Title: Effect of root exudates on pentachlorophenol adsorption by soil and its main chemical components

Authors: Weiwei Chen; Chunli Kang; Yueming Li; Xueying Gu; Xin Wen; Yang Song; Ping Guo

Addresses: Key Lab of Groundwater Resources and Environment, Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China ' Key Lab of Groundwater Resources and Environment, Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China ' Key Lab of Groundwater Resources and Environment, Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China ' Key Lab of Groundwater Resources and Environment, Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China ' Key Lab of Groundwater Resources and Environment, Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China ' Key Lab of Groundwater Resources and Environment, Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China ' Key Lab of Groundwater Resources and Environment, Ministry of Education, College of Environment and Resources, Jilin University, Changchun, 130012, China

Abstract: The relationship between root exudates (REs) and the adsorption of organic pollutants has important impacts on phytoremediation of organic contaminated soil. The effect of REs collected from alfalfa (Medicago sativa Linn.) on pentachlorophenol (PCP) adsorption by soil and its main chemical components was investigated. The experimental results indicated that the data of PCP adsorption was fitted to Langmuir equation well. PCP was adsorbed mainly by organic matter and Fe oxides, but inhibited by Mn oxides in soil. The thermodynamic processes of PCP adsorption onto different soil samples were not changed in the presence of REs, but the adsorption amounts of PCP decreased. The effect of REs was functioned through affecting PCP adsorption by the main chemical components of soil, whose influencing degree was related to the adsorption capacities of the soil components for PCP. The decreases of PCP adsorption were induced mainly by the low-molecular-weight REs promoting the organic matter release from the soil samples, and the higher the content of organic matter was, the more its release amount was.

Keywords: pentachlorophenol adsorption; PCP; root exudates; soil contamination; manganese oxides; iron oxides; organic matter; organic pollutants; environmental pollution; alfalfa; thermodynamics.

DOI: 10.1504/IJEP.2013.056357

International Journal of Environment and Pollution, 2013 Vol.52 No.1/2, pp.1 - 14

Received: 19 Nov 2011
Accepted: 17 Oct 2012

Published online: 11 Sep 2013 *

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