A comparative study of the treatment of ethylene plant spent caustic by neutralization and classical and advanced oxidation

J Environ Manage. 2015 Mar 15:151:105-12. doi: 10.1016/j.jenvman.2014.12.038. Epub 2014 Dec 26.

Abstract

The treatment of spent caustic produced from an ethylene plant was investigated. In the case of neutralization alone it was found that the maximum removal of sulfide was at pH values below 5.5. The higher percentage removal of sulfides (99% at pH = 1.5) was accompanied with the highest COD removal (88%). For classical oxidation using H2O2 the maximum COD removal percentage reached 89% at pH = 2.5 and at a hydrogen peroxide concentration of 19 mM/L. For the advanced oxidation using Fenton's process it was found that the maximum COD removal of 96.5% was achieved at a hydrogen peroxide/ferrous sulfate ratio of (7:1).

Keywords: Advanced oxidation; Ethylene plant; Neutralization; Oxidation; Spent caustic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Caustics / chemistry*
  • Ethylenes / chemical synthesis*
  • Ferrous Compounds
  • Hydrogen Peroxide / chemistry*
  • Industrial Waste / analysis
  • Iron
  • Oxidation-Reduction
  • Sodium Hydroxide / chemistry
  • Waste Disposal, Fluid / methods*
  • Water Pollutants, Chemical / chemistry*

Substances

  • Caustics
  • Ethylenes
  • Ferrous Compounds
  • Industrial Waste
  • Water Pollutants, Chemical
  • ferrous sulfate
  • Sodium Hydroxide
  • ethylene
  • Hydrogen Peroxide
  • Iron