本研究的目的是评估现有Alfred Merritt-Smith水处理设施（AMSWTF）过滤器的状况。AMSWTF是一个600 百万加仑/天（mgd）（2270兆升/天）直接过滤处理厂，利用 臭氧氧化作为一级消毒剂和二级配水系统的游离氯 消毒。由于米德湖水位下降，水质恶化，工厂的 AMSWTF是唯一的原水来源，最近过滤器运行时间缩短。虽然 最近，电厂取水量的降低改善了原水质量，减少了进水量 浊度、颗粒物计数和温度回到历史范围，预计湖泊水位将下降 继续下降。对过滤器的评估是为未来的工厂做准备的第一步 水质下降。 评估过程包括对过滤器和反冲洗操作的审查，以及 过滤介质特性的评估。一期、二期和二期各有四个过滤器 选择第三阶段的过滤器进行评估。使用来自的输入选择单个过滤器 工厂操作员和员工根据他们对过滤器运行时间较短、出水较高的观察 浑浊度、早期颗粒突破、疑似介质和支持介质打乱。少校 AMSWTF的单元工艺，以及构成过滤工艺的三个过滤复合物 与设施的其余部分相关，而为 评估以一个简化的工厂示意图呈现。从这三个数据中筛选数据 审查了施工阶段，包括对过滤器和反冲洗的评估 操作。此外，还对过滤介质特性进行了评估 包括滤床岩芯取样、筛分分析、絮体保留剖面分析、废过滤器清洗 水浊度剖面、滤层开挖和砾石层剖面。从过滤器中获取的数据 本研究选择了1982年第二阶段建造的15号。包括数字。

The purpose of this study was to evaluate the condition of the existing Alfred Merritt Smith Water Treatment Facility (AMSWTF) filters. AMSWTF is a 600 million gallon per day (mgd) (2,270 Megaliters per day) direct filtration treatment plant, utilizing ozone oxidation as the primary disinfectant and free chlorine for secondary distribution system disinfection. Due to the declining level and deteriorating water quality in Lake Mead, the plant's sole raw water source, the AMSWTF has recently experienced shortened filter runs. Although the recent lowering of the plant intake has improved the raw water quality, reducing the influent turbidity, particle counts and temperature back into historical ranges, lake levels are predicted to continue dropping. Evaluation of the filters is the first step in preparing the plant for future declines in water quality. The evaluation process included a review of the filter and backwash operations, as well as an assessment of the filter media characteristics. Four filters each from Phases I and II and two filters from Phase III were chosen for evaluation. Individual filters were selected with input from the plant operators and staff based on their observation of shorter filter runs, higher effluent turbidity, early particle break through and suspected media and support media upset. The major unit processes at AMSWTF, and the three filter complexes that make up the filtration process are shown in relation to the rest of the facility, while the individual filters chosen for evaluation are presented in a simplified plant schematic. Filter data from all three phases of construction were reviewed including an assessment of the filter and backwash operations. In addition, an assessment of the filter media characteristics was performed which included filter bed core sampling, sieve analysis, floc retention profile analysis, spent filter wash water turbidity profiling, filter excavation and gravel bed profiling. Data taken from Filter No. 15 constructed during Phase II in 1982 was chosen for this study. Includes figures.