APPLICATION OF FLY ASH AS AR%ELIORANT IN PEATLAND ENVIRONMENT: THE RELEASE OF MICRO NUTRIENTS AND mAVY METALS

Some researchers showed thatfly ash can be used to improve the chemicalpmperties ofsoil, such as increasingpH, exchangeable cations and base saturation. However, the application of fly ash as soil ameliorant in Indonesia is still constrained by government regulation thatfly ash is classzj2ed as toxic and dangerous waste materials due to the contains of heavy metals. The objective of this research is to study thereleme ofmicro nutrients andheavy metalsfiomfi ash in peat environment. This research was conducted by batch method with shakingfly ash in aquadest and peat water as solvent, and by column percolation method with flushing the mhture ofjIy ash andpeat. Cations of Fe, Mn, Cu, Zn, Pb, Cd, Cr and Ni dissolved infiltrate were measured by Atomic Absorption Spectrophotometer (AAS). Fly ashes used in this study originatedfrom peat boiler (PB), chip boiler (CB) and multi boiler (IMB). The results showed thatpeat water did not always dissolve elementsfiom fly ashes higher than those of aquadest. There was no signijicant relation between shaking time and amount of elements dissolve in the solution. Elements of Fe andMn were released more &om fly ash from PB, whereas the other elements releasedrelatively in the same amount in allfly ashes used. In column percolation test, peat treated with fly ash after 3 monthsmhing showed decreasing availability of heavy metals with increasingfly ash dosage. Leachatefiom column percolation test contain elements in various amount. Generally, the amount of elements in percolate decrease with the increase offishing time in order ofFe> Cu> Mn> Zn> Cr> Pb> Ni> Cd