@article {735,
	title = {Biological perchlorate reduction in packed bed reactors using elemental sulfur.},
	journal = {Environ Sci Technol},
	volume = {43},
	year = {2009},
	month = {2009 Jun 15},
	pages = {4466-71},
	abstract = {Sulfur-utilizing perchlorate (ClO4-)-reducing bacteria were enriched from a denitrifying wastewater seed with elemental sulfur (S0) as an electron donor. The enrichment was composed of a diverse microbial community, with the majority identified as members of the phylum Proteobacteria. Cultures were inoculated into bench-scale packed bed reactors (PBR) with S0 and crushed oyster shell packing media. High ClO4-concentrations (5-8 mg/L) were reduced to < 0.5 mg/L at an empty bed contact time (EBCT) of 13 h. Low C1O4- concentrations (60-120 microg/L), more typical of contaminated groundwater sites, were reduced to < 4 microg/L at an EBCT of 7.5 h. PBR performance decreased when effluent recirculation was applied or when smaller S0 particle sizes were used, indicating that mass transfer of ClO4- to the attached biofilm was not the limiting mechanism in this process, and that biofilm acclimation and growth were key factors in overall reactor performance. The presence of nitrate (6.5 mg N/L) inhibited ClO4- reduction. The microbial community composition was found to change with ClO4- availability from a majority of Beta-Proteobacteria near the influent end of the reactor to primarily sulfur-oxidizing bacteria near the effluent end of the reactor.},
	keywords = {Bacteria, Bioreactors, Environmental Pollutants, Medical Waste Disposal, Oxidation-Reduction, Perchloric Acid, Sulfur},
	issn = {0013-936X},
	author = {Sahu, Ashish K and Conneely, Teresa and N{\"u}sslein, Klaus R and Ergas, Sarina J}
}
