为了更好地控制消毒副产品的形成，最近颁布的《消毒剂/消毒副产品规则》要求美国地表水处理厂采用强化混凝。虽然这种处理技术已被证明能有效减少天然有机物，从而减少消毒副产物，但人们对其对水处理其他方面的影响提出了疑问，如颗粒物和病原体的去除。本研究旨在研究降低凝血pH值（增强凝血的一个组成部分）对去除隐孢子虫卵囊以及降低TOC、浊度和颗粒计数的影响。 进行了一系列中试试验，在不同pH水平下使用常用的混凝剂（三氯化铁、明矾和聚合氯化铝）处理含有大量隐孢子虫卵囊的河水。研究结果表明，在较低的pH水平下进行混凝可以显著提高TOC的去除率。结果进一步表明，在常规治疗期间，所有三种凝固剂均能有效去除隐孢子虫卵囊（平均去除率=4）。 3个对数单位）。然而，浑浊度和颗粒计数似乎是去除卵囊的不良指标。最后，研究表明，降低凝固pH值不会干扰隐孢子虫的处理去除。然而，关于在pH=5时使用明矾的问题仍然存在。包括21个参考文献、表格和图表。

In an effort to better control formation of disinfection byproducts, the recently promulgated Disinfectants/Disinfection Byproduct Rule requires that U.S. surface water treatment plants practice enhanced coagulation. While this treatment technique has been shown to effectively reduce natural organic matter, and consequently disinfection byproducts, questions have been raised concerning its impact on other aspects of water treatment such as particle and pathogen removal. The current study was designed to investigate the influence of decreased coagulation pH levels (an integral component of enhanced coagulation) on removal of Cryptosporidium oocysts as well as on reduction of TOC, turbidity, and particle counts. A series of pilot plant trials were conducted in which commonly used coagulants (ferric chloride, alum, and polyaluminum chloride) were utilized, at various pH levels, to treat river water spiked with large numbers of Cryptosporidium oocysts. The results of the study indicated that TOC removal is significantly enhanced by coagulation at lower pH levels. The results further showed that all three coagulants are effective in removing Cryptosporidium oocysts during conventional treatment (mean removal = 4.3 log units). However, turbidity and particle counts appear to be poor indicators of oocyst removal. Finally, the investigation suggested that lowering coagulation pH does not interfere with treatment removal of Cryptosporidium. However, questions remain concerning the use of alum at pH = 5. Includes 21 references, table, figures.