本文讨论了选择纳滤（NF）或反渗透（RO）的两种主要方法 在整个生命周期内进行成本比较的技术和方法。第一种方法是 使用NF膜，其在低进料压力下运行，但提供较少的污染物 拒绝使用这种方法，可以使用的混合程度是有限的 治疗所需的总马力仍然很高。第二种方法是 反渗透膜在高压下运行，但具有很高的污染物截留率， 从而减少生产特定混合水所需的处理水的体积 成品水质量。本文表明，在某些情况下，反渗透可能更具成本效益 而不是NF。这在一定程度上是因为反渗透产品在许多情况下都会产生水 可能比NF产品水的混合程度更高。 更大程度的混合也可能 考虑到资本和后续运维支出的减少。 本文研究了这些因素对全寿命周期成本的影响。 考虑了与新膜装置feed相关的资本成本 水质、成品水质量目标、膜技术（NF与RO）、压力 能量需求、拒绝、混合程度和系统容量 可以实现的复苏。包括表格、数字。

This paper presents a discussion of two main approaches for selecting a nanofiltration (NF) or reverse osmosis (RO) technology and a method for cost comparison over a full life cycle. The first approach is to use NF membranes, which operate at low feed pressure, but provide less contaminant rejection. Using this approach, the degree to which blending can be used is limited and overall horsepower required for treatment remains high. The second approach is to use RO membranes, which operate at high pressure, but provide high contaminant rejection, and therefore reduce the volume of treated water required to produce a specified blended finished water quality. This paper shows that RO in certain cases may be more cost-effective than NF. This is due in part to the fact that RO product waters in many cases may be blended to a greater extent than NF product water. Greater blending may also allow for a reduction in capital and subsequent O&M expenditures. This paper presents a study of the impacts of these factors on full life cycle costs. Considerations are given to capital costs associated with a new membrane plant, feed water quality, finished water quality goals, membrane technology (NF vs. RO), pressure energy requirements, rejection, the degree of blending, and the amount of system recovery that can be achieved. Includes tables, figures.