The effect of molecular weight (MW) distribution on ultrafiltration (UF) membrane fouling was investigated using humic acids, the mechanism explored by extended Derjaguin-Laudau-Verwey-Overbeek (XDLVO) theory. The short-ranged acid-base (AB) interaction energy was found dominant, followed by Van der Waals (LW), while electrostatic (EL) interaction energy was negligible. The organic colloid fractions with MW > 100 kDa contributed mainly to transmembrane pressure (TMP) increase, while the fractions < 1 kDa had less influence on membrane fouling due to its strong hydrophilicity, oleophobicity and polarity. However, there was no observed relationship between the MW size and its contribution to TMP increase, indicating the total interaction energy between organic colloids and membrane material was favor of prediction of membrane fouling compared with some characteristics of organics. Water from Yangtze River was ozonized prior to UF for the fouling control. With the addition of ozone, the proportion of organic fraction < 1 kDa increased, causing decreased absolute value of AB interaction energy between colloid and membrane. The inflection point of interaction energy variation was attained at 0.8 mg/L ozone dosage, corresponding to a slow rise in TMP as the increasing ozone dosage, while the least influent organic matter was attained with 1.2 mg/L. This indicated that it was more feasible to optimize ozone dosage according to interaction energy rather than the concentration of influent organic matter.

中文翻译：

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从相互作用能的角度看，有机分子量分布对臭氧氧化超滤系统中膜结垢的影响

使用腐殖酸研究了分子量（MW）分布对超滤（UF）膜结垢的影响，扩展的Derjaguin-Laudau-Verwey-Overbeek（XDLVO）理论探讨了该机理。发现短程酸碱（AB）相互作用能占优势，其次是Van der Waals（LW），而静电（EL）相互作用能则可忽略不计。MW> 100 kDa的有机胶体组分主要是促进跨膜压（TMP）的增加，而<1 kDa的有机胶体组分由于其强的亲水性，疏油性和极性而对膜污染的影响较小。但是，在分子量大小及其对TMP增加的贡献之间没有观察到关系，与有机物的某些特征相比，表明有机胶体与膜材料之间的总相互作用能有利于预测膜的结垢。在超滤之前，将长江水进行臭氧处理以控制结垢。随着臭氧的加入，<1 kDa的有机物比例增加，导致胶体与膜之间AB相互作用能的绝对值降低。在臭氧剂量为0.8 mg / L时，达到了相互作用能变化的拐点，这与随着臭氧剂量的增加而使TMP缓慢上升有关，而在1.2 mg / L的情况下，进水最少的有机物达到了。这表明，根据相互作用能而不是流入有机物的浓度来优化臭氧剂量更为可行。在超滤之前，将长江水进行臭氧处理以控制结垢。随着臭氧的加入，<1 kDa的有机物比例增加，导致胶体与膜之间AB相互作用能的绝对值降低。在臭氧剂量为0.8 mg / L时，达到了相互作用能变化的拐点，这与随着臭氧剂量的增加而使TMP缓慢上升有关，而在1.2 mg / L的情况下，进水最少的有机物达到了。这表明，根据相互作用能而不是流入有机物的浓度来优化臭氧剂量更为可行。在超滤之前，将长江水进行臭氧处理以控制结垢。随着臭氧的加入，<1 kDa的有机物比例增加，导致胶体与膜之间AB相互作用能的绝对值降低。在臭氧剂量为0.8 mg / L时，达到了相互作用能变化的拐点，这与随着臭氧剂量的增加而使TMP缓慢上升有关，而在1.2 mg / L的情况下，进水最少的有机物达到了。这表明，根据相互作用能而不是流入有机物的浓度来优化臭氧剂量更为可行。导致胶体与膜之间AB相互作用能的绝对值降低。在臭氧剂量为0.8 mg / L时，达到了相互作用能变化的拐点，这与随着臭氧剂量的增加而使TMP缓慢上升有关，而在1.2 mg / L的情况下，进水最少的有机物达到了。这表明，根据相互作用能而不是流入有机物的浓度来优化臭氧剂量更为可行。导致胶体与膜之间AB相互作用能的绝对值降低。在臭氧剂量为0.8 mg / L时，达到了相互作用能变化的拐点，这与随着臭氧剂量的增加而使TMP缓慢上升有关，而在1.2 mg / L的情况下，进水最少的有机物达到了。这表明，根据相互作用能而不是流入有机物的浓度来优化臭氧剂量更为可行。