Kilduff James E, Mattaraj Supatpong, Wigton Andrew, Kitis Mehmet, Karanfil Tanju
Department of Civil and Environmental Engineering, Rensselaer Polytechnic Institute, 110, 8th Street, Troy, NY 12180, USA.
Water Res. 2004 Feb;38(4):1026-36. doi: 10.1016/j.watres.2003.10.049.
A field reverse osmosis system was used to isolate dissolved organic matter (DOM) from two lacustrine and two riverine surface water sources. The rejection of DOM was on the order of 99% and did not vary significantly with pressure. A simple mass balance model using a single measured value of rejection predicted the concentration within the closed-loop isolation system. The effect of operating pressure and solution flux on mass recovery of DOM was evaluated in laboratory and field trials. Under controlled laboratory conditions, >99% of a lacustrine DOM could be accounted for. A fraction of the isolated DOM was not recoverable using hydrodynamic cleaning; however, this fraction was recovered by using a pH 10 NaOH wash solution. The mass recovered in the NaOH solution increased from <1% to >6% with increasing transmembrane pressures from 414 kPa (60 psi) to1000 kPa (145 psi), respectively. This is consistent with fouling that results from an increase in solution flux, and a decrease in tangential crossflow velocity. Under field conditions, mass balances were generally >95% and mass recovery was >90% in all cases. The effects of temperature on solution flux were consistent with changes in fluid viscosity; effects of temperature on membrane diffusivity or morphological properties were small. RO isolation under low pressure conditions designed to maximize DOM recovery had little effect on DOM reactivity evaluated in terms of nanofiltration membrane fouling, XAD-8 resin adsorption, activated carbon adsorption, competition with trichloroethylene for adsorption sites on activated carbon, and molecular weight distribution measured using size exclusion chromatography.
采用现场反渗透系统从两个湖泊和两个河流地表水水源中分离溶解有机物（DOM）。DOM的截留率约为99%，且随压力变化不显著。使用单一测量截留率值的简单质量平衡模型预测了闭环隔离系统内的浓度。在实验室和现场试验中评估了操作压力和溶液通量对DOM质量回收率的影响。在受控实验室条件下，可解释>99%的湖泊DOM。使用水力清洗无法回收一部分分离出的DOM；然而，通过使用pH值为10的氢氧化钠洗涤溶液可回收这部分DOM。随着跨膜压力分别从414 kPa（60 psi）增加到1000 kPa（145 psi），氢氧化钠溶液中回收的质量从<1%增加到>6%。这与溶液通量增加和切向错流速度降低导致的污染一致。在现场条件下，所有情况下质量平衡一般>95%，质量回收率>90%。温度对溶液通量的影响与流体粘度变化一致；温度对膜扩散率或形态特性的影响较小。在旨在最大化DOM回收率的低压条件下进行的反渗透分离，对根据纳滤膜污染、XAD - 8树脂吸附、活性炭吸附、与三氯乙烯竞争活性炭上的吸附位点以及使用尺寸排阻色谱法测量的分子量分布评估的DOM反应性影响很小。
