Developing low-cost and green simultaneous desulfurization and denitrification technologies is of great significance for sulfur dioxide (SO

2

) and nitrogen oxide (NO

x

) emission control at low temperatures

especially for small and medium-sized coal-fired boilers and furnaces. Herein

phosphorus sludge

an industrial waste from the production process of yellow phosphorus

has been developed to simultaneously eliminate SO

2

and NO

x

from coal-fired flue gas. The key factors affecting the experimental results indicate that desulfurization and denitrification efficiency of over 95% can be achieved at a low temperature of 55 ℃. Further

the absorption mechanism was investigated by characterizing the solid and liquid phases of the phosphorus sludge during the absorption process. The efficient removal of SO

2

is attributed to the abundance of iron (Fe

3+

) and manganese (Mn

2+

) in the absorbent. SO

2

can be rapidly catalyzed and converted to SO

4

2-

by them. The key to NO

x

removal is the oxidation of NO toward watersoluble high-valent nitrogen oxides by oxidizin

g reactive substances induced

via

yellow phosphorus

which are then absorbed by water and converted to NO

3

-

. Meanwhile

yellow phosphorus is oxidized to phosphoric acid (H

3

PO

4

). The spent absorption slurry can be reused through wet process phosphoric acid production

as it contains sulfuric acid (H

2

SO

4

)

nitric acid (HNO

3

)

and H

3

PO

4

. Accordingly

this is a technology with broad application prospects.