作为最后的障碍 在使用前，经过适当设计和操作的使用点（POU）水处理系统正在出现 作为保护公众健康的有效方式。 国家卫生基金会（NSF）测试碳块过滤器用于囊肿切除 使用活隐孢子虫卵囊或替代颗粒（如聚苯乙烯）的能力 微球或测试粉尘。标称试验粉尘（NTD）[粉末技术公司，明尼苏达州伯恩斯维尔] 可作为NSF规定的挑战性试验中隐孢子虫卵囊的替代物 标准53（NSF，2001b）。 NSF停止使用细试验粉尘（FTD）[粉末] 1993年，明尼苏达州伯恩斯维尔科技有限公司（Technology Inc.）将其作为隐孢子虫卵囊的替代物。如果一个过滤器 去除足够数量的测试灰尘颗粒，或足够数量的卵囊或卵囊 微球在被测试灰尘堵塞之前和之后，NSF将证明 该产品对去除卵囊有效。 比较了NTD和NTD对纸张的影响 block通过NSF挑战测试的能力。研究了电泳迁移率和粒度 用于描述碳块过滤的基本物理和化学过程。 两种测试粉尘、三种不同的碳块和碳块的原材料 对制造业进行了测试。在NTD的挑战下，三个碳块中只有一个 通过了NSF认证测试。当FTD被用作替代品时，所有三个碳块 有资格获得认证。碳块材料和试验粉尘在pH>时带负电 5，因此，表面电荷特性可以解释为什么两个碳块未能通过测试 NSF认证测试。然而，这些特征无法解释那些 通过了NSF认证测试。粒度分析显示，D15似乎是 通过NSF认证测试的决定因素。 包括24个参考文献、表格和图表。

As the final barrier before consumption, properly designed and operated point-of-use (POU) water treatment systems are emerging as a useful way of protecting the public health. The National Sanitation Foundation (NSF) tests carbon block filters for cyst removal capability by using either live Cryptosporidium oocysts or surrogate particles such as polystyrene microspheres or test dusts. Nominal test dust (NTD) [Powder Technology Inc., Burnsville, MN] may be used as a surrogate for Cryptosporidium oocysts in challenge tests as prescribed by NSF Standard 53 (NSF, 2001b). NSF discontinued the use of fine test dust (FTD) [Powder Technology Inc., Burnsville, MN] as a surrogate for Cryptosporidium oocysts in 1993. If a filter removes a sufficient number of test dust particles, or a sufficient number of oocysts or microspheres prior to and after being clogged with test dust, then NSF will certify that the product is effective for oocyst removal. The objective of this paper was to compare the effects of NTD and FTD on carbon block's ability to pass the NSF challenge test. Electrophoretic mobility and particle sizing were used to characterize the underlying physical and chemical processes of carbon block filtration. Two test dusts, three different carbon blocks, and the raw materials for carbon block manufacturing were tested. Under the challenge of NTD, only one of the three carbon blocks passed the NSF certification test. When FTD was used as a surrogate, all three carbon blocks qualified for certification. Carbon block materials and test dusts were negatively charged at pH > 5 and, therefore, the surface charge characteristics can explain why two carbon blocks failed the NSF certification test. However, these characteristics cannot explain those carbon blocks that passed the NSF certification test. Particle size analysis revealed that D15 appears to be one of the determining factors in passing the NSF certification test. Includes 24 references, tables, figures.