Effect of herbicide concentration and organic and inorganic nutrient amendment on the mineralization of mecoprop, 2,4-D and 2,4,5-T in soil and aquifer samples

• Published in: Environmental pollution (1987) 2007-07, Vol.148 (1), p.83-93
• Main Authors: de Lipthay, Julia R., Sørensen, Sebastian R., Aamand, Jens
• Format: Article
• Language: English
• Subjects: 2,4,5-T; 2,4,5-Trichlorophenoxyacetic Acid; 2,4-D; 2,4-Dichlorophenoxyacetic Acid; 2-Methyl-4-chlorophenoxyacetic Acid - analogs & derivatives; Adsorption; agricultural soils; Agronomy. Soil science and plant productions; Applied sciences; aquifers; Bacteria - metabolism; bioavailability; biodegradation; Biodegradation, Environmental - drug effects; Biological and medical sciences; Biostimulation; Decontamination. Miscellaneous; dose response; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Restoration and Remediation - methods; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Groundwater aquifer; Herbicides; Humic Substances; kinetics; mecoprop; mineral fertilizers; mineralization; Natural attenuation; organic fertilizers; Phenoxyalkanoic acid herbicides; Pollution; Pollution, environment geology; provenance; sediment contamination; soil amendments; Soil and sediments pollution; Soil and water pollution; soil bacteria; soil nutrients; Soil Pollutants; soil pollution; Soil science; sorption; Water Pollutants, Chemical; water pollution
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2006.11.005

The impact of the herbicide concentration (0.10–10 000 μg kg −1) and addition of organic and inorganic nutrients on mecoprop, 2,4-D and 2,4,5-T mineralization in aquifer and soil samples was studied in laboratory experiments. Generally, 2,4-D was most rapidly mineralized followed by mecoprop and 2,4,5-T. A shift from non-growth to growth-linked mineralization kinetics was observed in aquifer sediment with 2,4-D concentrations >0.10 μg kg −1 and mecoprop concentrations >10.0 μg kg −1. The shift was apparent at higher herbicide concentrations in soil coinciding with a lower bioavailable fraction and a higher herbicide sorption to soil. Herbicide addition did not affect the bacterial density, although 2,4-D and mecoprop applied at 10 000 μg kg −1 stimulated growth of specific degraders. Generally, nutrient amendments did not stimulate mineralization at the lowest herbicide concentrations. In contrast, the mineralization rate of higher herbicide concentrations was significantly stimulated by the amendment of inorganic nutrients. Natural attenuation and biostimulation potential of a wide concentration range of three phenoxyalkanoic acid herbicides were evaluated in agricultural soil and aquifer sediment.