Technologies are described for a process for in situ treatment of contaminated soil(s), water, waste, sludge, wastewater, sediment, other contaminated matrix, or combination thereof. The process comprises applying a reactive or treatment material and an adjunct to the contaminated matrix or in a flow path of the contaminant in the matrix. The adjunct is controllably released into the matrix and contributes to the treatment of the soil(s), water, waste, sludge, wastewater, sediment, other contaminated matrix, or combination thereof.