杨木P-RC APMP制浆废液的超滤膜浓缩技术

Application of Ultrafiltration Membrane Technique to Concentrate Aspen P-RC APMP Effluent

用聚醚砜超滤膜对杨木P—RC APMP制浆废液进行预浓缩，旨在将浓缩液与化学法制浆黑液一并蒸发后进行碱回收处理。通过考察废液通量，总固形物、CODcr和BOD5截留率等指标，得出了废液浓缩的优化工艺：截留相对分子质量10000、压力0．3MPa、转速400r／min、温度50℃、透过比0．93。优化实验得出：废液通量为23．0L／（m^2·h），废液总固形物从14．1g／L浓缩到87．6g／L，蒸发站负荷可降低86．2％。若不考虑膜设备投资和运行成本，用聚醚砜超滤膜将杨木P-RC APMP制浆废液总固形物浓度从1．4％浓缩至8．7％时，蒸发站耗电量可降低约3007kWh／t浆，废水减排量约为16．8t／t浆。

The polyethersulfone ultrafihration membrane separation technique was used to concentrate aspen P-RC APMP effluent before sending to multi-effect evaporation in alkali recovery plant. Flux, retentions of total solid, CODCr and BOD5 were studied, then the filtration parameters were optimized as follows： relative molecular weight cut-off 10000, trans-membrane pressure 0.3 MPa, feed temperature 50℃, cross-flow velocity 400 r/min and permeate rate 0.93. The average permeate flux under these conditions was 23.0 L/（ m^2 · h）, and the total solid content was increased from 14.1 g/L to 87.6 g/L,thus the evaporation amount could be reduced by 86.2%. Finally, energy conservation and emission reduction effieieneies of the technique were evaluated.