediments was studied employing Tenax beads as an infinite sink for sorbates. Rate constants for slow desorption were 2.9+/-0.4 x 10(-2) x h(-1), irrespective of the extent of sorbate planarity. Rate constants for very slow desorption were 2.1+/-0.5 x 10(-4) and 6.7+/-1.4 x 10(-4) x h(-1) for planar and non-planar compounds, respectively. Comparison with literature data suggests a priori estimates for rate constants for slow desorption to be 3 x 10(-2) x h(-1), and to be 2 x 10(-4) and 7 x 10(-4) x h(-1) for very slow desorption of planar and non-planar compounds, respectively. The ratio between the fractions in the very slowly desorbing domain and the rapidly desorbing domain was 15-38 for planar compounds which is higher than for non-planar compounds for which the ratio was 2.8-5.2. The ratio between the fractions in the slowly desorbing domain and the rapidly desorbing domain was 1.3-1.8 and independent of the sorbate planarity. The difference in influence of sorbate planarity on the very slowly desorbing domain as compared to the slowly desorbing domain points to different environments for the slowly and the very slowly desorbing fractions.

摘要

采用Tenax珠作为吸附质的无限汇，研究了原位氯苯、多环芳烃和多氯联苯从四种不同沉积物中的解吸动力学。慢速解吸的速率常数为2.9±0.4×10⁻² h⁻¹，与吸附质的平面度无关。平面和非平面化合物的极慢速解吸速率常数分别为2.1±0.5×10⁻⁴和6.7±1.4×10⁻⁴ h⁻¹。与文献数据比较表明，慢速解吸速率常数的先验估计值为3×10⁻² h⁻¹，平面和非平面化合物极慢速解吸的速率常数分别为2×10⁻⁴和7×10⁻⁴ h⁻¹。平面化合物在极慢速解吸域和快速解吸域中的分数比为15 - 38，高于非平面化合物，其分数比为2.8 - 5.2。慢速解吸域和快速解吸域中的分数比为1.3 - 1.8，且与吸附质的平面度无关。与慢速解吸域相比，吸附质平面度对极慢速解吸域的影响差异表明，慢速和极慢速解吸部分所处的环境不同。