为了满足地表水处理规则的要求，许多小型系统将需要安装过滤器。预涂层过滤因其体积小、运行和维护成本低、操作简单、除浊效果好以及可间歇使用而再次受到关注。本研究的重点是通过使用粉碎的颗粒活性炭和粉末状阴离子树脂对过滤介质进行改性，提高溶解性有机物的去除率。其目的是提供符合或超过《安全饮用水法案》浊度标准的滤液，并从原水中去除尽可能多的溶解有机前体物质。 在预涂和补体步骤中，使用强碱阴离子树脂对硅藻土进行改性，实现了后一个目标。

To meet the requirements of the Surface Water Treatment Rule, many small systems will need to install filters. Precoat filtration is receiving renewed attention as an option because of its compact size, lower operation and maintenance costs, simplicity of operation, excellent turbidity removal, and possibility for intermittent use. This study focused on improving the removal of dissolved organic materials by amending the filtration media with crushed granular activated carbon and powdered anionic resin. The objective was to provide filtrate meeting or exceeding the Safe Drinking Water Act turbidity standard and to initially remove as much dissolved organic precursor material from the raw water as possible. Amending diatomaceous earth with a strong base anionic resin in the precoat and bodyfeed steps achieved the latter objective.