Changes in solubility and chemical speciation of potassium, calcium, and silicon in wood ash by acid treatment

This study investigated the relationship between solubility and chemical speciation of plant nutritional elements (K, Ca, Si) in wood ash treated with a dilute solution sulfuric acid or phosphoric acid. The diluted solutions were added to fly (FA) collected from power plant, untreated acid-treated FAs analyzed for their contents K, Si. crystalline phases identified using X-ray diffraction (XRD), Si species determined absorption near-edge structure (XANES) spectroscopy. Sulfuric treatments did not affect K FA. Water soluble citrate FA decreased by addition these acids. water Ca content show significant change compared that FA, but it increased up 62 times It is suggested CaCO3, which was main transformed into syngenite gypsum treatment. Hydrochloric In contrast, NaOH-soluble fraction, method selectively extracting silica gel, especially results XANES analysis showed samples 10–30% had lower degree polymerization than corresponded generally FAs. However, 30% despite attributed pH. These suggest influenced decrease From viewpoint fertilizer use ash, consists both suitable fertilizer, has high Si,