Treatment of effluent from poplar APMP by photocatalysis with TiO2

An advanced oxidation process, photocatalytic degradation technique, has been developed for the treatment of poplar APMP effluent. Although APMP can produce pulp with advantages of high yield and good quality, the effluent of the APMP has dark brown color, which will pollute our environment heavily if discharged without treatment. Photocatalytic degradation technique is the prospect of complete mineralization of pollutants to environmentally harmless compounds. Due to its nonpoisonous and stable characteristics, TiO2 has become the most attractive metal oxides. In this paper, the degradation was carried by photocatalytic oxidation with middle pressure mercury pump as light source and TiO2 as catalyst. The main factors on the removal ratios of CODcr and color were investigated and their optimum conditions were as follows: 4g/L TiO2, 0.4% (mass fraction) H2O2, pH 9 (initial value), 6h radiation. The removal ratios of CODcr and color reached 70.2% and 94.1% respectively, indicating that the photocatalytic degradation technique is a feasible and efficient way to treat APMP effluent.