CONTEXT Perchlorate has been detected in U.S. drinking water supplies at levels ranging from 4 to 200 microg/liter as well as in agricultural products. Perchlorate is known to be a competitive inhibitor of iodine uptake by the thyroid through the sodium-iodide symporter. OBJECTIVE The objective of the study was to determine whether prolonged exposure (6 months) to low levels of perchlorate wo...

Biological reduction of perchlorate by autotrophic microorganisms attached to zerovalent iron (ZVI) was studied in flow-through columns. The effects of pH, flow rate, and influent perchlorate and nitrate concentrations on perchlorate reduction were investigated. Excellent perchlorate removal performance (> or = 99%) was achieved at empty bed residence times (EBRTs) ranging from 0.3 to 63 h and ...

Energy density, which is an important indicator of the performance solid propellants, known to increase with addition 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20). However, it remains unclear how CL-20 affects decomposition ammonium perchlorate (AP) and energy release. Here, effects on combustion agglomeration propellants were investigated. The decreased AP temperature req...

Abstract Ammonium nitrate (NH4NO3) represents a cheap, chlorine-free alternative to ammonium perchlorate for use as an oxidant solid propellants. But its poor ignitability and low burning rate are all disadvantages achieve such purposes. For this reason, it is necessary carry out studies improve combustion characteristics, seeking combine with catalysts or fuels. The present work explores the p...

Perchlorate contamination is a concern because of the increasing frequency of its detection in soils and groundwater and its presumed inhibitory effect on human thyroid hormone production. Although significant perchlorate contamination occurs in the vadose (unsaturated) zone, little is known about perchlorate biodegradation potential by indigenous microorganisms in these soils. We measured the ...

Most dissimilatory perchlorate reducing bacteria (DPRB) are also capable of respiratory nitrate reduction, and preferentially utilize nitrate over perchlorate as a terminal electron acceptor. The similar domain architectures and phylogenetic relatedness of the nitrate and perchlorate respiratory complexes suggests a common evolutionary history and a potential for functionally redundant electron...