Production of technical grade phosphoric acid from incinerator sewage sludge ash (ISSA)

Waste Manag. 2010 Aug-Sep;30(8-9):1634-42. doi: 10.1016/j.wasman.2010.04.009.

Abstract

The recovery of phosphorus from sewage sludge ash samples obtained from 7 operating sludge incinerators in the UK using a sulfuric acid washing procedure to produce a technical grade phosphoric acid product has been investigated. The influences of reaction time, sulfuric acid concentration, liquid to solid ratio and source of ISSA on P recovery have been examined. The optimised conditions were the minimum stoichiometric acid requirement, a reaction time of 120 min and a liquid to solid ratio of 20. Under these conditions, average recoveries of between 72% and 91% of total phosphorus were obtained. Product filtrate was purified by passing through a cation exchange column, concentrated to 80% H(3)PO(4) and compared with technical grade H(3)PO(4) specifications. The economics of phosphate recovery by this method are briefly discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon / chemistry*
  • Filtration
  • Incineration*
  • Phosphoric Acids / analysis
  • Phosphoric Acids / chemistry
  • Phosphoric Acids / isolation & purification*
  • Phosphorus / analysis
  • Phosphorus / chemistry
  • Sewage / chemistry*
  • Sulfuric Acids / chemistry
  • Waste Management / methods*

Substances

  • Phosphoric Acids
  • Sewage
  • Sulfuric Acids
  • Phosphorus
  • Carbon
  • phosphoric acid
  • sulfuric acid