Electrochemical Removal of Chromium from Wastewater

Abstract

We carried out a study to determine the feasibility of electrochemically removing chromium from plating wastewater. Hexavalent chromium is a carcinogen and its discharge is required to be near 1 ppm. In our work we determined the effects of key variables including temperature, electrolyte flow rate, pH, and electrode composition. At the low chromium concentrations found in plating wastewater, we determined that the rate of chromium ion removal was mass transfer limited. Of the four electrode types tested, only gold gave significantly enhanced performance; however, graphite would probably be the most cost-effective for large-scale application. Chromium reduction rate was significantly increased at reduced pH. Because chromium ion solubility increases at lower pH, the higher removal rate would need to be balanced against higher chromium redissolution rate in a practical system. A preliminary analysis based on our laboratory data indicates that a practical system based on electrochemical technology is feasible.

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Document Details

Document Type
Technical Report
Publication Date
Jul 15, 1992
Accession Number
ADA253772

Entities

People

  • Christine Walker
  • Geoffrey Prentice
  • Todd Wilson

Organizations

  • Johns Hopkins University

Tags

Communities of Interest

  • Human Systems

DTIC Thesaurus Topics

  • Chemical Engineering
  • Chromium
  • Current Density
  • Electrodes
  • Engineers
  • Feasibility Studies
  • Fluid Flow
  • Graphitic Materials
  • Hydrogen
  • Ions
  • Mass Transfer
  • Materials
  • Numbers
  • Personal Information Managers
  • Protons
  • Rotation
  • Square Roots

Fields of Study

  • Environmental science

Readers

  • Coastal and Marine Engineering/Sediment Transport/Hydraulic Engineering
  • Electrochemical Engineering/ Fuel Cell Technologies
  • Surface Engineering/Surface Coating Technology.