Systems, methods and indicator materials for assessing reduction state in soils
The present invention relates an indicator system for assessing a reduction state of unconsolidated material that includes a delivery tube defining an interior chamber, and a substrate disposed within the interior chamber and including a reactive coating thereon. The reactive coating is at least partially removable from the substrate upon exposure to a reducing condition of unconsolidated material over a period of time. An indicator device including a reactive coating comprising a manganese oxide is also disclosed.
1 . A method of producing a manganese oxide coating, comprising:
reducing a potassium permanganate (KMnO 4 ) solution using sodium (Na) lactate, wherein Na lactate:KMnO 4 molar ratio is greater than about 6.0;
removing excess Na lactate after said reducing step via one or more washing cycles; and
dialyzing said KMnO 4 solution for at least 3 days after said step of removing excess Na lactate.
2 . The method of claim 1 , wherein said manganese oxide coating is stored in a water suspension.
3 . The method of claim 1 , which said reducing comprises a reaction time of less than 120 minutes.
4 . The method of claim 3 , wherein said reducing comprises a reaction time of about 10 minutes to about 120 minutes.