Title of dissertation: USE OF TARTARIC ACID AND ISOPROPYL ALCOHOL IN THE REDUCTION OF HEXAVALENT CHROMIUM AND APPLICATION TO CHROMIUM CONTAMINATED SOILS AND CHROMITE ORE PROCESSING RESIDUE Dominic A. Brose, Doctor of Philosophy, 2012 Dissertation directed by: Professor Bruce R. James Department of Environmental Science and Technology Although chromium (Cr) is a naturally occurring metal, in the...

The increasing industrial development of recent decades has lead to the production of increasing quantities of waste containing heavy metals, elements often harmful to the environment, which in the past were not properly disposed of, thus inducing soil and groundwater pollution. In particular, chromium (Cr) and its derivatives are largely used in industries such as textiles, electronics, metall...

An evaluation of the chromium(VI) adsorption capacity of four magnetite sorbents coated with a polymer phase containing polymethacrylic acid or polyallyl-3-methylimidazolium is presented. Factors that influence the chromium(VI) removal such as solution pH and contact time were investigated in batch experiments and in stirred tank reactor mode. Affinity and rate constants increased with the mola...

High levels of hexavalent chromium (Cr(VI)) in groundwater are typically attributed to anthropogenic sources. However, scientific reports over the last decade have demonstrated that relatively high levels of Cr(VI) in groundwater may also be due to natural processes. Cr(VI) is among the most significant groundwater contaminants, since it is a potential carcinogenic compound that is commonly fou...

Effects of water contamination with perchlorate and hexavalent chromium [Cr (VI)] on the mosquito Culex quinquefasciatus were assessed. The chronic (10-day) LC50s values for perchlorate and chromium were 74+/-8.0 mg/L and 0.41+/-0.15 mg/L, respectively. Relative Growth Index, a measure of growth and mortality rates in a population, was significantly reduced within 5 days for levels of perchlora...

The present study describes management of oxidative stress induced by heavy metal chromium in marine Bacillus licheniformis (NCBI GenBank Accession NumberHM194725). It is identified that the isolate reduces 10-1500 mg/L of Cr (VI) within 24-72 h. Existence of chromium reductase in growth medium implies the possibility of enzymatic reduction of Cr (VI) to Cr (III). Nevertheless, no correlation w...

The current study aimed to isolate and characterize a chromate-resistant bacterium from tannery effluent, able to reduce Cr(VI) aerobically at high pH and salinity. Environmental contamination by hexavalent chromium, Cr(VI), presents a serious public health problem. Enrichment led to the isolation of 12 bacteria displaying different degrees of chromate reduction. Phenotypic characterization and...