title: Enhanced degradation of 14C-HCB in two tropical clay soils using multiple anaerobic-aerobic cycles.
abstract: The aim of the study was to induce and enhance the degradation of hexachlorobenzene (HCB), a highly-chlorinated persistent organic pollutant, in two ecologically different tropical soils: a paddy soil (PS) and a non-paddy soil (FS). The degradation of HCB was enhanced using two anaerobic-aerobic cycles in model laboratory experiments. There was greater degradation of HCB in the PS (half-life of 224 days) relative to the FS (half-life of 286 days). It was further shown that soils amended with compost had higher metabolite concentrations relative to the non-amended soils. In the first cycle, there was little degradation of HCB in both soils. However, in the second cycle, there was enhanced mineralization in the PS under aerobic conditions, with the compost-treated samples showing higher mineralization. There was also extensive volatilization in both soils. The metabolite pattern revealed that the increased mineralization and volatilization was due to the formation of lower chlorinated benzenes.
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Institute of Soil Ecology, 85764 Neuherberg, Germany.
authors.forename: Fredrick Orori
authors.initials: FO
authors.lastname: Kengara
authors.forename: Ulrike
authors.initials: U
authors.lastname: Doerfler
authors.forename: Gerhard
authors.initials: G
authors.lastname: Welzl
authors.forename: Bernhard
authors.initials: B
authors.lastname: Ruth
authors.forename: Jean Charles
authors.initials: JC
authors.lastname: Munch
authors.forename: Reiner
authors.initials: R
authors.lastname: Schroll
mesh_terms: D000332:Aerobiosis; D000538:Aluminum Silicates / Q000737:chemistry*; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D002250:Carbon Radioisotopes; D000077215:Clay; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006207:Half-Life; D006581:Hexachlorobenzene / Q000032:analysis / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D014329:Tropical Climate
chemical_list: D000538:Aluminum Silicates; D002250:Carbon Radioisotopes; D012987:Soil; D012989:Soil Pollutants; D006581:Hexachlorobenzene; D000077215:Clay