本文提供了开发过程中的关键假设和决策的基本原理 用于厂内循环流处理的紫外线（UV）消毒系统的设计 东湾大都市区（EBMUD）核桃溪直接过滤系统 水处理厂（WTP）。分析结果如下: 隐孢子虫是循环流中紫外线灭活的目标病原体； 自由游动的病原体是紫外线剂量选择的基础；和 系统的设计剂量为40 mJ/cm2； 可接受的UV系统具有以下属性: 验证紫外线剂量和紫外线传感器响应， 密闭容器配置，以及 石英套管和紫外线传感器探头的机械清洗； 紫外线透射率为85%（254nm和10mm光程）； 当前条件下的资本成本约为110万美元；和 在当前条件下，每1000加仑的运行维护成本约为0.06美元。 本文的目的是提供概念层面的布局和成本估算 厂内循环流的紫外线（UV）消毒。本文件的具体组成部分 本文的分析和相应的组织如下: 制定消毒目标和紫外线剂量要求； 讨论可接受紫外线系统的属性； 制定紫外线消毒系统配置和布局；和 提出资本和运营成本的估算。 以下是紫外线消毒系统的一般性能目标: 在植物内循环流中提供隐孢子虫和其他耐氯病原体的灭活；和 提供可靠的紫外线设备、系统和操作策略。包括表格、数字。

This paper provides rationale for key assumptions and decisions made in developing the design for the ultraviolet (UV) disinfection system for the in-plant recycle stream treatment system at the East Bay Metropolitan Urban District (EBMUD) Walnut Creek Direct Filtration Water Treatment Plant (WTP). Results of the analysis are as follows: Cryptosporidium is the target pathogen for UV inactivation in the recycle stream; free-swimming pathogens are the basis of UV dose selection; and, design dose for the system is 40 mJ/cm2; acceptable UV systems have attributes that include validated UV dose and UV sensor response, closed-vessel configuration, and mechanical cleaning of quartz sleeves and UV sensor probes; UV transmittance of 85% (254 nm and 10 mm pathlength); approximate capital cost of $1.1 million for current conditions; and, approximate O&M cost of $0.06 per 1,000 gallon for current conditions. The purpose of this paper is to provide conceptual level layouts and cost estimates for ultraviolet (UV) disinfection for in-plant recycle streams. Specific components of this analysis and corresponding organization of this paper are as follows: establish disinfection goals and UV dose requirement; discuss attributes of acceptable UV systems; develop UV disinfection system configuration and layout; and, present estimates for capital and operational costs. The following are the general performance goals of the UV disinfection system: provide inactivation of Cryptosporidium and other chlorine-resistant pathogens in in-plant recycle streams; and, provide reliable UV equipment, systems, and operational strategies. Includes tables, figures.