长滩水务部（LBWD），类似于南加州的许多部门 公用事业公司一直面临饮用水供应减少的问题。因为 长滩市地理位置优越，可充分利用 淡化海水作为饮用水的来源，并对 将淡化海水纳入其饮用水产品组合。然而 在海水淡化成为现实之前，还需要更多的进展 需要进一步降低海水淡化的成本。LBWD目前正在探索 在双通道结构中使用纳滤膜（NF）的可行性 评估实现额外成本降低的可能性，并满足 所有水质目标。为水质和运维问题提供清晰、量化的答案 与传统的海水反渗透（SWRO）相比- 通过纳滤过程 制定了一个积极的研究计划，建立了一个 使用全尺寸设备的“原型”研究设施每天都有加仑的水。 本文介绍了LBWD对SWRO的初步评估和初步评估 与双通道纳滤的比较。包括11个参考文献、表格、图表。

The Long Beach Water Department (LBWD), similar to many Southern California utilities, has been facing the issue of decreased potable water supplies. Because of its location, the City of Long Beach is ideally situated to take advantage of desalinated seawater as a source of drinking water and is interested in incorporating desalinated seawater into its potable water portfolio. However, before seawater desalination can become a reality, additional advances are needed to further reduce the cost of desalination. LBWD is currently exploring feasibility of using nanofiltration membranes (NF) in a dual-pass configuration to evaluate the possibility of achieving additional cost reduction as well as meeting all water quality objectives. To provide clear and quantifiable answers to water quality and O&M questions related to the traditional seawater reverse osmosis (SWRO) versus dual-pass nanofiltration process, LBWD has formulated an aggressive research program and constructed a 300,000 gallons per day permeate "Prototype" research facility using full-scale equipment. This paper presents LBWD's preliminary evaluation of SWRO and initial comparisons against dual-pass nanofiltration. Includes 11 references, tables, figures.