Removal of Sulfur Dioxide from Flue Gas Using the Sludge Sodium Humate

Table 3

The contents of humic acid and heavy metals in the product and the comparison with the standard.

Indexes	In the standard	In the product
Humic acid (g/L)	≥30	15.2
As (mg/L)	≤10	0.56
Cd (mg/L)	≤10	0.41
Pb (mg/L)	≤50	5.31

(SO₂: 2500 ppm; gas flow: 0.12 m³/h; absorption solution: 100 mL; O₂: 5 vol%; 25°C.)