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Title: The Use of Sodium Dithionite for the Remediation of Hexavalent Chromium in Mortendad Canyon

  1. Los Alamos National Laboratory
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Office of Environmental Management (EM)
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Technical Report
Country of Publication:
United States
Earth Sciences

Citation Formats

Telfeyan, Katherine Christina. The Use of Sodium Dithionite for the Remediation of Hexavalent Chromium in Mortendad Canyon. United States: N. p., 2018. Web. doi:10.2172/1422944.
Telfeyan, Katherine Christina. The Use of Sodium Dithionite for the Remediation of Hexavalent Chromium in Mortendad Canyon. United States. doi:10.2172/1422944.
Telfeyan, Katherine Christina. 2018. "The Use of Sodium Dithionite for the Remediation of Hexavalent Chromium in Mortendad Canyon". United States. doi:10.2172/1422944.
title = {The Use of Sodium Dithionite for the Remediation of Hexavalent Chromium in Mortendad Canyon},
author = {Telfeyan, Katherine Christina},
abstractNote = {},
doi = {10.2172/1422944},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2018,
month = 2

Technical Report:

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  • This treatability study was conducted by Pacific Northwest National Laboratory (PNNL), at the request of the U. S. Environmental Protection Agency (EPA) Region 2, to evaluate the feasibility of using in situ treatment technologies for chromate reduction and immobilization at the Puchack Well Field Superfund Site in Pennsauken Township, New Jersey. In addition to in situ reductive treatments, which included the evaluation of both abiotic and biotic reduction of Puchack aquifer sediments, natural attenuation mechanisms were evaluated (i.e., chromate adsorption and reduction). Chromate exhibited typical anionic adsorption behavior, with greater adsorption at lower pH, at lower chromate concentration, and atmore » lower concentrations of other competing anions. In particular, sulfate (at 50 mg/L) suppressed chromate adsorption by up to 50%. Chromate adsorption was not influenced by inorganic colloids.« less
  • The objective of this research was to validate the use of sodium sulfide and ferrous sulfate in reducing hexavalent chromium and removing heavy metals from electroplating, and industrial waste waters. Jar tests, and dynamic tests, were conducted using distilled water, electroplating rinse waters, and industrial waste waters from Tinker AFB Industrial Waste Treatment Plant. Optimum process parameters were evaluated as well as analysis of the effects of typical contaminants and complexing agents, along with the effects of the process on downstream treatment. The information obtained verified that the sulfide-treatment process will meet discharge-permit requirements while reducing chemical and disposal costs.more » The results were the basis for continuing to Phase II, Pilot-Scale Study on Actual Industrial Waste waters.« less
  • Laboratory batch and column experiments were conducted with Hanford sediments to develop the capability to predict (1) the longevity of dithionite in these systems, (2) its efficiency as a reductant of structural iron, and (3) the longevity and reactivity of the reduced iron with soluble inorganic and organic species. After an initial induction period, the loss of dithionite by disproportionation and oxidation could be described by pseudo-first-order (PFO) kinetics. Other than the initial reaction with ferric iron, the primary factor promoting loss of dithionite in this system was disproportion nation via heterogeneous catalysis at mineral surfaces. The efficiency of themore » reduction of structural iron was nearly 100% for the first fourth of the ferric iron, but declined exponentially with higher degrees of reduction so that 75% of the ferric iron could be reduced. This decrease in reduction efficiency probably was related to differences in the accessibility of ferric iron in the mineral particles, with iron in clay-sized particles being the most accessible and that in silt- and sand-sized particles less accessible. Flow-through column studies showed that a reduced-sediment barrier created in this manner could maintain a reducing environment.« less
  • At Site 5, three candidate sampling methods and two candidate analytical methods for hexavalent chromium were assessed. The conversion of hexavalent chromium (Cr (+6)) to other valence states of chromium during sampling and sample storage was of primary concern. Method 5-type samples and impinger train samples were collected by PEI Associates, Inc. Dilution train samples were collected bySouthern Research Institute. Method 5-type train samples were analyzed by Technology Applications, Inc.'s (TAI) staff under contract to EPA's Environmental Monitoring Systems Laboratory (EMSL) in Cincinnati, Ohio. Dilution train samples, Method 5-type samples, and impinger train samples were analyzed by Entropy Environmentalists, Inc.more » TAI used an ion chromatograph with post column reaction (IC/PCR) and inductively coupled argon plasmography/mass spectrometry (ICP/MS) to analyze the Method 5-type samples. A stable chromium isotope (63CR(+6)) spiked onto the Method 5 filter prior to sample collection was used to assess conversion of Cr(+6). The samples analyzed by Entropy were collected using a dilution train on an 8.5 in X 11 in glass fiber filter, a Method 5-type sampling train on an 82 mm quartz fiber filter, and an impinger sampling train with an alkaline impinger reagent, and spiked with native hexavalent chromium and a radioactively-labeled chromium isotope (51Cr(+6)). The samples were analyzed for hexavalent chromium by IC/PCR and for the radioactive isotopes by scintillation (gamma) counting. EMSL has not released the TAI data. The preliminary method evaluation testing demonstrated that all sampling methods had problems with conversion of hexavalent chromium.« less
  • Hexavalent chromium compounds are human carcinogens, classified as weight-of-evidence Group A (based on chromate production workers and animal data which indicates that inhaled hexavalent chromium compounds are carcinogenic) under the EPA Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986a). Evidence on potential carcinogenicity from animal studies is Sufficient, and the evidence from human studies is Sufficient. As stated in the U.S. EPA Health Assessment Document on chromium and compounds, metallic chromium is biologically inert and has not been reported to produce tumors in man or animal models. The no data are available on the carcinogenicity of metallic chromium. The potencymore » factor (F) for hexavalent chromium is estimated to be 389/(mg/kg/day) (based on epidemiological data for the inhalation of hexavalent chromium by chromate workers), placing it in potency group 1 according to the CAG's methodology for evaluating potential carcinogens (U.S. EPA, 1986b). Combining the weight-of-evidence group and the potency group, all of the hexavalent chromium compounds are assigned a HIGH hazard ranking for the purposes of RQ adjustment.« less