超低压膜工艺[纳滤（NF）和超滤（UF）]在实验室规模上进行了评估，以确定其从位于美国东部的三个地理位置不同的地表水中去除天然有机物（NOM）的能力。水中的总有机化合物（TOC）水平在5 mg/L到50 mg/L之间，和三卤甲烷生成潜能（THMFP）浓度从400 ug/L到大于2000 ug/L。四种NF类型和一种UF类型[具有三种不同的分子量（MWC）截止值]以7.5至11加仑/平方英尺/天（gfd）的通量率运行。NF膜和最低MWC超滤膜能够将THMFP降低到60 ug/L以下，TOC水平降低90%以上。虽然NF膜的去除效率相似，但比生产率（gfd/psi）差异显著。

Ultra-low pressure membrane processes [nanofiltration (NF) and ultrafiltration (UF)] were evaluated on a bench-scale level for their ability to remove naturally-occurring organic matter (NOM) from three geographically-distinct surface waters located in the eastern U.S. Total organic compound (TOC) levels in the waters ranged from 5 mg/L to over 50 mg/L, and trihalomethane formation potential (THMFP) concentrations from 400 ug/L to greater than 2,000 ug/L. Four NF types and one UF type [having three different molecular weight (MWC) cutoff values] were operated at flux rates of 7.5 to 11 gallons per square foot per day (gfd). The NF membranes and the lowest MWC UF membrane were capable of reducing THMFP to less than 60 ug/L and TOC levels by more than 90 percent. Although the removal efficiency of the NF membranes were similar, the specific productivity (gfd/psi) varied significantly.