title: Investigation of biomethylation of arsenic and tellurium during composting.
abstract: Though the process of composting features a high microbiological activity, its potential to methylate metals and metalloids has been little investigated so far in spite of the high impact of this process on metal(loid) toxicity and mobility. Here, we studied the biotransformation of arsenic, tellurium, antimony, tin and germanium during composting. Time resolved investigation revealed a highly dynamic process during self-heated composting with markedly differing time patterns for arsenic and tellurium species. Extraordinary high concentrations of up to 150 mg kg(-1) methylated arsenic species as well as conversion rates up to 50% for arsenic and 5% for tellurium were observed. In contrast, little to no conversion was observed for antimony, tin and germanium. In addition to experiments with metal(loid) salts, composting of arsenic hyperaccumulating ferns Pteris vittata and P. cretica grown on As-amended soils was studied. Arsenic accumulated in the fronds was efficiently methylated resulting in up to 8 mg kg(-1) methylated arsenic species. Overall, these studies indicate that metal(loid)s can undergo intensive biomethylation during composting. Due to the high mobility of methylated species this process needs to be considered in organic waste treatment of metal(loid) contaminated waste materials.
authors.affiliation: Microbiology I and Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitaetsstrasse 3-5, 45141 Essen, Germany. roland.diaz@uni-due.de
authors.forename: Roland A
authors.initials: RA
authors.lastname: Diaz-Bone
authors.forename: Maren
authors.initials: M
authors.lastname: Raabe
authors.forename: Simone
authors.initials: S
authors.lastname: Awissus
authors.forename: Bianca
authors.initials: B
authors.lastname: Keuter
authors.forename: Bernd
authors.initials: B
authors.lastname: Menzel
authors.forename: Klaus
authors.initials: K
authors.lastname: Küppers
authors.forename: Renatus
authors.initials: R
authors.lastname: Widmann
authors.forename: Alfred V
authors.initials: AV
authors.lastname: Hirner
mesh_terms: D000965:Antimony / Q000737:chemistry; D001151:Arsenic / Q000737:chemistry*; D001673:Biodegradation, Environmental; D002849:Chromatography, Gas / Q000379:methods; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants; D005857:Germanium / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods; D008745:Methylation; D032495:Pteris / Q000378:metabolism*; D012492:Salts / Q000737:chemistry; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*; D013997:Time Factors; D014001:Tin / Q000737:chemistry
chemical_list: D004785:Environmental Pollutants; D012492:Salts; D012987:Soil; D012989:Soil Pollutants; D005857:Germanium; D014001:Tin; D000965:Antimony; D001151:Arsenic; D013691:Tellurium