以麦草氧碱浆为对象进行QPo漂白和OQPo漂白,比较了筛前浆与筛后浆的QPo漂白及OQPo漂白效果,分析了终漂浆的纤维特性及漂白废水的污染负荷.结果表明：筛前浆和筛后浆的OQPo漂白终漂浆的白度优于QPo漂白终漂浆,但OQPo漂白浆的黏度损失比QPo漂白浆大,得率低于QPo漂白浆;筛前浆的白度增值率和总浆得率都明显高于筛后浆,总浆得率最多比筛后浆高10.6个百分点,白度增值率最多比筛后浆高4.9个百分点;筛前浆与筛后浆终漂浆的重均纤维长度都在0.78mm左右,筛后浆的纤维粗度大于筛前浆;OQPo漂白废水从根本上消除了可吸附有机卤化物（AOX）的产生,其BOD5和COD远远低于传统的CEH漂白.

Screened and unscreened oxygen-alkali pulps of wheat straw were bleached via QPo and OQPo sequences,and the bleaching effects were compared between screened and unscreened pulp.Furthermore,both the characteristics of the fibers in bleached pulp and the pollution load of the effluent were analyzed.The results show that,as compared with QPo bleaching sequence,OQPo bleaching sequence may result in higher brightness,heavy viscosity loss and low yield for both the screened and the unscreened pulps;that,as compared with the screened pulp,the unscreened pulp is of higher brightness-increasing rate（up to 4.9 percentage points） and total pulp yield（up to 10.6 percentage points）;that the fibers in the screened pulp is about 0.78 mm in weight-average length,which is similar to those in the unscreened pulp,while the fiber coarseness of screened pulp is much higher;and that OQPo bleaching is more environmentally friendly than the traditional CEH bleaching because it completely eliminates absorbable organic halogens and greatly reduces CODCr and BOD5 discharge.