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/(m2·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 ultrafiltration 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 efficiencies of the technique were evaluated.