Sewage sludge nutrient solubilization using a single-stage microwave treatment

J Environ Sci Health A Tox Hazard Subst Environ Eng. 2007 Jan;42(1):59-63. doi: 10.1080/10934520601015735.

Abstract

The effects of an advanced oxidation process combining microwave, hydrogen peroxide and acid hydrolysis in a single stage (MW/H2O2/H+ -AOP) on the process efficiency of sewage sludge treatment and nutrient recovery were investigated. At lower temperature regimes (60-80 degrees C), the soluble phosphate was substantially higher in a two-stage process than in a single stage MW/H2O2/H+ -AOP process. However, higher soluble phosphate concentration was obtained for single-stage treatment at the higher operating temperature regimes (100-120 degrees C). With the addition of an inorganic acid, a very high yield of soluble phosphate was obtained in the solution at 120 degrees C. In tests with acid addition, soluble ammonia increased as temperature increased. For single stage MW/H2O2/H+ -AOP, maximum soluble ammonia was obtained at 120 degrees C. Significant concentrations of soluble COD were also obtained in this treatment. A threshold temperature of 80 degrees C was observed, at which all of the COD could be solubilized. However, at higher temperatures (100-120 degrees C), further oxidation processes occurred to form carbon dioxide, resulting in decreased amounts of soluble COD in the solution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonia / analysis
  • Ammonia / chemistry
  • Ammonia / radiation effects
  • Hydrogen Peroxide / chemistry*
  • Microwaves*
  • Phosphates / analysis*
  • Phosphates / chemistry
  • Phosphates / radiation effects
  • Sewage / chemistry*
  • Solubility
  • Water Purification / instrumentation
  • Water Purification / methods*

Substances

  • Phosphates
  • Sewage
  • Ammonia
  • Hydrogen Peroxide