THIOTEQ™Scorodite is a process for the safe immobilisation of arsenic from liquids through the biological formation of highly stable bioscorodite (FeAsO4.2H2O).

Currently, the most acceptable form of arsenic disposal is by a chemical process that produces mineral Scorodite (FeAsO4.2H20). THIOTEQ™Scorodite successfully produces fully crystalline Scorodite in a biological process, reducing arsenic levels of several grams per litre to milligrams per litre in one step.

Typical application of THIOTEQ™Scorodite

  • Liquids with arsenic concentrations with at least 1 g/l Arsenate

Advantages of THIOTEQ™Scorodite over chemical processes which remove arsenic

  • Use of plain air as an oxidant
  • Operating at a lower temperature than other scorodite technologies
  • A lower leaching rate, well below authorities’ requirements
  • Less iron dosing, less solid waste than ferric arsenate
  • Bioscorodite is more stable than scorodite from conventional processes

Working principle

The patented THIOTEQ™Scorodite process is based on the production of Scorodite with the help of bacteria. These bacteria oxidise iron and (optionally) arsenic to the reaction products for Scorodite formation, namely ferric and arsenate. The in-situ bio-oxidation with plain air ensures minimal oversaturation in the bioreactor. This results in pure Scorodite crystals with a high stability in leaching tests.

THIOTEQ™Scorodite is currently in pilot trails.