Linked Life Data

12901656

Source:http://linkedlifedata.com/resource/pubmed/id/12901656

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
2003-8-6
pubmed:abstractText
Biodegradation kinetics of two phenoxy acid herbicides, MCPP [(+/-)-2-(4-chloro-2-methylphenoxy)propanoic acid; mecoprop] and 2,4-D [2,4-dichlorophenoxyacetic acid] were studied in laboratory batch microcosms at low concentrations (0.025-100 microg/L) using 14C technique with sediments and groundwater from a shallow aerobic sandy aquifer. Below a certain threshold concentration of approximately 1 microg/L for 2,4-D and 10 microg/L for MCPP, the biodegradation followed first-order nongrowth kinetics, and no adaptation was observed within the experimental period of 341 d. Half-lifes for ultimate degradation were 500 d for 2,4-D and 1100 d for MCPP at 10 degrees C in unpolluted aquifer sediment in this environmentally relevant concentration regime. Above the threshold concentrations, the biodegradation rate accelerated gradually due to selective growth of specific biomass, which was ascertained from 14C most probable number enumerations of specific phenoxy acid degraders. Atthe highest concentration tested (100 microg/ L), specific degraders increased from 10(-1) to 10(5) cells/g during the experiment, and half-lifes after adaptation decreased to approximately 5 d. The enhanced rate of degradation by adapted systems was maintained during degradation of the last residuals measured to less than 0.1 microg/L. In situ long-term preexposure of the aquifer sediment also resulted in significant higher degradation rates of the phenoxy acids.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0013-936X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3095-103
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Shifts in biodegradation kinetics of the herbicides MCPP and 2,4-D at low concentrations in aerobic aquifer materials.
pubmed:affiliation
Environment & Resources DTU, Groundwater Research Centre, Technical University of Denmark, DK-2800 Lyngby, Denmark.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't