Carbide slag can be used as desulfurizer in wet flue gas desulfurization system instead of limestone

but its chemical oxygen demand(COD) is an urgent problem to be solved. In this paper

a self-made aeration oxidation device was employed to study the effects of aeration rate

p H value and oxidant on removal rate of the COD in waste water of carbide slag desulfurization

and response surface method was used to carry out orthogonal analysis. The results show that

the removal rate of COD in the desulfurization wastewater of the carbide slag increased firstly and then decreased with the increasing aeration amount(2~10 L/min)

while it dropped with the increasing p H value(3.0~8.5). The addition of oxidants was beneficial to the removal of COD

and the order of the oxidants' COD removal effect(from great to little) was potassium permanganate

calcium hypochlorite. hydrogen peroxide

potassium and chlorate. In the orthogonal test

the order of the effect of each single factor(from great to little) was the addition amount of calcium hypochlorite

aeration rate and p H value. The optimum conditions were as follows: p H=3.5

aeration rate=7.86 L/min

ratio of calcium hypochlorite equivalent to COD content =3.0

under this condition

the maximum COD removal rate of the desulfurization wastewater can reach up to 95.89%.