The process of SO_2 absorption by basic aluminum sulfate solution and aluminum sulfate solution with different parameters was experimentally studied. The results show that

with the increasing SO_2 absorption

the p H value of both the basic aluminum sulfate solution and aluminum sulfate solution declined

But the active Al3+ in the basic aluminum sulfate solution has a strong buffering effect on the p H value's drop.In the basic aluminum sulfate solution

SO_2 reacted with the active Al3+ firstly

when the active Al3+ was exhausted

the gaseous SO_2 would dissolve into the water. However

in the basic aluminum sulfate solution

due to the absence of active Al3+

the gaseous SO_2 directly dissolved into the water. Therefore

in the basic aluminum sulfate solution with the same parameters

the SO_2 absorption rate decreased with the increasing temperature in absorption liquid

and the reduction degree turned higher when the absorption liquid temperature increased.When the absorption liquid temperature was lower than 50 ℃ and the SO_2 absorption amount in per liter basic aluminum sulfate solution was less than 5 L

the SO_2 absorption rate could reach at least 95.18 %

so the absorption effect is good.