由于美国西部水资源的不确定性，长滩水域 该部门（LBWD）正在考虑将海水淡化作为一种可能的来源，以增强其竞争力 现有供水。AwwaRF资助的一个项目正在研究双级纳滤 （NF2）用于海水淡化，作为传统反渗透（RO）膜的替代品 治疗这项研究的主要目标是确定这种脱盐系统是否能够 与传统的脱盐方法相比，降低成本更多 在生产饮用水的同时降低工作压力。 第二个目标是评估将脱盐海水混合到海水中的效果 LBWD的现有供水由经过处理的地下水（GW）和购买的地表水组成 水（西南）。一年中，现有成品水的成分各不相同，为100% 夏季为100%的GW，冬季为100%的SW，后者要么作为州政府提供 项目用水（SPW）或科罗拉多河水（CRW）。基于这些条件，目标是 确定可混合的脱盐水（DW）百分比，同时考虑 DBP形成、消毒剂残留和腐蚀性问题。 本文介绍了各种混合水的水质特征。这个 DW的特性取决于渗透液的盐度和pH目标。两个小灵通 被认为代表一种类似于该区域水的现有pH条件 配水系统（8.0），如果需要额外的硼抑制，则需要配水系统（带 级间pH值调整至pH 9.8）。包括4个参考文献、表格和图表。

Because of the uncertainty of water resources in the western U.S., the Long Beach Water Department (LBWD) is considering seawater desalination as a possible source to augment its existing water supplies. An AwwaRF-funded project is examining dual-staged nanofiltration (NF2) for seawater desalination as an alternative to traditional reverse osmosis (RO) membrane treatment. The primary goal of this research is to determine whether this desalination system can reduce the operational cost for desalination, as compared to more traditional methods, by lowering operating pressures while producing potable water. A secondary objective was to evaluate the effects of blending desalinated seawater into LBWD's existing water supplies made up of treated groundwater (GW) and purchased surface water (SW). The existing finished water varies in composition during the year, with 100 percent of GW in summer, and 100 percent of SW in winter, the latter being provided either as State Project water (SPW) or Colorado River water (CRW). Based on these conditions, the objective is to determine the percentage of desalinated water (DW) that can be blended while considering the issues of DBP formation, disinfectant residual, and corrosivity. The paper presents water quality characteristics for the various waters to be blended. The characteristics for DW vary depending on the permeate salinity and pH targets. The two pHs considered represent one that is similar to the existing pH condition of the water in the distribution system (8.0), and one that is required if additional boron rejection is required (with an interstage pH adjustment to pH 9.8). Includes 4 references, tables, figures.