Effects of Methane Fermentation on Spectral Properties of Fulvic Acid Extracted from Peat through Liquid Acid Precipitation

Figure 4

(a) UV-Vis of fulvic acid. UV-Vis of fulvic acid by (b) sulfuric acid precipitation, (c) nitric acid precipitation, (d) hydrochloric acid precipitation, and (e) phosphoric acid precipitation.

(a)

(b)

(c)

(d)

(e)