Analysis of fouling and juice quality in crossflow ultrafiltration of watermelon juice

Abstract Raw watermelon juice was clarified in a laboratory scale flat plate ultrafiltration system incorporating polyethersulphone membranes with a molecular weight cut-off of 50 kDa. The experiments have been carried out over a wide range of trans-membrane pressures (1-3 bar). The effect of ultrafiltration with molecular weight cut-off (MWCO) of 50 kDa PES membrane on permeate properties is reported. The effects of trans-membrane pressure (TMP) on permeate flux and resistances were studied. The flux decay was analyzed through the resistance in series model which showed increase of both reversible and irreversible resistance with trans-membrane pressure, The TSS content of the permeate was found to be almost the same with feed while the ascorbic acid content in the permeate was on the lower side as compared to in feed.

摘要：本研究采用分子量截留值（molecular weight cut-off, MWCO）为50 kDa的聚醚砜（polyethersulphone, PES）平板膜搭建实验室规模平板超滤系统，对西瓜原果汁进行澄清处理。实验在1~3 bar的宽跨膜压力（trans-membrane pressure, TMP）区间内开展。本研究探讨了MWCO为50 kDa的PES膜超滤工艺对透过液特性的影响，并考察了跨膜压力对透过液通量及膜阻力的作用规律。通过串联阻力模型对通量衰减过程进行分析，结果显示可逆阻力与不可逆阻力均随跨膜压力升高而增大。研究发现，透过液的总悬浮固体（Total Suspended Solids, TSS）含量与进料原液基本一致，但其抗坏血酸含量相较于进料原液偏低。